Feels Awful and Doesn't Sound Very Good, Either! Sometimes I just feel loejiggedy,' especially in school.

Transcription

1 chapter Feels Awful and Doesn't Sound Very Good, Either! Marie E. Anzalone and Shelly J. Lane Sometimes I just feel loejiggedy,' especially in school. Man, age w Introduction The Basics of Sensory Processing Sensory Modality Stimulus Intensity Stimulus Duration Sensory Integration and Processing Goodness of Fit Sensory Integration Theory Disorders of Sensory Integration and Processing Sensory Modulation Disorder Sensory Discrimination Disorder Sensory-Based Motor Disorders Evaluating and Categorizing Sensory Integration Dysfunction Intervention for Sensory Processing Disorders Outcomes of Intervention Summary Define the concepts of sensory processing and sensory integration. Describe the properties of sensory stimuli, including how they influence the sensory messages conveyed to the central nervous system. Explain the concept "goodness-of-fit." Define the sensory integrative disorders identified using the Sensory Integration and Praxis Tests. Differentiate between sensory modulation disorder, sensory discrimination, sensory-based motor disorder, and dyspraxia. Delineate the features of intervention that classify it as "sensory integration." Identify appropriate outcomes for sensory integration intervention.

2 438 Part 4 Pediatric Conditions and Their Impact on the Lives of Children I ntr()titict io n This chapter addresses sensory processing disorders (SPDs) and examines the foundations of sensory integration (SI) theory. In doing so, we describe the differences between sensory stimuli and sensation. Further, we look at how SI is expressed behaviorally in relation to ongoing experiences and how inadequate integration of sensation results in disorders of sensory processing. The essential components of SI assessment and intervention strategies will be introduced, although the details of both are beyond the scope of this text. For additional information the reader can look at the resources section at the end of this chapter. Throughout the chapter, vignettes are used to highlight some of the problems children with SPD experience. In recent years there has been some discussion over terminology applied to SI and processing (c.f., Miller, Anzalone, Lane, Cermak, and Osten, 2007). In this chapter, the term sensory integration will be used specifically in conjunction with the brain-behavior theory proposed by A. Jean Ayres (1972a, 1979). Dr. Ayres developed SI theory, based on her knowledge of neural science and her detailed observation of child behaviors (1972a). Ayres theorized that when sensory processing is impaired academic, social/emotional, motor, and/or functional problems may result. She developed SI intervention to address these problems. Ayres Sensory Integration (ASI ) will be used to reference the specific intervention based on this theory. This term was suggested by Smith- Roley, Mailloux, Miller-Kuhanek, and Glennon (2007) to capture the core principles of SI and link them clearly to their originator, A. Jean Ayres. Sensory processing disorder will be used as an umbrella term to describe dysfunction in the sensory integrative process. Although this use of terminology is not universal, it does represent the most currently proposed descriptions (Miller et al., 2007). Vignette Man: I Just Feet "Bejiggedg" In an attempt to help Alan figure out his needs, he and his therapist invented the word "bejiggedy." Bejiggedy refers to Alan's feeling of being overwhelmed and overresponsive to the sensory input in his environment. Alan's drawing of what it feels like to be "bejiggedy" is shown in Figure Alan was referred for occupational therapy (OT) because of disruptive behavior in school and at home. OT assessment revealed an SPD (sensory overresponsivity [SOR]). Part of Alan's OT treatment was provision of sensory integrative activities throughout the day as part of a sensory diet. Alan's sensory diet focused on sensations that helped him calm down and become less disruptive. When Alan started to feel bejiggedy he knew he needed to use his sensory diet tools to help him settle down. FIGURE 24-1 Alan's sensory experience. When asked to draw a picture of what it feels like to be "bejiggedy," Alan, 10 years old, drew the figure on the right. When asked to draw what it felt like after he did some things to calm himself down, he drew the figure on the left. Not all children feel "bejiggedy," but those children who do will need help to understand why sensory experiences that are routine and easily managed by most children are overwhelming and sometimes even painful to them. They are not alone in needing help to understand their parents and teachers also need help, since these children are different and often may not make sense to even the most experienced caregivers. SI theory can help us understand children with SPDs, like Alan. According to this theory, Alan can be described as having a sensory modulation disorder or, more specifically, sensory overresponsivity (SOR). This disorder makes typical sensory experiences seem intrusive or overwhelming. The overwhelming experience is combined with difficulty in regulating responses to typical levels of sensory input. In Alan's case, when he becomes overwhelmed, he strikes out at other children or becomes disruptive in class and cannot settle down to focus on his work. SOR is just one of many SPDs that can influence a child's ability to participate in age-appropriate occupations. When working with Alan, two different approaches were used to improve his sensory modulation. First, he received individualized ASI intervention as part of his CT. But just as important was integration of sensory activities throughout his days to help manage his responses and help his caregivers understand him better (this is referred to as a sensory diet). You will find more detail on SOR and other SPDs and interventions later in the chapter. Ilere'siNe Point > Sensory integration theory is a theory of brain-behavior relationships developed by A. Jean Ayres to explain how the integration of sensation influences our interactions with the environment.

3 Chapter 24 -& Sensory Processing Disorders Ayres SI is the treatment approach developed by Ayres, based on SI theory. IP- Sensory processing disorder is an umbrella term used here and elsewhere to describe the array of disorders associated with problems in SI. The Basics of Sensory Processing Both Alan (presented earlier) and Raul (presented later in the chapter) illustrate the challenges presented by children with SPD. Their behavior makes it difficult for them to learn and interact with peers; their behavior just does not make sense. It does not make sense, because activities and experience that other children take in stride are problematic for them. They have difficulty processing everyday experiences and that difficulty is expressed through a disruption of regulatory behaviors (e.g., attention or arousal), and not just sensory-related behaviors such as scratching or covering ears. To better understand how we get from sensory processing to behavioral regulation, we will begin with the basics of the sensory processing. Sensory processing comprises the intake and integration of sensation from the environment (both external and internal to our bodies) and its use for interaction with the environment. As a whole, sensory processing is what allows us to make sense of the sensory input we receive and use it to produce an effective interaction with the environment. In this section we will look at aspects of sensory input that must be considered when addressing processing. Understanding sensory processing and SI is central to understanding the properties of sensory input. Kandel, Schwartz, and Jessell (2000) identify three important properties of sensory stimuli: + Modality + Intensity + Duration Let's look at how these properties tell us important things about the sensory environment that surrounds the children with whom we work. SENSORY MODALITY The term sensory modality refers to the different types of sensory input that we perceive. If you ask a person on the street how many sensory modalities there are, they will most likely tell you that there are five (vision, hearing, smell, taste, touch). In reality, there are two more sensory modalities that are of equal concern to OT clinicians: + Vestibular + Proprioception Vestibular and proprioception, are often forgotten and are sometimes referred to as the hidden senses (Koomar and Friedman, 1992a, 1992b). They, along with touch, or the tactile system, are the senses that are body based. Ayres (1972a) differentiated between input from the body (e.g., proprioception, touch) and input from the environment (e.g., smell, vision, or hearing). Both types are important to consider during SI assessment and intervention but the body-based senses are the most important to us in this theory. Vestibular and proprioception are both bodybased senses; they are largely unconscious and we do not think about how our musdes feel as they move, or recognize the constant input from movement as we drive along in a car. We do not notice them; yet they are fundamental to our awareness of our bodies in space and our bodies as they interact with the environment. Each sensory modality has specific receptors located throughout the body, is sensitive to particular types of energy or input, and is associated with different functional capacities. Table 24-1 provides information about the different sensory modalities in terms of types of input that are perceived, types of receptors and locations, and functions associated with each modality. Merely identifying the sensory modality of input is not adequate to understanding a sensory event. Not all input in a given sensory modality is the same. It is also important to consider the intensity and duration of sensory input. Importantly, both intensity and duration are influenced by individual perception. STIMULUS INTENSITY Intensity refers to the strength of a given stimulus. To understand issues related to intensity, try the Active Learning activity described next. Actora teermang o 0 0 o 0 Touch the back of your hand firmly with your index finger. Now touch the back of your hand lightly with the index finger. Which touch input feels more intense, on the hand being touched or on the finger doing the touching? Most of us consider the light touch on the receiving hand more intense we want to scratch our hand to get rid of the tickle. Try this: touch the palm of your hand and your upper lip lightly, just moving one or two hairs. How do these touches compare with the light touch on the back of your hand? Which touch is more intense? Most of us will consider either the touch on the palm or upper lip to be more intense than that on the back of the hand. The light touch on the back of our hands does not seem so strong any more. 0 The point made in this exercise is that the intensity can be viewed as a continuum, but a crucial aspect of understanding the continuum is individual perception. No single type of touch is always intense, it is subjectively judged by each person for its intensity based on

4 440 Part 4 Pediatric Conditions and Their Impact on the Lives of Children TABLE 24-1 SENSORY MODALITY Sensory Modalities: Receptors and Locations, Types of Input, and Examples of Associated Functions LOCATION OF TYPES OF INPUT EXAMPLES OF ASSOCIATED RECEPTOR(S) RECEPTOR(S) PERCEIVED FUNCTIONS Vestibular Tactile Hair cells located in the semicircular canals and otolithic organs Many different encapsulated and unencapsulated receptors in skin (e.g., Meisner's corpuscles, Pacinian corpuscles, free nerve endings) Proprioception Many different types of encapsulated and unencapsulated (e.g., muscle spindle, Golgi tendon organs) Visual Auditory Olfactory (smell) Gustatory (taste) Rods and cones Hair cells Olfactory bulb Taste buds Inner ear with information processed primarily in the brainstem and cerebellum Embedded in skin and at base of hair cells Receptors in muscle joints, tendons, and muscles Retina Cochlea At base of brain Different taste sensitivities in different locations on the tongue Movement of the head in space in all planes. Bilateral vestibular and proprioceptive input is necessary for functional integration of vestibular input Many different submodalities perceived by these mechanoreceptors, e.g., pressure, light touch, pain, vibration, temperature, etc. Direction and force of muscle contraction and the amount of tension in the muscles and tendons Photo receptors responsive to different types and intensities of light Mechanoreceptors, sensitive to different frequency and intensity of sound Chemoreceptors sensitive to smells Chemoreceptors sensitive to different types of tastes (e.g., salty, sweet, bitter) Balance and equilibrium reactions, postural and primitive reflexes, muscle tone, bilateral integration and coordination, with vision and proprioception involved in control of extra-ocular muscles Important in discrimination of properties of objects, force of direction of movement on skin, thermoregulation, maintenance of alertness, pain, etc. Muscle force and control, important to grading of movement, with vestibular, important to postural functions Seeing (i.e., visual acuity), visual perception (e.g., visual figure ground, spatial perception, depth perception). Hearing, auditory perception (e.g., auditory figure ground, localization of sound, recognition of phonemes and other speech sounds), associated with language Smell, closely associated with taste, protective functions and emotions Taste, closely associated with taste Data from Bundy, A. C., Lane, S. J., and Murray, E. A. (Eds.). (2002). Sensory integration: Theory and practice (2nd ed.). Philadelphia: FA Davis; Kandel, E. R., Schwartz, J. H., and Jessell, T. M. (2000). Principles of neural science (4th ed.). New York: McGraw-Hill; and Schaaf, R. C., Schoen, S. A., Smith Roley, S., Lane, S. J., Koomar, J., and May-Benson, T. A. (2010). A frame of reference for sensory integration. In P Kramer and J. Hinojosa (Eds.), Frames of reference for pediatric occupational therapy (3rd ed., pp ). Philadelphia: Wolters Kluwer. the sensitivity of the receptors in a given location, and the relationship of current sensation to other experiences. An important aspect of intensity is that it is subject to individual perception; if you ask a group of people to compare the intensity of these different touches, they will not all agree. The way we perceive or rate intensity is highly subjective, differing both between and within individuals. This can be seen in the vignette of Raul, presented next. Vignette Raul: Poor Sensory Processing or Poor Mental Health? Raul was in preschool when first evaluated by OT. His teacher referred him to an occupational therapist because she was struggling to make sense out of his behaviors. In the class - room and on the playground, Raul fluctuated between being withdrawn and hesitant to interact with the other children, and exhibiting aggressive/explosive behavior. He seemed to want

5 Chapter 24 Sensory Processing Disorders 441 to be included in activities, but did not initiate participation. When encouraged to try, he frequently became aggressive. He avoided art tasks that were messy and watched others, but did not use the equipment on the playground. At the time of referral to OT, Raul was also being assessed for mental health concerns. It was considered important to be able to determine what, if any, contribution SPD made to mental health or behavioral concerns. Raul's avoidance of art activities might indicate that he finds the feel of things like glue and finger paint intense; he may strongly object to the way they feel and thus avoid touching them whenever possible. Similarly, Alan may have been responding to the intensity of sensory input in his environment when he became "bejiggedy." For Alan, perceived intensity across multiple sensory systems appeared to cause his disruptive behavior. Part of the variability within each individual over time relates to your sensory experiences. You may consider a particular type of input to be very intense or even overwhelming after a tiring day or during an exam, but can easily tolerate the same input when you are relaxed. This inconsistency in perception relates to the summation of input over time or space. The clinical significance of this is important and will be discussed later in this chapter. Although the tactile system has been used to illustrate this point, intensity applies to all modalities, even those we would not think of as being intense. 0 A4'0". Leitabag g c) Take your hand and hold it out about two feet from your face, now quickly bring it up to your nose. This is called visual looming. Now have someone do the same thing to you. Notice how the same stimulus seems very different in these situations. The visual example adds another dimension to the perception of intensity. Did you notice how much more intense the looming seemed when someone did it to you, as opposed to when you did it to yourself? Visual looming becomes even more intense if it is a face, instead of a hand, which is coming toward you. 0 The feature of sensory perception that is exemplified by visual looming is true for most sensory input we tolerate sensory input that we seek out or generate ourselves much more readily than input that is imposed upon us by others. This is very important when we try to understand the behaviors of the children with whom we work. For example, a child like Raul with sensory processing deficit may give hugs but find it difficult to receive them. STIMULUS DURATION Duration is the third property of a stimulus identified by Kandel and colleagues (2001). We should think about duration in two ways first, the absolute duration of the sensory event in the environment. For example, each of the touches discussed in the first Active Learning exercise were very brief, only a few seconds; this is their absolute duration. But how long did you continue to feel the effect of each touch? Most of us still "feel" the touch for much longer than that; our perception of sensation often exceeds the absolute duration. It takes us time to recover, or return to baseline. This property has important implications for the children with whom we work. If a child does not recover, or return to baseline, relatively quickly after a sensory event, the perception and consequences of sensory input will tend to accumulate over time. If that occurs, the child may become more readily overstimulated. Reflecting back to Raul once again, if he does perceive touch input to be highly intense, and is slow to recover, this could disrupt his ability to interact within his classroom throughout the day. Not only are art activities associated with touch, but any interaction with peers might result in unexpected (and unwanted) touch. Raul may feel the sense of a bump for a prolonged period of time, and very intensely. To cope, Raul tries to avoid touch in the classroom. His teacher describes this behavior as being withdrawn or emotionally unavailable. But is it really an emotional unavailability, or is it avoidance of touch that can result with how he interacts with his peers? An interesting and helpful way of thinking about sensory experiences is to differentiate between the objective physical properties of the sensory stimulus (e.g., a light touch exerting 1/2 ounce of pressure on a Winch square of skin on the palm of the hand for one second) and the sensation itself (i.e., the subjective experience of that sensory event) (Williamson, Anzalone, and Hanft, 2000). Unlike the objective physical nature of the sensory stimulus, sensation is variable and influenced by many factors, such as task demands, motivation, prior sensory experiences, state of arousal, and emotions. As noted earlier, Alan's unique interpretation of his complex sensory environment is what leads him to become disruptive. The same environment for other children in his classroom does not result in similar behavior. These factors contribute to the inconsistency we see in the subjective experience of sensation between individuals, as well as within an individual. Sensation is a dynamic property that interacts with experience. It is not stable like the color of your eyes or even your preference for one color versus another. This perspective helps us remember to evaluate both the changing context (i.e., the source of a sensory stimulus) and the child who perceives the sensation. It also is a reminder to acknowledge the fact that each of us is different. We all take in and experience information differently (Fig. 24-2). In fact, we should think about SI theory as a model of individual differences as well as a way of treating and describing dysfunction.

6 442 Part 4 Pediatric Conditions and Their Impact on the Lives of Children FIGURE 24-2 Our responses to sensation are individual; some children will love this activity, and others will run for Cover! (Photograph courtesy of Angie Carter.) Here's the Point Sensory stimuli have features of modality, intensity, and duration. Modality refers to the type of sensory input (e.g., vision, proprioception). - Intensity is the strength of sensory input. Our interpretation of intensity relies on the absolute intensity along with receptor sensitivity and individual perception. Duration is the length of the availability or application of sensation. Our interpretation of duration includes both the absolute duration, and our ability to recover from ongoing sensory input. Sensation is the subjective nature of the sensory experience. Sensation is dynamic and influenced by experience. Sensory Integration and Processing The preceding section provided information related to the sensory receptors, leading up to the point at which sensation gets to the central nervous system (CNS). Now that input must be "processed." Sensory integration encompasses the central registration of a sensory event, attaching significance to the event so that we orient to it; the processing and integration of input from more than one modality as appropriate; and the use of sensation to interact with the environment. This indudes the interpretation of sensation based on prior experience, an interpretation that is individual because it is based on prior experience. We all take in and organize sensory information as we interact with the environment. There are qualitative differences in how each of us does that, and this relates to individual perception of sensation described earlier. For example, some of you may require very little sensory input to become attentive and alert in the morning, Prove It! Sensory Processing Difficulties Several articles have explored the relationship between indicators of sensory processing difficulties and children's occupational performance (Ahn, Miller, Milberger, and McIntosh, 2004; Baranek et at., 2002; Bar-Shalita, Vatine, and Parush, 2008; Bundy, Shia, Long Qi, and Miller, 2007; Dunbar, 1999; White, Mulligan, Merrill, and Wright, 2007). More recently, researchers have used neurophysiological measures such as electroencephalography (EEG) (Davies and Gavin, 2007), and measurement of electrodermal activity (changes in the conductivity of the skin related to nervous system activity) to identify differences between typically developing children and those with developmental disorders (Mangeot et al., 2001; Miller et al., 1999; Schaaf, Miller, Seawell, and O'Keefe, 2003). From Pollock, N. (2009, Sept). Sensory integration: A review of the current state of the evidence. Occupational Therapy Now, 11, whereas others need more. Some of you like to be touched, but others do not. Some of you can quickly appraise complex environments and figure out what actions are needed to explore them, whereas others will slowly take their time. One child may be afraid of new contexts, whereas another thrives on change and novelty. The differences outlined in these examples reflect our individual differences in sensory registration based not only on the stimulus, but also on our interpretation of the stimulus in light of prior experiences. The individuality in sensory processing is not necessarily problematic; it simply makes us different. Those differences become a problem only when, and if, they interfere with our ability to participate in activities and occupations across the many contexts of life. Then these processing challenges may be indicative of an SPD. An interesting parallel can be drawn between the behaviors described earlier and individual temperament. Many of the differences we describe in sensory processing parallel those described as temperament related differences in personality (Fox and Polak 2004; Grist and McCord, 2010; Thomasgard, 2003; Thomasgard and Metz, 2004). Temperament researchers (Kagan, 2003; Rothbart and Bates, 2006;) would suggest that the individual manner or style with which we interact with our sensory environment is driven by the trait variables that define temperament (e.g., reactivity, introversion/extroversion). According to Rothbart and Bates (2006) temperament is one aspect of personality, but one that underlies the choices and styles of social interaction, leisure activities, and even career choice. Dunn (2001) expanded on this theory, linking characteristics of temperament to categories of SPDs. According to Dunn, although there may be overlap between studies of sensory processing and studies of temperament, "these different areas of inquiry are getting at some universal truths about being human, but from different

7 Chapter 24 Sensory Processing Disorders 443 points of view" (p. 615). Using both areas of inquiry will allow us to appreciate the complexity of these issues, and to move our understanding forward. Sensory processing disorder can result from the three different aspects of the sensory integrative process described earlier: taking in or registering the input, interpreting the input in light of previous experiences, and actually using the input in the environment. These three separate aspects lead to the categories of SPD that are described next. Vignette Raul (Continued) On the playground, Raul is observed to run around in a somewhat aimless manner. He will sit on the swings only if no other children are around. When he does so, he slowly rocks himself back and forth, but will not swing high or pump his feet to get the swing moving. When asked if he likes to swing, Raul responds, "No, swinging is for babies." Raul will use the slide and sit on the merry-go-round, but he seems to take no joy from these activities. He will watch as other children play on these pieces of equipment, and at times the watching seems to give him ideas for how to play. If no other children are around, Raul may try to do something on the playground equipment. However, if pushed to play on the equipment by his peers or teacher, Raul again becomes angry or extremely withdrawn. What does this additional information about Raul indicate about his sensory processing? He appears to register, or perceive, the movement (vestibular) input he gets on the swing, and may have prior experiences with the slide and the merry-go-round. He orients to the sensation as well, making note of it in his environment. What appears to be happening is that his processing and integration of the input beyond these two initial stages is faulty. Raul does not seem to enjoy movement sensation. Further, he does not seem to be able to figure out what to do to make the movement fun. Socially this is problematic because his peers seem to be having a great time. Raul expresses frustration with his inability to join his peers in some of his aggressive behavior. Using SI theory, we would suggest that Raul's use of vestibular and proprioceptive input to develop, plan and organize an adaptive response to the environment is inadequate. Because of this, he avoids movement as much as he can, and he avoids playing with his peers. GOODNESS OF FIT Understanding the processing of sensation can give us clear insight into the children with whom we work. Beyond this, it can give us insight into the physical and social environments in which these children can function optimally. Think about Alan, who sometimes feels bejiggedy. He has many problems in school, especially in the cafeteria and on the school bus. In contrast, he does much better at home in the predictable environment his mother has created for him, and where he has more control over his sensory environment. At home he can be in charge of the sensation he receives. The differences between Alan's functioning in both environments can be considered in terms of goodness of fit. There is a goodness-of-fit between Alan and his home environment, but not as good a fit between him and his school environment. Goodness-of-fit is a term first used by psychologists studying temperament (Chess and Thomas, 1977, and 1991), but it has direct relevance to sensory processing (Williamson, Anzalone, and Hanft, 2000). It refers to the fit, or congruence, among an individual's needs, interaction style, and the environment. If we think about the examples earlier, Alan, who is easily overwhelmed by loud and active places, may do fine in a quiet home as an only child. However, he may show problems managing himself when accompanying his mother to the supermarket or attending chaotic and crowded family holiday celebrations. There is a strong goodness-of-fit between Alan and his typical routine, but a poor goodness-of-fit in the more complicated environment of the grocery store or the family holiday. To use the terms introduced earlier, the intensity and duration of sensory input in the environment may be interpreted as overwhelming when there is a poor goodnessof-fit and fine when there is good fit. In some individuals, the challenge of finding a goodness-of-fit between their ability to take in sensation and the sensation the environment provides prevents participation or engagement in occupation. This would certainly be true of Raul. In that case, understanding sensory processing and applying SI theory provides a way of understanding and diagnosing dysfunction. Here's the Point > Parallels can be drawn between some aspects of SPD and temperament related differences in personality. > Interaction with the environment requires registration, orienting, processing, and integration of sensation; being able to process sensory information through these stages allows us to participate with peers. D- Consideration of goodness-of-fit between the child and the environment directs us to examine the child's needs and interaction style, and the environmental expectations and sensory properties to determine if there is a match. Sensory Integration Theory Sensory integration (SI) theory was first proposed by Ayres (1972a) as a way of understanding the difficulties that school-aged children with perceptual and learning disabilities have in basic processing of sensory information. The theory is based on Ayres's understanding of functional

8 444 Part 4 Pediatric Conditions and Their Impact on the Lives of Children performance as well as the underlying neural processes assodated with taking in, processing and responding to sensory information. She was particularly interested in how sensory information was organized to enable adaptive engagement in a changing flexible environment, and how to help improve that organization in those children with difficulty. Sensory integration theory is the application of the concepts discussed earlier to the occupational being; it is used as one means to help us interpret observed behaviors, and it is the foundation for SI intervention. This chapter describes the behavioral and performance aspects of SI theory. Understanding the neural science underlying the sensory processes within this theory is important, but is beyond the scope of this chapter. It is discussed in detail elsewhere, and therapists who plan to apply the theory in their practice are encouraged to learn more about the brain-behavior aspects of the theory (Ayres, 1972a; Bundy, Lane, and Murray, 2002; Schaaf and Smith-Roley, 2006; Smith-Roley, Blanche, and Schaaf, 2001). Ayres (1979) defined SI as the "organization of sensory information for use" (p. 1). Two aspects of this deceivingly simple definition are important to point out. First, SI is about organizing sensory information. That implies an active process through which information from different sensory modalities is integrated with previous experience and cognitive or emotional processes. Second, the sensory integrative process involves using sensation. Again, the active process is emphasized, and the sensation becomes the foundation of environmental interaction. When we think about Alan feeling bejiggedy, we can reflect on the fact that he has difficulty organizing the sensory events that surround him (he becomes overwhelmed and cannot accurately interpret his sensory environment). In addition, Alan cannot use the input as a foundation for adaptive behavior. He tends to react defensively rather than adaptively (e.g., he may hit a child who gets too dose), and is frequently unable to learn about, or modify, his environment to make it more comfortable or safe. For Alan, SI theory helps us to understand much about his behavior, his feelings about himself and others, and his learning style (Fig. 24-3). Here's the FIGURE 24-3 Being rolled in a mat provides deep touch, and may be useful for children like Alan in reducing the sensation of "bejiggedy." (Photograph courtesy of Joseph A. Werner, OTR.) diagnostic classification) designed to explicate current understanding of sensory processing deficits (Fig. 24-4). Within this dassification, sensory modulation disorder, sensory discrimination disorders, and sensory-based motor disorders are encompassed. These disorders are reflective of the three phases of SI discussed earlier: intake (sensory modulation disorder), interpretation (sensory discrimination disorder), and using the input (sensory-based motor disorder). Identification of a specific sensory processing problem is essential for parent and teacher education as well as the dinical reasoning preparatory to OT treatment planning and implementation. Intake Sensory registration and modulation Interpretation Discrimination and affective appraisal of input Sensory processing disorder Use of the lop _ Organizing action > SI theory can help us interpret the processing sensation as it lays the foundation for engagement in occupation. )1.- SI, as defined by A. Jean Ayres, is the organization of sensation for use. Sensory modulation disorder Sensory discrimination disorder Sensory-based motor disorder Disorders of Sensory Integration and Processing In an attempt to further darify the identification of disorders in sensory processing for research as well as clinical practice, Miller et al. (2007) proposed a nosology (or A problem in intake or affective appraisal A problem in discrimination A problem in using the input FIGURE 24-4 Typical sensory integrative process. [Adapted with permission from Miller, L. J., Anzalone, M. E., Osten, E., Lane, S. J., and Cermak, S. A. (2007). Concept evolution in sensory integration: A proposed nosology for diagnosis. American Journal of Occupational Therapy, 61, ]

9 Chapter 24 Sensory Processing Disorders 445 SENSORY MODULATION DISORDER Sensory modulation disorder (SMD) results from a problem in the initial registration and processing of sensory input. Children with sensory modulation disorder have difficulty using sensory input as a foundation for responding to the environment in a way that is consistent with its type and intensity. Response to sensory input in children with SMD is inconsistent with the expectations of the environment. They may overrespond (e.g., have an exaggerated reaction to a low-intensity stimulus such as an affectionate touch) or underrespond (e.g., not notice a loud noise in the environment); their responses are in line with how they perceive the intensity rather than the actual intensity of the stimulus. So for both Raul and Adam, their responses to relatively low intensity stimuli seem exaggerated. That is because to them, the stimuli are not low intensity. Reflecting back to the concept of goodness-of-fit, when a child has effective sensory modulation, there is a good fit between the child and environmental expectations resulting in a graded and appropriate response to sensation. In a child with SMD, there is a poor goodness-of-fit, or a mismatch, between the child's sensory responsivity and environmental expectations. This disparity between response and stimulus properties is thought to reflect processing at many levels of the CNS. Think back to Alan: as noted in the beginning of the chapter, Alan has an SMD that results in overresponsiveness to the sensation in his - school environment. Another child may have sensory un- -_ derresponsivity and be unaware of even important sensory events in their environment such as a honking car horn at an intersection or a teacher calling for their attention. One way to understand the resultant behavior of children who are overresponsive or underresponsive was introduced by Dunn (2001). She identified coping responses that were "passive" and "active." Passive reactions to sensory input are just that the individual does nothing to modify the input. Active reactions are used to avoid or obtain desired input or increase or decrease the perceived intensity of the sensory input. A child who is innately overresponsive, but actively coping with that overresponsiveness, will actively avoid sensory experiences, often by withdrawing from the environment. Another child may actively cope with very bright sunlight by squinting and covering the eyes; a passive response would be to do nothing to lessen the intensity of the sun. When thinking about sensory modulation disorder, therapists should think about sensory threshold as well as the child's behavioral coping pattern (Table 24-2). Children with increased sensitivity to sensation may have a lowered neurological threshold; sensation would more readily overwhelm them. This is reflected in increased responses to routine sensory events occurring in their environment. In contrast, children with a high neurological threshold may fail to register and respond to routine environmental sensation; they may not reach their sensory threshold during typical sensory experiences. TABLE 24-2 Sensory Threshold and Behavioral Coping LOW THRESHOLD HIGH THRESHOLD Copes Actively Sensory Sensory Acts in Overresponsivity Underresponsivity Accordance with Threshold Copes Sensory Sensory Seeking Passively Avoidance Attempts to Counteract Threshold Adapted from Dunn, W. (1999). The sensory profile manual. San Antonio, TX: Psychological Corporation; and Williamson, G. G., and Anzalone, M. E. (2001). Sensory integration and self-regulation in infants and toddlers: Helping very young children interact with their environment. Washington, DC: Zero to Three. Overresponsiveness and underresponsiveness may be apparent in different sensory systems and may coexist such that a child may be overresponsive to touch, but underresponsive to movement. Children with either overresponsitivity or underresponsivity may have problems adapting to and freely exploring both physical and social environments. Differences in sensory sensitivity are paralleled by behavioral responses, such that a child with increased sensitivity will appear overresponsive to environmental input, and children with diminished sensitivity will be underresponsive to environmental input. One way to think about the relationship between responsivity and sensitivity is that the magnitude of the response is in line with the magnitude of the perceived stimulus (i.e., intensity). For example, if the child perceives a stimulus as being overwhelming and very intense, the child may react as if he or she were threatened. In contrast, a child with underresponsivity, who barely notices the stimulus, may barely react to an event about which other children in the room are excited. Sensory Overresponsivity and Sensory Avoidance As conceptualized by Dunn (1994, 1999; Kientz and Dunn, 1997) and further documented in electrophysiological research by Miller and colleagues (Mangeot, Miller, McIntosh, McGrath-Clark Simon, Hagerman, and Goldson, 2001; Mdntosh, Miller, Shyu, and Hagerman, 1999; Miller et al., 1999), children with a low threshold are prone to overresponsiveness to sensory input. Dunn hypothesizes that a low sensory threshold may manifest in two different behavioral profiles based upon whether the child copes or responds to the sensory "challenge" in an active or passive manner. Children acting in accordance with their threshold (passive) will be overresponsive; they do nothing to diminish the intensity of the input and as a result their strong response parallels their perception of high stimulus intensity. Children with overresponsiveness tend to have a high arousal level, since they are often overstimulated. These children may show an

10 446 Part 4 a Pediatric Conditions and Their Impact on the Lives of Children inability to focus their attention and a negative affect, because of the stress of the sensory input coming their way. Finally, they tend to act impulsively or reactively in response to sensory input. In contrast, children actively working to counteract their sensory threshold are driven to avoid sensory input that they may find aversive in order to modulate their arousal. These children are considered by Dunn to be sensory avoidant They may shdw hyper vigilant attention, needing to register and attend to all sensory stimuli in order to avoid that which bothers them. Children with sensory avoidance may be fearful or anxious. and their actions may be constrained. They may actively avoid engaging in activities that could lead to age-appropriate learning and development. Children with sensory avoidance may succeed in managing their environments to create a better goodness-of-fit between their sensory needs and environmental sensory inputs (e.g., they may be able to play in a quiet corner of the playground, watching the other children from a safe distance). Unfortunately, it is not always possible to anticipate a sensory event and avoid it. As a result, children with sensory avoidance often become highly reactive when unable to exert control (e.g., another child jumps into their corner of the playground to catch a ball and accidentally touches them). Both Alan and Raul showed sensory overresponsivity. Alan's was in multiple sensory systems, such that his behavior became disorganized and disruptive when multiple things were happening in the environment. Initially Alan's response to the sensation that bothered him was passive; he did not work to decrease the bothersome feeling he got from sensory input. However, he and his therapist worked to develop a sensory diet, consisting of things he could do or sensory inputs he could seek when he started to feel "bejiggedy." The sensory diet was designed to help Alan create a better fit within the environment and to become more organized if he is overstimulated. In contrast, Raul showed sensory overresponsiveness to touch and movement, but his behaviors were designed to help him avoid touch and movement Raul tended to withdraw on the playground and avoid engaging in tactile activities like finger painting. Functionally, children who have a low threshold, either overresponsivity or sensory avoidance, may have strong preferences and inflexibility in dothing, play, or environmental preferences. They often have sleep dysregulation with irritability, difficulty getting to or returning to sleep, and may need to co-sleep with their parents (Henry, 2008; Williamson and Anzalone, 2001). These children also may have some challenges during mealtimes, with strong preferences and intolerances in food textures, temperature, tastes, and changes (Fig. 24-5) (Interdisciplinary Council on Developmental and Learning Disorders [ICDLI, 2005; Miller et al., 2007). For both Alan and Raul, their SMD interfered with their ability to play with peers and interact appropriately in their academic environments. FIGURE 24-5 As an infant, this boy was intolerant of new tastes and textures and highly sensitive to temperature, rejecting all warm foods and drinking formula at room temperature. He was eventually diagnosed with Asperger syndrome. (Photograph courtesy of Laura Horowitz.) Sensory Underresponsivity and Sensory Seeking Children with a high threshold may present as either underresponsive or sensory-seeking, depending upon whether they are active or passive in addressing their sensory threshold. Children with sensory underresponsivity (SUR) appear to have a decreased arousal level. They may appear drowsy or just disinterested, and their attention seems to be unfocused or inner directed. These children often seem to be sad or have a flattened affect. Their actions are restricted, and they may appear somewhat disinterested or passive (ICDL, 2005; Miller et al., 2007, Williamson and Anzalone, 2001). Children with underresponsiveness acting in accordance with this high threshold make no attempt to obtain the intensity or duration of sensory input needed for them to reach a more optimal level of attention and arousal. These are children that require a lot of help from adults in their environments, yet their behaviors do not elicit that support. In contrast, children with sensory seeking behavior also have a high threshold, but they make it their business to meet their threshold sensory needs. These children often have arousal levels that are appropriate and enable attention, but they tend to pay attention only to the sensory potential in their environments. For example, they may be uninterested in the learning potential in an environment, but very interested whether or not they can get high intensity sensory input through their environmental interactions (e.g., they may repeatedly crash into other children or objects rather than more adaptively interact with the child or learn about the object). Action is often rather impulsive in these children, and they tend to take a lot of risks; at times they may even seem accident-prone because of this risk-taking behavior. d re Sc to th ar pr ha a1 ru pe ne roj eq ob. (e.1 mi cul tas] Mil diff ove to hav and ade, prol be wiff Res Alth patti assu: siver ties. to s(

11 Chapter 24 Sensory Processing Disorders 447 Practice Wis do Is it Sensory or Is it Behavior? It is important to differentiate between children who are engaging in purposeful sensory seeking to meet a sensory threshold need and those children who are just engaging in disorganized play because they are overstimulated or just disorganized. The child with sensory-seeking will become more attentive and more organized after a period of sensory-seeking, whereas the child who is just engaging in disorganized sensory motor activities will become progressively more disorganized. Children with high threshold or under responsivity also have functional problems in participation in typical daily activities. Since children with SUR are not as responsive to the possibilities for action in the environment, and they have difficulty interacting with both social and physical environments. Children with SUR tend not to be aware of twisted clothing or even shoes that are on the wrong feet. This may lead to an appearance of disorganization and sloppiness. They may have preferences for strong, spicy, or crunchy foods, and may have a tendency to stuff food in their mouth because of a lack of awareness of smaller quantities. Most importantly, children with SUR may have disrupted developmental transactions with both adults and peers; they demand less interaction from adults than is needed to initiate and support interaction in their environment. This can place these children at risk for missing exploratory and learning opportunities. Other problems observed in this group may be a lack of awareness of risk (e.g., they may not notice obstades in their path or even minor injuries), developmental delay, dyspraxia, (difficulty conceptualizing, planning and/or executing motor tasks) and sensory discrimination disorder (ICDL, 2005; Miller et al., 2007). These children may also have sleep disorders, but of a different nature from those that are seen in the child with overresponsivity. Children with underresponsivity tend to have difficulty waking up in the morning, yet may also have difficulty getting to sleep at night (Williamson and Anzalone, 2001). This sleep pattern may lead to inadequate duration of sleep, which can itself exacerbate problems of underresponsivity (e.g., inattentiveness can be increased with sleep deprivation and is also associated with sensory underresponsivity). Responsiveness Inconsistency Although Dunn's model seems to clearly differentiate patterns of sensory responsiveness, it is based on the assumption that children have a stable pattern of responsiveness and that patterns are consistent across modalities. Unfortunately, that is not always the case; response to sensation is also context dependent. Thus, some children show a combination of SOR and sensory underresponsivity. Children may show overresponsivity within one sensory domain, while seeming to have underresponsivity in another domain. They may even show one pattern in the morning (e.g., underresponsiveness) but another in the evening after a full day of interaction and exploration (e.g., overresponsiveness). This combination of responses can make them very difficult for caregivers, teachers, peers, and siblings to understand. Because of this variability in responsiveness, there is more to understanding sensory modulation profiles than just understanding threshold for orientation, or the initial awareness of sensory events. An additional dimension that needs to be added to Dunn's model is the fact that sensory responsivity varies depending on other stresses experienced within the day, and other aspects of the child, such as arousal level. Sensory input supports arousal, although the degree of sensory input that results in optimal arousal differs among individuals. Optimal arousal is the point at which you are in a calm state (in babies we call that state quiet alert); at that point your behavior is organized, and you are able to take in new information, learn, think, and interact with both the physical and social environments. When arousal levels exceed "optimal," behavior becomes disorganized. You can see this in yourself when you have had too much caffeine in an attempt to prepare for a test; you have more difficulty staying focused, rather than less difficulty. To deal with this error you might go for a run or do something else physical, taking a break from tasks that require intense attention. In the face of a sensory modulation deficit, a child may not be aware of the intake of "too much" sensation. At that point behavior becomes progressively more disorganized. To restate, the child will have increasing organization up to a certain point, but beyond that point will have difficulty interacting adaptively in the environment. Figure 24-6 illustrates the dinical significance of this relationship. Children with SMD have difficulty maintaining an attentive organized state in which they are available for social interaction, sustained attention, and learning. Most of us have a wide Zone of Optimal Organization which gives us the flexibility to sustain interaction with our environment throughout the day in light of our changing sensory environments and demands. The Zone of Optimal Organization is bounded by two thresholds: threshold of orientation and threshold for aversion (Baranek, 2009) (see Fig. 24-6A). Problems with sensory modulation can result from an orientation threshold that is too high or too low, but also from a Zone of Optimal Organization that is too narrow (see Fig. 24-6B). An additional factor that needs to be considered in understanding this schematic of sensory modulation is the idea that taking in and recovering from sensory events is dynamic over the course of the day. The dynamic nature of sensory contributions is illustrated by the color and black arrows in Figure 24-6C.

12 448 Part 4 f4 Pediatric Conditions and Their Impact on the Lives of Children B C Behavioral disorganization with over responsivity t Zone of optimal organization Inattentive, low arousal with under responsivity Behavioral disorganization with over responsivity Narrowed zone of optimal organization Inattentive, low arousal with under responsivity Behavioral disorganization with over responsivity Inattentive, low arousal with under responsivity -4 Threshold for aversion Threshold for orientation -4 Threshold for aversion -4 Threshold for orientation -4 Threshold for aversion -4-- Threshold for orientation FIGURE 2q-6 Zone of optimal organization. A, An optimalsize band separates the threshold of orientation from the threshold of aversion, which enables the child to stay organized or focused. B, Some children have a narrowed zone of optimal organization, which limits availability for learning and interaction. C, The dynamic nature of sensory contributions is illustrated by the colored and black arrows. The colored arrows indicate desirable regulation, or activities that lead into the zone of optimal organization. In contrast, the black arrows indicate sensory input or experiences that tend to be disorganizing for the child, leading to overresponsivity or underresponsivity. [Modified from Baranek, G. (2009). Sensory Experiences Questionnaire, Version 2.1. Unpublished manuscript. Division of Occupational Science, University of North Carolina at Chapel Hill.] The colored arrows indicate desirable regulation that is, activities that lead into the zone of optimal organization. In contrast, the black arrows indicate sensory input or experiences that tend to be disorganizing for the child (either leading to overresponsivity or underresponsivity). Optimal organization is the goal of sensory modulation and self regulation: When a child's responses are modulated, they enable him or her to stay in the zone of optimal organization and engage in functional occupations. Our challenge as occupational therapists is to help children remain in the zone of optimal organization. This challenge is addressed both through direct intervention and through helping families and others understand the child's needs to more effectively avoid situations (i.e., the black arrows) that lead to disorganization and introduce sensory experiences to enable the child to reenter th e zone of optimal organization (i.e., the color arrows). It is important to recognize that regardless of whether a child's threshold for orientation is high or low, the threshold is only the initial awareness of sensory input. There is still an upper limit to organized behavior (threshold for aversion). Continued arousal and sensory input can lead to overresponsivity and a potential for behavioral disorganization. In other words, a child with a high threshold who was initially under-responsive may seek out so much stimulation so that he or she will exhibit disorganized behavior, such as increased activity, distractibility, refusals, or even tantrums. SENSORY DISCRIMINATION DISORDER Sensory discrimination involves the ability to distinguish between different stimuli and make sense out of the temporal and spatial qualities of sensory input. Discrimination is an important aspect of cognition and has been extensively studied in the fields of psychology, education, and neural science. It is not our intention to fully describe this extensive area of scholarship, but rather to briefly introduce the disorder in relation to the other SPDs more central to the theory of SI. The temporal qualities of sensation include such things as the timing of arrival of a sound at the two ears, which allows us to determine the location of the sound source. Repeated touch has temporal qualities, as does movement through space. The temporal qualities of sensory input allow us to understand the dynamics of the environment. The spatial qualities of stimuli are those we use to define shape, depth, and other spatial aspects of stimuli. Further, discrimination involves the ability to detect and use the salient qualities of a sensory input, that is, our ability to attend to what is important and to ignore what is not essential in identifying the qualities of a stimulus. This may involve the temporal features (e.g., think about a child repeatedly pulling on the hem of his mother's coat; she will attend to this input when the input accumulates over time), or spatial features (e.g., when we see part of an object for which we were searching, we can identify it because we have the skill of visual closure). Discrimination is a cognitive process that lays the foundation for the ability to organize, interpret, and learn from information obtained through the sensory receptors Examples of discrimination in the sensory systems most commonly addressed by occupational therapists are included in Table A deficit in sensory discrimination is the inability to optimally perceive and organize incoming sensation as a basis for action, interaction, and learning. It encompasses problems in understanding the characteristics of sensory stimuli and relating those characteristics to prior knowledge or experiences. This results in lessened capability to interpret or give meaning to the specific qualities of stimuli, to detect similarities and differences among stimuli, and

13 Chapter 24 Sensory Processing Disorders 449 TABLE 24-3 z Sensory Discrimination EXAMPLES OF SENSORY DISCRIMINATION SENSORY MODALITY DISCRIMINATION FUNCTION DISORDER AND FUNCTIONAL CONSEQUENCES Tactile Vestibular Proprioception Vision Audition Knowing where you have been touched and by what Two-point discrimination Determining direction of movement on skin Knowing head position relative to body and gravity Knowing up/down; relationship with gravity Maintaining balance; mounting equilibrium reactions Developing needed postural tone for the task at hand Moving through space without crashing Modulating force to match task Demonstrating smooth and coordinated movements Knowing where the body is in space Movement detection Shape identification Spatial perception Figure ground perception Visual memory Phenome (unit of speech distinguishing meaning) discrimination Auditory figure-ground Distinguishing the temporal and spatial qualities of sound Auditory memory Poor tactile localization Poor stereognosis Poor awareness of force during manipulation Poor awareness of body in space Reliance on vision during postural challenges Poorly graded movement Clumsiness Reliance on visual monitoring during movement Impaired Visual Figure Ground to differentiate the temporal and/or spatial qualities of stimuli. Thus, a child with a deficit in tactile discrimination would have difficulty reaching into his or her pocket and determining which of the items in the pocket was a key, for instance. Children with deficits in sensory discrimination can perceive that stimuli are present, and may be able to modulate their responses to the stimuli, but cannot identify what or where the stimulus is. In the pocket example, the child knows there are items in the pocket, but struggles to use the sense of touch and proprioception to determine exactly which object is the one sought. Because we use sensory input as the basis for the development of body scheme (an internal representation and awareness of the body-in-action), discrimination disorders affecting the tactile, vestibular, and proprioceptive systems can lead to disruptions of this scheme. Disruptions in the development of body scheme can lead to dyspraxia or problems with the planning and execution of smooth graded, coordinated movement. One way to think about your body scheme and how crucial it is to planning movement, is to imagine yourself climbing a set of stairs. Although you probably cannot tell us how high the step is, you always raise your leg high enough to clear the next step. That accuracy of movement is a result of your body scheme coupled with knowledge of the environment, and is based upon sensory discrimination, especially in the tactile and proprioceptive modalities. Consider Raul in the following vignette: Vignette Raul (Continued) Raul and the occupational therapist play on the playground while the other children are having snack. The occupational therapist notices that Raul likes to watch other people do things and, given enough time, he will try to imitate their actions. However, when the occupational therapist demonstrates climbing the monkey bars, Raul cannot figure out how to get started. He moves to the bars and puts one hand on the bars, but cannot determine what to do with his legs. He pulls himself up with his hands, but then his legs bump into the bars. Raul appears to have poor body scheme. Were we to evaluate Raul, we would potentially find that he has inadequate discrimination in his vestibular and proprioceptive systems. Raul's behavior on the playground suggests that he is not able to use information from the vestibular system, and the proprioception inputs from his muscles and joints, to help him figure out how to interact with the equipment on the playground. He does not know how to move his body in, around, and on the equipment to have fun, even though he does not have an obvious motor disability such as we would see in a child with cerebral palsy. Deficits involving visual and auditory discrimination can result in learning or language disability as the child,

14 450 Part 4,e Pediatric Conditions and Their Impact on the Lives of Children for example, is challenged to discriminate between letters such as "b" and "d," and differentiate between subtle differences in sounds and sound patterns. Children with discrimination deficits may also take extra time to process the salient or important aspects of sensory stimuli from their bodies, and display significant frustration with an inability to make sense out of the world. Discrimination deficits are not necessarily consistent across the sensory system (ICDL, 2005; Miller et al., 2007) and can occur in one or more systems at a time. Moving yields proprioceptive and vestibular feedback. That feedback tells the child about movement of the body as a whole (e.g., forward, side-to-side) and about changes in position of body parts (e.g., elbow flexed, body weight shifted over right leg). Feedback also comes in the form of visual input, as you receive the information that gives you knowledge of the results of your endeavor. The development of body scheme relies heavily on feedback, but is also the basis for feed forward, or the sensory expectation for new and novel motor behaviors. Sensory feedback is addressed in detail in the motor learning literature (Shumway-Cook and Woollacott, 2011). Feed forward is a preview of the action to be carried out; it is a function of the CNS used to determine if the intended plan for action matches environmental conditions and personal readiness (Kandel, Schwartz, and Jessell, 2000; Shumway-Cook and Woollacott, 2007). As a plan for action is sent to the musdes, the same plan is "fed-forward" to the cerebellum, where we can determine if the plan takes into account such things as our current body position and things happening in the environment. Because we are not stable, and environments often change, being able to use feed-forward means that we can make adjustments in a plan as we begin to implement it. Thus, if the plan is to run from the couch to the chair in a straight line, but the dog decides to go to his bowl in the kitchen, across our intended path to the chair, we can move to the side, stepping around the dog. This change is implemented "on-line," as we are doing the task. SENSORY -BASED MOTOR DISORDERS There are two categories of sensory-based motor disorders: dyspraxia and postural disorders. Poor sensory discrimination contributes to both of these disorders. In this section, we are primarily addressing discrimination within the body-centered sensory systems: tactile, vestibular, and proprioceptive systems. This link is in part due to the relationship of these sensory systems to the development of body scheme (Cermak and Larkin, 2002; Giuffrida, 2001; Reeves and Cermak, 2001). Praxis and Dyspraxia Praxis is the ability to conceptualize, plan, and execute unfamiliar purposeful actions. According to Ayres (1988), "praxis is to the physical world, what language is to the social, it enables interaction (p 1)." We can thi nk of praxis as a capability with three major component s: ideation, motor planning, and execution. Ideation involves perceiving the possibilities for action in the environment; this is what is meant by th e term "conceptualize' in the definition of praxis given earlier. Ideation "happens" when a toddler sees a large box and works to dimb into it; when a child faces a slide and decides to run up the metal slide rather than climb the ladder; and when a school-aged child determines that the railing on the stairs in the park would be perfect to grind on with the skateboard he has been riding. Ideation is the most clearly cognitive step of praxis, involving creativity and flexibility in activity and goal choice. When ideation is faulty, children cannot generate ideas for interaction with the environment; they do not see the potential for action and interaction. Children with poor ideation may watch more than do, finding ideas as they observe other children at play. We might want to consider an ideation problem with Raul, in addition to his poor body scheme. As a "watcher" rather than a "doer," Raul's behavior suggests he is having some ideation difficulties. Other children with poor ideation may be inflexible in their play, repeatedly doing the same things over and over without the elaboration more typical of play in most children. Because of its link to cognition, when evaluating children with intellectual disabilities, it is important to frame expectations in relation to that disability because of the link between ideation and cognitive processes. While ideation is about identifying opportunities for action, motor planning is about figuring out how to do it. It is a bridge between ideation and execution, putting together the pieces of how the body moves and how best to interact with the physical environment the plan for action. Motor planning involves sequencing and timing of a series of actions to complete a goal; it can only be seen during execution. The toddler wants to be in the box, and the first attempt has him leaning over, head first. This motor plan may not be the best, but it is a plan for action. A child on the playground running up the slide rather than sliding down has developed a sufficient somatosensory body scheme to enable her to move gracefully up the slide. Getting to the top, she is able to turn and slide while sitting on her bottom. Our skateboarder may need several tries at grinding on the hand rail, adjusting his plan with each attempt. Parameters he may change could include timing the approach to the rail, timing the release of the rail, where to put his weight on the board, and how to shift it (Fig. 24-7). The adjustments are based on feedback that adds information to the body scheme information stored in the brain. Children with dyspraxia are not able to plan movements so effortlessly. They tend not to benefit from typical amounts of feedback. As a result they will frequently

15 Chapter 24 Sensory Processing Disorders 451 FIGURE 24-7 Intervention to promote praxis often involves everyday play activities. (Photograph courtesy of Angie Carter.) be unable to make the adjustments described earlier for the skateboarder. A "failed attempt" for the skateboarder provides feedback that he is able to use to adjust the motor plan. A failed attempt for a child with dyspraxia does provide feedback, but this child cannot use that feedback to make adjustments in performance. This is the case with Raul. Although he receives feedback from his musdes and joints, as well as movement through the environment, he is unable to use it to adapt his motor plan for success, even when the tasks he is attempting are much easier than grinding on a handrail with a skateboard. Execution, the final step of praxis, involves actually doing the action. It is dependent upon adequate planning and ideation. When praxis is adequate, you see smooth and automatic movement, and adjustments to approach successful completion of the motor task. You see the toddler back out of the box, deciding that, instead of going in head-first, he will put one leg over the edge and dimb in that way. You see the slider maximizing on the fun by leaning back as she goes down the slide, to get just a bit more speed, and you see the skateboarder successfully mounting the rail, grinding, and dismounting after a few trials. Children with dyspraxia appear clumsy, and have difficulty benefiting from trial and error. When they do learn a skill they may have difficulty generalizing it to new contexts. Children with dyspraxia are also likely to have functional deficits (Ayres, 1977; Williamson and Anzalone, 2001). Most commonly they have disrupted play skills with some inflexibility (e.g., doing the same things repetitively), decreased tolerance of environmental changes, and a tendency to prefer to play with older (more predictable) or younger (more controllable) children. If verbal, these children will often try to use language to control others. For example, they will provide the rules for the game, rather then engage in the active play of the game. Children with dyspraxia dearly have disorganization in their motor activities, but disorganization also may be seen in other aspects of their performance (e.g., papers for school or dothing). Children with dyspraxia are often described anecdotally as having poor self esteem, since things that other children are able to do easily are difficult for them to accomplish. Finally, in these days of multi-tasking, children with dyspraxia are often "uni-taskers," since it takes more attention to perform even simple activities due to the limited automaticity of motor behaviors (Fig. 24-8). Raul has many of these characteristics. His interaction on the playground involves only running, and other activities seem beyond his ability In school, he has difficulty following instructions, especially if he has to listen and "do" at the same time. His self-esteem is suffering, and for Raul this plays out in his aggressive interactions with adults and other children. It is important to note that not all children with developmental motor delays have dyspraxia. Some children may have developmental coordination disorder (DCD), which is a delay in gross or fine motor skills that influences functional activities (Cermak and Larkin, 2002). DCD may or may not involve a sensory component. Sensory-Based Postural Disorder A postural disorder is one in which the greatest deficit is in postural control. Postural control involves the vestibular, FIGURE 24-8 Children with dyspraxia may spend more time watching play than engaging in it. (Photograph courtesy of Allison Mistrett.)

16 452 Part 4 Pediatric Conditions and Their Impact on the Lives of Children proprioceptive, and visual systems working together to provide a stable base upon which coordinated movement of the head, eyes, trunk, and limbs can be imposed. Postural disorder frequently occurs in the presence of vestibular, proprioceptive, and visual-motor problems and indudes poor stability in the trunk, poor righting and equilibrium reactions, poor trunk rotation, and poor oculo-motor control (ICDL, 2005). Children with postural disorder may also experience difficulty with bilateral skills. Postural disorder is an outgrowth of what was previously identified by Ayres, first as postural and bilateral integration disorder (Ayres, 1972a), and later as vestibular and bilateral integration disorder (Ayres, 1978). Inherent in both of these disorders are features of inadequate vestibular and proprioceptive processing, poor bilateral integration, and diminished posturalocular skills. With good postural control, a child can easily do such things as reach for a pencil that has fallen under the chair, without falling out of the chair in the process, and push chairs under the table after a meal, modulating the force and direction of the push while maintaining her body in an upright and balanced position. A child with good postural control can reach for a mug on a high shelf, while maintaining his balance. Children with poor postural control may not have the stability to maintain a good standing or sitting position. When a task requires adding body movement to what should be a stable "core," the child with poor postural control is very challenged. For instance, the child reaching for a mug on a high shelf might lose balance with the challenge of reaching and fall into the kitchen counter. Often children with poor postural control slouch in their chairs and lean over their desks during fine motor activities. How would we know if Raul had good postural control? We would need to examine his postural, ocular, and bilateral skills, as well as vestibular and proprioceptive processing. This could be accomplished by using s set of dinical observations, such as those developed by Blanche (2002). In broad terms, one would examine musde tone of the trunk (flexors and extensors), looking specifically at the use of these muscles against gravity during functional activities. It would be crucial to examine righting and equilibrium, with eyes opened and dosed; this would allow us to determine whether vision helped or hindered postural control. Visual tracking, quick localization, and convergence would be additional pieces of information needed to assess ocular skills. Other things to examine would indude bilateral symmetrical movements and rapid alternating movements of the arms and fingers. Postural disorder may be seen with or without dyspraxia. Thus, a child may be awkward and clumsy in movement, but on further evaluation the occupational therapist would find that ideation and planning are actually good; the difficulty exists when the child tries to execute the planned activity. This child would be identified as having adequate praxis, but a postural disorder. In contrast, a child may have difficulty with postural and ocular control, and also experience ideation and planning challenges. Here's the Point >- Sensory modulation disorder results from problems with registration and processing of sensory input. >- Sensitivity to sensation reflects the child's perception of stimulus intensity and duration; responsivity to sensation is reflected in the magnitude of the response. >- Sensory overresponsivity is seen when there is a low threshold to sensation; children with sensory overresponsivity will attempt to avoid sensory input, or will show negative responses to sensation that bothers them. >- Sensory underresponsivity is seen when there is a high threshold to sensation; children with sensory underresponsivity need input that is intense, or that has a long duration and without it they may appear to have low arousal, poor attention, and/or disinterest. >- Sensory seeking is seen when there is a high threshold to sensation, and children seek out the sensation they need. This leads to behaviors that appear impulsive and potentially aggressive. )1.- Responses to sensation may differ within a day, and between days because responses are context dependent. >- Sensory discrimination is the ability to distinguish between and make use of the temporal and spatial qualities of sensory stimuli in interacting with the environment. >- Deficits in discrimination are expressed differently across the different sensory systems, but a discrimination deficit in any sensory system diminishes our ability to obtain specific information from the environment and use it as a basis for planning and implementing a response. > Praxis is the ability to conceptualize, plan, and execute unfamiliar purposeful actions. > Dyspraxia can involve ideation, planning, and/or execution, and it results in difficulty producing successful motor actions in the environment. >- Sensory based postural disorders are seen when integration of the sensory input from systems that contribute to postural control (vestibular, proprioception, vision) is faulty. Evaluating and Categorizing Sensory Integration Dysfunction Evaluating and describing deficits in sensory processing is key to SI theory. Ayres initially developed the Southern California Sensory Integration Tests (SCSIT) (1972b) to

17 Chapter 24 Sensory Processing Disorders 453 guide this process. This battery was later revised and restandardized as the Sensory Integration and Praxis Tests (SIPT) (Ayres, 1989). The SIPT is a neuropsychological test battery consisting of 17 tests grouped in fives categories (visual perceptual, visual motor, vestibular and proprioceptive, somatosensory, and praxis). The battery was standardized on a national census based sample of children between the ages of 4 years and 8 years 11 months. Administration of this test battery is complex, and a certification process is available for individuals interested in learning to administer and interpret this test. The SIPT provides a wealth of information on sensory processing, bilateral hand skills, and praxis, and is currently the "gold standard" for identification of these deficits. It offers us detailed information on aspects of vestibular, tactile, and visual processing in addition, proprioception is addressed to a lesser extent. Praxis is a major focus of the SIPT; it addresses body centered, oral, verbal, and visual aspects of praxis. It can be administered in 2 to 2.5 hours by an experienced examiner, and is computer scored. The computer scoring produces a report that not only highlights the child's strengths and needs, it also takes a step toward interpreting the test scores. Based on interpretation of data from the SIPT, Ayres and colleagues defined types of sensory integrative dysfunction. Standardization data gathered from children with learning disabilities and typical children from across the USA and Canada was subjected to both factor and duster analyses. Cluster groups largely paralleled factor groupings; further examination and combination of the duster findings with clinical experience resulted in the identification of six SIPT types. These included (1989): 1. Low average bilateral integration and sequencing 2. Generalized sensory integrative dysfunction 3. Visuo- and somatodyspraxia 4. Low average SI and praxis 5. Dyspraxia on verbal command 6. High average SI and praxis Following up on this initial work, Mulligan was able to conduct a confirmatory factor analysis using an expanded data base (1998, 2002). Her analysis resulted in the identification of a general sensory integrative dysfunction, visuoperceptual deficit, bilateral integration and sequencing deficit, dyspraxia, and somatosensory deficit. Unfortunately, the SIFT cannot be administered to some children referred to OT for SI related deficits because of age, cognitive, attentional, or behavioral deficits (Spitzer, Smith- Roley, Clark, and Parham, 1996). Further, although it offers a great deal of information on many aspects of sensory processing, additional information is necessary for some constructs (for instance, sensory modulation). Additional observational information is also needed to ground the sensory processing deficit in occupational performance. Thus, identification of sensory processing deficits often involves parent and teacher report measures, as well as qualitative observations of children engaging in both novel and familiar sensorimotor and functional activities. As noted earlier, the categories of sensory integrative disorder identified by the SCSIT and SIFT were helpful, but not comprehensive, in guiding a dinical understanding of SPDs. Combining child performance on first the SCSIT, and later the SIPT, with clinical observations Ayres also identified disorders of modulation (1972a). Modulation is a CNS process in which sensory input is regulated, allowing us to use the input for an appropriate environmental response (Miller et al., 2007). The first modulation disorder identified, tactile defensiveness, was overresponsiveness to tactile sensory input. Subsequent work by dinicians and researchers has resulted in a more thorough understanding of the depth and breadth of sensory modulation disorders. Tools currently available that guide the identification of sensory modulation disorders indude the Sensory Profile (SP), available for infants and toddlers (Dunn, 2002), schoolaged children at home (Dunn, 1999) and in school (Dunn, 2006), and adolescents and adults (Brown and Dunn, 2002), and the Sensory Processing Measure (SPM), for home, main dassroom, and school environments and applicable to school-aged children (Miller-Kuhanek, Henry, and Glennon, 2007; Parham and Ecker, 2007). The SP for adolescents and adults is completed by the individual with potential sensory processing deficits, and the other tools are completed by adults in the child's environment. Thus, for the majority of these tools the perspective gained on sensory modulation is not that of the child, but rather that of an adult in the environment. In addition to gathering information on SI and processing using the SIPT and tools addressing sensory modulation, observation of the child engaging in specific tasks, and engaging in routine daily tasks, will add depth and breadth to your evaluation process. Earlier in this chapter the need to learn about the child's postural-ocular skills was mentioned. The best tool currently available for this is that developed by Blanche (2002). Blanche based her work on that of Ayres in developing a set of structured clinical observations that address a number of posturalocular skills. Items address somatosensory, vestibular, proprioceptive, and visual processing, motor sequencing, postural tone and control, bilateral integration, anticipatory movement skills, and protective reflexes. Blanche not only provides guidance on administration, she models the dinical reasoning that goes into interpretation of findings. Beyond these structured observations, therapists should spend time watching children as they participate in their day. For instance, free play, and the preferences children show for play activities, can provide insight into the skills the child actually uses during play. Knowing

18 454 Part 4 Pediatric Conditions and Their Impact on the Lives of Children what the child chooses to do, and the skills they choose to use, provide insight into perceived ability. Observation during a meal, at home or in the cafeteria can offer the therapist information about how the child copes with environments over which they may not have control. Observations in the classroom may unveil the behaviors that are disruptive to learning, or potentially to the dass as a whole. Unstructured observations can provide information on such things as ideation (how often does the child come up with an idea that shapes the next play episode?), planning (does the child organize their space and movement through space such that they can accomplish what they set out to do?), sensory preferences (does the child avoid playing on things that are unstable, like swings?), knowledge of body position in space (can the child move in, out, around, and through objects easily and without knocking them over?). What might you have seen had you been able to observe Alan in his dassroom, or in the cafeteria? What if you had taken the school bus with him as he rode to school, and then home again? The end result of these assessments should be an integrated understanding of the child. It should lead to the development of an intervention program that capitalizes on the strengths of the child while at the same time working on the child's needs. Here's the Point > The SIPT is the gold standard for assessment of sensory discrimination and praxis skills. Sensory modulation is not assessed in a formal manner by the SIPT; instead therapists might consider using aspects of the family of Sensory Profile tools, or the Sensory Processing Measure. )1- In addition to the use of standardized tools, observing the child engage in structured and unstructured activities will round out the evaluation process and provide information on SI and processing in the context of daily life. Intervention for Sensory Processing Disorders OT using an Ayres sensory integration approach (ASI ) requires that the therapist have a solid knowledge base in the neurosciences, as well as a firm understanding of the application of neuroscience to behavior. These features are the basis of SI theory. Beyond this knowledge base, ASI is child-focused and play-driven. This intervention approach uses activities tailored to the individual child's sensory and motor needs. As noted by many authors, it is a process-oriented approach to intervention (Case- Smith and Miller, 1999; National Board for Certification in Occupational Therapy, 2004; Smith-Roley, Blanche, and Schaaf, 2001; Spitzer, Smith-Roley, Clark, and Parham, 1996; Wading, Deitz, Kanny, and McLaughlin, 1999). As further described by the Sensory Integration Research Collaborative (SIRC, 2007), ASI uses an individualized approach to treatment and purposeful activities requiring an adaptive response; the overarching aims of treatment are to improve underlying neurological processing and organization. Just as was noted earlier for evaluating a child with SPD, ASI must consider the child in relation to the physical and social environments; it must look at the child in relation to ongoing experiences. This is what allows us to understand sensory modulation disorder and sensory based motor disorders. Thus an ASI intervention strategy will consider the child in the context of the physical and social environment, an approach consistent with the ecocultural framework presented earlier in this text. The child must function across many environmental contexts and domains, all of which will require the processing and integration of sensation, and all of which will present the child with challenges. Reflecting on what was stated earlier in this chapter, it is the goodness of fit between the child and the environment that can determine whether or not a child is provided the "just right challenge," or the challenge that motivates him or her to engage. In developing an ASI intervention program, the therapist begins with a review of records and assessments available on the child, much as is the case for any intervention approach. Information pertinent to the child's ability to process sensation and use it as a foundation for environmental interaction and engagement is closely assessed, as it is the heart of ASI. Parham and colleagues (2007) identified core process elements of ASI as follows: + A combination of sensory experiences, including those using tactile, vestibular, and/or proprioceptive inputs; + Just right challenges, i.e., challenges that are neither too difficult nor too easy, and provide the opportunity for the child to demonstrate adaptive responses; + Collaboration with child in activity choice; + Activities that guide self-organization, seen when the child makes choices and plans behavior; + Activities and interaction that support optimal arousal; + Activities and opportunities that create a context of play; + An environment designed to engage and entice the child, and offer opportunities that maximize the child's success; -:- An environment that ensures physical safety of the child; A therapy session that fosters a therapeutic alliance with the child, shows respect for the child's emotions, conveys positive regard toward the child, seems to connect with the child, and creates a climate of trust and emotional safety (Fig. 24-9). The challenges for the therapist are in setting up the physical and social environment, choosing sensory and

19 Chapter 24 Sensory Processing Disorders 455 Practice Wisd Reframing Behavior Children with sensory integration and processing disorders do not look "different" on the outside. As a result, when they have a temper tantrum in the grocery store because the lights are too bright, or the music too loud, passersby may simply perceive the child to be poorly behaved, or believe the parent to lack parenting skills. Even family members may have this impression. Reframing the temper tantrum from a "bad behavior" to sensory overresponsivity can help others understand, and reduce the sense of guilt, shame, frustration, the parent may be feeling. For instance, telling the parent such things as "for your child the lights in the grocery feel like noon sun in the tropics with no sun glasses," and "the music like someone screaming in the ear" may help them understand their child, and may give them what they need to explain it to others. Many parents have indicated that this simple process of reframing made a huge difference in their lives. FIGURE 24-ii OT/SI therapy should be fun! (Photograph courtesy of Joseph A. Werner, OTR.) motor activities designed to elicit adaptive responses by the child, and maintaining an interaction that is both child-directed and playful. If accomplished, the child's intrinsic drive is tapped, engagement takes place, and the child produces interactions that reflect the integration of sensory input and production of the adaptive response. Beyond direct intervention with the child, the therapist will need to engage and collaborate with the family, reframing the child's behavior as appropriate, and helping the family to develop effective strategies for improved participation in daily life within the family, school, and community. One way the therapist impacts the social environment with an ASI approach involves helping parents, other significant adults, and peers to understand the SPD. Parents need help understanding why their child may be pulling away from hugs or not actively interacting with their environment, and peers may need an explanation as well. Working together with caregivers and the child to develop strategies that can be implemented in all environments in which the child engages can be a very powerful intervention approach. Monitoring child progress, as the child is being guided through an intervention by another professional, is another intervention approach that might be useful for children with disorders of sensory processing. All of these intervention approaches are more thoroughly defined in the intervention chapters, ASI is optimally delivered by a therapist with advanced training and specialized education in SI. At minimum the occupational therapist must be licensed or registered, certified in ASI /SIFT, and have a minimum of 5 years experience providing ASI, under the supervision of a qualified expert. Likewise the ability to develop SI theory based strategies comes from experience and training. Here's the Point While ASI is grounded in neuroscience and brainbody interactions, it is also child-driven and play based. Thus, while there is a lot that goes into understanding, assessing and treating SI and processing disorders, therapy can look like "just play." )1.- The parameters of treatment that make it SI and not something else (e.g., sensory-motor) include such things as the just right challenge; the use of activities that guide self-organization, support optimal arousal, and opportunities that create a context of play; an environment that engages the child, maximizes success, and ensures safety; and collaboration between therapist and child in an alliance that respects the child's emotions and conveys positive regard toward the child. ASI can be implemented using direct, indirect, and consultation approaches; often a combination is needed to best meet the needs of the child. Outcomes of Intervention When using an ASI approach, the goals or outcomes of treatment need to reflect the problems that initiated the need for intervention. Remember, individual differences in sensory integrative functioning become SPDs

20 456 Part 4 Pediatric Conditions and Their Impact on the Lives of Children only if, or when, they interfere with participation in age-appropriate occupations. Increasing that participation, therefore, is the important outcome. In fact, increased social participation and an improved sense of self-worth were reported by Cohn, Miller, and Tickle-Degnen (2000) to be highly valued outcomes from intervention. As we have seen, Raul does not participate on the playground because of his dyspraxia and sensitivity to vestibular sensation. When identifying measurable outcomes, his team should consider his ability to initiate play interactions or participate in sports during recess. The team could also assess his participation in art activities, looking at whether he required coaxing or simply engaged in the activity alongside other children. Similarly, Alan's goals should not be about "tolerating" a particular type of sensory input, but rather should be considered in terms of his ability to participate in a group activity with active exploration. Since Alan is working on identifying his own sensory needs and developing strategies to get his needs met within the school environment, the therapist must examine Alan's sensory strategies to determine if they are appropriate, and determine if he is using them in the educational environment. The key is that therapists must think beyond the SPD to the "so what" question, i.e., "What is it that Alan wants to accomplish, or engage in, that he cannot due to his sensory processing problems?" Well-developed outcomes have strong answers to the "so what" question answers that take into account the desires of the family and the child, and answers that address the ability of the child to do the things she desires to do, within the context of everyday life. As noted by May-Benson and Koomar (2008), the outcomes from SI intervention are highly diverse. Here's the Point )0- Outcomes or goals of sensory integrative therapy should be considered in terms of function and changes in participation in occupations, not about simple changes in the sensory processing capacities themselves. Summary The processing of sensation is a crucial component of everyday lives. When we cannot make sense out of our environments, we cannot interact within them. Sensory processing disorders can present as differences in responsivity to sensory input, or as difficulty using sensory input to plan and execute a motor response both have the potential to disrupt the ability to participate in daily activities. The theory of SI helps us understand how these disorders are linked to CNS structure and function. It also provides us with the foundation for intervention and supports a crucial role for occupational therapists in the treatment of sensory integrative deficits. We are moving forward in our understanding of the underpinnings of SPDs and in the application of ASI. Continuing to develop a better understanding of SI, SPDs, and ASI will lead to evidence-driven practice. Koomar J., and Friedman. B. (1992a). The hidden senses. Your balance sense. Bethesda, MD: AOTA. Koomar, J., and Friedman. B. (1992b). The hidden senses. Your muscle sense. Bethesda, MD: AOTA. Jane Koomar and Barbara Friedman have written two books for children on the 'hidden senses. These titles can assist in explaining these somewhat elusive concepts to small children Ay res. A. J. (2004). Sensory integration and the child. Los Angeles: WPS. Bundy, A. C.. Lane, S.F., and Murray. EA. (1991). Sensory integration theory and practice. Philadelphia: FA Davis. Heller, S. (2002). Too loud, too bright, too fast, too tight. New York: Fla rpercolli ns. Kra nowi t z, C. S. (2005).T he out-of-sync child. (2nd ed.) New York: Perigee. Sensory integration and sensory processing are topics covered in a large number of books.the books may be written for parents (e.g., Sensory Integration and the Child), adults who experience sensory processing problems (Too loud, too bright, too fast, too tight), teachers (e.g., The Out-of-Sync Child) ortherapists (e.g., Sensory integration theory and practice by Bundy, Lane, and Murray). Each of these takes a slightly different approach to understanding children with disorders of sensory processing. The following books were written by occupational therapists and their colleagues about sensory integration and sensory processing disorders. This is not a comprehensive list, and there are many additional resources that could be added. These are largely written for the lay public. Aron, E N. (2002). The highly sensitive child. NY: Broadway Books. Auer, C. R, and Blumberg, S. L (2006). Parenting a Child with Sensory Processing Disorders:A Family Guide to Understanding and Supporting Your Sensory-Sensitive Child. Oakland, CA: New Harbinger. Ayres, A J., Erwin, P. R, and Mailloux, Z. (2004). Love, Jean. Inspiration for families living with dysfunction of sensory integration. Santa Rosa, CA: Crestport Press. Biel, L, and Peske, N. (2005). Raising a sensory smart child. NY Penguin Books. Emmons, P. G., and Anderson, L M. (2005). Understanding sensory dysfunction. Philadelphia:Jessica Kingsley Publishers. Henry D. (2001). Tools for parents. Glendale, AZ: Henry Occupational Therapy Services.