USING NEUROPSYCHOLOGY TO ASSESS TBI

Transcription

1 2015 Trial Lawyers Summit Brain & Traumatic Brain Injury January 20, 2015 USING NEUROPSYCHOLOGY TO ASSESS TBI Kenneth C. Kutner, PhD, ABPP-CN Fellow, National Academy of Neuropsychology Board Certified Neuropsychologist Professional Sports Concussion Care Miami Princeton 80 SW 8th Street 5 Independence Way Miami, FL Princeton, NJ Tel: Tel: DrKutner@proconcussioncare.com

2 USING NEUROPSYCHOLOGY TO ASSESS TBI 2015 Trial Lawyers Summit 1/20/15 Using Neuropsychology to Assess Traumatic Brain Injury (TBI) Abstract Kenneth C. Kutner, PhD, ABPP-CN 1,2 Neuropsychological Assessment provides important evidence for personal injury litigation. In cases of mild traumatic brain injury, Neuropsychological Assessment can reveal brain dysfunction when structural abnormalities cannot be seen on CT or MRI scans. This paper will briefly review neurodiagnostic methods and then focus on the role that Neuropsychological Evaluations play in assessing traumatic brain injury and establishing whether permanent sequelae have developed. Introduction According to the Center for Disease Control (CDC), over 2.5 million traumatic brain injuries occur each year (Faui et al 2010). Diagnostic tools utilized in assessing brain injury include Neuroimaging (CT & MRI), Neurophysiological Tests (EEG & QEEG), Neuropsychological Assessment, as well as experimental methods. These diagnostic methods will be briefly reviewed followed by a more detailed discussion of Neuropsychological Testing. This discussion will focus on the role of Neuropsychological Evaluation in determining whether permanent cognitive impairment has developed and if the resulting deficits will preclude or limit the individual returning to his or her occupation or school/college. Neuroimaging (CT & MRI) Neuroimaging is a well-established method for assessing brain trauma. The introduction of Computerized Tomography (CT) resulted in direct examination of the brain, protective brain coverings (meninges), and brain spaces (ventricles). CT scans provide accurate assessment of brain contusions, hemorrhages, increased cranial pressure, and hydrocephalus. CT scans are utilized to help determine whether effects of a brain injury require neurosurgical intervention (i.e. large subdural hematoma) or indicate conservative treatment (non-surgical). In addition, CT scans also provide accurate assessment of skull fractures and acute hemorrhaging. 1 Department of Neurological Surgery, Weill Cornell Medical College 2 Professional Sports Concussion Care, Miami, FL 2

3 Magnetic Resonance Imaging (MRI) was developed after the introduction of CT scans. MRI scans can detect small or subtle lesions, not discernable by CT scans. Advantages of MRI also include higher detail of brain structures, especially the back of the brain (posterior fossa). Recently, Diffusion Tensor Imaging (DTI) has been introduced, which provides more accurate assessment of damage to white matter in the brain. Functional MRI (fmri) provides mapping of physiology, which helps neuroscientists localize brain functions to specific areas (i.e. speech-left frontal cortex). However, fmri requires further research before it is ready for clinical diagnosis of traumatic brain injury (Edlow & Wu 2012). Other neuroimaging techniques such as Positron Emission Tomography (PET) and Magnetic Resonance Spectroscopy (MRS) are utilized in research, but have not been deemed ready for clinical use (Dimou & Lagopouos 2014). Single Photon Emission Computerized Tomography (SPECT) results have been admitted as evidence in a few states, including Florida (Hammer v. Sentinel Insurance Company). Electrophysiological (EEG & QEEG) Electroencephalograms (EEGs) have a well-established role in the assessment of post-traumatic seizures and epilepsy. However, EEGs are typically noncontributory in determining whether a head injury has occurred. Even in the 10 percent of cases in which EEG is positive following brain trauma, it is only sensitive for the initial 48 hours after injury (Arciniegas 2004). Researchers have been attempting to utilize Quantified Electroencephalograms (QEEGs) in assessment of head trauma for some time. The methodology of these initial studies had significant problems, including not controlling for medication and psychiatric history. With published studies of QEEG being poorly designed, the American Academy of Neurology (AAN) dictated that QEEG remained investigational and should not be utilized in civil or criminal judicial proceedings (Nuwer 1997). However, recent research with improved methodology has been undertaken. Studies measuring electrophysiological recovery after sports-related head injury have shown potential efficacy of QEEG (Prichep et al 2013; Barr et al 2012). In November of 2014, The FDA cleared the approval of a QEEG device (BrainScope Ahead System) as an adjunct to standard clinical practice for patients who sustain a closed head injury within the past 24 hours, present with a mild traumatic brain injury, and are between the ages of Blood Studies (Serum) With the high prevalence of brain trauma sustained in combat-blast injuries, considerable research has been conducted to determine if blood tests can be utilized to determine whether or not a concussion occurred. Neuroscientists have been looking for a protein or protein breakdown marker, which can be utilized for diagnosis of a mild traumatic brain injury. Multiple blood factors including Neuron Specific Enolase (NSE), SB100, and Glial Fibrillary Acidic Protein (GFA) have been 3

4 researched. Isolated studies have found elevations in select blood factors. However, the results to date have not been replicated. At this time, blood studies are not being utilized to clinically diagnose brain damage (Mondello et al 2011). It is likely that a panel of blood markers will be required in order to determine if an injury has taken place. Optic Tracking Optic tracking is another recently developed approach in evaluating traumatic brain injury. This method assesses response time in reacting to specific sensory information (Maruta & Ghajar 2014). While studies have shown optic tracking to be sensitive to concussion, findings are not specific to head injury. Optic tracking does not appear to differentiate head trauma from individuals who have pain or dehydration. Neuropsychological Assessment Neuropsychological Testing is one of the core diagnostic tools utilized to diagnose and quantify effects of brain injury. It has been well established that traumatic brain injury results in cognitive impairment. Research has revealed that brain trauma frequently results in impairment with concentration, processing speed, reasoning, language, memory, and visual-spatial skills. While neuroimaging and EEG studies are quite helpful, they do not measure cognitive functioning. Direct assessment of cognitive functions is required to determine if deficits with attention, memory, and other domains have developed. Neuropsychological Testing will be detailed in the next section. NEUROPSYCHOLOGICAL ASSESSMENT Neuropsychological Assessment provides objective and scientifically-based examination of brain functioning. Specifically, this method assesses cognitive functioning. Neuropsychological Testing can determine whether neurocognitive impairment has occurred and if such impairment is permanent. Currently, Neuropsychological Assessment is utilized in the NFL and NHL, as well as at major teaching medical hospitals. For a clinical method to be scientifically supported and for test results to be deemed admissible, it must be both reliable and valid. In addition, as impaired test scores can result from suboptimal effort, response-bias procedures should be utilized in order to determine whether findings are due to brain damage (neurogenic) or psychological (psychogenic) etiology. These topics will be discussed in the following section. Neuropsychological Evaluation Neuropsychological Evaluation consists of administration of a battery of tests, which measure cognitive domains subserved by the brain. While neuroimaging can reveal brain structure, CT Scans and MRI s cannot measure cognition. The best window 4

5 into the brain for assessing cognitive functioning is by direct measurement through Neuropsychological Evaluation. Neuropsychological Tests are administered, which measure cognitive domains subserved by the brain including: attention/concentration, speed of information processing, psychomotor speed, reasoning, language, working memory, memory, and visual-spatial skills. In cases of moderate and severe traumatic brain injury, measurement of academic skills may be performed. Tests are administered in a 1:1 setting. Computerized Neuropsychological Testing with baseline and post-injury is utilized with sportsrelated concussions. However, this approach is only a screening device and does not have the accuracy of a full Neuropsychological Evaluation. Neuropsychological Evaluations include a detailed educational, vocational, and medical history in order to interpret test results. In addition, a neurobehavioral status examination is administered in order to assess for anxiety, depression, and brain injury induced personality changes. Reliability & Validity Tests need to be both reliable and valid. Reliability is necessary, but not sufficient for establishment of validity. Reliability is the consistency of measurement, meaning that repeated administrations of a test need to result in consistent findings. Reliability indicators are frequently characterized as Marginal ( ), Adequate ( ), High ( ), and Very High ( ). It is evident that a test can be reliable with repeated administrations resulting in consistent scores, but that the test is not valid. Validity reflects how well a test examines what it is supposed to be measuring. In Neuropsychological Testing, it means that the test actually measures cognitive functioning. Validity is measured in multiple ways including: Contentrelated, Construct-related, Criterion-related, and Response Processes. (Lezak 2004). Interpretation Pre-injury neuropsychological test results are rarely available for comparison. Similarly, premorbid medical lab findings are typically not available for comparison. For example, few individuals present to the hospital or their physician with a preillness white blood cell count or blood glucose level. Determination of illness is made by comparing the patient s current test results to reference ranges (results from individuals of their age & gender). As in medicine, neurocognitive tests scores are compared to normative data from individuals of their age, gender, culture, and educational level. Interpretation utilizing normative data is critical as education and age are especially important factors. (Smith et al 2008, Hannary & Lezak 2004). Test results are interpreted as either falling within the normal or impaired range. If impaired, the level of impairment is next established. Impairment levels are: Mild, Mild-Moderate, Moderate, Moderate-Severe, and Severe. Research indicates that neurocognitive sequelae in traumatic brain injury are dose-responsive (Rohling et al 2003). In other words, individuals with a Mild Traumatic Brain Injury frequently develop Mild or Mild-Moderate cognitive impairment. However, they would not 5

6 develop severe cognitive impairment. Permanency is established when testing at > 1 year reveals impaired test scores. (Dikmen 1995, Pagulayan, et al 2006) Malingering/Symptom Magnification As there are movement artifacts in radiological studies, test results from Neuropsychological Assessment can contain artifacts. Studies suggest that assessment of motivation and effort is critical when conducting a Neuropsychological Evaluation (Boone 2007). Practice Standards (ACN 2007) in Clinical Neuropsychology indicate that effort measures should be administered in order to determine if test scores are due to brain impairment or psychological causes i.e. symptom enhancement (Bush et al 2005). The advantage of administering these procedures is that impaired test scores in individuals who pass these effort measures can be directly related to the traumatic brain injury. Neuropsychological Role by level of TBI The role Neuropsychological Assessment plays in TBI varies by the level of injury. Traumatic brain injury is classically divided into Mild, Moderate, and Severe levels (Ropper & Samuels 2009). Mild traumatic brain injury (concussion) is defined by a Glasgow Coma Score of 13 15, loss of consciousness (LOC) 0 30 min and Posttraumatic Amnesia of < 24 hrs. In the vast majority of these cases, abnormal findings do not appear on either CT or MRI. Here, Neuropsychological Assessment often provides the best determination that a brain injury has occurred. While defined as mild, many of these patients will be unable to return to their usual occupation, especially if it requires complex cognitive functioning. Moderate traumatic brain injury is defined by a Glasgow Coma Score of 9 12, loss of consciousness ranging from > 30 minutes to < 24 hours and Posttraumatic Amnesia persisting for > 24 hours to < 7 days. Positive findings (hemorrhage, hematoma, contusion) are often evident on neuroimaging. In these cases, Neuropsychologists can determine if neurocognitive impairment has developed and if it precludes the individual from returning to their prior occupation and at times, even any form of competitive employment. In many cases, hemorrhages are absorbed; contusions resolve with subsequent CT and/or MRI studies being unremarkable. Neuropsychological Assessment can establish if neurocognitive impairment persists despite resolution of findings on neuroimaging. Severe traumatic brain injury is defined by a Glasgow Coma Scale of 3 8, loss of consciousness of > 24 hours and Posttraumatic Amnesia of > 7 days. Individuals with this severe level of injury typically have a period of being comatose. In these cases, Neuropsychologists can determine if a patient s brain damage precludes them from any type of competitive employment and if they require 24-hour supervision. 6

7 Training As with any medical expert, Neuropsychologists should complete requisite education and training requirements. Ideally, the Neuropsychologist should complete doctoral training in Neuropsychology, taking courses in neuroanatomy, neurological bases of cognition, and neuropsychometric assessment. Two years of postdoctoral training (residency/fellowship) provides the level of experience required for competent practice. Board Certification by the American Board of Clinical Neuropsychology (ABCN) provides the best format to ensure that the Neuropsychologist has completed requisite courses, training, and acquired the level of experience required to practice at the highest level. Admissibility of Neuropsychological Experts Admissibility of neuropsychological expert testimony is typically governed by the particular rules of evidence on the qualifications needed for the doctor to provide expert testimony. Specifically, the witness should be qualified as an expert by knowledge, education, skills, experience, and training to form his or her opinion. Admissibility of a Neuropsychologist to testify as to the existence of a brain injury is accepted in most jurisdictions. However, the ability of the Neuropsychologist to provide expert testimony as to the cause of the brain injury and prognosis may be limited in a few states i.e. Florida (Jenkins v. United States). In such cases, it may be helpful to have the Neuropsychologist explain the anatomy of the brain, what happens to the brain when it is injured, and what deficits can be expected. After the Neuropsychologist explains impairment found on the testing, the jury can draw their own conclusion whether or not deficits found on cognitive testing were related to the traumatic brain injury (Stern). Summary Neuropsychological Assessment plays an important role in determining that permanent brain damage has resulted from a traumatic brain injury. In cases of mild traumatic brain injury, Neuropsychological Testing can reveal brain dysfunction when structural abnormalities cannot be identified on CT or MRI scans. In cases of moderate traumatic brain injury, Neuropsychological Testing can reveal brain dysfunction even when initial findings on CT and MRI scans resolve on repeat imaging. Research has revealed that Neuropsychological Tests are both reliable and valid. Test results from this clinical diagnostic tool can be utilized to determine if neurocognitive impairment from a brain injury precludes an individual from returning to their usual occupation or school/college and if they are unable to perform competitive employment. 7

8 References American Academy of Neuropsychology-Board Directors. Practice Guidelines for Neuropsychological Assessment and Consultation. The Clin Neuropsych, 2007, 21: Arciniegas D., Anderson, C., Rojas, D. Electrophysiological Techniques. In: Silver JM, McAllister TW, Yudofsky SC, editors. Textbook of traumatic brain injury. Washington. American Psychiatric Publ; Barr, W., Prichep, L., Chabot, R., Powell, M., & McCrea, M. Brain Injury. 2012, vol 26. Boone, K. Assessment of Feigned Cognitive Impairment. Guilford Press, Bush, S., Ruff, R., Troster, A., Barth, J., Koffler, S., Pliskin, N., Reynold, C. & Silver, C NAN Position Paper: Symptom validity assessment: Practice issues and medical necessity. Arch of Clin Neuropsych 2005, 20: Edlow, B. & Wu, O. Advanced Neuroimaging in Traumatic Brain Injury. Seminars in Neurology. 2012: 32(4), Dikmen, S., Machamer, J., Winn, H. & Temkin, N. Neuropsychological Outcome at 1- year post head injury. Neuropsychology, 1995, 9, Dimou, S., & Lagopoulos, J. Toward Objective Markers of Concussion in Sport: A Review of White Matter and Neurometabolic Changes in the Brain after Sports- Related Concussion. J of Neurotrauma, 2014, 31: Faui, M, Xu L, Wald, M, Coronado, VG. Traumatic brain injury in the United States: emergency department visits, hospitalizations, and deaths. Atlanta (GA): Centers for Disease Control and Prevention, National Center for Injury Prevention and Control; Hannay, J. & Lezak, M. The Neuropsychological Examination: Interpretation In: Lezak, M., Howieson, D., & Loring, D. Neuropsychological Assessment, 4 th Ed. Oxford Maruta, J. & Ghajar, J. Detecting eye movement abnormalities from concussion. Prog Neurol Surg. 2014, 28: Montello, S., Muller, U., Jeromin, A., Streeter, J., Hayes, R., & Wang, K. Expert Rev Mol Diag. 2011; 11(1) Nuwer, M. Assessment of digital EEG, quantitative EEG and EEG brain mapping: Report of the American Academy of Neurology and the American Clinical Neurophysiology Society. Neurology, 1997; 49: ) 8

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