A STUDY OF THE EFFECTS OF A VESTIBULAR REHABILITATION PROGRAM ON PATIENTS WITH PERIPHERAL VESTIBULAR DYSFUNCTIONS

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1 The Indian Journal of Occupational Therapy : Vol. XXXVI : No. 1 (April - July 04) A STUDY OF THE EFFECTS OF A VESTIBULAR REHABILITATION PROGRAM ON PATIENTS WITH PERIPHERAL VESTIBULAR DYSFUNCTIONS * Pina S. Shah ** J. S. Kale * Seth G.S. Medical College, K.E.M. Hospital, Mumbai ABSTRACT: Balance is a complex process requiring interaction among visual, vestibular & proprioceptive systems. Dysfunctions of the vestibular system result in imbalance, vertigo and functional limitations. These are treated with Vestibular rehabilitation therapy that incorporates activities and exercises, to achieve vestibular compensation. The effects of Vestibular rehabilitation program was assessed on following parameters related to vestibular dysfunctions: 1. Postural stability, 2. Intensity and duration of vertigo, 3. Self perceived levels of independence in ADL. This study was conducted on 20 OPD patients having history of chronic stable peripheral vestibular dysfunctions.initial assessments on each of the 3parameters were performed, prior to administering Vestibular rehabilitation therapy program. Follow-up evaluations on each of the 3parameters were performed 4weeks and 6weeks post- therapy. Post-therapy statistically significant improvement (p<0.01) was observed in each of the 3 parameters respectively. Vestibular rehabilitation is effective in eliminating vertigo, retraining balance and achieving maximal functional independence. KEY WORDS: Vestibular dysfunctions, Vertigo, Balance, ADL, Vestibular Rehabilitation, Occupational Therapy. INTRODUCTION: Balance is a complex process requiring interaction among visual, vestibular & proprioceptive systems. Vestibular system plays an important role in balance. The primary symptoms of vestibular dysfunctions 1 are: Vertigo Blurred vision Imbalance Disorientation in space The secondary symptoms of vestibular dysfunctions are: Anxiety due to motion-provoked vertigo, fear of falling and social withdrawal 2. * Pina.S.Shah B.Sc.(OT), M.O.Th. Student Seth G.S.Medical College, K.E.M. Hospital, Mumbai. Tel : Shahpina@Yahoo.Com ** Professor of Occupational Therapy The recipient of Kailash Merchant Award for the Best Scientific Paper on Neurology, presented in 41st Annual Nat. Conf. of AIOTA in the year 2004 at New Delhi. The overall effects are: Physical deconditioning Body stiffness due to limitation of movement Social isolation Thus a vicious cycle is set up whereby the primary and secondary symptoms ultimately lead to limitations inadl 2. On a routine basis patients with peripheral vestibular dysfunctions are treated with vestibular suppressant drugs. But these drugs are known to have side effects like drowsiness, which further affects participation in ADL tasks 2. Cohen et al have emphasized role of Occupational therapy intervention for Vestibular dysfunctions through Vestibular rehabilitation 1,3,4. Vestibular rehabilitation is defined as the use of activities and exercises to treat vertigo, imbalance and functional limitations, caused by impairments of the vestibular system 3. This study was designed to assess the effects of Vestibular rehabilitation program on following parameters related to vestibular dysfunctions: 1) Postural stability 2) Intensity and duration of vertigo 11

2 3) Self perceived levels of independence in ADL METHODOLOGY 20 patients (11 males and 9 females) mean age 45 yrs; having history of peripheral vestibular dysfunctions of chronic nature were included in the study. Exclusion Criteria: Central Vestibular Dysfunctions (Cerebellopontine angle tumors, migraine, cervical spondylitis) Patients with Meniere s Disease. Patients > 60 years of age Patients diagnosed as having Clinical Depression Initial and follow-up evaluations were done with the below mentioned assessments: [I] Clinical Test of Sensory Interaction and Balance (CTSIB): It was developed by Shumway-cook & Horak and is also known as the Foam and Dome test 5. The test consisted of 6 sensory conditions, in which the patient stood with arms at the side, feet together & head in neutral position. Condition 1 : Quiet standing on floor Condition 2 : Quiet standing on floor, eyes blind folded Condition 3 : Quiet standing on floor, wearing visual conflict dome Condition 4 : Quiet standing on the foam, eyes open Condition 5 : Quiet standing on foam, eyes blind folded Condition 6 : Quiet standing on foam, wearing the visual conflict dome. The duration of stance maintained by the patient, was noted with a stopwatch, the maximum duration for each trial being 30 seconds. A sum total of 3 trials were calculated for each of the 6 conditions. [II] University of Michigan Vestibular Testing Center Habituation Training Evaluation: This test was developed by Telian & Shepard 6 (1990) to measure the intensity and duration of vertigo. Patients were expected to change head and body posture through 16 different maneuvers as guided by the therapist. The patients reported subjective intensity (I) of the vertigo experienced, which was scored from 0-5 where 0- no vertigo, 5 severe vertigo. Using a stopwatch the therapist measured the duration (D) of vertigo and scored it from 0-3. Finally a motion sensitivity quotient (MSQ) was computed with the formula: Total Score (I+D) x positions MSQ = x Where, 2048 = maximum score obtained. [III] Vestibular Disorders Actives Daily Living Scale (VADL) Scale: This scale measured self-perceived level of independence in activities of daily living (ADL) developed by Cohen H.S. and Kimball (2000) 7. There were total 28 tasks with following subtasks: Functional subscale (12) : self care Ambulation subscale (9) : walking & stair climbing Instrumental subscale (7) : home management, productivity and leisure activities. The independence in ADL for each task was rated from 1 to 10 such that higher scores indicate impairment. Vestibular rehabilitation Program : Each patient was treated on an out patient basis for 3 times a week and a home based exs program was given. All exercises were done twice daily. 1) Habituation Exercises : These were exercises and activities in which patient made rapid, repetitive head movements 3,5. 2) Gaze Stabilization Exercises : These are eye head exercises for restoring visual -vestibular interaction 3,8. 3) Balance Retraining : Treatment tasks were graded in difficulty from static stance on a solid stationary support surface, to dynamic stance on compliant surfaces like foam 3, 8. 4) Reconditioning Program : A walking program was suggested to the patients. 8 First Set : Numbers (1 6) were Eye & Head exercises, which were performed in sitting position. Each exercise was first performed slowly &speed was increased gradually. 12

3 1) Keeping head in neutral, eyes were moved up & down 20 times. 2) Keeping head in neutral position, eyes were moved from side to side 20 times. 3) Fixing gaze on a target at arm s length head was moved up & down 20 times. 4) Fixing gaze on a target at arm s length head was moved side to side 20 times. 5) Eyes closed, head was moved up & down 20 times. 6) Eyes closed head was moved from side to side 20 times. 7) Marching on floor both with eyes open & with eyes closed 20 times. 8) In sitting, overhead ball throwing from one hand to another, gaze fixed at the ball 20 times, 9) In sitting, ball throwing underneath the chair & picking up 20 times, 10) Walking on the floor with head turning from side to side so as to look at objects in the surrounding. Turning on completing one round. Performed10 times. Second Set : I) Eye and Head Exercises: Exercises similar to set I Numbers (1 6) were performed in standing position. For exercises (3) and (4) of set I, the target was kept at 8-10feet away from patient s position & gaze was fixed at the target, with head in neutral position. II) Marching on foam surface, first with eyes open & then with eyes closed was performed - 20 times. III) Exercises (8) and (9) were performed in standing. IV) Same as exercise (10) but walking on a foam surface, instead of floor. V) Walking outside home for minutes DATA ANALYSIS AND RESULTS The assessments were done thrice: - Initial i.e. Pre-therapy - First follow up: 4 weeks post therapy - Second follow up: 6 weeks post therapy. Student s 2 tailed paired t test & was applied to the data obtained. It detected the significant increase / decreases in scores from pre-therapy to 1st follow up and from pre therapy to 2 nd follow up respectively. The probability p value of the calculated t corresponding to degrees of freedom is found out by referring to t table. Abbreviations : ADL : activities of daily living score F : functional subscore A : ambulation subscore I : instrumental subscore C 1 : standing with eyes open on floor C 2 : standing with eyes closed on floor C 3 : standing on floor, wearing visual dome C 4 : standing with eyes open on foam surface C 5 : standing with eyes closed on foam surface C 6 : standing on foam surface, wearing visual dome MSQ : motion sensitivity quotient Initial / basal : pre therapy values 1 F/U : first follow up 2 F/U : second follow up * P < 0.05 ** P < 0.01 *** P < DISCUSSION Clinical Test of Sensory interaction and balance (CTSIB) was utilized for the purpose of evaluating balance deficits in these patients. From the data presented in Table I, it can be noted that the duration of stance had declined successively, from conditions 1 to 6.In peripheral vestibular dysfunctions, there is sensory disorganization & motor dyscoordination, i.e. inappropriate selection of postural control strategy. Balance retraining exercises were included in the vestibular rehabilitation program. Post therapy results indicated statistically significant improvement in the CTSIB scores in all 6 conditions (p < 0.001) as shown in table I & graphs II & I. The underlying physiologic mechanisms leading to improvements are: Central sensory substitution Rebalancing of tonic activity General CNS adaptivity 13

4 GRAPH-I Comparison of C1, C2 and C3 score at, FU1 & FU2 GRAPH-II Comparison of C4, C5 and C6 score at, FU1 & FU2 GRAPH-III Comparison of MSQ Score at, FU1 & FU2 GRAPH-III Comparison of ADL, F, A and I Score at, FU1 & FU2 Table - I Comparison of the CTSIB scores for conditions C1 to C6 maintained at initial, first follow up and second follow up evaluations. Mean + S.D. values are presented. Variables C1 C2 C3 C4 Initial F/U F/U t value p value < 0.01** < 0.01** t value p value <0.001*** Initial to 1 F/U Initial to 2 F/U C5 C Table I suggests that, the duration of stance (in seconds) reduced from condition 1 to 6. The C1 to C6 scores improved statistically at 1st & 2nd follow-up evaluations, as compared to initial scores, as indicated by p values. IJOT : Vol. XXXVI : No April - July 2004

5 Table - II Motion sensitivity quotient (MSQ) values i.e. mean ± SD at initial, first follow-up and second follow-up evaluations, have been compared. MSQ Initial F/U F/U Initial to 1 F/U t value 25.7 p value Initial to 2 F/U t value 52.2 p value From table II, we infer that there has been a significant decrease in MSQ values at first and second follow-up, as compared to initial values. This indicates improvement, which is statistically highly significant (P < 0.001). For above all three mechanisms to be possible, a repetition of training in different situations and in a graded manner is essential. In 4 different research studies, Cohen et al, Cass et al, Keim et al, Horak et al had similarly found improvement in balance function of patients with vestibular dysfunctions, following a structured vestibular rehabilitation program 9,10,11,12. Vertigo i.e. the illusion of self-motion has been reported as the most disabling symptom of vestibular dysfunctions, as it causes restriction of physical activities, psychological problems and social withdrawal. Vertigo occurs because of inequality of signals ascending the vestibular nerves to the vestibular nuclei. University of Michigan Vestibular Center Evaluation was used in this study, to evaluate the intensity and duration of vertigo. Subsequently Motion Sensitivity Quotient (MSQ) was computed. As shown in Table II there is statistically significant reduction in MSQ (P < 0.001). The habituation exercises enabled reduction in vertigo due to reduction in response magnitude with repetitive provocation. Table - III It shows comparison between ADL total scores, Functional subscore, Ambulation subscore, Instrumental subscores on initial, first follow up and second follow up evaluations. The values presented are mean + S.D. VARIABLES ADL F A I Initial F/U F/U Initial to 1 F/U t value p value < *** < *** < 0.01 ** < *** Initial to 2 F/U t value p value < *** < *** < 0.01 ** < *** Table III indicates that ADL, F, A & I values at initial evaluations were high, but at first and second follow-up evaluations, there was a decrease in scores, implying improvement. The improvement is statistically highly significant for ADL score, F & I subscores (P<0.001) and significant for A score. (P<0.01). 15

6 Shepard et al and Mruzek et al in their respective studies found 80-85% of patients had significant reduction in vertigo, following vestibular rehabilitation 13, 14. The repercussions of vestibular dysfunctions are the greatest in areas of ADL. Hence ADL assessment forms an integral part of OT evaluation and guides the appropriate planning of therapy program. In this study the outcome measure used for ADL evaluation was: Vestibular disorders activities of daily living scale [VADL]. On the initial evaluation, the total ADL score and all 3 subscores were high [as shown in Table III] thus indicating functional limitations in the patients. The instrumental tasks were more affected as compared to functional and ambulation tasks [as shown in Graph IV]. Post therapy there was statistically significant improvement in ADL total scores and subscores as shown in Table III and graph IV. For achieving maximum functional independence, patients acceptance of the symptoms is essential. Patient counseling about the cause of symptoms and how to alleviate the symptoms through participation in therapy program is necessary. Physical inactivity leads to deconditioning and hence performance of routine ADL tasks is encouraged. In two different studies, Cohen H.S. et al had similarly found significant improvement in ADL performance, following therapy 15,16. CONCLUSION It may also be concluded that graded vestibular rehabilitation program which helps to reduce vertigo, retrain balance, promote visual-vestibular interaction and cause physical reconditioning, is imperative to achieve maximum functional independence. This improvement occurring by chance or spontaneously is low, because the duration of symptoms had lasted for more than 3 months. This study was based on a generalized vestibular rehabilitation approach. An individualized therapy program must be studied for long-term effects. ACKNOWLEDGEMENTS: We would like to extend our sincere gratitude to Dr. Mrs. I.R.Kenkre (Professor and Head of Occupational therapy School and Center, Seth G.S.Medical College) for her guidance and support. We would like to extend our acknowledgement to Dr. Shirahatti, Dean Seth G.S. Medical College and KEM hospital for granting us permission to carry out the study. We would like to acknowledge Dr. S.B.Ogale Head of ENT Department KEM hospital, Dr. Ninad Gaikwad Lecturer, ENT Department, KEM Hospital for referring patients for this study. We would also like to thank all patients for their utmost cooperation. We would like to thank Mr.Arekar for helping us with statistics. Last but not the least thanks to all teachers, parents and friends for their constant support and encouragement. REFERENCES: 1) Cohen: Vestibular rehabilitation improves daily life function. American Journal of Occupational Therapy (1994); 48(10), ) Yardley et al: Feasibility and effectiveness of providing vestibular rehabilitation for dizzy patients in the community. Clinical Otolaryngology (1998); 23, ) Cohen: Vertigo and Balance disorders. Vestibular rehabilitation. OT practice (2000), ) Cohen: Vestibular rehabilitation reduces functional disability. Otolaryngology, Head Neck surgery (1992); 107, ) Shumway-Cook & Horak: Assessing the influence of sensory interaction on balance, suggestions from the field. Physical therapy (1986); 66(10), ) Smith-Wheelock, Shepard &Telian: Physical Therapy program of vestibular rehabilitation. American journal of Otology (1991); 12(3), ) Cohen, Kimball: Development of Vestibular disorder activities of daily living scale. Archives of Otolaryngology, head neck surgery (2000); 1226, ) Shumway-Cook & Horak: Rehabilitation strategies for patients with vestibular deficits. Neurologic clinics of North America (1990);8(2), ) Cohen, Blatchhy, Gombash: A study of the Clinical Test of Sensory interaction and Balance. Physical Therapy (1993); 73(6), ) Cass, Borello-France, Furman: Functional outcome of Vestibular rehabilitation in patients with abnormal sensory organization testing. American Journal Of Otology (1996); 17, ) Keim, Cook and Martini: Balance rehabilitation therapy. Laryngoscope (1992); 102, ) Horak, Black, Shumway-cook: Effects of vestibular rehabilitation on dizziness and imbalance. Otolaryngology head neck surgery (1992): 106, ) Shepard and Telian: Programmatic vestibular rehabilitation. Otolaryngology head neck surgery (1995); 112, ) Mruzek et al: Effects of Vestibular rehabilitation and social reinforcement on recovery following ablative vestibular surgery. Laryngoscope (1995); 105, ) Cohen, Miller, Kane-Wineland, and Hatfield: Vestibular rehabilitation with graded occupations. American Journal of Occupational Therapy (1995); 49(4), ) Cohen, Kimball, Adams: Application of Vestibular disorders activities of daily living scale. Laryngoscope (2000); 110, l 16