BASIC SCIENCE REVIEW EDWlN W RUBEL, MD Basic Science Review Editor
Rehabilitation therapy for patients with disequilibrium and balance disorders HORST R. KONRAD, MD, DAVID TOMLINSON, PhD, CHARLES W. STOCKWELL, PhD, MARCEL NORRE, MD. PhD, FAY B. HORAK, PhD. NEIL T. SHEPARD, PhD, and SUSAN J. HERDMAN, PhD,
Springfield, Illinois, Toronto, Ontario, Canada, Southfield and Ann Arbor, Michigan, Leuven, Belgium, Portland, Oregon, and Baltimore, Maryland Vestibular rehabilitation is based on the use of adaptive and compensatory mechanisms already existing in the human brain. Research using animals provides a great deal of information on the neural mechanisms responsible for these functions and suggests strategies that should be helpful in rehabilitation of patients with disequilibrium and balance disorders. Research in animals and human beings suggests that rehabilitation should be specifically designed, depending on the patients’ deficits. It also suggests that to be effective it needs to be started soon after impairment and that vestibulosuppressivemedication may reduce recovery. Studies are now underway to evaluate the effectiveness of vestibular rehabilitation on several groups of patients and to answer some fundamental questions about the mechanisms and the effectiveness of these treatment methods. Current information suggests that vestibular rehabilitation is an effective method of therapy for many patients with disequilibrium and balance disorders and that for some patients it is the best therapy available. (OTOLARYNGOL HEAD NECK SURG 1992;107:105,)
T h e neural mechanisms for adaptation and compensation relating to equilibrium are fairly well known in animals. We know much about the anatomic pathways involved and there is now a rapidly growing body of information that demonstrates adaptation, compensation, and plasticity in the human being.” There is evidence that adaptation and compensation are related to stimulus magnitude, duration, and d i r e ~ t i o nInterven.~ tional rehabilitation should be able to take advantage of this plasticity, re-establish system sensitivity, and reset the symmetry of its resting levels. This should
From the Southern Illinois University School of Medicine (Dr. Konrad), the University of Toronto (Dr. Tomlinson), Providence Hospital, Southfield (Dr. Stockwell), the University of Belgium (Dr. None), the R.W. Dow Neurological Sciences Institute (Dr. Horak), the University of Michigan (Dr. Shepard), and Johns Hopkins Hospital (Dr. Herdman). Presented at the Annual Meeting of the American Academy of Otolaryngology-Head and Neck Surgery, San Diego, Calif., Sept. 913, 1990. Received for publication Aug. 26, 1991; accepted Dec. 4, 1991. Reprint requests: Horst R. Konrad, MD, Southern Illinois University School of Medicine, P.O. Box 19230, Springfield, IL 62794-9230. 23/1/35330
result in an improved vestibulo-oculomotor control and improved posture and locomotion. Rehabilitation may be limited by factors such as age, integrity of other sensory systems, and integrity of central mechanisms. Higher central functions such as memory, decisionmaking ability, and motor task initiation may also be important factors. The body’s physical integrity (skeleton, muscle strength, joints, and body weight) may also have a bearing on the success or failure of interventional rehabilitation. Basic Anatomy Sensory input related to equilibrium includes vision, vestibular, proprioception, and hearing. The information from these senses is integrated in the central nervous system and appropriate motor activity is generated to coordinate the eyes, stance, and locomotion. Some of this activity is transmitted through the vestibulooculomotor reflex (VOR) or the vestibulospinal reflexes, whereas most locomotor activity requires even more complex neuronal circuitry and functions, which include learning and memory. Even the “simple” VOR circuit has at least a parallel circuit that includes the cerebellum and the inferior olive. Circuits that deal with fast eye movements include frontal and parietal cortex,
Downloaded from oto.sagepub.com at UNIV CALIFORNIA SANTA BARBARA on September 9, 2015
105
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106 KONRAD et al.
superior colliculus and substantia nigra,5 midbrain, pons, and cerebellum. Animal Studies Current animal research involving vestibular lesions suggests that several mechanisms are involved in recovery from such lesions. A unilateral labyrinthectomy results in spontaneous nystagmus, a decreased gain of the VOR (less eye velocity per head velocity), and a decreased time constant. The spontaneous nystagmus diminished over time, apparently unaffected by vision or exercise.6 The decreased gain reverts to normal but is improved by exercise with vision and the change in time constant does not seem to i m p r ~ v e . ~ The - ' " change in gain seems to require both cerebellum and inferior olive."." Human Studies Studies in human beings show similar abnormalities as a result of unilateral labyrinthectomy. The VOR asymmetry manifested by spontaneous nystagmus compensates greatly within the first 2 days of surgery and disappears by the twenty-first day. l 3 A decrease in sensitivity, especially at low frequencies (and to caloric stimulation in the ear not operated on), may pers i ~ t . ' ~At - ' high ~ frequencies and high magnitude, stimulation response asymmetries to rotational stimulation may compensate partly but not completely. " , I 8 Patients with bilateral vestibular loss have much difficulty during rapid head movements and when visual and proprioceptive clues are not available. Vision blurs during head movements faster than the pursuit and optokinetic mechanisms can follow, and ambulation is difficult in the dark or on rough ground.'' We should be cautious, however, not to use lack of caloric responses as evidence of complete loss of vestibular function, because higher-frequency responses may persist. In addition, cervico-ocular reflexes may come into play in patients who lost vestibular sensitivity.'" Studies on Rehabilitation Rehabilitation is a method of therapy for vertigo as important as medical and surgical therapy. Just as medical therapy is important in the management of acute incapacitating vertigo, nausea, and vomiting and surgical ablative therapy is important in stopping incapacitation episodic vertigo, rehabilitation therapy has specific indications. To be effective, like medical and surgical therapy, rehabilitation therapy must be performed on the basis of specific diagnostic findings. It is not the therapy to be tried when all else fails, but is frequently the best-and at times the only rational-means of helping the patient. Fortunately it relies on the normal
built-in adaptive mechanisms individual patients already have working for them."-26 Vestibular rehabilitation exercises are designed to stimulate and enhance these normal adaptive mechanisms. Patients with benign paroxysmal positional vertigo seem to respond well to rehabilitation This is particularly true if their symptoms are fairly stable and they have no central abnormalities. Patients are placed in various provocative head positions of positional nystagmus and Hallpike maneuvers and scores are assigned positive if they have vertigo with a particular maneuver (M ) and scored as (M + N ) if they have both vertigo and nystagmus with that maneuver. Patients with provoked vertigo or nystagmus are selected for treatment. Patients may have a large variety of vertigo or nystagmus responses and therapy must be individually programmed to reflect the provoked responses. In addition, individual patients' patterns may vary from day to day. Therefore, exercises are designed specifically for each patient on the basis of their provoked vertigo and nystagmus and modified if the patients' responses change over time. Responses to treatment were less rapid in aged patients (more than 60 years old) and in patients who also had signs of central abnormalities. Eventually even elderly patients and patients with cerebral insufficiency would respond with improvement being seen in their test scores (M N ) and their symptoms. Recently investigators are developing prospective controlled studies to investigate specific questions that relate to vestibular rehabilitation. A study by Dr. Fay Horak compares the effectiveness of vestibular rehabilitation, general conditioning exercises, and vestibular suppressive medication in patients with BPPV randomly assigned into the three treatment groups for 6 weeks. Balance was evaluated by assessment of body sway under six different sensory conditions and by having patients stand on one foot with eyes open and eyes closed. Dizziness was evaluated by placing patients in 12 head positions. Duration of dizziness and severity (scale 0 to 10) were rated. Although the number of positions and seventy of vertigo were improved in all three groups, positional sway in sensing conditions requiring vestibular information and one foot standing were improved only in patients receiving vestibular rehabilitation, but not by general exercises or medication. This confirms previous studies which suggest that vestibulosuppressive medication may actually retard central compensation.30 Thus, balance improved only in patients who were provided with balance training exercises. A detailed discussion of therapy protocol has already been published (Shumway-Cook and Horak, 1989).
+
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Volume 107 Number 1 July 1592
Rehabilitation therapy: Disequilibrium and balance disorders 107
A study by Dr. Neil Shepard evaluates the effect of custom-tailored vestibular exercises on patients with disequilibrium from various causes. Symptom-response score was evaluated after therapy, with disability score evaluated before and after therapy.” The majority of patients (85%) showed reduction of symptoms after therapy, whereas only 9% reported no change and 6% reported worsening of symptoms. The authors note that some subgroups (head injury patients and patients with poor visual vestibular interactions) had poorer responses. At this point in time, however, there are insufficient data to support exclusion of any diagnostic category from vestibular rehabilitation, because many patients in all groups improved. A study by Dr. Susan Herdman prospectively evaluates the effect of brief vestibular exercises on gaze and postural stability in patients with vestibular deficits. It also evaluates the effect of early intervention on recovery. Vestibulo-oculomotor gain and visual acuity were measured during head movements. Postural stability was evaluated using posture platform and timed balance tests (Rhomberg and Sharpened Rhomberg). Vertigo and disequilibrium were also assessed. This study is at a very preliminary stage, but suggests that vestibular exercises very early after unilateral surgery improve speed and extent of compensation.
exercises used in therapy. The exercises most likely to be beneficial are those that provoke vestibular symptoms or nystagmus in the patient. Patients with static unilateral peripheral vestibular disorders or patients with benign paroxysmal positional vertigo seem to respond best to therapy. Patients with episodic vertigo, such as Meniere’s disease, may not respond as well. Patients with evidence of central disorders may also respond to rehabilitation exercises and should not be denied treatment. Their improvement is generally slower. Vestibular rehabilitation should be part of the methodology available to patients with disequilibrium. Vestibular rehabilitation plays an important part and, in many patients, is the treatment of choice. REFERENCES 1. Jones GM. Adaptive modulation of VOR parameters by vision.
2.
3.
4.
CONCLUSION
Scientific study of the effect of rehabilitation on patients with disequilibrium is still in an early period. Many experiments on animals and human beings support the effectiveness of this method of therapy for patients with disequilibrium. Prospective controlled studies in human beings are now in progress in order to answer specific questions about the design of the therapy and the effect of concomitant medical or surgical intervention. A few points brought out at a recent symposium on vestibular rehabilitation seem to be generally recognized. In order for rehabilitation exercises to be effective, they must include head movements with vision. The exercises should begin as soon after the vestibular injury as possible. There may be a critical period of less than 72 hours after which recovery is less complete. The use of vestibulosuppressive medication such as meclizine hydrochloride and phenothiazine should be restricted to the management of severe symptoms only, because long-term use of such medication may reduce rehabilitation. An intact cerebellum is important for recovery and cerebellar function should be evaluated before operations on the vestibular labyrinth or nerve. A careful evaluation of the patient to determine which movements cause symptoms is important and is used to design the
5.
6
7
8
9
10
II
12
13
In: Berthoz A, Jones GM, eds. Adaptive mechanisms in gaze control. New York: Elsevier Science Publishers, 1985:21-50. Collewijn H. Integration of adaptive changes of the optokinetic reflex, pursuit and the vestibulo-ocular reflex. In: Berthoz A. Jones GM, eds. Adaptive mechanisms in gaze control. New York: Elsevier Science Publishers, 1985:s 1-69. Optican LM. Adaptive properties of the saccadic system. In: Berthor A , Jones GM, eds. Adaptive mechanisms in gaze control. New York: Elsevier Science Publishers, 1985:71-8. Scbmid R, Jeannerod M. Vestibular habituation: an adaptive process‘? In: Berthoz A, Jones GM, eds. Adaptive mechanisms in gaze control. New York: Elsevier Science Publishers, 1985:113-22. Konrad HR. Clinical application of saccade reflex testing in man. Laryngoscope 1990;101: 1293.302. Fetter M, Zee DS, Proctor LR. Effect of lack of vision and of occipital lobectomy upon recovery from unilateral labyrinthectomy in rhesus monkey. J Neurophysiol 1988;59:394-407. Lisberger SC, Miles FA. Role of primate vestibular nucleus in long-term adaptive plasticity of vestibulo-ocular reflex. J Neurophysiol 1980;43:1725-45. Miles FA. Braitman DJ. Long-term adaptive changes in primate vestibulo-ocular reflex. 11. Electrophysiological observations on semicircular canal primary afferents. J Neurophysiol 1980; 43: 1426-36. Paige GD. Vestibule-ocular reflex and its interactions with visual following mechanisms in the squirrel monkey. I. Response characteristics in normal animals. J Neurophysiol 1983a;49:134-51. Paige GD. Vestibulo-ocular reflex and its interactions with visual following mechanisms in the squirrel monkey. 11. Response characteristics and plasticity following unilateral inactivation of horizontal canal. J Neurophysiol 1983b;49: 152-68. Courjon JH, Flandrin JM, Jeannerod M, Schmid R. The role of the flocculus in vestibular compensation after hernilabyrinthectomy. Brain Res 1982;239:25 1-7. Demur JL, Robinson DA. Effects of reversible lesions and stimulation of olivocerebellar system on vestibulo-ocular reflex plasticity. J Neurophysiol 1982;47:1084-107. Stockwell C, Graham M. Vestibular compensation following labyrinthectomy and vestibular neurectomy. In: Nadol JB, ed. Second international symposium on Meniere’s disease. Amsterdam: Kugler & Ghedini, 1989:489-98.
Downloaded from oto.sagepub.com at UNIV CALIFORNIA SANTA BARBARA on September 9, 2015
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108 KONRAD et 01.
14. Jager J , Henn V. Vestibular habituation in man and monkey during sinusoidal rotation. Ann N Y Acad Sci 1981;374: 330-9. 15. Honrubia V. Jenkins H, Baloh R, et al. Vestibulo-ocular reflexes in peripheral labyrinthine lesions: I. Unilateral dysfunction. Am J Otolaryngol l984;5: 15-26. 16. Jenkins H. Long-term adaptive changes of the vestibulo-ocular reflex in patients following acoustic neuroma surgery. Laryngoscope 1985;95:1224-34. 17. Shimazue H, Precht W. Tonic and kinetic responses of the cat’s vestibular neurons to horizontal angular acceleration. J Neurophysiol 1965;28:991-1013. 18. Paige G . Nonlinearity and asymmetry in the human vestibuloocular reflex. Acta Otolaryngol 1989;108: 1-8. 19. JC (anonymous). Living without a balancing mechanism. N Engl J Med 1952;246:458-60. 20. Kasai T, Zee D. Eye-head coordination in labyrinthine defective human beings. Brain Res 1978;144:123-41. 21. N o d ME. Treatment of unilateral vestibular hypofunction. In: Oosterveld WJ, ed. Otoneurology. New York: J Wiley and Sons, 1984:23-39. 22. Norre ME. Rationale of rehabilitation treatment for vertigo. Am J Otolaryngol 1987;8:31-5.
.
~
23. Norre ME. Rehabilitation treatments for vertigo and related syndromes. CRC: Critical Reviews in Physical and Rehabilitation Medicine (in press). 24. Norre ME. Posture in otoneurology report. Acta Otorhinolaryngol Belg (in press). 25. Shumway-Cook A, Horak FB. Vestibular rehabilitation: an exercise approach to manage symptoms of vestibular dysfunction. Semin Hear 1989;10:196-208. 26. Crutchfield CA, Shumway-Cook A, Horak FB. Balance and coordination training. Phys Ther 1990;825-43. 27. Brandt T, Daroff R. Physical therapy for benign paroxysmal positional vertigo. Arch Otolaryngol 1980;106:484-5. 28. N o d ME, Beckers A. Exercise treatment for paroxysmal positional vertigo: comparison of two types of exercises. Arch Otolaryngol 1987;244:291-4. 29. N o d ME, Beckers A. Benign paroxysmal positional vertigo in the elderly. J Am Geriatr SOC1988;36:425-9. 30. Pfaltz CR, Kamath R. Central compensation of vestibular dysfunction: I. Peripheral lesions. Adv Otorhinolaryngol 1983; 30:335. 3 1, Smith-Wheelock M, Shepard NT, Telian SA. Physical therapy program for vestibular rehabilitation. Am J Otol 1991;12:21825.
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Otolaryngology Head and Neck Surgery March 1993
News and Announcements
held July 26-30, 1993, at the Tamarron Resort in Durango, Colorado. This 28 hour review and update will encompass all the clinically important areas of MR imaging. Important new concepts and pathological/imaging correlations in the body, musculoskeletal system, ENT, head and neck, brain, and spine will be explored. Daily case presentations will supplement these lectures and will serve to test the registrants' diagnostic abilities in MR imaging. This complete review of MR imaging will be presented by nationally recognized leaders in magnetic resonance imaging. As a result of this comprehensive review, registrants will become familiar with current applications of MR imaging and will be able to integrate many of these applications directly into their practice. Program chairmen for this presentation will be Robert Quencer, MD (University of Miami), Victor Haughton, MD (Medical College of Wisconsin). Twenty-eight credits of Category I will be available. For further information, please contact Marti Carter, CME, Inc., 11011 West Nort Ave., Milwaukee, Wisconsin 53226, or call (414) 771-9520. Ear, Nose, and Throat Diseases: 1993 Update
Children's Hospital of Pittsburgh will hold its 18th Annual Symposium, "Ear, Nose, and Throat Diseases in Children: A 1993 Update." This symposium will be held July 30-31, 1993. CME credits will be awarded.
For further information, please contact the Department of Pediatric Otolaryngology, Children's Hospital of Pittsburgh, 3705 Fifth Avenue at DeSoto St., Pittsburgh, Pennsylvania 15213, or call (412) 692-8577. Twenty-fifth Annual Meeting - Head and Neck Oncologists
The Association of Head and Neck Oncologists of Great Britain will sponsor the Twenty-fifth Annual Meeting of Head and Neck Oncology, to be held in Edinburgh, Scotland, United Kingdom, on August 23-26, 1993. International and local faculty will present extensive social and family programs. For further information, please contact Mr. P. J. Bradley, Honorary Secretary, Department of Otorhinolaryngology-Head and Neck Surgery, University Hospital, Queens Medical Centre, Nottingham, NG7 2UH, England, or phone 0602421421. Sixth International Congress on Interventlonal Ultrasound
The Sixth International Congress on Interventional Ultrasound will be held in Copenhagen, Denmark, on September 7-10, 1993. For further information, please contact Christian Nolsoe, Congress Secretary, Department of Ultrasound, Herlev Hospital, University of Copenhagen, DK-2730 HerlevDenmark, or call + 45/ 44 53 53 00 ext. 3240.
CORRECTION
The Supplement to the December 1992 issue of the JOURNAL (Volume 107, Number 6, Part 2), incorrectly listed Dr. Bruce R. Gordon as Chief of Otolaryngology at the Massachusetts Eye and Ear Institute. Dr. Joseph Nadol is Chief of Otolaryngology at the Massachusetts Eye and Ear Infirmary. Dr. Gordon is Chief of Otolaryngology at Cape Cod Hospital.
Rehabilitation therapy for patients with disequilibrium and balance disorders HORST R. KONRAD, MD, DAVID TOMLINSON, PhD, CHARLES W. STOCKWELL, PhD, MARCEL NORRE, MD. PhD, FAY B. HORAK, PhD. NEIL T. SHEPARD, PhD, and SUSAN J. HERDMAN, PhD,
Springfield, Illinois, Toronto, Ontario, Canada, Southfield and Ann Arbor, Michigan, Leuven, Belgium, Portland, Oregon, and Baltimore, Maryland Vestibular rehabilitation is based on the use of adaptive and compensatory mechanisms already existing in the human brain. Research using animals provides a great deal of information on the neural mechanisms responsible for these functions and suggests strategies that should be helpful in rehabilitation of patients with disequilibrium and balance disorders. Research in animals and human beings suggests that rehabilitation should be specifically designed, depending on the patients’ deficits. It also suggests that to be effective it needs to be started soon after impairment and that vestibulosuppressivemedication may reduce recovery. Studies are now underway to evaluate the effectiveness of vestibular rehabilitation on several groups of patients and to answer some fundamental questions about the mechanisms and the effectiveness of these treatment methods. Current information suggests that vestibular rehabilitation is an effective method of therapy for many patients with disequilibrium and balance disorders and that for some patients it is the best therapy available. (OTOLARYNGOL HEAD NECK SURG 1992;107:105,)
T h e neural mechanisms for adaptation and compensation relating to equilibrium are fairly well known in animals. We know much about the anatomic pathways involved and there is now a rapidly growing body of information that demonstrates adaptation, compensation, and plasticity in the human being.” There is evidence that adaptation and compensation are related to stimulus magnitude, duration, and d i r e ~ t i o nInterven.~ tional rehabilitation should be able to take advantage of this plasticity, re-establish system sensitivity, and reset the symmetry of its resting levels. This should
From the Southern Illinois University School of Medicine (Dr. Konrad), the University of Toronto (Dr. Tomlinson), Providence Hospital, Southfield (Dr. Stockwell), the University of Belgium (Dr. None), the R.W. Dow Neurological Sciences Institute (Dr. Horak), the University of Michigan (Dr. Shepard), and Johns Hopkins Hospital (Dr. Herdman). Presented at the Annual Meeting of the American Academy of Otolaryngology-Head and Neck Surgery, San Diego, Calif., Sept. 913, 1990. Received for publication Aug. 26, 1991; accepted Dec. 4, 1991. Reprint requests: Horst R. Konrad, MD, Southern Illinois University School of Medicine, P.O. Box 19230, Springfield, IL 62794-9230. 23/1/35330
result in an improved vestibulo-oculomotor control and improved posture and locomotion. Rehabilitation may be limited by factors such as age, integrity of other sensory systems, and integrity of central mechanisms. Higher central functions such as memory, decisionmaking ability, and motor task initiation may also be important factors. The body’s physical integrity (skeleton, muscle strength, joints, and body weight) may also have a bearing on the success or failure of interventional rehabilitation. Basic Anatomy Sensory input related to equilibrium includes vision, vestibular, proprioception, and hearing. The information from these senses is integrated in the central nervous system and appropriate motor activity is generated to coordinate the eyes, stance, and locomotion. Some of this activity is transmitted through the vestibulooculomotor reflex (VOR) or the vestibulospinal reflexes, whereas most locomotor activity requires even more complex neuronal circuitry and functions, which include learning and memory. Even the “simple” VOR circuit has at least a parallel circuit that includes the cerebellum and the inferior olive. Circuits that deal with fast eye movements include frontal and parietal cortex,
Downloaded from oto.sagepub.com at UNIV CALIFORNIA SANTA BARBARA on September 9, 2015
105
OtolaryngologyHead and Neck Surgery
106 KONRAD et al.
superior colliculus and substantia nigra,5 midbrain, pons, and cerebellum. Animal Studies Current animal research involving vestibular lesions suggests that several mechanisms are involved in recovery from such lesions. A unilateral labyrinthectomy results in spontaneous nystagmus, a decreased gain of the VOR (less eye velocity per head velocity), and a decreased time constant. The spontaneous nystagmus diminished over time, apparently unaffected by vision or exercise.6 The decreased gain reverts to normal but is improved by exercise with vision and the change in time constant does not seem to i m p r ~ v e . ~ The - ' " change in gain seems to require both cerebellum and inferior olive."." Human Studies Studies in human beings show similar abnormalities as a result of unilateral labyrinthectomy. The VOR asymmetry manifested by spontaneous nystagmus compensates greatly within the first 2 days of surgery and disappears by the twenty-first day. l 3 A decrease in sensitivity, especially at low frequencies (and to caloric stimulation in the ear not operated on), may pers i ~ t . ' ~At - ' high ~ frequencies and high magnitude, stimulation response asymmetries to rotational stimulation may compensate partly but not completely. " , I 8 Patients with bilateral vestibular loss have much difficulty during rapid head movements and when visual and proprioceptive clues are not available. Vision blurs during head movements faster than the pursuit and optokinetic mechanisms can follow, and ambulation is difficult in the dark or on rough ground.'' We should be cautious, however, not to use lack of caloric responses as evidence of complete loss of vestibular function, because higher-frequency responses may persist. In addition, cervico-ocular reflexes may come into play in patients who lost vestibular sensitivity.'" Studies on Rehabilitation Rehabilitation is a method of therapy for vertigo as important as medical and surgical therapy. Just as medical therapy is important in the management of acute incapacitating vertigo, nausea, and vomiting and surgical ablative therapy is important in stopping incapacitation episodic vertigo, rehabilitation therapy has specific indications. To be effective, like medical and surgical therapy, rehabilitation therapy must be performed on the basis of specific diagnostic findings. It is not the therapy to be tried when all else fails, but is frequently the best-and at times the only rational-means of helping the patient. Fortunately it relies on the normal
built-in adaptive mechanisms individual patients already have working for them."-26 Vestibular rehabilitation exercises are designed to stimulate and enhance these normal adaptive mechanisms. Patients with benign paroxysmal positional vertigo seem to respond well to rehabilitation This is particularly true if their symptoms are fairly stable and they have no central abnormalities. Patients are placed in various provocative head positions of positional nystagmus and Hallpike maneuvers and scores are assigned positive if they have vertigo with a particular maneuver (M ) and scored as (M + N ) if they have both vertigo and nystagmus with that maneuver. Patients with provoked vertigo or nystagmus are selected for treatment. Patients may have a large variety of vertigo or nystagmus responses and therapy must be individually programmed to reflect the provoked responses. In addition, individual patients' patterns may vary from day to day. Therefore, exercises are designed specifically for each patient on the basis of their provoked vertigo and nystagmus and modified if the patients' responses change over time. Responses to treatment were less rapid in aged patients (more than 60 years old) and in patients who also had signs of central abnormalities. Eventually even elderly patients and patients with cerebral insufficiency would respond with improvement being seen in their test scores (M N ) and their symptoms. Recently investigators are developing prospective controlled studies to investigate specific questions that relate to vestibular rehabilitation. A study by Dr. Fay Horak compares the effectiveness of vestibular rehabilitation, general conditioning exercises, and vestibular suppressive medication in patients with BPPV randomly assigned into the three treatment groups for 6 weeks. Balance was evaluated by assessment of body sway under six different sensory conditions and by having patients stand on one foot with eyes open and eyes closed. Dizziness was evaluated by placing patients in 12 head positions. Duration of dizziness and severity (scale 0 to 10) were rated. Although the number of positions and seventy of vertigo were improved in all three groups, positional sway in sensing conditions requiring vestibular information and one foot standing were improved only in patients receiving vestibular rehabilitation, but not by general exercises or medication. This confirms previous studies which suggest that vestibulosuppressive medication may actually retard central compensation.30 Thus, balance improved only in patients who were provided with balance training exercises. A detailed discussion of therapy protocol has already been published (Shumway-Cook and Horak, 1989).
+
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+
+ +
Volume 107 Number 1 July 1592
Rehabilitation therapy: Disequilibrium and balance disorders 107
A study by Dr. Neil Shepard evaluates the effect of custom-tailored vestibular exercises on patients with disequilibrium from various causes. Symptom-response score was evaluated after therapy, with disability score evaluated before and after therapy.” The majority of patients (85%) showed reduction of symptoms after therapy, whereas only 9% reported no change and 6% reported worsening of symptoms. The authors note that some subgroups (head injury patients and patients with poor visual vestibular interactions) had poorer responses. At this point in time, however, there are insufficient data to support exclusion of any diagnostic category from vestibular rehabilitation, because many patients in all groups improved. A study by Dr. Susan Herdman prospectively evaluates the effect of brief vestibular exercises on gaze and postural stability in patients with vestibular deficits. It also evaluates the effect of early intervention on recovery. Vestibulo-oculomotor gain and visual acuity were measured during head movements. Postural stability was evaluated using posture platform and timed balance tests (Rhomberg and Sharpened Rhomberg). Vertigo and disequilibrium were also assessed. This study is at a very preliminary stage, but suggests that vestibular exercises very early after unilateral surgery improve speed and extent of compensation.
exercises used in therapy. The exercises most likely to be beneficial are those that provoke vestibular symptoms or nystagmus in the patient. Patients with static unilateral peripheral vestibular disorders or patients with benign paroxysmal positional vertigo seem to respond best to therapy. Patients with episodic vertigo, such as Meniere’s disease, may not respond as well. Patients with evidence of central disorders may also respond to rehabilitation exercises and should not be denied treatment. Their improvement is generally slower. Vestibular rehabilitation should be part of the methodology available to patients with disequilibrium. Vestibular rehabilitation plays an important part and, in many patients, is the treatment of choice. REFERENCES 1. Jones GM. Adaptive modulation of VOR parameters by vision.
2.
3.
4.
CONCLUSION
Scientific study of the effect of rehabilitation on patients with disequilibrium is still in an early period. Many experiments on animals and human beings support the effectiveness of this method of therapy for patients with disequilibrium. Prospective controlled studies in human beings are now in progress in order to answer specific questions about the design of the therapy and the effect of concomitant medical or surgical intervention. A few points brought out at a recent symposium on vestibular rehabilitation seem to be generally recognized. In order for rehabilitation exercises to be effective, they must include head movements with vision. The exercises should begin as soon after the vestibular injury as possible. There may be a critical period of less than 72 hours after which recovery is less complete. The use of vestibulosuppressive medication such as meclizine hydrochloride and phenothiazine should be restricted to the management of severe symptoms only, because long-term use of such medication may reduce rehabilitation. An intact cerebellum is important for recovery and cerebellar function should be evaluated before operations on the vestibular labyrinth or nerve. A careful evaluation of the patient to determine which movements cause symptoms is important and is used to design the
5.
6
7
8
9
10
II
12
13
In: Berthoz A, Jones GM, eds. Adaptive mechanisms in gaze control. New York: Elsevier Science Publishers, 1985:21-50. Collewijn H. Integration of adaptive changes of the optokinetic reflex, pursuit and the vestibulo-ocular reflex. In: Berthoz A. Jones GM, eds. Adaptive mechanisms in gaze control. New York: Elsevier Science Publishers, 1985:s 1-69. Optican LM. Adaptive properties of the saccadic system. In: Berthor A , Jones GM, eds. Adaptive mechanisms in gaze control. New York: Elsevier Science Publishers, 1985:71-8. Scbmid R, Jeannerod M. Vestibular habituation: an adaptive process‘? In: Berthoz A, Jones GM, eds. Adaptive mechanisms in gaze control. New York: Elsevier Science Publishers, 1985:113-22. Konrad HR. Clinical application of saccade reflex testing in man. Laryngoscope 1990;101: 1293.302. Fetter M, Zee DS, Proctor LR. Effect of lack of vision and of occipital lobectomy upon recovery from unilateral labyrinthectomy in rhesus monkey. J Neurophysiol 1988;59:394-407. Lisberger SC, Miles FA. Role of primate vestibular nucleus in long-term adaptive plasticity of vestibulo-ocular reflex. J Neurophysiol 1980;43:1725-45. Miles FA. Braitman DJ. Long-term adaptive changes in primate vestibulo-ocular reflex. 11. Electrophysiological observations on semicircular canal primary afferents. J Neurophysiol 1980; 43: 1426-36. Paige GD. Vestibule-ocular reflex and its interactions with visual following mechanisms in the squirrel monkey. I. Response characteristics in normal animals. J Neurophysiol 1983a;49:134-51. Paige GD. Vestibulo-ocular reflex and its interactions with visual following mechanisms in the squirrel monkey. 11. Response characteristics and plasticity following unilateral inactivation of horizontal canal. J Neurophysiol 1983b;49: 152-68. Courjon JH, Flandrin JM, Jeannerod M, Schmid R. The role of the flocculus in vestibular compensation after hernilabyrinthectomy. Brain Res 1982;239:25 1-7. Demur JL, Robinson DA. Effects of reversible lesions and stimulation of olivocerebellar system on vestibulo-ocular reflex plasticity. J Neurophysiol 1982;47:1084-107. Stockwell C, Graham M. Vestibular compensation following labyrinthectomy and vestibular neurectomy. In: Nadol JB, ed. Second international symposium on Meniere’s disease. Amsterdam: Kugler & Ghedini, 1989:489-98.
Downloaded from oto.sagepub.com at UNIV CALIFORNIA SANTA BARBARA on September 9, 2015
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Otolaryngology Head and Neck Surgery March 1993
News and Announcements
held July 26-30, 1993, at the Tamarron Resort in Durango, Colorado. This 28 hour review and update will encompass all the clinically important areas of MR imaging. Important new concepts and pathological/imaging correlations in the body, musculoskeletal system, ENT, head and neck, brain, and spine will be explored. Daily case presentations will supplement these lectures and will serve to test the registrants' diagnostic abilities in MR imaging. This complete review of MR imaging will be presented by nationally recognized leaders in magnetic resonance imaging. As a result of this comprehensive review, registrants will become familiar with current applications of MR imaging and will be able to integrate many of these applications directly into their practice. Program chairmen for this presentation will be Robert Quencer, MD (University of Miami), Victor Haughton, MD (Medical College of Wisconsin). Twenty-eight credits of Category I will be available. For further information, please contact Marti Carter, CME, Inc., 11011 West Nort Ave., Milwaukee, Wisconsin 53226, or call (414) 771-9520. Ear, Nose, and Throat Diseases: 1993 Update
Children's Hospital of Pittsburgh will hold its 18th Annual Symposium, "Ear, Nose, and Throat Diseases in Children: A 1993 Update." This symposium will be held July 30-31, 1993. CME credits will be awarded.
For further information, please contact the Department of Pediatric Otolaryngology, Children's Hospital of Pittsburgh, 3705 Fifth Avenue at DeSoto St., Pittsburgh, Pennsylvania 15213, or call (412) 692-8577. Twenty-fifth Annual Meeting - Head and Neck Oncologists
The Association of Head and Neck Oncologists of Great Britain will sponsor the Twenty-fifth Annual Meeting of Head and Neck Oncology, to be held in Edinburgh, Scotland, United Kingdom, on August 23-26, 1993. International and local faculty will present extensive social and family programs. For further information, please contact Mr. P. J. Bradley, Honorary Secretary, Department of Otorhinolaryngology-Head and Neck Surgery, University Hospital, Queens Medical Centre, Nottingham, NG7 2UH, England, or phone 0602421421. Sixth International Congress on Interventlonal Ultrasound
The Sixth International Congress on Interventional Ultrasound will be held in Copenhagen, Denmark, on September 7-10, 1993. For further information, please contact Christian Nolsoe, Congress Secretary, Department of Ultrasound, Herlev Hospital, University of Copenhagen, DK-2730 HerlevDenmark, or call + 45/ 44 53 53 00 ext. 3240.
CORRECTION
The Supplement to the December 1992 issue of the JOURNAL (Volume 107, Number 6, Part 2), incorrectly listed Dr. Bruce R. Gordon as Chief of Otolaryngology at the Massachusetts Eye and Ear Institute. Dr. Joseph Nadol is Chief of Otolaryngology at the Massachusetts Eye and Ear Infirmary. Dr. Gordon is Chief of Otolaryngology at Cape Cod Hospital.
