You are in: eMedicine Specialties > Otolaryngology and Facial Plastic Surgery > VERTIGO AND DIZZINESS Vestibular RehabilitationArticle Last Updated: Dec 19, 2007AUTHOR AND EDITOR INFORMATIONSection 1 of 8
  Author: Philip E Zapanta, MD, Assistant Professor of Surgery, Associate Director of Otolaryngology Residency Program, Division of Otolaryngology-Head and Neck Surgery, George Washington University Medical Center; Consulting Staff, Division of Otolaryngology-Head and Neck Surgery, Medical Faculty Associates Philip E Zapanta is a member of the following medical societies: American Academy of Otolaryngic Allergy, American Academy of Otolaryngology-Head and Neck Surgery, and Christian Medical & Dental Society Coauthor(s): Carol A Bauer, MD, Associate Professor, Department of Surgery, Division of Otolaryngology, Southern Illinois University School of Medicine; Marian Girardi, MA, † Former Director of the Vestibular Clinic, Former Clinical Instructor, Department of Surgery, Division of Otolaryngology, Southern Illinois University School of Medicine Editors: Robert A Battista, MD, FACS, Assistant Professor of Otolaryngology, Northwestern University Medical School; Consulting Staff, Ear Institute of Chicago, LLC; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Peter S Roland, MD, Chair, Professor, Department of Otolaryngology, University of Texas Southwestern Medical Center; Christopher L Slack, MD, Otolaryngology-Facial Plastic Surgery, Private Practice, Associated Coastal ENT; Medical Director, Treasure Coast Sleep Disorders; Arlen D Meyers, MD, MBA, Professor, Department of Otolaryngology-Head and Neck Surgery, University of Colorado School of Medicine Author and Editor Disclosure Synonyms and related keywords: vestibular rehabilitation, balance therapy, vestibular rehabilitation therapy, VRT, physical therapy, balance disorders, dizziness, vestibular function, vestibular deficit, vestibuloocular reflex, VOR, nystagmus, electronystagmography, infrared oculography, electrooculography, computer dynamic posturography, sensory organization testing, SOT, VRT exercise, limits of stability testing, LOS testing INTRODUCTIONSection 2 of 8
  An estimated 90 million Americans (42% of the current population) will experience dizziness at least once in their lifetime. Some patients develop permanent balance deficits with subsequent functional limitations. The etiology of peripheral and central vestibular deficits includes the following: age-related multisensory deficits, strokes and vascular insufficiencies, cerebellar degeneration, chemical and drug toxicities, benign paroxysmal positional vertigo, uncompensated Ménière disease, vestibular neuritis, labyrinthitis, and head trauma. Balance disorders are significant risk factors for falls in elderly individuals. Falls have been estimated to be the leading cause of serious injury and death in persons older than 65 years. Falls account for 50% of accidental deaths in the elderly, and 10% of falls result in hospitalization. The projected annual direct costs of fall-related injuries will be $32 billion in the Vestibular rehabilitation therapy (VRT) has been a highly effective modality for most individuals, including children, with disorders of the vestibular or central balance system. In a number of studies, customized VRT programs were significantly more effective than generic exercises in resolving symptoms. The basis for the success of VRT is the use of existing neural mechanisms in the human brain for adaptation, plasticity, and compensation. The extent of vestibular compensation and adaptation is closely related to the direction, duration, frequency, magnitude, and nature of the retraining stimulus. Specifically designed VRT exercise protocols take advantage of this plasticity of the brain to increase sensitivity and restore symmetry, which results in an improvement in vestibulo-ocular control, an increase in the gain of the vestibulo-ocular reflex (VOR), better postural strategies, and increased levels of motor control for movement. Most VRT exercises involve head movement, and head movements are essential in stimulating and retraining the vestibular system. Other factors that may affect the degree of individual compensation that can be achieved include overall physical status, the functional status of remaining sensory systems, integrity of central brain mechanisms, age, and higher sensory functions such as memory, motor coordination, and cognitive ability. VESTIBULAR REHABILITATION THERAPYSection 3 of 8
Definition VRT is a specific form of physical therapy designed to promote habituation and compensation for deficits related to a wide variety of balance disorders. VRT is effective in improving the functional deficits and subjective symptoms resulting from unilateral and bilateral peripheral vestibular hypofunction as well as from central balance disorders. Goals By improving vestibular function and promoting mechanisms of central adaptation and compensation, VRT aims to do the following:
The process of compensation depends on various mechanisms, including substitution strategies, prediction strategies, and cognitive strategies. When combined, this results in a progressive waning of symptoms of imbalance, disequilibrium, and motion-induced unsteadiness. As compensation occurs for a vestibular deficit, the remaining CNS processes allow sufficient control of eye, head, and body movements to maintain stable gaze, posture, and position. Substitution strategies use several techniques, including alternate sensory inputs, to drive motor output, alternate secondary motor responses instead of primary motor responses, and incorporate strategies of prediction and anticipation of intended motor behavior. The cervical-ocular reflex (COR) may be developed as an alternate source of visual stability during head movements; this is an example of a substitution strategy for deficits in the VOR. VRT also takes advantage of the adaptive characteristics of the CNS to reestablish homeostasis within the vestibular system. This results in increased VOR accuracy, refinement of oculomotor skills, improvement in postural control, and use of appropriate movement strategies. Adaptation serves to extinguish symptoms of dizziness provoked by motion or visual stimulation. Specifically tailored exercises promote adaptation by altering the input-output relationships of the VOR, including gain, timing, and direction. VESTIBULAR REHABILITATION THERAPY PROGRAMSection 4 of 8
Designing an individualized VRT program Several factors must be considered when designing a VRT program for an individual patient. Therapeutic efficacy may be limited by the extent and location of damage to the vestibular system. The status of visual and proprioceptive systems, physical strength, motor skills, and integrity of the cerebellum are critical to the successful application of a VRT program. Other factors that affect the outcome of a VRT program include general physical health, decision-making and cognitive abilities, age, memory, and the presence of psychological and anxiety disorders. VRT is typically designed as a therapist-directed, patient-motivated, home-based exercise protocol. Individuals visit the therapist on a limited basis. The patient engages in custom-designed exercises at home several times a day without therapist supervision. VRT exercises are graduated, beginning at the minimal skill level that the patient is capable of performing; complexity is increased as compensation and habituation occur. Patients have regular follow-up visits with the therapist until compensation and habituation are complete and optimal balance is attained. Components of VRT program An effective VRT program uses a team of healthcare providers to assess and treat patients with balance disorders. This team should include a physician trained in the evaluation and treatment of balance disorders (typically a neuro-otologist, otolaryngologist, or neurologist), a vestibular or physical therapist trained in balance testing and vestibular therapy, and an occupational therapist. The accurate diagnosis and assessment of a patient is critical for a successful individualized VRT program. The diagnosis and assessment include quantifying the degree of damage to peripheral vestibular structures and central vestibular pathways and evaluating the individual level of physiologic and neurologic compensation. Functional abilities such as gait, ambulation with head movement, balance with altered sensory cues, and balance under static (eg, sitting, standing) and dynamic conditions are assessed. Sensory evaluation should include visual and proprioceptive abilities because multisensory deficits can impede functional progress. Patient assessment should also include complete evaluation of the patient's medical history and detailed history of the patient's balance symptoms. The clinician should elicit a clear description of the type of symptoms experienced by the patient (eg, vertigo, imbalance, disequilibrium, presyncopal sensations, gait ataxia) and the frequency and duration of the symptoms. Specific activities and head or body positions that provoke symptoms should be determined. Visual disturbances, such as oscillopsia (blurred vision with head movement), should be documented. Finally, the patient's perception of the impact of the symptoms on daily activities should be evaluated. The Dizziness Handicap Inventory (DHI) is an accepted, standardized questionnaire that addresses the subjective rating of balance dysfunction. The DHI has a high test-retest reliability and internal consistency. The DHI measures total subjective handicap and individual subscales of physical, emotional, and functional health. QUANTITATIVE VESTIBULAR TESTINGSection 5 of 8
Electronystagmography Electronystagmography (ENG) involves a battery of tests that assess central and peripheral vestibular function and organization. Central vestibular function is reflected in oculomotor tests for nystagmus, reflexes (optokinetic nystagmus), and integrated motion (saccade, pursuit). Peripheral eighth cranial nerve and labyrinthine function is evaluated in response to various stimuli (eg, positional/positioning, caloric, rotational chair testing). Nystagmus can be observed, recorded, and quantified. Electro-oculography (EOG) indirectly measures eye movement by detecting changes in the electrical charges produced by the corneal-retinal potential using skin electrodes. Eye movements can also be quantified directly using infrared oculography (IRO). IRO techniques allow direct observation of eye movements and eliminate many artifactual elements present on EOG. Computer dynamic posturography Computerized dynamic posturography (CDP) assesses the 3 major senses involved in balance: vestibular, vision, and proprioception and somatosensation. A force plate measures body sway under different visual and postural conditions. The sensory organization test (SOT) measures postural stability under 6 different sensory conditions. The first 3 conditions are tested with the patient standing on a firm surface with eyes open and closed and with perturbed vision (sway-referenced visual enclosure on a fixed platform) The final 3 conditions test the patient while standing on a perturbed surface with the same 3 visual conditions (eyes open, eyes closed, sway-referenced). The patient's reliance on particular sensory information is determined by comparing sway with normative values for each condition. VRT exercises then can be designed to address the specific areas of deficit. Limits-of-stability (LOS) testing is used to determine how well an individual can move the center of gravity over the base of support while maintaining an upright posture. Information from this test battery is useful for predicting fall risk and for determining specific balance exercises to improve movement skills without the patient experiencing a fall. PATIENT SELECTIONSection 6 of 8
VRT should be considered for patients with stable symptomatic vestibular deficits that have not completely resolved by means of natural compensation. These groups of patients traditionally gain the most from vestibular rehabilitation. Individuals with unstable lesions (eg, demyelinating disease, seizure disorder, migraine), progressive degenerative processes, or fluctuating or episodic symptoms of imbalance are not candidates for VRT. Optimal candidates have stable central or peripheral vestibular deficits; symptoms provide specific activities or stimuli; and intact cognitive, cerebellar, visual, and proprioceptive systems. Patient motivation is a significant factor in successful implementation of a VRT program. Although some reports are conflicting, vestibular exercises are generally effective regardless of the patient's age and duration of symptoms. One should also consider the impairment of the dizziness because all dizziness does not need rehabilitation. The patient must also stop any vestibular suppressants prior to any VRT; this encourages the vestibular system to fully adapt to its new thresholds. Typically, physicians prescribe VRT for patients who have not recovered after 2-3 months. The brain usually takes 3 months to recover from either an organic insult or surgical trauma. In an effort to advocate earlier VRT, Venosa and Bittar recently published a study showing that VRT for acute vertigo lessens the duration of symptoms and the need for vestibular suppressants.2 Thus, VRT should be helpful for acute and chronic vertiginous patients. EXERCISE PROTOCOLSSection 7 of 8
The VOR maintains stable gaze and visual focus during active and passive head motion. VOR exercises are performed to improve the gain and accuracy of the VOR. For head movements in phase with a target (X1 viewing), hold a card with lettering at arm's length with eyes focused on the letters. Move the head from side to side, increasing speed with progressions. Repeat the entire cycle 20-30 times. The head can also be moved vertically and diagonally. Progress from sitting to standing with the feet shoulder width apart to standing with the feet together to standing partially pointed (ie, one foot half way ahead of the other) to standing pointed (ie, one foot completely in front of the other). Progress from standing on a firm surface to standing on a compliant surface. Post the card on the wall with a plain background and progress to posting on a wall with a busy patterned background. For head movement out of phase with target (X2 viewing), hold a card with lettering at arm's length with eyes focused on the letters. Move the head to the right and the card to the left, keeping the eyes focused on the letters. Then move the head to the left and the card to the right, keeping the eyes focused on the letters. Begin slowly and increase speed as the test progresses, but keep the letters in focus. Repeat the entire cycle 20-30 times. This test can also be performed in a vertical direction. Progress from sitting to standing to a sharpened stance as described above. Ocular motor exercises To increase pursuit gain, hold a card with lettering at arm's length. Move the card left and right across the visual field, tracking with eye movement and keeping the head still. Repeat the full cycle 20-30 times. Perform the test in the vertical and diagonal directions as well, increasing speed but being certain to keep the letters in focus. Progress from sitting to standing to a sharpened stance as described above (see VOR stimulation exercises above). To improve saccade latency, velocity, and accuracy, hold a card with lettering in each hand approximately 15 inches apart at arm's length. Keeping the head still, move the eyes back and forth from card to card, 1 second per card. Repeat 20-30 times for the complete cycle. This test also can be performed in the vertical and diagonal planes. Progress from sitting to standing to a sharpened stance as described above (see VOR stimulation exercises above). Balance exercises Stand with the feet together. The patient may maintain balance by reaching out and touching the wall in front of them. Take the hands off the wall for progressively longer periods. Begin by taking 1 hand at a time off the wall, alternating hands. Sharpen the stance. Stand with the feet shoulder-width apart, looking at a target on the wall. Narrow the base of support by sharpening the stance. Perform first with arms outstretched, then close to the body, then folded across the chest. Perform exercises by sitting, then standing with the head bent forward 30°, and, finally, standing with the head bent backward 30°. Reach up as though for an object over the head. Bend over as though picking up an object from the floor. Progress from sitting to standing to a sharpened stance. Perform exercises with the room lights lowered and then with eyes closed. Progress to standing on foam or pillow and then to standing on 1 leg. Another exercise is making a circle with a ball. Focus the eyes on the ball. Move it in a circular fashion in both directions with increasing speed. Move the head and body with the ball. Progress from sitting to standing to a narrowed stance. Gait exercises In walking exercise 1, begin by walking next to a wall, with the hand out for support, and gradually increase the number of steps without support. Narrow the width of the gait, and progress eventually to heel-to-toe walking. In walking exercise 2, walk with the head in motion, left and right, with increasing speed. Narrow the width of the gait. Move the head in the vertical direction (ie, nodding up and down) as well. Practice turning when walking, first with large circles, then with gradually smaller turns, in both directions. In walking exercise 3 (sit to stand), with 2 chairs approximately 10 feet apart, walk from one to the other. Upon reaching the first chair, sit without using the hands, and, after 5 seconds, rise without using the hands. Go to the second chair, touch it, and, with support, practice standing on 1 leg for 5 seconds. Repeat the entire cycle 10 times. Add head movements as the exercise progresses, increase walking speeds, and decrease width of gait. Combined category exercises For an obstacle course, step over objects and around furniture. Perform activities such as bending over, picking up objects, throwing and catching objects, bouncing them off walls, and walking on differing compliance surfaces. To walk at the grocery store, practice with minimal and then no support from the cart. Begin with slow, small head movements, increasing speed and degree. Go when few people are shopping and then when the grocery store is busy. Make an effort to look at items that are on the top and bottom shelves. To walk at the mall, walk slowly, stay near the walls, and go with flow of the crowd. Increase speed, move away from the walls, and go against traffic. Window shop with head movements. Computer-aided rehabilitation Recent advances in the ongoing research of vestibular dysfunction and rehabilitation have incorporated technology in the treatment sessions. One group incorporated virtual reality VRT into the traditional VRT sessions and documented improved posturography, vertigo, and mental health scores. NASA has used this virtual reality technology and taken it one step further.3 They hope to train the vestibular system to decrease motion sickness, increase function in disorienting environments, and speed recovery when returning to gravity and solid ground. The use of this technology is definitely exciting. REFERENCESSection 8 of 8
Vestibular Rehabilitation excerpt Article Last Updated: Dec 19, 2007 |
