The Importance of Peripheral Vestibular Assessment in Diagnosing Imbalance in People with Multiple Sclerosis

Balance problems and falls are common in people with multiple sclerosis (MS) but their cause and nature are not well understood. It is known that MS affects many areas of the central nervous system that can impact postural responses to maintain balance, including the cerebellum and the spinal cord. Studies from several countries have shown that 50% to 70% of people with MS report falls in the preceding 6 months. Traditional ways of treating imbalance in MS (which is typically due to cerebellar and central vestibular dysfunction) is by using static and dynamic balance exercises and strengthening exercises. Subclinical, nonspecific or unreported peripheral vestibular involvement contributing to imbalance is often missed in MS clinics. Retrospective case note review of all MS patients at the Cleveland Clinic Abu Dhabi (CCAD) who had imbalance without features of peripheral vertigo and for whom vestibular function tests were done. The tests were Vestibular Evoked Myogenic Potential Ocular (oVEMP), Vestibular Evoked Myogenic Potential Cervical (cVEMP), computerized posturography, and the Video Head Impulse Test (VHIT). The oVEMP tests the utricle and superior nerve response from the extraocular muscle when stimulated. The cVEMP tests the saccule and inferior nerve response from the sternocleidomastoid muscle. The computerized posturography test detects postural sway by measuring shifts in the center of gravity (COG) as a person moves within their limits of stability. Finally, the VHIT is an instrumented technique that is used to help diagnose reduction in vestibular function in one ear versus the other by moving head rapidly in both directions. Overall, 8 patients were identified. None had been referred to ear, nose, and throat physician for vertigo.Out of these 8 patients, 2 showed peripheral vestibular weakness and 6 did not show any abnormality in peripheral vestibular system. Twentt-five percent of MS patients complaining of imbalance without features of peripheral vertigo had peripheral vestibular dysfunction which is possibly contributing to their imbalance. It is important to do peripheral vestibular assessment in MS patients complaining of imbalance. This may open up further treatment opportunities such as vestibular rehabilitation.