Brief Insight About Audiovestibular Findings In Multiple Sclerosis

Abstract

Multiple sclerosis (MS) is a highly variable disease in its course, site of the lesion and   even at the rate of progression. A full picture of the hearing affection cannot be predicted. Most of MS cases start as relapsing-remitting multiple sclerosis (RRMS) then with time it turns into secondary progressive multiple sclerosis (SPMS).Pure tone thresholds may not challenge the auditory system strong enough to detect underlying dysfunction, such as that detected by stimuli varying in the temporal domain.The most common studies of auditory evoked potential (AEP) in MS are the brainstem auditory evoked potential (BAEP), the auditory middle latency response (MLR) and the event related potentials.The most common deficits that were observed in BAEP of MS patients are increased latencies of waves III and V, increased I-III, III-V and I-V interpeaks, the absence of one or more components, and poor reproducibility and morphology of the later components suggesting dyssynchrony.The MLR is considered one of the best tests to evaluate the central auditory nervous system, and it is also a useful tool in the design and monitoring of the therapeutic process. Central auditory processing abnormalities are present in 90% of MS patients. Difficulty in speech perception in background noise   was reported by many researchers. Gab in noise (GIN) test is a simple, sensitive test for temporal resolution ability which also affected in MS patients. Patients with MS may develop dizziness or vertigo as the initial disease manifestation or during the course of illness. Many patients experience chronic, intermittent dizziness and ~5 % label dizziness or vertigo as their worst symptom of the disease. The vestibular system function could be evaluated via videonystagmography (VNG), which evaluates peripheral and central vestibular functions.