Abstract
The author shows examples of lesion site detection in vestibular disorders using vestibular evoked myogenic potentials (VEMP). First, studies in vestibular neuritis are shown. When VEMP testing was performed in patients with vestibular neuritis, half of the patients showed abnormal VEMP results on the affected side, while the remaining half showed normal responses. These results imply that patients with vestibular neuritis can be subdivided into 2 categories based on combined use of caloric testing and VEMP testing; those with superior vestibular neuritis and those with total (superior and inferior) vestibular neuritis. Furthermore, combined use of electrical stimulation and acoustic stimulation allowed us to differentiate between labyrinthine lesions and retro-labyrinthine lesions. Then, the majority of patients with so-called vestibular neuritis had nerve lesions, while some patients could have had only labyrinthine lesions. VEMP testing was also useful for assessment of the recovery of the peripheral vestibular function after vestibular neuritis. Then, studies in central nervous system disorders are shown. Prolongation of the VEMP latencies was often observed in patients with multiple sclerosis and spinocerebellar degeneration, especially Machado-Joseph disease. Finally, future perspectives for ocular VEMP (oVEMP) and VEMP in the extremities are discussed.
