Vestibular syncope.

ABSTRACT

PURPOSE OF REVIEW This review considers recent observations on vestibular syncope in terms of clinical features, laboratory findings, and potential mechanisms. RECENT FINDINGS: Vestibular syncope, potentially associated with severe fall-related injuries, may develop multiple times in about one-third of patients. Meniere's disease and benign paroxysmal positional vertigo are the most common causes of vestibular syncope, but the underlying disorders remain elusive in 62% of cases with vestibular syncope. The postictal orthostatic blood pressure test exhibits a lower diagnostic yield. Vestibular function tests, such as cervical vestibular-evoked myogenic potentials and video head impulse tests, can reveal one or more abnormal findings, suggesting compensated or ongoing minor vestibular dysfunctions. The pathomechanism of syncope is assumed to be the erroneous interaction between the vestibulo-sympathetic reflex and the baroreflex that have different operating mechanisms and action latencies. The central vestibular system, which estimates gravity orientation and inertia motion may also play an important role in abnormal vestibulo-sympathetic reflex. SUMMARY: Vestibular disorders elicit erroneous cardiovascular responses by providing false vestibular information. The results include vertigo-induced hypertension or hypotension, which can ultimately lead to syncope in susceptible patients.