Clinical investigation on hypotensive patients with vertigo.

The aim of this study was to investigate the characteristic of hypotensive patients with vertigo. Twenty hypotensive patients with rotatory vertigo, 15 hypotensive subjects without vertigo, and 15 mitral valve prolapse subjects without vertigo underwent a battery of tests including audiometry, electronystagmography (ENG), and vestibular evoked myogenic potential (VEMP) test. The abnormal rates in terms of audiometry, eye tracking, optokinetic nystagmus, visual suppression, and caloric tests were 15, 35, 35, 10, and 42% for the first group; 13, 20, 33, 0, and 0% for the second group; and 7, 13, 60, 0, and 3% for the third group, respectively. Comparison of the first group with the other two control groups revealed that significant difference existed only in the abnormality of caloric responses. Fifteen (75%) of 20 hypotensive patients with vertigo having abnormal ENG results, asymmetric caloric responses, or delayed VEMPs were attributed to vertigo of central origin, possibly from ischemic disorder. In contrast, five patients (25%) had neither central signs in ENG nor abnormal VEMPs, but showing bilateral normal or hyperactive caloric responses were classified as autonomic dysfunction. After 3 months of medication, all patients with autonomic dysfunction had their vertigo and autonomic symptoms subsided, whereas 27% of the patients with ischemic disorder had vertigo persisted, showing a significant difference. In conclusion, hypotensive patients with vertigo could be due to either direct autonomic dysfunction or ischemic disorder mediated by autonomic deficits.