Altered coriolis stress susceptibility in essential hypertension.

Patients with hypertension frequently have vague complaints of dizziness and many other symptoms experienced by healthy individuals with motion sickness. We examined vestibular function in patients with essential hypertension, and we determined whether patients with essential hypertension are more prone to motion sickness using Coriolis stress testing. Vestibular function and Coriolis stress susceptibility were measured in 12 normotensive (NT) and seven asymptomatic patients with mild essential hypertension (HT). The Coriolis stress susceptibility index (CSSI) was calculated from the number of head movements in the four cardinal directions an individual could complete while being rotated in a computerized chair at increasing velocity before they developed motion sickness. The patients with hypertension had normal vestibular function and normal vestibuloocular responses as measured by standard techniques. Subjects with hypertension had significantly decreased Coriolis stress susceptibility scores compared to normotensive subjects (NT, 29.70 +/- 4.8; v HT, 5.48 +/- 2.0, P less than .001) and significantly decreased suppression of postrotatory nystagmus (NT, 44.5% +/- 3.8; v HT, 19.1% +/- 6.9, P less than .05). Medical treatment of hypertension did not result in an increased tolerance to provocative stimuli for motion sickness. It is suggested from our data that an increased susceptibility to motion sickness and abnormal vestibular responses to normal motion may account for many of the vague symptoms of "dizziness" reported by a large number of hypertensive patients.