The complete elimination of the episodes of benign positional paroxysmal vertigo in a patient with the involvement of the posterior semicircular canal following the eccentric rotation test

Abstract

The objective of the present study was the clinical and neurophysiological analysis of the observations of a 42 year-old female patient suffering from benign paroxysmalpositional dizziness (BPPD) associated with the lesion of the posterior semicircular canal. The dynamic evaluation of the utricular function was performed during eccentric rotation of the patient in the vestibulometric chair at a speed of 300 degrees. The chair together with the patients was atomatically displaced during the rotation 3.5--4.0 cm to the right or left off the vertical axis, and the error in subjective perception of the deviation from the vertical was estimated. The saccular function was evaluated by recording cervical vestibular evoked myogenic potentials. The symptoms of BPPD were found to completely disappear after the eccentric rotation. Not a single spell of benign paroxysmalpositional dizziness was documented within 6 months after the eccentric rotation. The mechanisms underlying the elimination of these symptoms as a result of eccentric rotation are discussed.