Vestibular Evoked Myogenic Potential Abnormalities in Early and Late Stage Parkinson Patients

Abstract

ABSTRACT
 Aim: Loss of balance can be seen in idiopathic Parkinson's disease (IPD) There are only a few studies in the literature in which brainstem involvement in IPD has been researched with neurophysiological tests such as vestibular evoked myogenic potential (VEMP). In this study, it was investigated whether there is a difference in the results of VEMP testing in early or late stage of IPD.
 Material and method: The IPD cases were classified as early stage and late stage according to the Hoehn-Yahr scale. The presence of a positive wave with a latency of P13 and a negative wave with a latency of N23 was investigated as the first reflex response The latencies of these potentials and the absolute amplitude of the P13-N23 component were measured. The VEMP results of the patients with early and late stage IPD were compared with those of the control group.
 Results: The right P13 latency mean value in the late stage patient group was significantly prolonged than in the early stage patient group and the control group. The right P13-N23 amplitude mean value of the late and early stage patient groups was significantly smaller than that of the control group (p < 0.002 and p < 0.001, respectively). Among the patients with IPD, the P13 latency was statistically increased in those with a fall history than in those without a fall history.
 In conclusion, this study indicates that the VEMP pathway is affected over time especially in patients with late stage Parkinson’s disease.