Vestibular evoked myogenic potentials and videonystagmography findings in type 2 diabetes mellitus patients with and without polyneuropathy

Abstract

Background Vestibular impairment is a common pathology in patients with type 2 diabetes mellitus (DM) due to ischemia of the vestibular end organs and lysis of the myelin of the vestibular nerve. We aimed to evaluate function of the vestibular end organs and vestibular nerve in patients with type 2 DM with polyneuropathy and compare results to those of the patients without polyneuropathy. Method The participants consisted of three groups: thirty patients with type 2 diabetes mellitus without polyneuropathy (DM), thirty patients with type 2 diabetes mellitus with polyneuropathy (DPN), and thirty healthy non-diabetic individuals as the control group. Clinical examination, videonystagmography, cervical vestibular evoked myogenic potential(cVEMP), ocular vestibular evoked myogenic potential (oVEMP), Gans Sensory Organization Performance (SOP) test, and nerve conduction study were all performed on all groups. Results P1 and N1 cVEMP latencies and n1 and p1 oVEMP latencies were statistically significantly delayed in both the DM and DPN groups than the control. Also, amplitudes of P1-N1 and n1-p1 were statistically significantly lower in the DM and DPN groups than the control group. DPN patients had longer latencies and lower amplitude of the cVEMP and oVEMP response compared to diabetes patients without neuropathy. There was a statistically significant prevalence of BPPV in the DPN group compared to the control and DM groups. DPN included the following: 4 (13.3%) had vestibular pattern, 12 had polyneuropathic pattern, and 5 (16.7%) had vestibular and polyneuropathic pattern as regards the Gans Sensory Organization Performance (SOP) test. Conclusion VEMP is considered a promising objective tool in the assessment of the vestibular end organ disorders in patients with type 2 DM with and without polyneuropathy. Diabetics with prominent diabetic polyneuropathy showed higher vestibular impairment than diabetics without DPN, which may increase the risk of falling.