Brainstem Auditory Responses in Type-2 Diabetes Mellitus

Abstract

Background: Diabetes mellitus causes pathophysiological changes at multiple organs. Brainstem Evoked Response Auditory (BERA) represents a non-invasive tool to detect diabetes related sensorineural hearing loss. The aim was to assess diabetes related central auditory pathway involvement using BERA. Methods: The study comprises two groups, (i) Diabetic group (n=15), (ii) Control group (n=15). The controls were matched for age and sex with the study group. BERA was done for all these patients after detailed clinical examination and relevant blood investigations. Results: There was significant latency differences found in wave III, V and interpeak latencies I-III, III-V and I-V between control and study groups at 70 dBnHL and 80 dBnHL. At 90 dBnHL the diabetic group demonstrated significant latency differences in waves I, III and V and interpeak I-III, III-V and I-V compared to controls. The duration of DM was 5-10 years in 8 patients (53.3%) out of which 7 subjects (87.5%) had prolonged BERA. 7 patients (46.6%) were diabetic for more than 10 years of which all patients (100%) had prolonged latencies. Conclusions: The wave I latency was found non significant which suggests that the pathway from 8th nerve to cochlear nucleus is not affected in diabetic patients. The delay in latencies III and V and interpeak latencies I-III, III-V and I-V in diabetic patients compared to the controls suggests brainstem and midbrain involvement. So the study suggests that BERA helps in early detection of central neuronal axis involvement in type-2 diabetes mellitus.