Abstract
Background: Overweight and obesity are known to be associated with major health risks. Their detrimental effects on central nervous system (CNS) have begun to be appreciated too. The data for cranial nerve involvement and CNS conduction delays, however, are still sparse.

Aims and Objectives: The study intended to assess the extent of influence by recording pattern reversal visual evoked potential (PRVEP) and brainstem auditory evoked potential (BAEP) in overweight and obese individuals. Materials and Methods: PRVEP and BAEP were recorded in 85 individuals (30 obese, 30 overweight, and 25 controls) in the age group of 18-70 years. Indian-specific body mass index (BMI) cutoff points (controls: BMI <23, overweight: BMI 23-25, and obese: BMI >25) were used for classifying the individuals. PRVEP P100 latency and N75-P100 amplitude and BAEP absolute and interpeak latencies were compared among the three groups using one-way ANOVA and Tukey’s multiple comparison tests. P < 0.05 was considered statistically significant.

Results: Statistically significant prolongation of PRVEP P100 latency (P < 0.01), BAEP absolute latency of wave III and V (P < 0.0001), and interpeak latencies I-III and I-V (P < 0.001) was obtained in obese and overweight individuals as compared to the controls with no significant alteration in N75-P100 amplitude among the three groups (P > 0.05).

Conclusion: Overweight and obesity document derangements in visual evoked potentials and BAEPs, indicating CNS conduction delays with brainstem as well as cerebral cortical involvement. The influence of raised BMI (BMI >23) can affect the clinical interpretation of these tests.

Key words: Obese; Overweight; Brainstem Auditory Evoked Potentials; Visual Evoked Potentials