Evaluation of the Peripheral Vestibular System due to Inner Ear Barotrauma in the Hyperbaric Environment

The aim of this study was to investigate changes that may occur in the peripheral vestibular system due to inner ear barotrauma in self-contained underwater breathing apparatus (SCUBA) divers exposed to hyperbaric environments.

This prospective study was conducted on 45 healthy volunteers. In this study, after otologic and audiological examinations were performed on two groups as control (n = 24) and SCUBA (n = 21), cervical vestibular evoked myogenic potentials (c-VEMP) were evaluated for peripheral vestibular system functions. The SCUBA group comprised individuals who had completed a minimum of 75 dives and held a World Confederation of Underwater Activities 2 certificate. Statistical analysis was performed on immittance metric measurements, pure-tone hearing thresholds (0.5-18 kHz), and P1-N1 latencies and amplitudes from c-VEMP tests.

The SCUBA group demonstrated statistically significant differences in pure-tone low and high frequency thresholds within the normal hearing range compared to the control group (p = 0.001). The c-VEMP responses showed statistically significant prolongation of P1-N1 latencies in right ears and N1 latencies in left ears in the SCUBA group (p < 0.05), along with a statistically significant increase in amplitudes (p = 0.0001).

Based on our findings, the increased amplitudes in c-VEMP responses observed in SCUBA divers exposed to hyperbaric environments suggest enhanced saccular plasticity, likely resulting from barotrauma effects on otolith structures.

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