抄録
A total of 23 cochleas in 15 chinchillas were treated with cryosurgery and the damage to the organ of Corti was evaluated with the scanning electron microscope (SEM) and the auditory evoked brain stem response (ABR). The apical half-turn was treated in 11 of the cochleas and the basal half-turn in 10. Apical exposure to the cryoprobe generally resulted in severe damage to sensory cells in the apical turn whereas basal turn exposure generally resulted in mild damage to sensory cells in the basal turn. On occasion, severe damage from apical turn exposure resulted in severe damage that extended to the basal turn. The first row of outer hair cells were the most susceptible to damage, while inner hair cells the least. ABR to click stimuli were recorded before treatment and again before decapitation. Below 50 dB stimulus level, ABR wave IV latency was prolonged after cryosurgery to the basal turn. However, no significant change was observed in wave IV latency after treat ment to the apical turn.
