[N100m findings of auditory-evoked fields in patients with psychogenic hearing impairment]

We recorded the auditory-evoked fields in five patients with psychogenic hearing impairment and ten healthy controls. The maximum N100m peak amplitude and latency were measured under 1000 and 2000-Hz tone burst stimuli in each ear. The mean N100m amplitude in the patients was smaller than that in the controls. Especially, regardless of the side of stimulation, the mean amplitude in the left-hemisphere was significantly smaller in the patients than in the controls, except for the 2000-Hz stimulus condition in the left ear. There was no significant difference in the latency of the N100m peak between patients and controls. We attribute the findings of attenuation of the N100m amplitude to the peculiar auditory perception in patients with psychogenic hearing impairment. Concerning the cause of this finding, we suggest two possible mechanisms: inhibitory auditory processing and attention deficit.