ヒトの聴性脳幹反応の頭皮上電位分布および潜時分布に関する研究

抄録

The scalp topography of the auditory brainstem responses (ABRs) to monaural stimulation was studied in 28 normal young adults. The amplitudes and latencies of waves I through V were measured. On the basis of these data, the interpolated values were calculated by a computer and were displayed two dimensionally as a potential map. The results were shown as follows; 1) Wave I: The electrode ipsilateral to stimulation showed a low potential and the contralateral electrode showed a high potential to monaural stimulation. No left and right latency difference was noted. From the above, a dipole proceeding from ipsilateral to contralateral regions was hypothesized. 2) Wave II: High potentials areas appeared at the parietal occipital region on the ipsilateral side, but the latency was prolonged compared to the corresponding region. It is hypothesized that two dipoles exist at these regions. 3) Wave III: This wave was similar to the amplitude potential distribution of wave I with a high potential at the contralateral region. However, the ipsilateral latency was shorter than the contralateral latency. We hypothesize dipoles oriented both verticaly and horizontaly. 4) Wave IV: High potential areas were distributed widely over the vertex region. No difference between the contralateral and ipsilateral sides, and anterior and posterior regions were noted. However, the latency decreased at the ipsilatetral region and prolonged at the contralateral region. We hypothesize that two different dipoles of similar size proceeding in the vertical direction may exist. 5) Wave V: High potential regions were widely distributed at the contralateral region. The latency decreased at the contralateral region and prolonged markedly at the temporal regions with a difference of approx. 0.3msec. From the above, a large dipole proceeding in the vertical direction at the contralateral region and a small dipole are hypothesized. The statistics gathered from the normal subjects in this study will allow more accurate diagnosis of pathological conditions.