Objectives: Abnormal cortical responses in patients with functional hearing loss were evaluated by magnetoencephalography, which can better separate bihemispherical activity than electroencephalography. Methods: Auditory evoked fields in response to 1 kHz or 2 kHz tone bursts at 80 dB sound pressure level were measured by a helmet-shaped magnetoencephalography system in 22 patients with functional hearing loss (18 females, mean age 13.2 years) as well as 5 control subjects under 10 years old. Waveform, latency, and equivalent current dipole of N100m responses were used to evaluate activity in the bilateral auditory cortices. Results: Abnormal N100m of the contralateral response to the stimulated ear, either absence or delayed latency in comparison to normal adult subjects, was found in 6 of the 7 patients with functional hearing loss aged 9 years or younger, but in only 3 of the 15 patients aged 10 years or older. However, such abnormalities were also observed in younger control subjects. Conclusion: Auditory evoked field may be applied to objectively evaluate cortical auditory function in patients with functional hearing loss, but the normal findings for young children have not yet been established.
|ジャーナル||International Journal of Pediatric Otorhinolaryngology|
|出版ステータス||Published - 2009 10|
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