Yoshizaki Naoto, Kawase Tetsuaki, Nakasato Nobukazu, Kanno Akitake, Okitsu Takuji, Sunose Hiroshi, Kobayashi Toshimitsu
Department of Otolaryngology, Head and Neck Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan.
Int J Pediatr Otorhinolaryngol. 2009 Oct;73(10):1368-72. doi: 10.1016/j.ijporl.2009.06.015. Epub 2009 Jul 23.
Abnormal cortical responses in patients with functional hearing loss were evaluated by magnetoencephalography, which can better separate bihemispherical activity than electroencephalography.
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.
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.
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.
通过脑磁图评估功能性听力损失患者的皮质反应异常，脑磁图比脑电图能更好地分离双侧半球活动。
采用头盔形脑磁图系统，测量22例功能性听力损失患者（18例女性，平均年龄13.2岁）以及5名10岁以下对照受试者在80分贝声压级下对1千赫或2千赫短纯音的听觉诱发场。使用N100m反应的波形、潜伏期和等效电流偶极来评估双侧听觉皮质的活动。
在7例9岁及以下的功能性听力损失患者中，有6例对受刺激耳的对侧反应存在异常N100m，即与正常成人相比潜伏期缺失或延迟，但在15例10岁及以上患者中只有3例出现这种情况。然而，在较年轻的对照受试者中也观察到了此类异常。
听觉诱发场可用于客观评估功能性听力损失患者的皮质听觉功能，但尚未确定幼儿的正常表现。
