Kimiskidis V K, Lalaki P, Papagiannopoulos S, Tsitouridis I, Tolika Th, Serasli E, Kazis D, Tsara V, Tsalighopoulos M G, Kazis A
C Department of Neurology, Aristotle University of Thessaloniki, G Papanikolaou Hospital, Greece.
Otol Neurotol. 2004 Mar;25(2):178-82. doi: 10.1097/00129492-200403000-00017.
To assess the role of inferior colliculi as a generator of Wave V of brainstem auditory evoked potentials and in modulating the olivocochlear efferent auditory system.
Case review.
University and tertiary referral centers.
Case report of a patient with word deafness caused by mesencephalic hemorrhage according to audiologic and electrophysiologic findings.
The patient is a 48-year-old woman who suffered word deafness caused by hemorrhage localized at the quadrigeminal plate (including the inferior colliculi). At a follow-up visit, her pure-tone audiogram revealed symmetric severe sensorineural hearing loss that had partially resolved, whereas speech audiometry showed persistent word deafness. Acoustic reflexes were elicited, with normal thresholds bilaterally. Transient evoked otoacoustic emissions were recorded from both ears, with normal response and signal-to-noise ratio, but there was a failure for their amplitude to be suppressed with contralateral sound stimulation. Brainstem auditory evoked potentials were of normal amplitude and latencies bilaterally.
The finding of normal brainstem auditory evoked potentials supports the view that the neural generator of Wave V lies caudally to the inferior colliculi. Moreover, the abnormal suppression of transient evoked otoacoustic emissions indicates that descending collicular input is capable of modulating levels of excitability within the olivary nucleus and the cochlea.
评估下丘作为脑干听觉诱发电位V波的产生源以及在调节橄榄耳蜗传出听觉系统中的作用。
病例回顾。
大学及三级转诊中心。
根据听力学和电生理学检查结果，报告一例因中脑出血导致词聋的患者。
该患者为一名48岁女性，因出血位于四叠体板（包括下丘）而导致词聋。随访时，其纯音听力图显示对称的重度感音神经性听力损失已部分恢复，而言语测听显示持续性词聋。双侧引出声反射，阈值正常。双耳记录到瞬态诱发耳声发射，反应和信噪比正常，但对侧声音刺激时其幅度未能被抑制。双侧脑干听觉诱发电位的幅度和潜伏期均正常。
脑干听觉诱发电位正常的结果支持V波的神经发生器位于下丘尾侧的观点。此外，瞬态诱发耳声发射的异常抑制表明下丘的下行输入能够调节橄榄核和耳蜗内的兴奋性水平。
