Bolay H, Bayazit Y A, Gündüz B, Ugur A K, Akçali D, Altunyay S, Ilica S, Babacan A
Department of Neurology, Faculty of Medicine, Gazi University, Besevler, Ankara, Turkey.
Cephalalgia. 2008 Apr;28(4):309-17. doi: 10.1111/j.1468-2982.2008.01534.x. Epub 2008 Feb 13.
Otoacoustic emission (OAE) testing enables us to identify the cochlear component of a hearing disorder and to monitor objectively minute changes in cochlear status undetectable by other audiological methods. Contralateral sound-induced suppression is mediated by medial superior olivary complex efferents which induce hyperpolarization counteracting the amplifying effects of outer hair cell (OHC) activity. The aim of this study was to assess functions of cochlea and its efferents in migraine using OAE testing and contralateral suppression of transiently evoked OAEs (TEOAE). Fifty-three migraineurs (106 ears) and 41 healthy subjects (82 ears) were included and pure tone audiometry (PTA), speech discrimination scores (SDS), distortion product OAE (DPOAE), TEOAE and contralateral suppression of TEOAEs were tested. PTA and SDS of migraineurs and controls were not different (P > 0.05). DPOAEs were tested between 1 and 6 kHz and a significant difference was detected only at 5 kHz frequency, where DPOAE amplitudes in migraine with aura (MA) were lower than in controls (P < 0.03). The mean amplitudes of TEOAEs were statistically insignificant between controls and migraine groups. Contralateral sound stimulus induced significant decrease in amplitudes of TEOAE (P = 0.005) in controls. In patients with migraine without aura and MA, mean amplitudes of TEOAEs were not suppressed by contralateral sound stimulus (P > 0.05). As PTA, SDS and DPOAE tests demonstrate normal functioning of inner ear between 1 and 4 kHz, absence of suppression of the TEOAEs by contralateral sound stimulation indicates the presence of dysfunction either in the medial olivocochlear complex in the brainstem or at the synaptic transmission between olivocochlear efferents and OHCs in the cochlea. Disruption in the contralateral suppression may be one of the mechanisms predisposing to the phonophobia symptom associated with migraine headache.
耳声发射（OAE）测试使我们能够识别听力障碍的耳蜗成分，并客观监测其他听力学方法无法检测到的耳蜗状态的微小变化。对侧声音诱发的抑制由内侧上橄榄复合体传出神经介导，这些传出神经诱导超极化，抵消外毛细胞（OHC）活动的放大作用。本研究的目的是使用OAE测试和对侧瞬态诱发耳声发射（TEOAE）抑制来评估偏头痛患者耳蜗及其传出神经的功能。纳入了53名偏头痛患者（106只耳）和41名健康受试者（82只耳），并进行了纯音听力测定（PTA）、言语辨别得分（SDS）、畸变产物耳声发射（DPOAE）、TEOAE以及TEOAE的对侧抑制测试。偏头痛患者和对照组的PTA和SDS没有差异（P>0.05）。在1至6kHz之间测试了DPOAE，仅在5kHz频率检测到显著差异，其中有先兆偏头痛（MA）患者的DPOAE振幅低于对照组（P<0.03）。对照组和偏头痛组之间TEOAE的平均振幅在统计学上无显著差异。对侧声音刺激在对照组中导致TEOAE振幅显著降低（P = 0.005）。在无先兆偏头痛和MA患者中，对侧声音刺激未抑制TEOAE的平均振幅（P>0.05）。由于PTA、SDS和DPOAE测试表明内耳在1至4kHz之间功能正常，对侧声音刺激未能抑制TEOAE表明脑干内侧橄榄耳蜗复合体或耳蜗中橄榄耳蜗传出神经与OHC之间的突触传递存在功能障碍。对侧抑制的中断可能是偏头痛头痛相关的恐音症状的易感机制之一。
