Wolak Tomasz, Cieśla Katarzyna, Lorens Artur, Kochanek Krzysztof, Lewandowska Monika, Rusiniak Mateusz, Pluta Agnieszka, Wójcik Joanna, Skarżyński Henryk
World Hearing Center, Institute of Physiology and Pathology of Hearing, 10 Mochnackiego Street, 02-042, Warszawa, Poland.
World Hearing Center, Institute of Physiology and Pathology of Hearing, 10 Mochnackiego Street, 02-042, Warszawa, Poland.
Hear Res. 2017 Nov;355:81-96. doi: 10.1016/j.heares.2017.09.012. Epub 2017 Sep 28.
Although the tonotopic organisation of the human primary auditory cortex (PAC) has already been studied, the question how its responses are affected in sensorineural hearing loss remains open. Twenty six patients (aged 38.1 ± 9.1 years; 12 men) with symmetrical sloping sensorineural hearing loss (SNHL) and 32 age- and gender-matched controls (NH) participated in an fMRI study using a sparse protocol. The stimuli were binaural 8s complex tones with central frequencies of 400 Hz, 800 Hz, 1600 Hz, 3200 Hz, or 6400 Hz, presented at 80 dB(C). In NH responses to all frequency ranges were found in bilateral auditory cortices. The outcomes of a winnermap approach, showing a relative arrangement of active frequency-specific areas, was in line with the existing literature and revealed a V-shape high-frequency gradient surrounding areas that responded to low frequencies in the auditory cortex. In SNHL frequency-specific auditory cortex responses were observed only for sounds from 400 Hz to 1600 Hz, due to the severe or profound hearing loss in higher frequency ranges. Using a stringent statistical threshold (p < 0.05; FWE) significant differences between NH and SNHL were only revealed for mid and high-frequency sounds. At a more lenient statistical threshold (p < 0.001, FDRc), however, the size of activation induced by 400 Hz in PAC was found statistically larger in patients with a prelingual, as compared to a postlingual onset of hearing loss. In addition, this low-frequency range was more extensively represented in the auditory cortex when outcomes obtained in all patients were contrasted with those revealed in normal hearing individuals (although statistically significant only for the secondary auditory cortex). The outcomes of the study suggest preserved patterns of large-scale tonotopic organisation in SNHL which can be further refined following auditory experience, especially when the hearing loss occurs prelingually. SNHL can induce both enlargement and reduction of the extent of responses in the topically organized auditory cortex.
尽管人类初级听觉皮层（PAC）的音频定位组织已被研究，但感音神经性听力损失如何影响其反应的问题仍未解决。26名患有对称性斜坡型感音神经性听力损失（SNHL）的患者（年龄38.1±9.1岁；12名男性）和32名年龄及性别匹配的对照者（NH）参与了一项使用稀疏协议的功能磁共振成像（fMRI）研究。刺激为双耳8秒复合音，中心频率分别为400赫兹、800赫兹、1600赫兹、3200赫兹或6400赫兹，以80分贝（C）呈现。在NH组中，双侧听觉皮层均发现对所有频率范围的反应。一种显示活跃频率特异性区域相对排列的优胜图方法的结果与现有文献一致，并揭示了听觉皮层中对低频有反应的区域周围呈V形的高频梯度。在SNHL组中，由于高频范围存在重度或极重度听力损失，仅观察到对400赫兹至1600赫兹声音的频率特异性听觉皮层反应。使用严格的统计阈值（p<0.05；FWE），NH组和SNHL组之间仅在中高频声音方面显示出显著差异。然而，在更宽松的统计阈值（p<0.001，FDRc）下，发现与语后聋患者相比，语前聋患者的PAC中由400赫兹诱发的激活大小在统计学上更大。此外，当将所有患者获得的结果与正常听力个体的结果进行对比时，该低频范围在听觉皮层中的代表范围更广（尽管仅在次级听觉皮层中具有统计学意义）。该研究结果表明，SNHL中存在大规模音频定位组织的保留模式，这可以在听觉经验后进一步细化，尤其是当听力损失发生在语前时。SNHL可导致在局部组织的听觉皮层中反应范围的扩大和缩小。
