Cochlear implant efficiency in pre- and postlingually deaf subjects - A study with (H2O)-O-15 and PET
Cochlear implant efficiency in pre- and postlingually deaf subjects - A study with (H2O)-O-15 and PET
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DOI：
10.1093/brain/119.4.1297
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发表时间：
1996-08-01
期刊：
影响因子：
14.5
通讯作者：
Konishi, J
中科院分区：
文献类型：
--
作者：
Okazawa, H;Naito, Y;Konishi, J
我们在一项PET研究中使用了O-15标记的水来测试人工耳蜗(CI)将听觉信息传输到大脑的效率，研究对象为10名深度失聪的受试者。5个是语后聋，5个是语前聋，所有受试者都是右利手白噪声，通过顺式刺激传递的语言刺激用于皮质激活。同样的任务由6名右撇子听力受试者完成，作为对照组。在语言后聋受试者中，言语刺激主要激活CI对侧的横额回(初级听觉皮质)。左侧颞叶后上回(Wemicke区)和左侧额下回(Broca区)也被激活，而与刺激侧无关。活化灶的位置与对照组相同。白噪声刺激仅导致语后聋患者初级听皮层局部脑血流量(RCBF)增加，且仅在CI对侧，且激活强度小于言语刺激。在语言前期失聪的受试者中，韦尼克区和布罗卡区被言语刺激显著激活，而初级听觉皮层则没有激活。白噪声不能激活语前受试者的初级听觉皮质。这些发现表明，语言的大脑皮层表征不依赖于早期的听觉经验，而初级听觉皮质的加工则依赖于经验。语后聋组在Broca‘s区和Wernike区的rCBF较语前聋组增加更多，句子理解能力也更好，提示rCBF增加与口语识别能力之间存在平行关系。听觉刺激(H2O)-O-15-PET是客观量化聋人顺应性脑损伤后听觉皮质和联想皮质反应的有效手段。
We used O-15-labelled water in a PET study to test the efficiency of cochlear implants (CIs) in transmitting auditory information to the brain in 10 profoundly deaf subjects. Five were postlingually deaf and five were prelingually deaf All the subjects were right-handed White noise and verbal stimuli, delivered through the CIs, were used for cortical activation. Similar tasks were performed by six right-handed hearing subjects as a control group. In the postlingually deaf subjects, verbal stimulation activated the transverse temporal gyri (primary auditory cortices) mainly on the side contralateral to the CI. The left posterior superior temporal gyrus (Wemicke's area), and the left inferior frontal gyrus (Broca's area) were also activated irrespective of stimulated side. The location of these activated foci was the same as that of the control group. White noise stimulation led to an increase of regional cerebral bloodflow (rCBF) only in the primary auditory cortices of the postlingually deaf subjects, only on the side contralateral to the CI, and the intensity of activation was less than that obtained with verbal stimulation. In the prelingually deaf subjects, Wernicke's area and Broca's area were significantly activated by verbal stimulation, whereas there was no activation in the primary auditory cortices. White noise did not activate the primary auditory cortex in the prelingually subjects. These findings: suggest that cortical representation of language is not dependent on early auditory experience, while processing in the primary auditory cortices is experience-dependent. The postlingually deaf subjects had a greater increase of rCBF in the Broca's and Wernicke's areas and better sentence comprehension than the prelingually deaf subjects, which suggests a parallel relation between rCBF increase and the ability to recognize spoken language. (H2O)-O-15-PET with auditory stimulation is apt effective means of objectively quantifying the response of auditory and association cortices after CIs in deaf subjects.