Department of Neurology, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany.
Neuropsychologia. 2012 Apr;50(5):926-38. doi: 10.1016/j.neuropsychologia.2012.01.032. Epub 2012 Feb 4.
In contrast to lesions of the visual and somatosensory cortex, lesions of the auditory cortex are not associated with self-evident contralesional deficits. Only when two or more stimuli are presented simultaneously to the left and right, contralesional extinction has been observed after unilateral lesions of the auditory cortex. Because auditory extinction is also considered a sign of neglect, clinical separation of auditory neglect from deficits caused by lesions of the auditory cortex is challenging. Here, we directly compared a number of tests previously used for either auditory-cortex lesions or neglect in 29 controls and 27 patients suffering from unilateral auditory-cortex lesions, neglect, or both. The results showed that a dichotic-speech test revealed similar amounts of extinction for both auditory cortex lesions and neglect. Similar results were obtained for words lateralized by inter-aural time differences. Consistent extinction after auditory cortex lesions was also observed in a dichotic detection task. Neglect patients showed more general problems with target detection but no consistent extinction in the dichotic detection task. In contrast, auditory lateralization perception was biased toward the right in neglect but showed considerably less disruption by auditory cortex lesions. Lateralization of auditory-evoked magnetic fields in auditory cortex was highly correlated with extinction in the dichotic target-detection task. Moreover, activity in the right primary auditory cortex was somewhat reduced in neglect patients. The results confirm that auditory extinction is observed with lesions of the auditory cortex and auditory neglect. A distinction can nevertheless be made with dichotic target-detection tasks, auditory-lateralization perception, and magnetoencephalography.
与视觉和躯体感觉皮层的病变不同，听觉皮层的病变与明显的对侧缺损无关。只有当两个或更多的刺激同时呈现给左、右耳时，单侧听觉皮层损伤后才会观察到对侧失认。由于听觉失认也被认为是忽视的标志，因此临床区分听觉忽视与听觉皮层损伤引起的缺陷具有挑战性。在这里，我们直接比较了以前用于单侧听觉皮层病变或忽视的多项测试，这些测试在 29 名对照者和 27 名单侧听觉皮层病变、忽视或两者均有的患者中进行了比较。结果表明，双声道语音测试揭示了听觉皮层病变和忽视都具有相似程度的失认。双耳间时间差定位的单词也得到了类似的结果。在双声道检测任务中，听觉皮层病变后也观察到了一致的失认。忽视患者在双声道检测任务中表现出更普遍的目标检测问题，但没有一致的失认。相比之下，在忽视中，听觉侧化感知偏向右侧，但听觉皮层病变的干扰要小得多。听觉皮层诱发磁场的侧化与双声道目标检测任务中的失认高度相关。此外，忽视患者的右初级听觉皮层的活动略有减少。结果证实，听觉失认在听觉皮层病变和听觉忽视中都有观察到。然而，通过双声道目标检测任务、听觉侧化感知和脑磁图可以进行区分。
