Tanaka Y, Kamo T, Yoshida M, Yamadori A
Department of Neurology, Jichi Medical School Hospital, Tochigi, Japan.
Brain. 1991 Dec;114 ( Pt 6):2385-401. doi: 10.1093/brain/114.6.2385.
Two patients with severe, persistent hearing loss caused by bilateral cerebral lesions are described. To determine the location of lesions responsible for the severe hearing loss, we examined magnetic resonance images and compared the lesions in these 2 patients with those in another with only mild hearing loss following extensive bilateral temporoparietal lesions. The extent of bilateral damage to the white matter adjacent to the posterior half of the putamen proved crucial in determining the severity of the hearing loss. Hearing loss was more severe when the white matter immediately ventral and lateral to the posterior half of the putamen was involved bilaterally. Based on this observation and from a review of the literature, we infer that the auditory radiations in humans course in a dense tract from the medial geniculate body up to the sublenticular region, and disperse from there to the primary auditory cortex as well as to the other auditory-related areas, partly by coursing through the white matter immediately ventral to the posterior half of the putamen, and partly by penetrating the ventral and lateral portions of the posterior half of the putamen. Accordingly, bilateral lesions in the white matter ventral and lateral to the posterior half of the putamen appear to interrupt all the projection fibres from the medial geniculate bodies to the auditory-related areas, resulting in severe, persistent hearing loss.
本文描述了两名因双侧脑损伤导致严重、持续性听力丧失的患者。为了确定导致严重听力丧失的病变位置，我们检查了磁共振成像，并将这两名患者的病变与另一名在广泛双侧颞顶叶病变后仅有轻度听力丧失的患者的病变进行了比较。结果证明，壳核后半部相邻白质的双侧损伤程度对于确定听力丧失的严重程度至关重要。当双侧累及壳核后半部下腹侧和外侧紧邻的白质时，听力丧失更为严重。基于这一观察结果并结合文献回顾，我们推断，人类的听觉辐射以密集束状从内侧膝状体延伸至豆状核下区，并从那里分散至初级听觉皮层以及其他听觉相关区域，部分通过壳核后半部下腹侧紧邻的白质传导，部分通过穿透壳核后半部的腹侧和外侧部分传导。因此，壳核后半部下腹侧和外侧白质的双侧病变似乎中断了从内侧膝状体到听觉相关区域的所有投射纤维，导致严重、持续性听力丧失。
