Shiroma Ayano, Nishimura Masahiko, Nagamine Hideki, Miyagi Tomohisa, Hokama Yohei, Watanabe Takashi, Murayama Sadayuki, Tsutsui Masato, Tominaga Daisuke, Ishiuchi Shogo
Department of Neurosurgery, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara-machi, Nakagami-gun, Okinawa, 903-0215, Japan.
Department of Radiology, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara-machi, Nakagami-gun, Okinawa, 903-0215, Japan.
Cerebellum. 2016 Dec;15(6):645-662. doi: 10.1007/s12311-015-0726-0.
The cerebellum is a crucial structure for cognitive function as well as motor control. Benign brain tumors such as schwannomas, meningiomas, and epidermoids tend to occur in the cerebellopontine angle cisterns and may cause compression of the posterior lateral cerebellum near the superior posterior fissure, where the eloquent area for cognitive function was recently identified. The present study examined cognitive impairment in patients with benign cerebellar tumors before and after surgical intervention in order to clarify the functional implications of this region in humans. Patients with cerebellar tumors showed deficits in psychomotor speed and working memory compared with healthy controls. Moreover, these impairments were more pronounced in patients with right cerebellar tumors. Functional magnetic resonance imaging during performance of a lure task also demonstrated that cerebellar tumors affected pattern separation or the ability to distinguish similar experiences of episodic memory or events with discrete, non-overlapping representations, which is one of the important cognitive functions related to the hippocampus. The present findings indicate that compression of the human posterior lateral cerebellum affects hippocampal memory function.
小脑是认知功能以及运动控制的关键结构。诸如神经鞘瘤、脑膜瘤和表皮样囊肿等良性脑肿瘤往往发生在桥小脑角池，并可能压迫上后裂附近的小脑后外侧，最近在该区域发现了与认知功能相关的明确区域。本研究检查了良性小脑肿瘤患者手术干预前后的认知障碍，以阐明该区域在人类中的功能意义。与健康对照组相比，小脑肿瘤患者在精神运动速度和工作记忆方面存在缺陷。此外，这些损伤在右侧小脑肿瘤患者中更为明显。在执行诱饵任务期间进行的功能磁共振成像还表明，小脑肿瘤影响模式分离，即区分情节记忆或事件的相似经历以及具有离散、不重叠表征的能力，这是与海马体相关的重要认知功能之一。目前的研究结果表明，人类小脑后外侧受到压迫会影响海马体记忆功能。
