Bugalho Paulo, Correa Bernardo, Viana-Baptista Miguel
Serviço de Neurologia, H. Egas Moniz, Departamento de Psiquiatria e Saúde Mental, Faculdade de Ciências Médicas, Lisboa, Portugal.
Acta Med Port. 2006 May-Jun;19(3):257-67. Epub 2006 Sep 7.
Although classically considered to be involved only in motor coordination, the cerebellum has more recently been implicated also in cognitive control. Anatomical studies have shown the cerebellum to be linked to pre-frontal, occipito-parietal and temporal cortical associative areas, as well as to the limbic system, in a closed loop circuit. Functional studies revealed activation of the cerebellum during performance on cognitive tasks not related to movement. Pathological, morphological and functional imaging studies have shown the cerebellum to be one of the cerebral structures affected in some of the cognitive and behavioural developmental disorders, like Attention Deficit with Hyperactivity Disorder, Autism and Schizophrenia. Neuropsychological studies in patients with degenerative cerebellar ataxia also showed cognitive dysfunction, mainly of the executive type. Investigation performed with child and adult patients with focal lesions of the cerebellum has helped to better discriminate the cognitive role of specific areas on the cerebellum, revealing a characteristic constellation of cognitive deficits, affecting executive, visual-spatial, linguistic and behavioural functions. However, much remains to be explained on the precise nature of cerebellar contributions to cognition, in part because of the difficulty in finding adequate investigation models. Studies performed on primates have contributed to better delineate the connections between the cerebellum and cortical cognitive domains, but is always uncertain to transfer this kind of data to the human brain. Functional imaging studies although useful to investigate directly in the human model and in real time, are not yet able to completely isolate cerebellar cognitive and behavioural functions. Degenerative and developmental disorders are not the most adequate model for studying cerebellar influence on higher mental functions, as they affect other regions besides the cerebellum. Young patients with isolated cerebellar stroke provide a useful clinical model for investigating cerebellar cognitive functions, because they permit to isolate in space and time the specific contribution of the cerebellum to the cognitive deficits.
虽然传统上认为小脑仅参与运动协调，但最近它也被认为与认知控制有关。解剖学研究表明，小脑通过闭环回路与前额叶、枕顶叶和颞叶皮质联合区以及边缘系统相连。功能研究显示，在执行与运动无关的认知任务时，小脑会被激活。病理、形态和功能成像研究表明，小脑是一些认知和行为发育障碍（如注意力缺陷多动障碍、自闭症和精神分裂症）中受影响的脑结构之一。对退行性小脑共济失调患者的神经心理学研究也显示出认知功能障碍，主要是执行功能类型的障碍。对患有小脑局灶性病变的儿童和成人患者进行的调查有助于更好地区分小脑特定区域的认知作用，揭示出一系列特征性的认知缺陷，影响执行、视觉空间、语言和行为功能。然而，关于小脑对认知的贡献的确切性质仍有许多需要解释的地方，部分原因是难以找到合适的研究模型。对灵长类动物进行的研究有助于更好地描绘小脑与皮质认知领域之间的联系，但将这类数据应用于人类大脑始终存在不确定性。功能成像研究虽然有助于直接在人体模型中进行实时研究，但尚未能够完全分离出小脑的认知和行为功能。退行性和发育性障碍并非研究小脑对高级心理功能影响的最合适模型，因为它们除了影响小脑外还会影响其他区域。患有孤立性小脑卒中的年轻患者为研究小脑认知功能提供了一个有用的临床模型，因为他们能够在空间和时间上分离出小脑对认知缺陷的具体贡献。
