Clinical Functional Topography in Cognition

In 1998, Schmahmann and Sherman defined the new clinical entity “cerebellar cognitive affective syndrome” (CCAS), which refers to the behavioral and cognitive symptoms that can be encountered in patients affected by cerebellar pathologies. In the last 15 years, increasing evidence has been obtained on nonmotor cerebellar functions, and in 2011, Tedesco et al. Characterized the cognitive profile of subjects affected by focal cerebellar lesions. Focal cerebellar lesions consist of ischemic or hemorrhagic stroke or surgical ablation due to arteriovenous malformations or tumors, and they involve discrete portions of cerebellar lobules. Thus, subjects with focal damage represent an optimal model to analyze cerebellar functional topography. Furthermore, since the cerebellum is known to modulate supratentorial activity and contribute to distinct functional networks related to higher-level functions, it is conceivable that one or more networks rather than isolated regions may be dysfunctional. This is particularly true when dealing with cerebellar degenerative diseases, in which abnormal connectivity within specific cerebello-cortical regions might explain the widespread deficits typically observed in patients.