The CODECS study: COgnitive DEficits in Cerebellar Stroke.

Part of the extra-pyramidal system, the cerebellum is more and more recognized by its non-motor functions known as the cerebellar cognitive affective syndrome. Several studies have identified disturbances specifically in executive and attentional functions after focal cerebellar lesions. However, most studies were performed in small and heterogeneous patient groups. Furthermore, there is a substantial variation in the methodology of assessment. Here, we present the results of a large and homogeneous cohort of patients with isolated uniform cerebellar lesions. After three months post-stroke all patients underwent structural neuroimaging to confirm an isolated lesion and were given neuropsychological testing. The results show that cerebellar lesions relate to mild but long-term cognitive impairment in a broad spectrum of neurocognitive functions compared to normative values. These findings confirm involvement of the cerebellum in cognitive processing and supports the theory of 'dysmetria of thought' based upon uniform cerebellar processing in multiple cognitive domains. This study highlights the following results: 1-Cognitive impairments after isolated cerebellar stroke is confirmed in several cognitive domains. 2-Semantic and phonemic fluency are most affected in cerebellar stroke patients. 3-Verbal deficits show an age-independent long term effect post-stroke and should be studied further in depth. 4-Cognitive disorders after cerebellar stroke are more prominent in women than men.