Cerebellum and neuropsychiatric disorders: insights from ARSACS.

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a rare neurodegenerative disorder characterized by ataxia, spastic paraparesis, polyneuropathy, and evidence of superior cerebellar vermis atrophy at magnetic resonance imaging (MRI). Reports of atypical presentations and additional clinical or MRI findings have been recently published, but psychiatric disturbances have never been associated with ARSACS. We describe four ARSACS patients manifesting severe psychiatric symptoms including psychosis, panic disorder, and depression during the course of the disease. Our case reports further expand the ARSACS phenotype and add clinical data in favor of the hypothesized relationship between cerebellar dysfunction and psychiatric disorders.