Cerebellar Cognitive Affective Syndrome in Costa da Morte Ataxia (SCA36)

Area of Science:

• Neurology
• Genetics
• Cognitive Neuroscience

Background:

• Spinocerebellar ataxia type 36 (SCA36) is an autosomal dominant neurodegenerative disorder.
• It is caused by a GGCCTG repeat expansion in the NOP56 gene.
• SCA36 primarily affects families in the Costa da Morte region of Spain.

Purpose of the Study:

• To characterize the cognitive and affective manifestations of SCA36.
• To investigate early signs of the cerebellar cognitive and affective syndrome (CCAS) in SCA36.
• To assess the impact of disease stage (preataxic vs. ataxic) on these manifestations.

Main Methods:

• A cohort of 30 SCA36 mutation carriers (11 preataxic, 19 ataxic) was studied.
• A comprehensive battery of standardized neuropsychological tests was administered.
• Assessment included evaluation of verbal fluency and mood (depression).

Main Results:

• Preataxic SCA36 patients showed mild impairment in phonological verbal fluency.
• Ataxic patients exhibited significant deficits in both phonological and semantic verbal fluency.
• Depression was prevalent in both preataxic and ataxic stages, being more severe in ataxic patients.

Conclusions:

• This study provides the first systematic evidence of a mild cerebellar cognitive and affective syndrome in SCA36.
• Cognitive and emotional changes are present early in the disease course, even in the preataxic stage.
• Routine assessment of cognitive and emotional functions in SCA36 mutation carriers is recommended for early detection and intervention.