Cognitive impairments in multiple system atrophy: MSA-C vs MSA-P

OBJECTIVE: We evaluated comprehensive neuropsychological tests and regional brain blood flow to compare cognitive dysfunction between two types of multiple system atrophy: predominant cerebellar ataxia (MSA-C) and predominant parkinsonism (MSA-P). METHODS: Twenty-one patients with MSA-C, 14 patients with MSA-P, and 21 age- and education-matched control subjects were subjected to neuropsychological tests and SPECT. The neuropsychological tests examined general cognition, verbal and visual memory, working memory, visuospatial and constructional ability, language, executive function, depression, and anxiety, while SPECT analysis examined brain perfusion. RESULTS: Patients with MSA-P showed severe involvement of visuospatial and constructional function, verbal fluency, and executive function compared with control subjects. Patients with MSA-C showed involvement only in visuospatial and constructional function compared with control subjects and a milder degree of involvement compared with patients with MSA-P. Patients with MSA-P tended toward a wide and severe impairment in cognitive function compared with patients with MSA-C. In addition, neuropsychological impairment in patients with MSA-P was significantly correlated with a decrease in prefrontal perfusion. This significant relation was not correlated to other factors such as age, education, and severity of cerebellar ataxia and parkinsonism, which are relevant factors associated with cognitive performance. CONCLUSIONS: Patients with multiple system atrophy-parkinsonism show more severe and more widespread cognitive dysfunctions than patients with multiple system atrophy-cerebellar ataxia. Our results also indicate that cognitive dysfunction in patients with multiple system atrophy-parkinsonism may be associated with prefrontal involvement.