[Neuropsychology of primary progressive multiple sclerosis].

INTRODUCTION: Cognitive impairment is a symptom of multiple sclerosis (MS); however, in the primary progressive form of the disease (PPMS), data on the prevalence and type of cognitive impairment are controversial.

AIM: To evaluate the frequency of cognitive impairment, according to the diagnostic criteria defined by Thompson, in Brazilian patients with PPMS attending a referral center for the treatment of MS in Rio de Janeiro, Brazil.

SUBJECTS AND METHODS: A battery of neuropsychological tests was used to evaluate the following cognitive functions: screening for dementia, attention/concentration, speed of information processing, verbal fluency, memory and abstract/conceptual thought. The Beck scale was used to evaluate mood disorders. Twenty-six patients with PPMS and 26 controls paired for gender, age and education level were evaluated. Statistical analysis was based on the study performed by Rao.

RESULTS: The frequency of cognitive impairment in the PPMS patients in the present study was 50%. The cognitive functions most affected were: recent memory (60%), verbal fluency (40%) and speed of information processing (40%). Depression was more common in the PPMS patients compared to the control group; however, no association was found between cognitive impairment and depression.

CONCLUSION: These results confirm the presence of cognitive impairment in PPMS and emphasize the need for further studies with larger sample sizes.