RESUMO
BACKGROUND/AIMS: Few studies have described mild cognitive impairment (MCI) and cognitive characteristics in early-onset Parkinson's disease (EOPD). This study describes attention/working memory, language, memory, visuospatial abilities, executive function, and frequency of MCI and dementia in EOPD. METHODS: Eighty-one EOPD patients were administered neuropsychological tests and the Beck Depression Inventory. Scores were compared with age/education-appropriate norms and were correlated to years of disease progression and severity of motor symptoms. The frequency of MCI and dementia was determined by the Movement Disorder Society criteria. RESULTS: Thirty-one percent of patients met the MCI criteria, but none had dementia. Commonly affected domains were memory, visuospatial, and executive function. Cognitive dysfunction was not explained by depression or severity of motor symptoms. CONCLUSION: One third of EOPD patients presented with MCI, which was not associated with the same risk factors as reported in late-onset Parkinson's disease. MCI could have a different prognostic value in EOPD.