Mild cognitive impairment in Parkinson's disease: Characterization and impact on quality of life according to subtype.

Aim: Mild cognitive impairment (MCI) was initially described as a risk factor for Alzheimer's disease. Because of differences in baseline cognitive abilities, MCI in Parkinson's disease (PD; PD-MCI) requires distinct neuropsychological criteria for diagnosis and follow up. In addition to representing a risk factor for PD-related dementia, PD-MCI results in higher morbidity, which can be reduced through early detection.