Mild cognitive impairment in Parkinson’s disease: a critical update

Abstract

Evaluation of: Aarsland D, Bronnick K, Williams-Gray C et al.: Mild cognitive impairment in Parkinson disease: a multicenter pooled analysis. Neurology 75, 1062–1069 (2010). A clinical analysis of 1346 patients with Parkinson’s disease (PD) from eight different cohorts, using standardized criteria and cognitive tests, revealed an incidence of mild cognitive impairment (MCI) in 25.8%. It affected various cognitive domains, most frequently memory (13.3%), visuospatial (11%) and attention-executive abilities (10.1%). MCI was classified as nonamnestic and amnestic single domain (11.2 and 8.9%, respectively), and amnestic and nonamnestic multiple domain (4.8 and 1.3%, respectively). The author comments on this clinical study of a well-characterized multicenter cohort showing that PD-MCI was associated with older age at disease onset, male gender, depression, more severe motor symptoms and advanced disease stage. The potential mechanisms underlying MCI in PD patients are compared with non-PD patients, and recent data on heterogeneous neuropathology in both PD-MCI and non-PD-MCI are discussed.