Michael S. Okun, MD reviewing Pedersen KF et al. Neurology 2017 Jan 20.

Rates of MCI increased during a 5-year study, and persistent MCI was associated with increased dementia risk.

To examine mild cognitive impairment (MCI) in Parkinson disease (PD), investigators followed up on an incident population of patients newly diagnosed with PD who underwent neuropsychological testing over a 5-year period. The authors classified MCI dementia using the Movement Disorders Society level one criteria in the domains of attention, executive function, memory, and visuospatial ability.

Twenty percent of 178 patients met MCI criteria at the first neuropsychological examination. The incidence of MCI was 10% at year 1, 23% at year 3, and 29% at year 5. Among those with MCI diagnosed at baseline or during the 5-year follow-up, 39% progressed to dementia. Among those with MCI at both baseline and 1-year exam, 59% later converted to dementia. Among those with incident MCI or MCI at the first follow-up visit, 28% and 24%, respectively, reverted to normal cognition by the study's end. However, only 9.4% of patients with two consecutive abnormal neuropsychological examinations reverted to normal cognition.

CITATION(S):

Pedersen KF et al. Natural course of mild cognitive impairment in Parkinson disease: A 5-year population-based study. Neurology 2017 Jan 20; [e-pub]. 

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