Evolution of mild cognitive impairment in Parkinson disease

Neurology. 2013 Jun 21. [Epub ahead of print]

Broeders M, de Bie RM, Velseboer DC, Speelman JD, Muslimovic D, Schmand B.

Source

From the Department of Brain and Cognition (M.B., B.S.), University of Amsterdam, Amsterdam; Department of Neurology (M.B., R.M.A.d.B., D.C.V., J.D.S., B.S.), Amsterdam Medical Center, Amsterdam; and Department of Medical Psychology and Psychiatry (D.M.), Groene Hart Hospital, Gouda, the Netherlands.

Abstract

OBJECTIVE:

We examined the development of Parkinson disease (PD)-mild cognitive impairment (MCI) in patients with newly diagnosed PD over 5 years using recently proposed consensus criteria, and we assessed the reliability of the criteria.

METHODS:

Patients with PD (n = 123) underwent extensive neuropsychological testing at baseline and after 3 (n = 93) and 5 years (n = 59). Two neuropsychologists independently applied the PD-MCI criteria to examine the interrater and intrarater reliability.

RESULTS:

At baseline, 35% of patients had PD-MCI. Three years later, 53% of the patients had PD-MCI. At 5-year follow-up, 20 patients who had PD-MCI at an earlier assessment had converted to PD dementia and 50% of the remaining patients without dementia had MCI. The interrater reliability (kappa) was 0.91. The intrarater reliabilities were 0.85 and 0.96.

CONCLUSION:

Approximately one-third of patients with newly diagnosed PD fulfill the consensus criteria for PD-MCI; after 5 years, this proportion is approximately 50% of patients without dementia. The criteria have good interrater and intrarater reliability.