Efficacy of rivastigmine on executive function in patients with Parkinson's
disease dementia.
Author(s): Schmitt FA, Farlow MR, Meng X, Tekin S, Olin JT.
Affiliation(s): University of Kentucky, Sanders-Brown Center on Aging, Lexington, KY 40536-0230,
USA. fascom@email.uky.edu
Publication date & source: 2010, CNS Neurosci Ther. , 16(6):330-6
BACKGROUND AND OBJECTIVE: Rivastigmine is approved in the USA for the treatment
of mild to moderate Alzheimer's disease and Parkinson's disease dementia (PDD).
Executive function (EF) deficits are a core symptom of PDD. The current objective
was to investigate the effects of rivastigmine capsules versus placebo on EF in
PDD, focusing on secondary outcome measures from a large, international,
randomized, double-blind, placebo-controlled, 24-week trial (EXPRESS,
CENA713B2311).
METHODS: Secondary outcomes included Delis-Kaplan Executive Function System
(D-KEFS) measures of EF. Data from three D-KEFS subtests (Card Sorting, Letter
Fluency, Color-Word Interference), plus the Symbol Digit Modalities Test were
analyzed in the observed case (OC) population. Changes from baseline in the
rivastigmine versus placebo groups were evaluated using the van Elteren test
blocking for country.
RESULTS: Of 541 patients in the EXPRESS study, 402, 71, 97, and 65 patients
provided data for Letter Fluency, Card Sorting and Color-Word Interference
subtests, and the Symbol Digit Modalities Test, respectively. On Letter Fluency,
rivastigmine was associated with improvements in correct responses, set loss
errors, and responses made (all P < 0.05), but not repetition errors. Higher Card
Sorting recognition description score (P= 0.03), and more correct substitutions
on the Symbol Digit Modalities Test (P= 0.02) were also recorded.
CONCLUSION: Rivastigmine was associated with significant improvements over
placebo on EF tests evaluating flexibility of thinking, problem solving and
planning in patients with PDD. These findings support the hypothesis that
rivastigmine may affect frontal subcortical circuits, which potentially
contributes to observed clinical improvement associated with EF.
|