Effects of Antiparkinson Medication on Cognition in Parkinson’s Disease: A Systematic Review

• Published in: Canadian journal of neurological sciences 2018-07, Vol.45 (4), p.375-404
• Main Authors: Roy, Marc-André, Doiron, Maxime, Talon-Croteau, Jessica, Dupré, Nicolas, Simard, Martine
• Format: Article
• Language: English
• Subjects: Antiparkinson Agents - therapeutic use; Attention; Brain damage; Cognition & reasoning; Cognition Disorders - drug therapy; Cognition Disorders - etiology; Cognitive ability; Dopamine; Double-blind studies; Executive function; Genes; Humans; Memory; Neuropsychology; Original Article; Parkinson Disease - complications; Parkinson Disease - drug therapy; Parkinson's disease; Systematic review
• ISSN: 0317-1671; 2057-0155
• DOI: 10.1017/cjn.2018.21

Objective: This study aimed to systematically review the effects of currently prescribed antiparkinson medication on cognition in patients with mild-to-moderate Parkinson’s disease (PD) who were either cognitively intact or mildly impaired. Methods: English- and French-language studies published between 1969 and 2017 were accessed via MedLine, PsychNET, EMBASE and EBSCO databases. Methodological quality (MQ) was evaluated with the quality assessment instrument of the Cochrane Collaboration Depression, Anxiety and Neurosis Review (scores from 0% to 44% indicate very low quality; scores from 45% to 64% indicate low quality; scores from 65% to 84% indicate medium quality; and scores from 85% to 100% indicate high quality). Hedges’ g and Student’s t-test were performed on all cognitive outcome measures reported. Results: In total, 14 studies assessed the cognitive effects of levodopa (L-D), pramipexole (PRX), selegiline (SEL) and rasagiline (RAS) in mild-to-moderate non-demented PD patients. The MQ was overall low, with an average score of 49.1%. Results for L-D showed deleterious effects on a test of cognitive inhibition, as well as benefits on tests of attention/processing speed/working memory, executive functions and episodic memory. Pramipexole was associated with a worsening of episodic memory and impulse control. Results on SEL indicated a deterioration of global cognition over time and of concept formation. Rasagiline had some benefits on working memory and verbal fluency. Conclusion: Antiparkinson medications can have deleterious (L-D; PRX; SEL) and beneficial (L-D; RAS) effects on cognition. However, randomized double-blind placebo-controlled trials with larger sample sizes are required to better elucidate this issue. Objectif: Cette étude vise à recenser systématiquement les effets cognitifs de certains antiparkinsoniens chez des patients aux stades léger à modéré de maladie de Parkinson (MP) avec ou sans atteintes cognitives légères. Méthode: Les publications anglophones et francophones de 1969 à 2017 ont été recensées via MedLine, PsychNET, EMBASE et EBSCO. La qualité méthodologique (QM) a été évaluée avec un instrument de la Cochrane Collaboration Depression, Anxiety and Neurosis Review (0% à 44% signifie une très faible qualité; 45% à 64% une faible qualité; 65% à 84% une qualité moyenne; 85% à 100% une haute qualité). Le g de Hedges et le t de Student ont été calculés pour tous les résultats cognitifs. Résultats: Quatorze études évaluaient les e