Exercise improves cognition in Parkinson's disease: The PRET-PD randomized, clinical trial

Abstract

Background: This article reports on the findings of the effect of two structured exercise interventions on secondary cognitive outcomes that were gathered as part of the Progressive Resistance Exercise Training in Parkinson's disease (PD) randomized, controlled trial.

Methods: This study was a prospective, parallel-group, single-center trial. Fifty-one nondemented patients with mild-to-moderate PD were randomly assigned either to modified Fitness Counts (mFC) or to Progressive Resistance Exercise Training (PRET) and were followed for 24 months. Cognitive outcomes were the Digit Span, Stroop, and Brief Test of Attention (BTA).

Results: Eighteen patients in mFC and 20 patients in PRET completed the trial. At 12 and at 24 months, no differences between groups were observed. At 12 months, relative to baseline, mFC improved on the Digit Span (estimated change: 0.3; interquartile range: 0, 0.7; P = 0.04) and Stroop (0.3; 0, 0.6; P = 0.04), and PRET improved only on the Digit Span (0.7; 0.3, 1; P < 0.01). At 24 months, relative to baseline, mFC improved on the Digit Span (0.7; 0.3, 1.7; P < 0.01) and Stroop (0.3; 0.1, 0.5; P = 0.03), whereas PRET improved on the Digit Span (0.5; 0.2, 0.8; P < 0.01), Stroop (0.2; -0.1, 0.6; P = 0.048), and BTA (0.3; 0, 0.8; P = 0.048). No neurological or cognitive adverse events were observed.

Conclusions: This study provides class IV level of evidence that 24 months of PRET or mFC may improve attention and working memory in nondemented patients with mild-to-moderate Parkinson's disease.

Trial registration: ClinicalTrials.gov NCT00591344.

Keywords: Parkison's disease; attention; memory; progressive resistance exercise; randomized controlled trial.

Figure 1

These box plots illustrate the off-medication change from baseline z-scores in the modified Fitness Counts (mFC) and Progressive Resistance Exercise Training (PRET) for (A) the Digit Span Forwards and Backwards, (B) the Stroop Color-Word Interference, and (C) the Brief Test of Attention at 12, and 24 months. Positive z-scores indicate improvement in the Digit Span Forwards and Backwards sum score, the Stroop Color-Word Interference T-score, and the Brief Test of Attention sum score.