Major Finding: Exercise and medication use significantly improved cognitive function in patients with Parkinson’s disease based on results of the Stroop Color and Word Test. Exercise improved performance on the Brief Test of Attention and the Digit Span Forward and Backward Task when patients were off medication but not when they were on medication.

Data Source: An analysis of 48 Parkinson’s disease patients who completed 6 months of a strengthening and balance exercise program under the guidance of a personal trainer.

Disclosures: The study was supported by an American Academy of Neurology Medical Student Summer Research Scholarship and by a grant from the National Institute of Neurological Disorders and Stroke.

HONOLULU – Patients with Parkinson’s disease who participated in a 1-hour exercise program twice a week for 6 months experienced improvements in certain cognitive deficits, results from a single-center study showed.

“Exercise should be considered adjunct therapy in Parkinson’s disease because it improves cognitive function in patients when not on medication,” lead study author Jeffrey R. Olech said in an interview during a poster session at the meeting.

Mr. Olech, a second-year student at the University of Illinois at Chicago, and his associates presented results from 48 Parkinson’s disease patients who completed 6 months of a strengthening and balance exercise program under the guidance of a personal trainer. The researchers administered cognitive assessments when patients were “on” and “off” Parkinson’s medication at baseline and at completion of the 6-month program.

Cognitive tests included the Stroop Color and Word Test, the Brief Test of Attention (BTA), and the Digit Span Forward and Backward Task. The researchers performed a two-way repeated measures analysis of variance on the cognitive measures with time (baseline vs. 6 months) and medication (on vs. off) as factors.

The mean age of patients was 59 years, and 58% were men. The mean baseline motor United Parkinson’s Disease Rating Scale score was 34.6 among those off medication and 21.3 among those on medication.

At 6 months, exercise and medication use significantly improved cognitive function based on results of the Stroop Color and Word Test. A significant interaction was observed between exercise and medication use based on results of the BTA test and the Digit Span Forward and Backward Task. Exercise improved performance on both of these tests when patients were off medication, but not while they were on medication.

“It was surprising to us that cognitive function was improved without medication over different domains of cognitive assessments,” Mr. Olech said. “Previous research has demonstrated that Parkinson’s patients on medication without exercise will maintain their level of cognitive performance over a 6-month period of time. Reasons improvement on cognitive outcomes off medication were observed could potentially be due to increased neural plasticity as a result of exercise, or an improvement in dopaminergic output during periods throughout the day that the drug’s therapeutic benefit wanes.”

He and his associates plan to collect data in this cohort of patients at 18 and 24 months of follow-up to determine if the associations persist.

Mr. Olech acknowledged certain limitations of the study, including its lack of an intervention control group and its single-center design.