To determine the effect of baseline cognition on outcomes after a 10-week gait training program for people with Parkinson disease (PD).

Cognitive impairment is highly prevalent in PD and may limit the ability to compensate for gait impairments, thus impacting the response to gait training.

Participants had PD and were classified as having no cognitive impairment (PD-NCI) or mild cognitive impairment (PD-MCI) based on neuropsychological assessment and consensus conference. Baseline executive function and memory were assessed. The intervention was a 10-week gait training program consisting of twice-weekly sessions on a treadmill, with structured speed and distance progression and verbal cues for gait quality. Gait speed was the primary outcome. Transfer was assessed with dual-task walking. Short-term effects were assessed after week 2, and long-term effects after week 10.

Participants (n=19; 12 PD-NCI, 7 PD-MCI) had a mean (standard deviation) age of 66.5 (6.3) years, disease duration of 8.8 (6.3) years, and MDS-UPDRS III score of 21.3 (10.7). Gait speed, stride length, trunk excursion, and arm swing excursion increased at short-term and long-term assessments and did not differ between cognitive groups. Transfer to dual-task walking was demonstrated by increased dual-task gait speed, stride length, trunk excursion, and arm-swing excursion at long-term assessment and did not differ between groups. Lower MDS-UPDRS III scores and better baseline memory performance were independently associated with greater improvements in gait speed in unadjusted and age-adjusted models.

Across both groups, gait speed improved in response to training, and benefits transferred to dual-task walking. The association with better memory suggests memory may be more critical to effective gait rehabilitation than other cognitive domains. More severe motor involvement may also limit the response to gait rehabilitation. A better understanding of the factors influencing the response to gait training is critical to optimize rehabilitation for people with PD.