Medication status and dual-tasking on turning strategies in Parkinson disease

Parkinson disease (PD) patients have turning impairments that may increase fall risk. Clinics lack specialized kinematic equipment used in gait and turn analysis and require a simple method to evaluate fall risk and advise patients in turning strategy selection.

To enhance understanding of PD turning strategies and determine if turning can be assessed using a video-recording and categorization method, we compared 180-degree and 90-degree turns as a function of medication status and dual-tasking (DT).

21 PD participants (H&Y stage 1-3) in PD-ON and PD-OFF medication states and 16 controls completed 180-degree and 90-degree turn-tasks with and without DT. Video-recordings of tasks permitted classification of 180-degree turns into Few-Step turns (FST) vs. Multi-Step turns (MST) and 90-degree turns into Step vs. Spin-turns. FST were further sub-classified into Twisting vs. Sideways turns and MST into Backward, Festination, Forward or Wheeling turns. Percentages of subtypes were analyzed across groups by task.

IN 180-degree tasks, there was an effect of group: FST vs. MST F(2,55) = 9.578, p < .001. PD participants in the off-medication state (PD-OFF) produced significantly more MST with a larger number of different turning subtypes vs. controls or PD on medication (PD-ON). In 90-degree tasks, controls significantly increased their proportion of Step-turns while DT (p < .001), an adaptation not observed in PD-ON or PD-OFF.

PD turning impairments may stem from an inability to select a unified turning strategy and to adapt to the turning environment, which may be exacerbated in PD-OFF. Video-analysis may prove beneficial in predicting a clinical course for PD patients by revealing features of turning dysfunction.