Motor imagery of usual walking and obstacle negotiation in early-stage Parkinson's disease: An electroencephalographic study

Objective: To assess gait imagery related activations by means of high-density electroencephalography (hdEEG) in a population of early-stage PD patients and age-matched healthy controls. Methods: Fifteen patients with early-stage PD (Hohen & Yahr range: 1–2.0) and 14 age matched controls were recruited. They were asked to visually imagine walking on a straight pathway and on a straight pathway while crossing a hurdle in the middle. We registered hdEEG in the participants and analyzed α and β bands Event Related Desynchronizations (ERDs). Results: PD patients showed reduced low α and high β activity and more widespread ERDs in the high α range compared to the controls. On the contrary, a similar behavior in the low β band was found between the two groups. Conclusions: Findings about α activity in PD might indicate an abnormal basal ganglia-sensorimotor interaction (high α), together with attentional and executive functions deficit (low α). Low β ERD modulation is normal in patients with PD, whereas high β ERD results may indicate top-down control impairments. Significance: By uncovering disparities in gait imagery related activations between the two groups, our protocol could potentially help in better understanding gait pathophysiology in the early stages of PD.