External cueing improves motor imagery quality in patients with Parkinson disease

Patients with Parkinson disease (PD) are often profoundly slow in their performance of physical tasks, as well as in motor imagery (MI). This may limit the implementation and potential benefits of MI practice during rehabilitation.

The authors investigated whether the quality of MI could be improved by external cueing.

Fourteen patients with PD and 14 healthy controls physically executed and visually imagined a goal-directed aiming task and a box-and-block task, both in the presence and absence of visual and auditory cues. Mental chronometry and eye movement recording allowed objective evaluation of the temporal and spatial characteristics of MI when compared with physical execution. Visual analogue scales were used to assess imagery vividness.

The presence of visual cues significantly reduced the patients' bradykinesia during MI and increased their imagery vividness.

Visual cueing optimizes MI quality for PD patients and is a potential tool to increase the efficacy of MI practice in PD rehabilitation.