In this study 7 patients with Parkinson's disease were compared with 7 age-matched controls in a task of tracing out the four corners of a square in an anticlockwise direction using a plastic rod with a reflective marker at the tip, held in the dominant hand. The task was first performed with the eyes open and then with blindfold. Subjects were instructed that accuracy of movement was more important than speed. Arm movements were recorded by means of a high-definition system (Me Reflex, Qualisys, Partille, Sweden) employing two cameras and using specially developed software. The position in space of the reflective marker was recorded throughout the movement sequence at a sampling frequency of 50 Hz from which instantaneous velocities were calculated. Movement time, peak velocity and final position error were measured for each side of the square. Position error was measured as tangential error and lateral error. Statistical analysis included 2 × 2 × 4 ANOVA (with factors: group, condition and position in the sequence). Patient performance did not differ from controls in terms of position error, neither were patients' scores worse than controls in performing the task without visual control. Our results suggest that parkinsonian patients can keep track of a simple repetitive movement sequence without visual control.
|Number of pages||1|
|Journal||Italian Journal of Neurological Sciences|
|Publication status||Published - 1999|
ASJC Scopus subject areas
- Clinical Neurology