Article

Freezing of gait (FOG) is a significant clinical problem in Parkinson
disease (PD). Similar freezing-like episodes occur during finger movements, but
little is known about ongoing motor problems during repetitive hand movements.
OBJECTIVE: To investigate if the regulation of bimanual movements is impaired in
those with FOG and if withdrawal of an auditory cue amplifies this problem.
METHODS: A total of 23 PD patients (11 with and 12 without FOG) and 11 controls
(CTRLs) performed repetitive finger movements, either externally paced or
following cue withdrawal. Movement frequency, amplitude, and coordination pattern
were manipulated. The stability and accuracy of movement were evaluated after
exclusion of freezing trials. RESULTS: With auditory pacing present, movement
performance was comparable between groups. Following cue withdrawal, motor
control deteriorated in those with FOG, resulting in smaller and less stable
amplitudes, hastened and more variable frequency, and decreased coordination
stability. Conversely, the performance of those without FOG remained mostly
similar to that of CTRLs. CONCLUSIONS: Compared with those without FOG, those
with FOG show greater continuous dyscontrol of bimanual movements, similar to the
continuous timing and scaling difficulties during locomotion. Those with FOG also
benefit from auditory cueing during upper-limb movements, but these are highly
cue dependent. This implies that internal timekeeping functions are more
disturbed in those with FOG,
who may require rehabilitation strategies for
repetitive upper-extremity tasks that include cueing and imagery.

Langue : ANGLAIS