Article

Motor imagery (MI) enhances physical performance and skill
acquisition in healthy and neurorehabilitation populations, yet little is known
about the use of strategies to guide MI. OBJECTIVES: To examine the relative
effectiveness of visual, auditory, and combined (visual + auditory) cueing of an
imagined finger abduction task on corticomotor excitability. METHODS: A total of
15 young (20-35 years) and 15 older people (over 55 years) and 10 people with
chronic stroke, who could make voluntary movements of selected muscles,
participated. Motor evoked potentials (MEPs, primary outcome) were measured
following transcranial magnetic stimulation applied while participants imagined
abducting their index finger under guidance of cueing strategies. Amplitudes of
the MEPs from the first dorsal interosseous (FDI), abductor pollicis brevis
(APB), and abductor digiti minimi (ADM) muscles were compared with rest,
contrasted with MEPs elicited during active task performance, and expressed
relative to rest to reflect facilitation. RESULTS: Cued MI enhanced MEPs in all
groups, preferentially to the target FDI muscle. In stroke, APB was also
facilitated. ADM was least affected by cueing. Analyses of simple effects of
condition on FDI MEPs in each group revealed that visual cueing was most
effective in young people, whereas auditory cueing was most effective in healthy
older people and when directed at the nonparetic side in stroke ( P < .04). On
the paretic side, strategies were equally effective. In all cases, MEPs were
largest during physical performance. CONCLUSIONS: Cued MI augments corticomotor
excitability associated with healthy and paretic muscles related to the imagined
task. Age should be considered when selecting a cueing strategy for maximum
effectiveness.

Langue : ANGLAIS