Article

Motor imagery (MI) is increasingly recognized as a treatment option
after stroke, but not all stroke patients are able to perform MI. OBJECTIVE: To
examine if severe somatosensory deficits would affect MI ability. METHODS: The
Box and Block Test (BBT) was used to evaluate mental chronometry as 1 component
of MI. Two groups of stroke patients and an age-matched healthy control group
(CG) were studied. Patient group 1 (n = 10, PG1) had a severe somatosensory
impairment on the affected side and PG2 (n = 10) had pure motor strokes. All
subjects first performed the BBT in a mental and in a real version. The time
needed to move 15 blocks from 1 side of the box to the other was measured. To
compare the groups independently of their performance level, a (real
performance--MI)/(real performance) ratio was calculated. Corticospinal
excitability was measured by transcranial magnetic stimulation at rest and while
the subjects performed an imagined pinch grip. RESULTS: The CG performed the BBT
faster than both patient groups, and PG1 was slower than PG2. MI ability was
impaired in PG1 but only for the affected hand. Transcranial magnetic stimulation
data showed an abnormally low MI-induced corticospinal excitability increase for
the affected hand in PG1, but not in PG2. CONCLUSIONS: Severe somatosensory
deficits impaired mental chronometry. A controlled study is necessary to clarify
if these patients benefit at all from MI as an additional treatment.

Langue : ANGLAIS