Article

Studies demonstrate that most arm motor recovery occurs within three
months after stroke, when measured with standard clinical scales. Improvements on
these measures, however, reflect a combination of recovery in motor control,
increases in strength, and acquisition of compensatory strategies. OBJECTIVE: To
isolate and characterize the time course of recovery of arm motor control over
the first year poststroke. METHODS: Longitudinal study of 18 participants with
acute ischemic stroke. Motor control was evaluated using a global kinematic
measure derived from a 2-dimensional reaching task designed to minimize the need
for antigravity strength and prevent compensation. Arm impairment was evaluated
with the Fugl-Meyer Assessment of the upper extremity (FMA-UE), activity
limitation with the Action Research Arm Test (ARAT), and strength with biceps
dynamometry. Assessments were conducted at: 1.5, 5, 14, 27, and 54 weeks
poststroke. RESULTS: Motor control in the paretic arm improved up to week 5, with
no further improvement beyond this time point. In contrast, improvements in the
FMA-UE, ARAT, and biceps dynamometry continued beyond 5 weeks, with a similar
magnitude of improvement between weeks 5 and 54 as the one observed between weeks
1.5 and 5. CONCLUSIONS: Recovery after stroke plateaued much earlier for arm
motor control, isolated with a global kinematic measure, compared to motor
function assessed with clinical scales. This dissociation between the time
courses of kinematic and clinical measures of recovery may be due to the
contribution of strength improvement to the latter. Novel interventions, focused
on the first month poststroke, will be required to exploit the narrower window of
spontaneous recovery for motor control.

Langue : ANGLAIS