BILATERAL HEMISPHERIC ACTIVATION IN THE EARLY RECOVERY OF MOTOR FUNCTION AFTER STROKE

Background and Purpose-Functional recovery after cerebral infarction i s a complex phenomenon that depends on various factors. The aim of thi s study was to investigate changes in cerebral perfusion during motor activity in stroke patients with very early recovery of motor function . Methods-We included 9 consecutive patients hospitalized for acute-on set hemiparesis who showed complete functional recovery within 24 hour s. CT of the brain showed an ischemic or hemorrhagic cerebral lesion i n areas compatible with the symptomatology. Within 36 hours (range, 28 to 36) all patients were examined for the effects of a thumb-to-finge r opposition task on cerebral blood flow in the middle cerebral arteri es, evaluated by means of bilateral transcranial Doppler ultrasonograp hy, Data were compared with those of 9 healthy subjects matched for ag e and sex. In patients, the evaluation was repeated 2 to 4 months late r. Results-A comparable increase in flow velocity (% mean+/-SD) was ob served with respect to baseline in the contralateral middle cerebral a rtery during motor activity with patients' normal (8.8+/-2.0%) and rec overed hand (9.7+/-4.1%) and with both hands of control subjects (10.6 +/-1.4%). In the middle cerebral artery ipsilateral to the hand perfor ming the motor task, the increase in flow velocity was significantly h igher (P<0.0001) during movement of the recovered hand in patients (8. 6+/-2.7%) than during movement of the normal hand in both patients (2. 6+/-1.6%) and control subjects (1.4+/-0.7%). In patients, pattern of c hanges in flow velocity during motor performance remained the same in the second evaluation. Conclusions-These observations suggest that are as of the healthy hemisphere can be activated soon after a focal injur y and contribute to the positive evolution of a functional deficit in some patients. This phenomenon of ipsilateral activation cannot be con sidered transient because it is evident months after stroke onset.