OBJECTIVETo explore the function and motor pathway of remained cerebral hemisphere by studying motor evoked potential of both upper extremities on patients long term after anatomical hemispherectomy.

METHODSFive patients after anatomical hemispherectomy, who were marked 5 dispersive sites on head to perform transcranial magnetic stimulation. Recording motor evoked potential of target muscles (brachioradialis muscle and abductor pollicis brevis) of both upper extremities respectively when muscle resting and contracting.

RESULTSOnly affected abductor pollicis brevis of case 2 and only affected brachioradialis muscle of case 4 and 5 recorded motor evoked potential when muscle resting. Motor evoked potential of some cases can be recorded simultaneously in homonymous muscles of both sides when muscle resting or contracting.

CONCLUSIONSThere exists motor cortex that controls movement of ipsilateral limbs and also ipsilateral motor pathway of corticospinal connection at patients after anatomical hemispherectomy. It also means that the motor function of affected limbs has potency to recover well after hemispherectomy. The mirror movement after hemispherectomy is possible relate to overlap of both limbs' motor cortex.