Hyperkinesia contralateral to acute hemiplegia: relevance of previous frontal lesions

Two patients with a hyperkinetic syndrome contralateral to acute hemiplegia are presented. One patient showed a right-sided hemiplegia associated with abnormal movements of the left upper limb. In the other patient hemiplegia was localised on the left side while abnormal movements involved the right lower limb. Brain imaging showed acute infarctions (respectively left middle cerebral artery area and right lacunar infarctions) associated with a pre-existing contralateral infarction involving anterior non-primary motor areas. Hyperkinetic syndromes in stroke are mainly related to acute lesion of the contralateral subcortical areas. In our patients, the acute lesions were located ipsilateral to the hyperkinetic body part while the pre-existing lesions were located contralateral to the hyperkinetic side. We speculated that these pre-existing lesions might play a role in the pathophysiology of this clinical syndrome.