Role of the Premotor Cortex in Recovery From Middle Cerebral Artery Infarction

Open Access
Publisher Website
Google Scholar
Abstract
MECHANISMS influencing clinical recovery from hemiparesis in brain infarction involve hemodynamic, biochemical, neurophysiological, and neuropsychological factors that we are only begining to understand.1,2 Evidence based on large clinical cohorts indicates that approximately 45% of patients with hemiplegic stroke suffer from persistent hemiparesis,3,4 whereas the larger proportion of patients recover mostly during the first 4 weeks after stroke.5,6 As demonstrated by neurophysiological and morphometric studies, the severity of pyramidal tract damage appears to be a major predictor of outcome.7 Accordingly, in patients with striatocapsular stroke, initial hemiplegia may regress completely when the posterior part of the internal capsule is spared8 or when the magnetic evoked motor potentials are preserved.9 Activation studies with positron emission tomography (PET) in such patients showed that the sensorimotor cortex is recruited when the recovered hand is moved.9,10 Against this background, the additional bilateral premotor cortical activations not seen in normal subjects during the same motor tasks11 seemed to participate in rather than substitute motor cortex activity.