Teaching NeuroImages: All Hemiparesis Are Not Contralateral

Abstract

A 56-year-old hypertensive man presented with left-sided weakness of 2-hour duration. He made complete recovery from right hemiparesis because of left parietal infarct. Examination showed dysarthria and left hemiparesis (NIHSS 8/42). MRI brain showed both left parietal acute infarct and gliosis from old infarct (Figure 1). He was successfully thrombolyzed with intravenous alteplase. Present stroke was diagnosed as ipsilateral hemiparesis, confirmed by diffusion tensor imaging (Figure 2). Ipsilateral hemiparesis, mostly seen with posterior fossa malformations and remote infarctions,1 results from injury to uncrossed corticospinal tract (CST) in patients of remote brain injury or with no decussation of CST or injury to ipsilateral extrapyramidal motor pathway.2