Ataxic hemiparesis from strategic frontal white matter infarction with crossed cerebellar diaschisis

Background - Ataxic hemiparesis is a classic lacunar syndrome that most often localizes to the pons. Results - We report 3 patients who presented with left-sided ataxic hemiparesis and were found on imaging to have small right frontal subcortical white matter infarcts in similar locations by diffusion-weighted MRI. [Tc-99m] hexamethylpropylenamine oxime single-photon emission computed tomography (SPECT) scans in all 3 patients showed decreased metabolism in the contralateral cerebellar hemisphere, indicative of crossed cerebellar diaschisis (CCD). Conclusion - CCD is under-recognized in ataxic hemiparesis and may have implications for functional recovery after this type of ischemic stroke.