Intrahemispheric Diaschisis in Subcortical Lesions

ABSTRACT

OBJECTIVE: The aim of this study was to investigate the incidence of intrahemispheric diaschisis in subcortical lesions and relationships between involved structures and intrahemispheric diaschisis using positron emission tomography (PET). METHOD: Thirty stroke patients with unilateral subcortical lesions without cortical structural abnormality were recruited. The findings of [18F]Fluoro-2-Deoxy-D-Glucose PET were interpretated by experienced radiologist. RESULTS: In the lesions around basal ganglia, hypometabolism of ipsilateral whole hemisphere was observed in 8 of 20 patients and ipsilateral parietal, frontal, temporal, occipital lobe was observed in order of incidence. Intrahemispheric diaschisis had a tendency to expand when the centrum semiovale was involved. Crossed cerebellar dia-schisis was observed in 17 of 20 patients. In the lesions around thalamus, hypometabolism of ipsilateral whole hemisphere was observed in 6 of 8 patients, and ipsilateral frontal, temporal, parietal lobe was observed in order of incidence. Intrahemispheric diaschisis had a tendency to expand when the internal capsule was involved. Crossed cerebellar diaschisis was observed in 5 of 8 patients. CONCLUSION: This study shows that intrahemispheric diaschisis was observed in all patients with subcortical lesions without cortical structural abnormality and had a tendency to expand to larger area of the cerebral cortex when the connecting fibers between cortical and subcortical structures were involved.