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 diaschisis 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. (J Korean Acad Rehab Med 2002; 26: 495-501)

Objective: To find out the motor recovery in stroke patients according to the presence of diaschisis.

Method: Computed tomography (CT) and/or magnetic resonance imaging (MRI) scan and single photon emission computed tomography (SPECT) study were performed on a consecutive series of 98 inpatients from July 1995 to August 1996. Among them 42 stroke patients were included in this study with cerebellar, pontine, and bilateral hemispheric lesions excluded.

Results: The types of diaschisis were crossed cerebellar diaschisis (CCD) (36 cases), thalamocortical diaschisis (6 cases), striatocortical diaschisis (5 cases), and capsulocortical diaschisis (1 case). And the functional recovery scale improved from 37.5 points to 53.0 points by the motricity index and from 41.2 points to 68.8 points by the MBI score. Only the motricity index showed a significant inverse correlation with the asymmetry index in CCD.

Conclusion: Although other types of diaschisis were found, the most frequent type was CCD. The lower the asymmetry score was the lower motricity index. Therefore, CCD could be a prognostic factor for the motor recovery.