FLUORINE-18-FDG EVALUATION OF CROSSED CEREBELLAR DIASCHISIS IN HEAD-INJURY

This study investigates the phenomenon of crossed cerebellar diaschisi s in head injury patients. Methods: We visually compared fluorine-18-f luorodeoxyglucose (FDG)-PET images to radiograph computed tomography o r magnetic resonance images in 19 patients with head injury. Results: We found that of 68 focal unilateral lesions, 40% were associated with contralateral cerebellar hypometabolism and 19% were associated with ipsilateral cerebellar hypometabolism. Of supratentorial, extraparench ymal lesions (n = 20), 45% were associated with contralateral cerebell ar hypometabolism, whereas 15% had ipsilateral cerebellar hypometaboli sm. Intraparenchymal lesions were associated with contralateral cerebe llar hypometabolism in 38% of the patients and with ipsilateral cerebe llar hypometabolism in 21% of the patients. Of the cortical lesions th at were the patients' most severe injury, 69% were associated with con tralateral cerebellar hypometabolism, whereas only 8% were associated with ipsilateral cerebellar hypometabolism. In patients with focal sup ratentorial lesions alone, 50% of all focal lesions were associated wi th contralateral cerebellar hypometabolism and 13% had ipsilateral hyp ometabolism. Of patients with both focal and diffuse brain injuries, 2 7% of the focal lesions had contralateral cerebellar hypometabolism an d 27% had ipsilateral cerebellar hypometabolism to the most severe foc al injury. Conclusion: Crossed cerebellar diaschisis is seen more ofte n in patients with focal cortical or extraparenchymal injuries and is not seen in patients with multiple or diffuse brain injuries. Furtherm ore, this predominance is more pronounced with lesions of the greatest severity.