Crossed cerebellar hyperperfusion on ictal FDG PET in astrocytoma.

Crossed cerebellar hyperperfusion (CCH) is a rare phenomenon and reflects the close anatomical and functional relationship between the frontal brain region and its mediated remote effect on the contralateral cerebellum via the corticopontocerebellar pathway. Although it is well documented on cerebral single photon emission tomography (SPECT) in patients with epilepsy, it is rarely observed in seizures originating from brain tumours. We report a 41-y-old man who whilst undergoing (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) for investigation of suspected glioma, developed a generalized seizure. The scan performed shortly after seizure onset demonstrated intense metabolic activity in the right superior frontal lobe and in the contralateral cerebellar hemisphere consistent with CCH.