Dyke-Davidoff-Masson Syndrome With Cerebral Hypometabolism and Unique Crossed Cerebellar Diaschisis in 18F-FDG PET/CT.

A 23-year-old man with Dyke-Davidoff-Masson syndrome (DDMS) was admitted to the hospital with increasing frequency of epileptic seizures. Physical examination revealed mental retardation, left facial asymmetry, and left-sided spastic hemiparesis. Dysdiadochokinesia on the left upper limb was detected, and there was no dysmetria. MRI confirmed the well-known radiological features of DDMS. PET/CT demonstrated cerebral and contralateral cerebellar hypometabolism. We present DDMS with crossed cerebellar diaschisis, which was demonstrated by PET/CT.