Cerebral hypermetabolism demonstrated by FDG PET in familial Creutzfeldt-Jakob disease.

Right cerebral and contralateral cerebellar hypermetabolism were observed on FDG PET in a 68-year-old woman with familial Creutzfeldt-Jakob disease (CJD) at an early stage before seizures occurred. The disease progressed with frequent seizures, myoclonus, and a startle reaction. In all past reports, FDG PET studies demonstrated hypometabolism in the cerebrum, cerebellum, and thalamus in patients with CJD. Focal hypermetabolism corresponding with epileptic foci is a common finding in ictal epilepsy patients, and hypometabolism is common in patients with myoclonus or the startle reaction. This finding may reflect a prodromal pathophysiology of epilepsy. Attention should be paid to the diagnosis of CJD while using FDG PET.

Hypermetabolism in patients with dementia with Lewy bodies.

PURPOSE: Detection of hyperperfusion by I-123 N-isopropyl-p-iodoamphetamine single photon emission computed tomography can be helpful to diagnose dementia with Lewy bodies (DLB). This study characterized hypermetabolism in DLB. MATERIALS AND METHODS: A total of 22 probable cases of DLB were examined by F-18 2-fluoro-2-deoxy-D-glucose positron emission tomography. RESULTS: Hypermetabolism was found in the peri-motor area, basal ganglia, and cerebellum. Eleven patients had hypermetabolism in all 3 areas, 6 in 2 areas, 4 in 1 area, and 1 in no area. Hypermetabolism was most frequent in the cerebellum. Comparison of the 11 patients with hypermetabolism in all 3 areas to the other 11 cases found no significant differences in age (P = 0.2555), sex (P = 0.1889), Mini-Mental State Examination score (P = 0.0897), and Parkinsonism. However, visual hallucinations were significantly more frequent in the patients with hypermetabolism in all 3 areas (P = 0.0018). CONCLUSIONS: Hypermetabolism is common in patients with DLB and may be related to visual hallucinations.