Creutzfeldt-Jakob disease (CJD) and other prion diseases are rapidly progressive spongiform encephalopathies that are invariably fatal. Clinical features and magnetic resonance imaging, electroencephalogram, and cerebrospinal fluid abnormalities may suggest prion disease, but a definitive diagnosis can only be made by means of neuropathologic examination. Fluorodeoxyglucose positron emission tomography (FDG-PET) is not routinely used to evaluate patients with suspected prion disease. This study includes 11 cases of definite prion disease in which FDG-PET scans were obtained. There were 8 sporadic CJD cases, 2 genetic CJD cases, and 1 fatal familial insomnia case. Automated FDG-PET analysis revealed parietal region hypometabolism in all cases. Surprisingly, limbic and mesolimbic hypermetabolism were also present in the majority of cases. When FDG-PET hypometabolism was compared with neuropathologic changes (neuronal loss, astrocytosis, spongiosis), hypometabolism was predictive of neuropathology in 80.6% of cortical regions versus 17.6% of subcortical regions. The odds of neuropathologic changes were 2.1 times higher in cortical regions than subcortical regions (P=0.0265). A similar discordance between cortical and subcortical regions was observed between FDG-PET hypometabolism and magnetic resonance imaging diffusion weighted imaging hyperintensity. This study shows that there may be a relationship between FDG-PET hypometabolism and neuropathology in cortical regions in prion disease but it is unlikely to be helpful for diagnosis.
Departments of *Neurology
¶Quantitative Health Sciences, Cleveland Clinic
Departments of †Radiology
**Neurology, University Hospitals Case Medical Center
∥National Prion Disease Pathology Surveillance Center
#Department of Neuroradiology, Humanitas Research Hospital IRCCS, Milano, Italy
The National Prion Disease Pathology Surveillance Center is supported by the Centers for Disease Control and Prevention (grant UR8/CCU515004 to J.G.S.).
Present address: Karin P. Mente, MD, MS, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD.
The authors declare no conflicts of interest.
Reprints: Karin Mente, MD, MS, NIH/NINDS, 10 Center Drive, Bethesda, MD 20892 (e-mail: firstname.lastname@example.org).
Received September 27, 2016
Accepted December 19, 2016