Positron emission tomography imaging in a case of E200K mutation-related spongiform encephalopathy with non-diagnostic magnetic resonance imaging and cerebrospinal fluid testing

OBJECTIVE: Creutzfeldt–Jakob disease is a rapidly progressive spongiform encephalopathy. The E200K mutation is found in a majority of genetically transmitted Creutzfeldt–Jakob disease cases. METHODS: We describe the case and associated neuroimaging of an E200K-129M gene-mutation-related fatal spongiform encephalopathy with resultant clinical insomnia and thalamic changes. RESULTS: A 46-year-old Caucasian male presented with, who was well until 2 months prior to admission, a rapidly progressive dementia followed by a change in personality with auditory and visual hallucinations. His wife noted progressively worsening jerking and other limb movements and that he kept his eyes open overnight and was “awake” at all hours. Magnetic resonance imaging, electroencephalogram and initial cerebrospinal fluid analysis were essentially non-diagnostic. Positron emission topography revealed severe bilateral thalamic hypometabolism. Posthumous cerebrospinal fluid analysis revealed abnormal PrP 27-30 protein. Autopsy confirmed prion disease and presence of the E200K-129M mutation. CONCLUSION: This report highlights that positron emission topography imaging may help diagnose E200K-129M mutation-related spongiform encephalopathy. In cases of non-diagnostic magnetic resonance imaging, electroencephalogram and cerebrospinal fluid studies, early positron emission topography may help in the workup of rapidly progressive dementia.