Creutzfeldt-Jakob disease is a spongiform encephalopathy which is believed to be caused by infectious protein particles called prions. Clinically it resembles Alzheimer's disease; however the dementia is usually much more rapidly progressive leading to death. The diagnosis can only be proven by brain biopsy. On EEG, generalized triphasic waves may be seen. The most common MR appearance is normal. Increased T2 signal may be seen in the basal ganglia and the cortex. SPECT may mimic Alzheimer's disease showing markedly decreased perfusion to the affected areas. The finding in this case of abnormal cortical signal on the FIR images only is non-specific. Other considerations include a metabolic or paraneoplastic encephalopathy. The lack of gadolinium enhancement in the cortex or in the meninges makes an acute infectious meningitis or encephalitis very unlikely. Vasculitis is a consideration; however, findings in CNS vasculitis tend to be more consistent with small infarcts in the cortical and subcortical regions with some abnormal enhancement in the affected areas. This patient was diagnosed with Creutzfeldt-Jakob disease by the combination of clinical, EEG, and imaging findings. No biopsy was performed. The patient died 6 months after the onset of dementia. Related Cases
