Sporadic Creutzfeldt-Jakob Disease Initially Presenting With Posterior Reversible Encephalopathy Syndrome

Introduction: Sporadic Creutzfeldt-Jakob disease (sCJD) is a fatal neurodegenerative condition caused by prion proteins. Cortical and subcortical diffusion-weighted imaging restriction on magnetic resonance imaging (MRI) is associated with sCJD. Posterior reversible encephalopathy syndrome (PRES) results from impaired vessel autoregulation due to an identifiable trigger, which is associated with subcortical fluid-attenuated inversion recovery changes on MRI. We report a case of sCJD initially presenting with PRES. Case Report: A 70-year-old woman presented to an outside hospital with progressive confusion and difficulty in managing activities of daily living. Initial examination revealed stuporous mental state and stimulus-induced myoclonus. MRI revealed bilateral subcortical occipital lobe T2-fluid-attenuated inversion recovery hyperintensities without contrast enhancement suggestive of PRES. Electroencephalogram (EEG) revealed frequent generalized periodic discharges meeting criteria for nonconvulsive status epilepticus. Clinical examination and EEG did not improve despite escalating antiseizure medications. Initial lumbar puncture was unremarkable. She was transferred to our hospital with a presumptive diagnosis of PRES, although there was no clear trigger. Continuous EEG revealed ongoing generalized periodic discharges with myoclonic activity meeting criteria for myoclonic seizures that were refractory to multiple antiseizure medications. Repeat MRI showed resolution of PRES but revealed subtle diffuse cortical diffusion-weighted imaging restriction. Repeat lumbar puncture was performed and 14-3-3 and real-time quaking-induced conversion returned positive, confirming sCJD. Conclusions: This case reports highlights that sCJD can present with neuroimaging consistent with PRES. The diagnosis of sCJD should be considered in patients with PRES who continue to show neurological decline despite optimal management and radiographic improvement of PRES on MRI. Further research is needed to identify a pathophysiological relationship between these clinical phenotypes.