Case Presentation: A 70 year old male with past medical history of chronic kidney disease was admitted with three weeks of progressive right-sided upper and lower extremity weakness, tremors, and slurred speech. He first noticed right upper extremity weakness and tremors three weeks ago when he could not play his guitar and presented to the emergency department. He was sent home with outpatient follow-up after a negative head CT. However, given his rapidly progressive symptoms, he presented again to the emergency department and was admitted for further work-up.   On admission, vitals were normal, he was alert and oriented x4. Exam was notable for staccatoed speech, right sided intention tremor, dysmetria, dysdiadochokinesia, and cerebellar ataxia.   Labs were unremarkable. Urine toxicology was negative. CT head showed no acute intracranial abnormalities.  Over the course of the next few days, patient became increasingly confused and altered (now oriented only to self), his speech became more slurred and soft, and his tremors progressed to multifocal myoclonic jerks accompanied by progressive weakness.  MRI brain showed cortical ribboning of the left parietal lobe. EEG did not show seizure-like activity but revealed periodic complexes. Cerebral spinal fluid studies revealed very elevated neuron-specific enolase (NSE). 14-3-3, total and p-tau, MaTa antibodies, Mayo autoimmune encephalitis panel, and RTquic (real-time quaking-induced conversion) were sent. RTquic returned as positive. Based on the patient’s rapid clinical course and positive RTquic, the patient met criteria for probable sporadic Creutzfeldt-Jakob disease (CJD). He unfortunately continued to deteriorate rapidly and passed away shortly afterwards. A brain autopsy was performed and final results are still pending.

Discussion: CJD, which affects one person in every one million per year, can present in diverse ways. Most cases of sporadic CJD occur in adults aged 45-75. Common presenting symptoms are weakness, gait ataxia, and rapidly progressive dementia. Significant myoclonus is a common feature later in CJD.   When making such a devastating diagnosis, MRI can be very helpful. The cortical ribboning on MRI can also be caused by prolonged seizures so EEG is needed to rule this out. Although physical contact with CJD patients entails no risk of transmission, hospitalists should be careful when doing a lumbar puncture in a patient suspected to have CJD where contact with infected material is possible and the appropriate precautions should be taken. The very elevated NSE in this case is suggestive of CJD but not specific. 14-3-3 is 90% sensitive but only 80% specific. RTquic measures real-time conversion of the prion protein (PrP) into its mis-folded form and has a sensitivity of 92% and specificity approaches 100% for CJD.

Conclusions: Hospitalists commonly see patients with dementia which can have wide differentials including degenerative, metabolic/toxic, endocrine, infectious, autoimmune, and vascular causes. When there is rapidly progressive dementia especially with a progressive movement disorder or any other neurologic findings, CJD should be suspected. Although sporadic CJD is the most common form of prion disease, a thorough family history should be obtained to look for any history of dementia or cerebellar or parkinsonian disorder which would raise suspicion for genetic prion disease. RTquic when positive helps to make a probable diagnosis of CJD. Definitive diagnosis can only be made from frozen brain tissue.