Case Presentation: This is a case of a 66-year-old woman with history of hypertension and hypothyroidism who was brought in by her family due to confusion. At baseline, patient was a high functioning individual, working as a customer service representative and living independently. About a month prior to presentation, her family noticed a decline in her memory, such as not knowing where she kept her medications. She had increasing forgetfulness and inability to carry out her activities of daily living, not remembering where the bathroom was located in her house and had trouble brushing her teeth and feeding her pets. She presented to an outside hospital about two weeks prior where she reportedly had a negative work up and discharged. On presentation, she was afebrile with vital signs within normal limits. On exam, she was alert and oriented to person only, cranial nerves were intact and her motor exam and sensation were normal. She had clear speech but incorrectly named common objects, as well as echolalia and perseveration. The rest of her exam was normal and a complete metabolic panel and complete blood count were unremarkable. Thyroid stimulating hormone was normal and rapid plasma reagin was negative. SARS-CoV-2 PCR was negative. Magnetic resonance imaging of the brain showed bilateral convexity gyral diffusivity signal abnormalities with restriction and FLAIR signal changes. Continuous EEG revealed subclinical seizures. Cerebrospinal fluid (CSF) studies showed normal cell count, protein, and glucose. CSF Venereal Disease Research Laboratory (VDRL) test and autoimmune encephalopathy panel were negative. CSF 14-3-3 protein was positive and tau protein was elevated five times upper limit of normal. CSF Real-time Quaking-induced Conversion (RT-QuIC) was positive. A diagnosis of Creutzfeldt-Jakob disease (CJD) was made based off these results. She had a rapid decline in her mental status and breakthrough seizures while on antiepileptic medications. She was transitioned to hospice care and expired less than three months after symptom onset.

Discussion: CJD is a neurodegenerative disorder that carries a grave prognosis. Patients usually present with rapidly progressive dementia, then progress to develop myoclonus and seizures. Death occurs within one year of onset. Premortem diagnosis remains challenging due to low index of suspicion given the rarity. Worldwide annual incidence is 1-1.5 per million persons. The most common type of CJD is sporadic, making up 85% of the total cases. Other types are familial, variant, and iatrogenic. There are also retrospective studies that have found evidence to suggest a causal relation of surgery with a non-negligible proportion of CJD cases (1). Although no direct link has been found, she interestingly had a history of a dental bone graft a few years prior to presentation.While 14-3-3 and tau proteins are not specific to CJD, it can be helpful in arriving at a diagnosis when a patient presents with rapidly progressive dementia and otherwise negative work up. Unfortunately, no treatment has been identified to slow the progression of the disease. Supportive care is recommended.

Conclusions: This was a case of a rare disease CJD. Though rare, it is an important differential diagnosis to consider in patients presenting with rapidly progressive dementia. Though there is no treatment, the diagnosis can help guide discussions regarding goals of care with the patient and family.