Case Presentation: A 78-year-old female with a medical history of hypertension and hypothyroidism was admitted for evaluation of altered mental status. She had experienced significant decline in memory and functional capacity over the previous three weeks, which prompted her hospitalization. Prior to this, she had been fully independent and was a retired ICU nurse by profession.She had no history of psychiatric illness, seizure disorder, or neurodegenerative disease. The patient had recently traveled to Italy, where she consumed locally prepared veal, raising concern for possible prion exposure .Vital signs on admission were within normal limits.Physical examination revealed occasional myoclonus, particularly involving the upper extremities, and bilateral upper extremity ataxia. There were no focal neurological deficits. Reflexes were brisk, and Babinski sign was absent.Laboratory evaluation revealed a markedly elevated TSH (151 mIU/L). She was also diagnosed with a urinary tract infection, both of which were initially suspected contributors to her encephalopathy. She was also given a trial of high-dose steroids for possible steroid-responsive encephalopathy, but there was no improvement; she developed transient visual hallucinations likely secondary to corticosteroids near the end of the treatment course. MRI Brain: Bilateral restricted diffusion in the caudate nuclei, putamen, and thalamus, highly suggestive of Creutzfeldt–Jakob disease. Video EEG: Diffuse slowing without epileptiform activity. Infectious Workup: Blood and urine cultures, HIV, RPR, HSV PCR, and Lyme serologies were negative. Autoimmune Encephalitis Panel : Negative.RT-QuIC (CSF) Positive — Identifies disease-causing prion proteinT-tau protein (CSF) 12,215 pg/mL 0–1,149 pg/mL Elevated14-3-3 Gamma(CSF) 96,855 AU/mL 173–1,999 AU/mL ElevatedDespite supportive care, the patient’s mental status progressively deteriorated during hospitalization. She developed mutism and profound cognitive dysfunction. She was transitioned to palliative care and passed away within three months of initial presentation, consistent with the typical clinical course of sCJD.
Discussion: CJD remains a diagnostic challenge due to its rarity and the overlap of early symptoms with more common conditions such as metabolic encephalopathy, infection, or psychiatric illness. In this case, initial findings suggested UTI-related delirium and hypothyroidism-induced encephalopathy, both of which were appropriately treated but failed to reverse cognitive decline.The diagnosis was ultimately confirmed by characteristic MRI findings and CSF biomarkers, The RT-QuIC assay has significantly improved the sensitivity and specificity of CJD diagnosis by detecting prion seeding activity.No curative treatment currently exists. Prognosis remains poor, with most patients dying within one year of symptom onset. However, early diagnosis allows for timely counseling, advance care planning, and avoidance of unnecessary interventions.
Conclusions: This case highlights the importance of considering CJD in patients with rapidly progressive dementia, particularly when initial metabolic and infectious causes have been excluded. MRI and CSF biomarkers, especially RT-QuIC, are invaluable in establishing the diagnosis. Although treatment is supportive, early recognition facilitates appropriate care planning and family support.