Initial Manic Presentation in Creutzfeldt-Jakob Disease: A Case Report.

BACKGROUND Creutzfeldt-Jakob disease (CJD) is a rare and fatal neurodegenerative condition caused by misfolded prion proteins. It most commonly presents with rapidly progressive dementia and neurological deterioration. While psychiatric symptoms are not unusual in the early stages of CJD, it is very uncommon for the disease to begin with manic features as the primary presentation. CASE REPORT We describe the case of a 65-year-old woman who initially developed symptoms consistent with mania. These included an elevated mood, emotional instability, and insomnia. Over time, her clinical condition worsened, and she began to experience hallucinations, along with a noticeable motor decline. Due to the atypical nature of her initial symptoms, she was first treated for viral encephalitis, which contributed to a delay in establishing the correct diagnosis. Subsequent investigations played a key role in clarifying the underlying pathology. Brain magnetic resonance imaging (MRI) revealed characteristic findings of CJD, including cortical ribboning and changes in the basal ganglia. Electroencephalography (EEG) showed periodic sharp-wave complexes, further supporting the diagnosis. Cerebrospinal fluid analysis tested positive for prion protein using real-time quaking-induced conversion (RT-QuIC), confirming a final diagnosis of sporadic CJD (sCJD). CONCLUSIONS Although rare, mania can be an early sign of CJD. This case illustrates the diagnostic challenges that arise when psychiatric symptoms dominate the initial clinical picture. It emphasizes the importance of maintaining a broad differential diagnosis when evaluating new-onset psychiatric symptoms in older adults, especially when these symptoms are accompanied by a rapid decline in cognition or motor function. Early consideration of CJD in such scenarios may help expedite diagnosis, avoid unnecessary treatments, and provide clarity for patients and families facing a progressive and life-limiting illness.