An Atypical Case of Creutzfeldt-Jakob Syndrome Presenting with Cacosmia and Amyloid Positivity.

This report presents a challenging case of Creutzfeldt-Jakob Disease (CJD), a rare and rapidly progressing neurological disorder. The patient exhibited diverse and progressive neuro-psychiatric symptoms, including memory impairment, behavioral changes, and hallucinations associated with cacosmia. The diagnosis of CJD is complicated due to its variable clinical presentation, limited awareness, and the need for tissue pathology confirmation. Diagnostic tests, particularly brain magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) analysis, played crucial roles in the evaluation. The MRI revealed characteristic cortical ribboning patterns. CSF analysis initially suggested Alzheimer's disease pathology continuum. Repeated Real-time-quaking-induced assay testing (RT-QuIC) confirmed the diagnosis despite an initial negative result. This case underscores the significance of contemplating CJD in individuals exhibiting rapidly progressive dementia, even in the presence of atypical clinical features. Furthermore, it emphasizes the importance of recognizing that an initial negative result from the RT-QuIC test should not preclude consideration of CJD, particularly when characteristic MRI findings are present.