Probable Creutzfeldt-Jakob Disease With Negative Cerebrospinal Fluid (CSF) 14-3-3 Protein: Diagnostic Value of Diffusion-Weighted MRI.

Creutzfeldt-Jakob disease is a rare prion disorder that may present with rapidly progressive neurological and neuropsychiatric deterioration, making early diagnosis challenging. We report the case of a 55-year-old woman admitted for rapidly progressive balance impairment evolving over three months, associated with dysarthria, upper-limb dystonia, visual and auditory hallucinations, progressive loss of autonomy, mutism, refusal of oral intake, and myoclonus involving the face and limbs. A history of a similar neurological disorder in her mother was reported. Routine cerebrospinal fluid (CSF) analysis was unremarkable, onconeural antibody testing was negative, and cerebrospinal fluid 14-3-3 protein was negative. Electroencephalography showed slowing with short pseudo-periodic activity over the right hemisphere. Repeat brain magnetic resonance imaging demonstrated bilateral asymmetric cortical diffusion restriction, more marked in the right frontoparietotemporal region and the left parieto-occipital cortex, associated with the involvement of the right caudate and lentiform nuclei and the left caudate nucleus. There was no pathological enhancement, hemorrhage, or thalamic involvement. Based on the rapidly progressive neurological course, myoclonus, extrapyramidal signs, suggestive electroencephalographic abnormalities, and characteristic cortical-basal ganglia diffusion restriction, a diagnosis of probable Creutzfeldt-Jakob disease was favored. This case highlights the diagnostic value of diffusion-weighted magnetic resonance imaging in suspected prion disease, especially when cerebrospinal fluid 14-3-3 protein is negative, and emphasizes the importance of considering a possible familial background when a similar disorder is reported in a first-degree relative.