Table 1.

Diagnostic criteria for Creutzfeldt-Jakob disease (CJD) (12).

Definite sporadic CJD	• Diagnosed by standard neuropathologic techniques (e.g., protease-resistant prion proteins on immunohistochemistry and/or western blot)
Probable Sporadic CJD	• Neuropsychiatric disorder plus positive real time quaking induced conversion (RT-QuIC) testing -OR- • Rapidly progressive dementia with at least two of the following:  ∘ Myoclonus  ∘ Visual and/or cerebellar signs  ∘ Pyramidal and/or extrapyramidal signs  ∘ Akinetic mutism -AND- • One of the following positive test results:  ∘ Periodic sharp wave complexes on electroencephalogram  ∘ Positive 14-3-3 cerebrospinal fluid test with a disease duration of < 2 years  ∘ High signal in caudate/putamen or at least two cortical regions (temporal, parietal, occipital) on DWI or FLAIR sequences of a brain MRI -AND- • Other investigations exclude an alternative diagnosis
Possible Sporadic CJD	• Progressive dementia and at least two of the following:  ∘ Myoclonus  ∘ Visual or cerebellar signs  ∘ Pyramidal or extrapyramidal signs  ∘ Akinetic mutism • Duration of illness < 2 years • Other investigations exclude an alternative diagnosis
Iatrogenic CJD	Progressive cerebellar syndrome in a recipient of human cadaveric-derived pituitary hormone; or CJD with a recognized acquired prion disease exposure risk
Familial CJD	Definite or probable CJD in a patient with definite or probable CJD in a first degree relative; and/or symptoms of CJD plus a disease-specific PRNP mutation

DWI, diffusion weighted imaging; FLAIR, fluid attenuated inversion recovery; MRI, magnetic resonance imaging.