Table 1. Clinical diagnostic criteria for sporadic Creutzfeldt-Jakob disease (sCJD). This table outlines the World Health Organization (1998), University of California San Francisco (2007), and MRI-CJD Consortium (2008) criteria for diagnosing probable sCJD and possible sCJD. Brain biopsy is required for premortem diagnosis of definite sCJD.

World Health Organization diagnostic criteria (1998) Probable sCJD = A + at least 2 of B + at least 1 of C Possible sCJD = A + at least 2 of B + duration <2 years
A.	Progressive dementia
B.	Specific neurological manifestations Myoclonus Visual or cerebellar disturbance Pyramidal or extrapyramidal dysfunction Akinetic mutism
C	Laboratory tests Positive EEG: periodic sharp wave complexes Positive CSF: 14-3-3 protein
D.	Routine investigations should not suggest an alternative diagnosis
University of California San Francisco diagnostic criteria (2007) Probable sCJD = A + at least 2 of B + at least 1 of C + D Possible sCJD is not defined in this criteria set
A.	Rapid cognitive decline
B.	Specific neurological manifestations Myoclonus Pyramidal or extrapyramidal Visual Cerebellar Akinetic mutism Other focal higher cortical sign (e.g., neglect, aphasia, apraxia, acalculia)
C.	Laboratory tests Positive EEG: periodic epileptiform discharges Positive MRI: subcortical or cortical gyral hyperintensity (cortical ribboning) on DWI and preferably restricted diffusion on ADC map
D.	Routine investigations do not suggest an alternative diagnosis
MRI-CJD Consortium diagnostic criteria (2009) Probable sCJD = at least 2 of A + at least 1 of B Possible sCJD = at least 2 of A + duration < 2 years
A.	Clinical signs Dementia Cerebellar or visual Pyramidal or extrapyramidal Akinetic mutism
B.	Laboratory tests Positive EEG: periodic sharp wave complexes Positive CSF: 14-3-3 protein in patients with a disease duration of less than 2 years Positive MRI: high signal abnormalities in caudate nucleus and putamen or at least two cortical regions (temporal-parietal-occipital) either on DWI or FLAIR

sCJD, sporadic Creutzfeldt-Jakob disease; EEG, electroencephalography; CSF, Cerebrospinal fluid; MRI, magnetic resonance imaging; DWI, diffusion-weighted imaging; ADC, apparent diffusion coefficient.