Table 2.

ECDC and CDC current guidelines for sCJD diagnosis.

sCJD Diagnostic	Signals and Symptoms
Possible	Progressive dementia AND at least 2 out of the following 4 clinical features: Myoclonus, cerebellar or visual disturbance, pyramidal and extrapyramidal dysfunction, akinetic mutism; AND the absence of a positive result for any of the 4 tests that would classify a case as “probable”; AND duration of illness less than 2 years; AND without routine investigations indicating an alternative diagnosis.
Probable	Neuropsychiatric disorder plus positive RT-QuIC in cerebrospinal fluid (CSF) or other tissues OR rapidly progressive dementia; AND at least 2 out of the following 4 clinical features: Myoclonus, cerebellar or visual disorder, pyramidal and extrapyramidal dysfunction, akinetic mutism; AND a positive result on at least 1 of the following laboratory tests: A typical EEG (periodic sharp wave complexes) during an illness of any duration, a positive 14-3-3 CSF assay in patients with a disease duration of less than 2 years, high signal in caudate/putamen on magnetic resonance imaging (MRI) brain scan or at least 2 cortical regions (temporal, parietal, occipital) either on diffusion-weighted imaging (DWI) or fluid-attenuated inversion recovery (FLAIR); AND without routine investigations indicating an alternative diagnosis.
Definite	Neuropathological confirmation and/or confirmation of PrPres by immunocytochemistry or Western blot and/or presence of scrapie fibers.