According to the latest diagnostic criteria released by the Centers for Disease Control and Prevention (CDC) in 2018, a definite diagnosis of CJD can only be determined through positive brain tissue testing. This would include standard neuropathological techniques (i.e., histology and immunohistochemistry); and/or western blot confirmed protease-resistant PrP. This testing is usually performed at the time of autopsy.
Confirming or ruling out a diagnosis of CJD in a living patient can be difficult. A patient can be considered as having probable CJD if they fulfil the following criteria and other appropriate diseases have been ruled out.
Probable CJD criteria:
- neuropsychiatric disorder plus positive RT-QuIC in cerebrospinal fluid (CSF)
- OR dementia accompanied by at least two of the following four clinical features:
- Myoclonus
- Visual and/or cerebellar signs
- Pyramidal and/or extrapyramidal signs
- Akinetic mutism
AND a positive result on at least one of the following laboratory tests
- EEG suggestive of CJD (periodic sharp wave complexes)
- A positive 14-3-3 CSF test in patients with a disease duration of fewer than 2 years.
- High signal in caudate/putamen on magnetic resonance imaging (MRI) brain scan and/or at least two cortical regions(temporal, parietal, occipital) either on diffusion-weighted imaging (DWI) or fluid-attenuated inversion recovery (FLAIR).1
Genetic forms of the disease can be determined through genetic sequencing on blood samples.
Click here to be redirected to the CDC's Diagnostic Criteria for CJD page for more information.
References
1. Zerr I, Kallenberg K, Summers DM, Romero C, Taratuto A, Heinemann U, et al. "Updated clinical diagnostic criteria for sporadic Creutzfeldt Jakob disease". Brain 2009;132:2659–68.
https://doi.org/10.1093/brain/awp191.