The different types of human prion disease are distinguished by the clinical characteristics and investigations, together with a history of a relevant iatrogenic exposure or a family history of a similar disorder. A definite diagnosis requires examination of brain tissue, usually after post-mortem. The characteristics of the various forms of disease are discussed in the links below.

• The different types of human prion disease
• The clinical features of human prion disease
• Investigations undertaken in possible cases of human prion disease

Improving the diagnosis of CJD is a vital area of research. The NCJDRSU is involved in developing specialist investigations for CJD in collaboration with colleagues in Europe and internationally. The utility of electroencephalography (EEG), magnetic resonance imaging (MRI) and CSF proteins, including 14-3-3 and tau, is being studied at the Unit and recently a promising new CSF test, real time quaking induced conversion (RT-QUiC), has been developed.  There is also wide ranging research on the neuropathological and molecular aspects of diagnosis, including how prion protein correlates with phenotypic diversity in CJD, and on improved detection methods for prion protein, including the use of  specialised monoclonal antibodies, conformation dependent immunoassay (CDI) and amplification methods such as protein misfolding cyclic amplification (PMCA).

Suspect cases are classified according to internationally recognised published criteria, last updated in 2017.

• Diagnostic criteria for human prion disease