- Last edited on April 30, 2020
Creutzfeldt-Jakob Disease (CJD)
Primer
Creutzfeldt-Jakob Disease (CJD) is a rare, fatal, progressive neurodegenerative disorder. It affects about 1 in every 1 million people per year worldwide. CJD has a rapid course and usually appears in late life. There is a very short survival time, death usually occurs within one year of symptom onset.
Prevalence
There approximately 1 or 2 cases per million people. The peak age for the sporadic CJD is 67 years.
Classification
Major or mild neurocognitive disorder (NCD) due to prion disease includes the group of subacute spongiform encephalopathies including Creutzfeldt-Jakob disease, variant Creutzfeldt-Jakob disease, kuru, Gerstmann-Sträussler-Scheinker syndrome, and fatal familial insomnia.
Diagnostic Criteria
Criterion A
The criteria are met for major or mild neurocognitive disorder.
Criterion B
There is insidious onset, and rapid progression of impairment is common.
Criterion C
There are motor features of prion disease, such as myoclonus or ataxia, or biomarker evidence.
Criterion D
The neurocognitive disorder is not attributable to another medical condition and is not better expiated by another mental disorder.
Symptoms
CJD should always be considered in a patient with the combination of the two cardinal clinical features:
- Rapid, progressive mental deterioration including dementia and behavioural abnormalities. Concentration, memory, and poor judgment may be early signs. Psychiatric symptoms including depression, apathy, and anxiety may also occur.
- Myoclonus and abnormal movements (including ataxia, chorea, or dystonia). A myoclonus provoked by startle reflex is also common. Myoclonus, especially provoked by startle (hyperekplexia), is present almost all patients at some point during the disease course.
Pathophysiology
CJD is caused by transmissible agents known as prions. The most common type is sporadic Creutzfeldt-Jakob disease (sCJD). Variant CJD (vCJD) is much rarer and is associated with transmission of bovine spongiform encephalopathy, also known as “Mad Cow disease.” There is a genetic component in up to 15% of cases of CJD, associated with an autosomal dominant mutation.
Investigations
Neuroimaging
Prion disease is diagnosed with least one of the characteristic biomarker features: cortical ribboning or lesions on magnetic resonance imaging with DWI (diffusion-weighted imaging)[1] or FLAIR (fluid-attenuated inversion recovery).
Cerebrospinal Fluid
Tau or 14-3-3 protein in cerebrospinal fluid can be used to discriminate CJD from other neurodegenerative diseases.[2]
EEG
Characteristic triphasic waves can be seen on electroencephalogram.