For the third month in a row, Hong Kong health authorities are reporting a suspected case of sporadic Creutzfeldt-Jakob disease (CJD).
The case that was recorded on April 16, 2015, affects a 74-year-old woman with underlying illnesses. She presented with confused speech, decreased general condition and malaise since February 1, 2015 and was admitted to a public hospital on February 14. Subsequently, she developed progressive dementia, myoclonus, visual and cerebellar disturbance, pyramidal and extrapyramidal dysfunction and akinetic mutism.
Electroencephalography finding was compatible with CJD. She was classified as a probable case of sporadic CJD. She had no known family history of CJD. No risk factors for iatrogenic or variant CJD were identified. Her condition was serious.
Creutzfeldt-Jakob disease (CJD) is a rare, degenerative, invariably fatal brain disorder. It affects about one person in every one million people per year worldwide.
CJD belongs to a family of human and animal diseases known as the transmissible spongiform encephalopathies (TSEs). Spongiform refers to the characteristic appearance of infected brains, which become filled with holes until they resemble sponges under a microscope. CJD is the most common of the known human TSEs.
CJD usually appears in later life and runs a rapid course. Typically, onset of symptoms occurs about age 60, and about 90 percent of individuals die within 1 year. In the early stages of disease, people may have failing memory, behavioral changes, lack of coordination and visual disturbances. As the illness progresses, mental deterioration becomes pronounced and involuntary movements, blindness, weakness of extremities, and coma may occur.
There are three major categories of CJD:
- In sporadic CJD, the disease appears even though the person has no known risk factors for the disease. This is by far the most common type of CJD and accounts for at least 85 percent of cases.
- In hereditary CJD, the person has a family history of the disease and/or tests positive for a genetic mutation associated with CJD. About 5 to 10 percent of cases of CJD in the United States are hereditary.
- In acquired CJD, the disease is transmitted by exposure to brain or nervous system tissue, usually through certain medical procedures. There is no evidence that CJD is contagious through casual contact with a CJD patient. Since CJD was first described in 1920, fewer than 1 percent of cases have been acquired CJD.