What is the Difference Between CJD and VCJD?

Creutzfeldt-Jakob Disease (CJD) and Variant Creutzfeldt-Jakob Disease (vCJD) are both rare, fatal prion diseases that cause progressive degeneration of the brain. However, there are several key differences between the two:

1. Age of onset: vCJD predominantly affects younger people, with a median age at death of 28 years, while the median age at death for classic CJD in the United States is 68 years.
2. Clinical features: vCJD has atypical clinical features, with prominent psychiatric or sensory symptoms at the time of clinical presentation, and delayed onset of neurologic abnormalities, including ataxia within weeks or months, dementia, and myoclonus. In contrast, classic CJD is characterized by rapidly progressive neurologic signs and initial symptoms such as problems with muscle coordination, personality changes, impaired vision, insomnia, depression, and unusual sensations.
3. Duration of illness: The duration of illness for vCJD is typically longer than for classic CJD, with most cases lasting more than one year.
4. Causes: Both CJD and vCJD are caused by prions, which are abnormal, pathogenic agents that can cause other brain cell proteins to become misshapen. Classic CJD is often caused by a genetic mutation in the gene for the body's normal prion protein, while vCJD is strongly linked to the consumption of cattle infected with bovine spongiform encephalopathy (BSE), also known as "mad cow disease".
5. Transmission: Unlike CJD, vCJD has been acquired by food exposure and transmitted by blood transfusion.

Despite these differences, both CJD and vCJD have very similar underlying causes and life expectancies, and both diseases are ultimately fatal.

Comparative Table: CJD vs VCJD

Here is a table outlining the differences between Creutzfeldt-Jakob Disease (CJD) and its variant (vCJD):

Both CJD and vCJD are caused by prions, which are abnormal proteins that attach to other brain cell proteins and cause them to bend, eventually killing clusters of brain cells and creating small holes in the brain, leading to the symptoms of the diseases and eventually death.