Creutzfeldt-Jakob Disease (CJD) is a rare and fatal condition that affects the brain. It is a neurodegenerative disorder that causes unique changes in brain tissue and affects muscle coordination, thinking, and memory. CJD is caused by abnormal forms of proteins called prions, which accumulate at high levels in the brain and cause irreversible damage to nerve cells. There are several types of CJD, including:

• Classic CJD: This is the most common type of CJD and occurs sporadically in persons with no known risk factors or inherited genetic mutations. It is a rapidly progressive, invariably fatal neurodegenerative disorder with characteristic clinical and diagnostic features.

• Variant CJD: This type of CJD is likely caused by consuming meat from a cow that had bovine spongiform encephalopathy (BSE, or "mad cow" disease) . It is distinct from classic CJD and has a slower progression.

• Familial CJD: This is a very rare genetic condition where a person inherits a gene that causes prions to form in their brain during adulthood, triggering the symptoms of CJD.

Symptoms of CJD include loss of memory, personality and behavioral changes, difficulty sleeping, impaired thinking, weakness, loss of balance and coordination, difficulty walking and talking, and involuntary muscle jerking. The disorder is fatal in a short time, usually within 8 months. There is no cure for CJD, and treatment is focused on relieving symptoms.