Prion diseases, or transmissible spongiform encephalopathies (TSEs), are considered fatal and incurable due to several factors detailed in various sources:

Nature of Prions

Prions are misfolded proteins that can induce other normal proteins in the brain to misfold. This abnormal folding results in a chain reaction that leads to widespread brain damage. Unlike bacteria or viruses, prions do not contain nucleic acids (DNA or RNA), making them resilient and difficult to target with treatments (NIAID).

Lack of Immune Response

The immune system does not recognize prions as foreign invaders because they are derived from normal body proteins. This lack of recognition prevents the immune system from attacking them, allowing prions to proliferate unchecked (Montefiore Einstein Neuroscience Center).

Progressive Neurodegeneration

Prions cause the brain tissue to develop holes, giving it a sponge-like texture. This leads to severe neurological symptoms, including loss of coordination, memory failure, and behavioral changes, ultimately resulting in death (Merck Manuals).

Absence of Effective Treatments

There are no current treatments that can effectively cure prion diseases. Research in this area is ongoing, but the unique and resistant nature of prions makes finding a cure extremely challenging. Current approaches focus more on symptom management rather than curing the disease (CDC).

Rapid and Inevitable Progression

Once symptoms appear, prion diseases progress rapidly, and the damage to the brain is irreversible. Treatments are primarily aimed at alleviating symptoms and providing supportive care, rather than curing the disease. Most individuals with prion diseases die within months to a few years after symptoms appear (Cleveland Clinic).

Ongoing Research

Several studies and institutes like the Broad Institute are exploring potential treatments, including gene-silencing tools, to manage the progression of prion diseases. However, these are still in experimental stages and not widely available.

Relevant Images and Visuals

These insights highlight why prion diseases are fatal and incurable, demonstrating both the complexity and resilience of prions as well as the challenges faced in medical research to combat these diseases.