Spongiformní

Spongiformní refers to a characteristic appearance or condition that resembles a sponge. In a medical context, it describes tissues that have become porous and riddled with small holes, giving them a spongy texture. This appearance is often caused by the loss of nerve cells or the accumulation of abnormal proteins.

The most well-known examples of spongiform changes are found in transmissible spongiform encephalopathies (TSEs), a group of fatal neurodegenerative diseases affecting the brain and nervous system of animals and humans. These diseases are characterized by progressive degeneration of the central nervous system, leading to severe neurological symptoms and ultimately death.

Prion diseases are a subset of TSEs caused by infectious proteins called prions. Prions are misfolded proteins that can induce normal proteins to also misfold, leading to an accumulation of abnormal prion protein aggregates in the brain. These aggregates damage and destroy nerve cells, resulting in the characteristic spongiform changes.

Examples of prion diseases include Creutzfeldt-Jakob disease (CJD) in humans, bovine spongiform encephalopathy (BSE or "mad cow disease") in cattle, and scrapie in sheep and goats. While the exact mechanisms of transmission and pathogenesis vary between different TSEs, the resulting spongiform pathology is a common hallmark. Diagnosis often involves neurological examination, imaging, and laboratory tests, with definitive diagnosis usually requiring examination of brain tissue.