Cholesteatoma - Cholesteatoma of the petrous apex. Contrast-enhanced HRCT scans with a soft-tissue window (A) and a bone window (B) show an oval well-delineated, nonenhancing lesion (white arrows) with erosion of the posterior wall of the pyramidal segment of the internal carotid artery (thin black arrow) and the anterior wall of the jugular bulb (thick black arrow). C, DWI demonstrates diffusion restriction in the lesion (white arrow), supporting the diagnosis of a cholesteatoma.
Stroke is the loss of brain function due to blocked blood circulation to the brain. Strokes may be caused by an uncommon type of narrowing, obstruction, or leak in the lining of the carotid artery. This leaking of blood into the artery wall (dissection) may cause a clot to form, reducing blood flow and raising the risk of stroke. The leak may arise from an injury to the neck, which means strokes caused by carotid dissection may occur in young people as well as older people.