Giant Cell Arteritis
- Giant Cell Arteritis is a primary vasculitis which traditionally affects large to medium arteries. Although arteries throughout the body can be affected, the disease most often involves the branches of the carotid artery, especially the temporal artery.
- Giant Cell Arteritis primarily affects elderly individuals after their fifth decade.
- Giant Cell Arteritis is characterized by granulomatous Inflammation especially around the internal elastic lamina of the tunica intima, which can result in its fragmentation. Presence of giant cells within the granuloma is frequent, providing this disease its namesake. Inflammation results in thickening and narrowing of the arterial lumen which can additionally undergo thrombosis. Subsequent fibrotic organization of the thrombosis can convert the artery into a solid cord.
- The pathogenesis of Giant Cell Arteritis is poorly understood but may result from inappropriate activation of CD4+ T-cells to antigens within the vascular wall.
- The symptomology of Giant Cell Arteritis is primarily a result of stenosis or obliteration of the involved vessels and thus downstream hypoperfusion. In addition, patients frequently display constitutional symptoms. Headache is usually a prominent feature especially due to involvement of the temporal artery which can display tenderness and nodularity. A feared complication is visual impairment or blindness which can occur due to involvement of the opthalmic artery. Roughly half of patients with Giant Cell Arteritis display polymyalgia rheumatica, a potentially related disease characterized by muscular neck pain, back pain, and pain in the shoulders and hips.