Temporal Arteritis

Optic Nerve Disease
	Compressive Optic Neuropathy
	Optic Neuritis
	Acute Ischemic Optic Neuropathy
	Temporal Arteritis

Temporal arteritis, or giant cell arteritis, is a common systemic vasculitis of unknown etiology and was originally described as inflamed and swollen temporal arteries. In general, temporal arteritis can be thought of as a vasculitis involving medium-to-large arteries originating from the aorta. Although it was originally believed to be a rare entity, it is more commonly recognized today. Temporal arteritis occurs in an estimated 15-30 individuals per 100,000. It almost exclusively affects individuals older than 50 years and is believed to have a prevalence as high as 1 case per 500 individuals in this age group. An association between temporal arteritis and polymyalgia rheumatica (proximal muscle pain and stiffness for at least one month) is also thought to exist. 15 – 30 % of patients with PMR develop temporal arteritis and 30 - 50% of patients with temporal arteritis have PMR.

Pathophysiology

The exact cause of temporal arteritis is not well delineated. It is characterized by a granulomatous inflammatory process that is most pronounced along the internal elastic lamina of arterial walls. Temporal artery biopsy demonstrates a predominance of mononuclear cells or multinucleated giant cells with fragmentation of the intima. Inflammation may be followed by intimal proliferation and eventual stenosis or occlusion of the involved arterial segment. The clinical findings are a result of decreased blood flow and include jaw or tongue claudication; extremity stiffness; scalp tenderness; and visual changes with anterior ischemic optic neuropathy (AION), amaurosis fugax, or optic atrophy leading to blindness in as many as 60% of patients.