Horton Syndrome

Severe throbbing headache syndrome characterized by inflammation of the temporal (pulseless, enlarged superficial artery) and other cranial arteries. Patients present with anorexia, insomnia, and low-grade fever. Blindness may occur if process reaches the ophthalmic artery. Rarely presents before the sixth decade of life.

Arteritis Temporalis (of Horton); Horton Arteritis; Horton Disease I; Horton Giant Cell Arteritis; Horton Temporal Arteritis; Horton-Gilmour Disease; Horton-Magath-Brown Syndrome; Hutchinson-Horton Syndrome; Giant Cell Arteritis (GCA); Granulomatosis Arteritis; Senile Arteritis; Temporal Arteritis; Temporal Megacellular Arteritis.

NB: Do not confuse with Bing-Horton syndrome or Horton disease II (cluster headache and erythroprosopalgia).

Systemic arteritis affecting major and small arteries. First described by Jonathan Hutchinson in 1890.

More common in the northern latitudes (15-30:100,000 persons) compared to southern latitudes (<2:100,000 persons). Rather common in northern Europe. Rare in nonwhites. Both sexes affected, but females twice as often as males.

Not a genetic disorder even though genetic factors may predispose to the disease (three allelic variants of the HLA-DRB1*04 family are overrepresented in patients with biopsy-proven disease). Familial aggregation has been observed. People of Hispanic descent seem genetically protected against the syndrome.

The pathogenesis is not fully understood, but the underlying cause of the inflammation is an autoimmune reaction to the lining of temporal and related arteries (mainly the adventitia); however, Horton syndrome cannot be considered an autoimmune disease. Histologically, there is lymphocyte, plasma cell, and multinucleated giant cell infiltration of the vessel wall. A cell-mediated autoimmune mechanism against elastin is suggested. The cellular infiltrate predominantly consists of CD4 + T lymphocytes and monocytes. High levels of IL-1 and IL-2 have been identified in the lesions of Horton syndrome, as well as in polymyalgia rheumatica, suggesting a common pathogenesis. Chlamydia pneumoniae may play a significant role (data suggest the organism could be viable and undergo active vegetative growth in temporal artery tissues in affected patients). Increased endothelin-1 plasma levels have been reported, and the significance is under evaluation.

Positive temporal artery biopsy. Characteristic history in the absence of biopsy.

General symptoms include weight loss, pyrexia (may have acute onset), symmetrical muscle stiffness, and pain that is worse in the morning. Cranial symptoms include paroxysmal burning pain (typically unilateral and beginning behind one eye), headache, jaw claudication, rarely scalp necrosis, or lingual ischemia secondary to arterial occlusion. Skin overlying arteries may appear inflamed in the acute phase. Ocular problems include blindness caused by anterior ischemic optic atrophy, transient visual loss, and diplopia. The vasculitis increases the risk of aortic aneurysm (usually thoracic/dissecting), coronary arteritis causing myocardial ischemia, and cerebral arteritis causing infarction, most usually in a posterior cerebral artery distribution. Vertebral arteritis may result in auditory loss and vestibular dysfunction (vertigo). Abdominal claudication and bowel necrosis are reported. Erythrocyte sedimentation rate and C-reactive protein are elevated. Treatment consists of high-dose glucocorticoid therapy in the acute phase, subsequently reduced to a lower maintenance dose for up to 6 months.

Full medical history and physical examination for evidence of coronary artery disease and cerebral infarction must be obtained. History of chronic steroid use, must plan to supplement the steroid prior to anesthesia. Examine for coexisting disease. ECG mandatory; echocardiogram as clinically indicated. Chest radiograph to examine for evidence of thoracic aortic aneurysm.

The potential for myocardial ischemia is the major concern; therefore, avoid myocardial depression, treat hypotension aggressively, and avoid tachycardia. Consider use of invasive monitoring. Consider suitability for regional anesthesia. Some patients have reduced jaw opening (trismus) and are at risk for difficult tracheal intubation.

Ensure adequate perioperative steroid supplementation in the presence of long-term treatment.

Polymyalgia Rheumatica: Severe aching and stiffness in the neck, shoulder girdle, and pelvic girdle; unknown origin.

Bing-Horton Syndrome (Cluster Headache; Horton Disease Type II; Paroxysmal Nocturnal Cephalalgia; Erythromelalgia of the Head; Sphenopalatine Neuralgia): Characterized by cluster headache consisting of recurrent brief attacks of sudden, severe, unilateral periorbital pain. The pathophysiology is not understood; however, typical periodicity has been attributed to hypothalamic (particularly suprachiasmatic nuclei) hormonal influences. It is thought to be generated at the level of the pericarotid/cavernous sinus complex. Immunologic and vasoregulatory factors, as well as the influence of hypoxemia and hypocapnia, have been suggested but are controversial. The incidence in the United States is estimated at 0.4% in men and 0.08% in women. It is predominant in the republic of San Marino with a prevalence of 0.7%. More common in men, with a male-to-female ratio of 5:1.