Stabbing headache in patients with autoimmune disorders.

Stabbing headache is a relatively rare type of chronic "primary" headache with distinctive features with respect to more common forms of paroxysmal headache, such as cluster headache and trigeminal neuralgia. Drug treatment is empirical because of the lack of knowledge on the pathophysiology of stabbing headache. We examined 26 patients recruited over 10 years, who met the diagnostic criteria for stabbing headache. Interestingly, more than half of these patients had autoimmune disorders, including multiple sclerosis, Sjögren's disease, Systemic Lupus Erythematosus, Behçet's disease, autoimmune vasculitis, and antiphospholipid antibody syndrome. We speculate that stabbing headache may develop as a result of neuroinflammation and, at least in some cases, may be an epiphenomenon of focal demyelinating lesions of the upper or lower brain stem.