Headache in type I Chiari malformation.

We analyzed the headaches in 50 patients with type I Chiari malformation. Of the 50, 14 (28%) had a rather specific, usually protracted, suboccipital-occipital headache of variable quality and duration that was aggravated by Valsalva's maneuver, effort, cough, or postural changes and relieved by occipital-suboccipital craniectomy. Only the degree of tonsillar herniation significantly correlated with the presence of this pain. Both migraine and tension-type headache occurred with the expected frequency for the general population.