Is chronic tension-type headache a vascular headache? The relation between chronic tension-type headache and cranial hemodynamics.

Twenty-seven patients with chronic tension-type headache were studied as to end-tidal PCO2, heart rate, mean blood pressure, diameter and blood flow of the common carotid arteries, cranial vascular resistance, and headache intensity at supine rest, after administration of nitroglycerin, and at head down tilt. The results were compared to the results of nitroglycerin and head down tilt provocations in age- and sex-matched controls. During supine rest, no change in chronic tension-type headache occurred. Nitroglycerin and tilting induced significant increase of the headache intensity compared to baseline in patients with chronic tension-type headache (P=0.01 and P<0.05, respectively) in contradistinction to controls who did not develop significant headache. Common carotid artery blood flow changes were similar during nitroglycerin provocations in the two groups, but greater (P<0.05) during head down tilt in patients than in controls. Lumbar cerebrospinal fluid pressure was found to be greater than 20 but less than 26 cm H2O in 45% of the 22 patients studied with chronic tension-type headache. The results indicate that the pain in chronic tension-type headache is related to cranial hemodynamics, presumably to distention of intracranial veins.