INFLUENCE OF CAFFEINE AND CAFFEINE WITHDRAWAL ON HEADACHE AND CEREBRAL BLOOD-FLOW VELOCITIES

Caffeine consumption may cause headache, particularly migraine. Its wi thdrawal also produces headaches and may be related to weekend migrain e attacks. Transcranial Doppler sonography (TCD) has shown changes in cerebral blood flow velocities (BFV) during and between attacks of mig raine. In order to examine whether headache and changes in BFV could d evelop from controlled caffeine alterations, 20 healthy volunteers, wi thout a headache history, underwent clinical evaluation, TCD and serum caffeine measurements on four occasions, comparing conditions of regu lar caffeine intake, caffeine withdrawal and ''re-caffeination''. Afte r 24 h of complete caffeine abstinence, 10 suffered from moderate to s evere headaches with complete recovery within 1 h after caffeine intak e. The BFVs in both middle cerebral, both posterior cerebral and basil ar arteries were higher following the withdrawal period, reaching stat istical significance in the left middle cerebral, basilar and both pos terior cerebral arteries. BFVs decreased significantly within half an hour after caffeine intake in all subjects, and were similar to baseli ne values after 2 h. Our results emphasize the relationship between ca ffeine withdrawal, the development of headache and alterations in cere bral blood flow velocities. Also, these findings indicate that accurat e interpretation of TCD measurements should account for the influence of caffeine on BFVs.