Total 5-hydroxyindoles in blood related to migraine attacks.

The total 5-hydroxyindoles (5HI) in whole blood were measured in 20 migraine patients during spontaneous migraine attacks and in headache-free periods. A statistically significant fall in blood 5-HI was found during headache in 17 patients suffering from classical and common migraine. In one patient with complicated migraine no change was found, and in two patients, one with common migraine and one with migraine and associated symptoms, there was a rise in total blood 5-HI during migraine attacks. The results are compared with previous findings in this field, and it is suggested that during migraine attacks there might be a rise in the plasma 5-HI. The possibility of using the 5-HI fall during spontaneous migraine attacks as a simple test for the diagnosis of migraine is discussed.