Mast cell activation in children with migraine before and after training in self-regulation

Migraine may affect as many as 9% of all schoolchildren and often presents with abdominal symptoms of pain, nausea, and vomiting. Even though the path ophysiology of migraine remains unknown, self-regulation techniques appear to be more effective in prevention of childhood migraine than conventional pharmacotherapy which is often associated with adverse effects. Mast cells have been implicated in the pathogenesis of migraine in adults, but have no t been previously studied in children with migraine. Mast cells are found close to the vessels and nerves in the meninges where they can release multiple vasoactive, neurosensitizing, and pro-inflammator y mediators. Therefore, we investigated whether children with migraine may have increased urinary levels of mast cell mediators and whether practicing relaxation imagery exercises has an effect on the frequency of headache, a s well as on mast cell activation. Urine was collected for 24 hours from children with and without migraine af ter a 5-day amine-restricted diet. Children with migraine also collected ur ine during migraine episodes. The mean levels of urinary histamine, its mai n metabolite, methylhistamine, and the mast cell enzyme, tryptase, were hig her in children than generally found in adults, but they did not differ sta tistically in any of the categories studied. However, in 8 of 10 children w ho practiced relaxation imagery techniques and successfully reduced the num ber of migraines, the urine tryptase levels were also significantly lower. There was no relationship between successful practice and sex or age of the child. These results suggest that stress may activate mast cells which cou ld be involved in the pathophysiology of migraine.