Children referred to the Headache Center at Children’s Hospital Medical Center, Cincinnati, OH, Sept 1996-June 1997, were evaluated for clinical characteristics of the headaches, using criteria of the International Headache Society (IHS), and older criteria by Vahlquist and Prensky and Sommer for comparison. Questionnaires were completed by 184 patients and their families. The age range was 2-18 years (mean, 11 yrs), and the majority had suffered 5 or more headaches. The headache duration was less than 2 hours in 25 (13.6%), 2-4 hours in 65 (35%) of whom 54 were younger than 15 years, 4-72 hours in 71 (39%), and more than 72 hours in 22 (12%). Only 62 patients (34%) satisfied the IHS diagnostic criteria. By amending these criteria to include a duration range from 2-48 hours for children younger than 15 years, 109 (59%) met the criteria. If headache duration was excluded entirely from the IHS criteria, 147 (80%) qualified for a migraine diagnosis. The modified IHS criteria matched the Prensky and Sommer but not the Vahlquist criteria. The duration factor should be a minor criterion for migraine in children, and only headaches longer than 72 hours should be excluded in children younger than 15 years. 
COMMENT. The authors suggest that the IHS criteria for pediatric migraine should be revised, and the duration factor removed or made a minor diagnostic criterion. Many children with a shorter duration and a number with a very long duration headache still fit the diagnosis of migraine, using the modified criteria. The majority have bilateral, usually frontal, headache, and unilateral location is uncommon.
Prothrombotic risk factors in coexistent migraine and stroke. In 17 patients with coexistent disease, the prevalence of factor V Leiden (5.8%) and other prothrombotic genotypes was not significantly different from that determined in 107 patients with ischemic cerebrovascular disease without migraine, 106 migraine patients, and 202 control subjects. Prothrombotic tendencies do not increase the risk of stroke in patients with migraine. 
Migraine precipitating factors. Of 226 children with headaches, 148 (65%) had migraine without aura, 43 (19%) migraine with aura, 25 (11%) daily headache, and 16 (4%) had tension/migraine. Precipitating factors were elicited in 206 children (91%); 141 (62%) had one factor and 53 (29%) had two or more. In decreasing frequency, these included stress (23%), sleep deprivation (16%), hunger (11%), heat (11%), bright light (9%), exercise (8%), foods (7%), motion (6%), and medications (5%); MSG and caffeine, odors, and reading were precipitants in less than 5% each. Analgesic rebound occurred in 36% of the daily headache group compared to 1.5% of other headache patients. Environmental manipulations and avoidance of precipitating factors may obviate the need for daily medications in the treatment of childhood migraine . In my own experience and that of colleagues in the UK, specific foods are more frequent precipitants of headache (see Progress in Pediatric Neurology I and II, PNB Publ, 1991;pp542-3, 1994;ppl66-168).
Mast cell activation in migraine. Mean levels of urinary histamine, its metabolite, methylhistamine, and the mast cell enzyme, tryptase, were higher in children than in adults. In 8 of 10 children who successfully practiced relaxation imagery techniques for migraine, urine levels of tryptase were significantly lower than controls. Stress may activate mast cells that could be involved in the pathophysiology of migraine. 
Intranasal sumatriptan for acute migraine. A randomized double-blind placebo-controlled crossover study showed that 12 of 14 patients (6-10 years of age) reported a decrease in pain intensity after sumatriptan versus 6 of 14 after placebo (p=0.031), and complete relief was obtained in 9 of 14 vs 2 of 14 (p=0.016).