• migraine with aura;
  • migraine without aura;
  • placebo;
  • stratification

Objective.—To compare the intensity of pain and associated symptoms after placebo administration in patients with migraine with aura and migraine without aura.

Background.—Studies that evaluate drugs used in the acute treatment of migraine ideally should include a placebo arm. The International Headache Society also recommends stratification according to age and sex but not by the presence versus absence of aura.

Methods.—The study was conducted as part of a placebo controlled randomized survey comparing four active drugs against placebo in the acute treatment of migraine. Patients were blinded as to treatment received. Placebo consisted of 10 mL of normal saline (0.9%) intravenously. Pain intensity was evaluated by a 10-point analogical-verbal scale. Nausea, photophobia, and phonophobia were evaluated by a four-point analogical-verbal scale. For statistical analysis, unpaired t-test with Welch correction was used.

Results.—After placebo administration, reduction of symptom intensity (pain, nausea, photophobia, and phonophobia) in patients with migraine without aura was significantly greater than that observed in patients with migraine with aura.

Conclusions.—Our findings suggest that studies comparing placebo against an active drug should use stratification according to the presence versus absence of aura.