The effect of preoperative migraine headache frequency on surgical outcomes.

Background: The Global Burden of Disease ranks migraine headache among the most disabling of conditions, and in the United States, migraine headache is one of the top five causes of visits to the emergency room. As migraineurs turn to surgical treatment for relief, it is unknown how migraine frequency influences outcomes.

Methods: In total, 488 patients prospectively completed the migraine headache questionnaires preoperatively and at least 11 months postoperatively. Patients were grouped into three cohorts based on migraine frequency of one to 14 per month (episodic), 15 to 29 per month (chronic), or at least daily (daily). Statistics were performed with paired t tests, linear regression, and analysis of variance with Tukey's honestly significant difference test.

Results: All groups experienced a significant benefit from surgery in terms of frequency, duration, and severity of migraine headache, and Migraine Headache Index. Patients experienced significantly different final outcomes based on their frequency cohort with respect to duration (p = 0.02), frequency (p < 0.0001), and Migraine Headache Index (p < 0.0001). However, when the preoperative score is controlled for, the only significant difference between cohorts occurred in Migraine Headache Index among daily migraineurs compared with episodic (p = 0.0003) and chronic (p = 0.0008) migraineurs. No other significant findings persisted.

Conclusions: All cohorts, regardless of their frequency of migraine headache, achieved significant improvement in frequency, duration, severity, and Migraine Headache Index. The groups also achieved statistically different final outcomes, but no group benefits more than the other when improvement is quantified, and patients can expect similar relative improvement.