Botulinum neurotoxin type A in the preventive treatment of refractory headache: a review of 100 consecutive cases.

OBJECTIVES: To review the efficacy of botulinum neurotoxin type A (BoNT-A) in the preventive treatment of refractory headache.

BACKGROUND: Even after receiving expert care, some patients with refractory headache continue to have high disability and persistent headaches.

METHODS: Clinical records and headache calendars of 100 patients fulfilling the following inclusion criteria were reviewed: (1) age from 18 to 65 years; (2) primary headache with previous failure of at least four preventive treatments; and (3) have received BoNT-A and have been followed for at least 6 months after the BoNT-A injections. BoNT-A (100 units) was diluted in 4-cc normal saline. The muscles injected included some or all of the following: frontalis, temporalis, corrugator, procerus, occipitalis, semispinalis, splenius capitis, trapezius, cervical paraspinalis, and sternocleidomastoid. Migraine-related disability was assessed using the Migraine Disability Assessment (MIDAS) questionnaire.

RESULTS: There was a statistically significant reduction of the frequency of headache days 1 month after BoNT-A was administered (14.2 vs 28.2 days at the baseline, P <.001), which was maintained through the 3 months of study; similarly, a significant reduction in the headache index (22.3 vs 40.3, P <.001) and number of severe days with headache per month (2.6 vs 7.4, P <.001) were found at 1 month and maintained through the 3 months of study. MIDAS scores were reduced from 34.5 at baseline to 15.9 at 3 months (P <.001). A similar pattern was found in those overusing versus nonoverusing acute medication, though the response was more dramatic in the nonoverusing subgroup.

CONCLUSION: BoNT-A may play a role in the preventive treatment of refractory headache. A significant number of patients showed decrease in clinically important measurements of their headaches as well as reduced headache-related disability with this treatment. Prospective, controlled studies must be considered for severely disabled, refractory patients.