Duration of Migraine Is a Predictor for Response to Botulinum Toxin Type A


  • Eric J. Eross DO,

  • Jonathan P. Gladstone MD,

  • Susan Lewis RN,

  • Robert Rogers PA,

  • David W. Dodick MD, FRCP(C), FACP

  • From the Mayo Clinic College of Medicine, Mayo Clinic Scottsdale, Scottsdale, AZ.

Address all correspondence to Dr. David W. Dodick, Mayo Clinic Scottsdale, 13400 E. Shea Blvd, Scottsdale, AZ, 85259.


Objective.—To identify the clinical characteristics and/or injection parameters that predict a favorable response to botulinum toxin type A in patients with episodic and chronic migraine.

Background.—There is emerging scientific and clinical evidence to support the utility of botulinum toxin type A (BoNT-A) in the prophylaxis of episodic and chronic migraine headache. However, the patient characteristics and injection strategies that predict a favorable treatment response are unknown.

Methods.—We conducted a prospective, open-label study on 74 patients from our clinic receiving BoNT-A for episodic or chronic migraine. For all patients, migraine-related disability (Migraine Disability Assesment [MIDAS]), headache frequency, and average headache intensity were obtained at baseline and at 3 months post-BoNT-A. Information regarding demographic characteristics and injection parameters was also collected.

Results.—Sixty-one patients met the study criteria and were available for 3-month follow-up. At the 3-month follow-up visit, the mean MIDAS scores of the 61 qualified study patients had decreased from 102 at baseline to 49 (52% decrease, P < .001). The mean number of headache days was reduced from 60 to 39 (P < .001), and the mean headache intensity decreased from 7.6 at baseline to 5.9 (P < .001). Frequency of migraine attacks, presence of analgesic overuse, total BoNT-A dose, and presence of underlying muscle tenderness were not predictive of treatment response. Age and duration of migraine were the only clinical factors significantly predictive of treatment response. Age likely was a predictor only as a consequence of duration of illness as subjects with migraine duration greater than 30 years were significantly less likely to respond to treatment with BoNT-A.

Conclusion.—BoNT-A may be effective in decreasing headache frequency, headache intensity, and headache-related disability in episodic and chronic migraine patients. Duration of illness emerged as a predictor of treatment response. Randomized controlled studies should evaluate headache-related disability as a primary endpoint in patients with episodic and chronic headache.