Duration of migraine is a predictor for response to botulinum toxin type A

Headache. 2005 Apr;45(4):308-14. doi: 10.1111/j.1526-4610.2005.05067.x.


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.

Publication types

  • Clinical Trial

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Botulinum Toxins, Type A / therapeutic use*
  • Chronic Disease
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Migraine Disorders / prevention & control*
  • Neuromuscular Agents / therapeutic use*
  • Prospective Studies
  • Time Factors
  • Treatment Outcome


  • Neuromuscular Agents
  • Botulinum Toxins, Type A