Botox for chronic migraine

Feature Summary

To reduce the frequency and severity of headache attacks in patients with Chronic Migraine.



It is estimated migraine occurs in 10-15% of the general population, and migraine is the 8th leading causes of disability among all non-fatal sequelae of diseases and injuries according to the World Health Organization. Chronic Migraine (CM) is defined as headache occurring at a frequency of more than 15 days a month, at least 8 of which are migraine, for at least 3 months. About 2% of the general population suffers from CM, and it is a major cause of migraine-related disability.



Treatment options approved for the treatment of CM is limited, and onabotulinumtoxinA injection is one of them. The evidence of onabotulinumtoxinA injection is derived from the PREEMPT 1 and PREEMPT 2 studies, which are double-blind placebo-controlled international trials designed to verify the efficacy of onabotulinumtoxinA injection in CM. According to the published results, regular injections result in significant reduction of migraine attacks and cumulative headache duration.



OnbotulinumtoxinA injection is carried out at regular intervals of 12 weeks for patients with confirmed diagnosis of CM, and patients are asked to keep a headache diary to monitor the frequency and severity of their headache attacks. The PREEMPT protocol consists of two parts. At the first part, 31 injections are given in a fixed-site-fixed-dose fashion for the designated cranial and cervical muscles. For patients with more extensive involvement, additional injections are delivered in a follow-the-pain fashion, and muscles at certain locations with focal tenderness are treated. Patients are monitored for 10-20 minutes for potential side effects.



Side effects of onabotulinumtoxinA injection are not uncommon, although discontinuations due to adverse events occurs in only 3.8% of patients according to the PREEMPT 1 & 2 trials. Commonly reported side effects are listed as follows:

  • Neck pain (6.7%)
  • Muscular weakness (5.5%)
  • Eyelid ptosis (3.3%)
  • Musculoskeletal pain (2.2%)
  • Injection site pain (3.2%)

However, it is noteworthy that for East Asian patients, lateral eyebrow elevation is reported in 1/4 to 1/5, which could be manageable or preventable by giving additional injection at lateral frontal regions.


Estimated Cost

The procedure cost is about 24,400-36,600 NTD, prices are subject to change without prior notice, need to pay in accordance with the actual medical expenses.