Headaches are one of the most common nervous system disorders and a major cause of disability worldwide, affecting 47% of adult population in the United States alone. According to the International Headache Society, a headache is classified as a primary headache disorder if the headache itself is the illness and there are no other causes diagnosed. The most common primary headache disorder in clinical practice is migraine. Up to 15% of the world’s population is afflicted with the debilitating disorder. The World Health Organization ranks chronic migraine (CM) to be as disabling as dementia, psychosis, and quadriplegia—severely impacting the quality of life. It causes disruption of household and social activities, and functional impairment.
Treating migraines with botulinum toxin
Botox is a botulinum toxin (BT) preparation used for prophylactic treatment of chronic migraine, but other BT products available in the market are being used off-label. The disorder is characterized by 15 or more headache days per month, lasting 4 hours or more. The pharmaceutical agents available for migraine have not been successful in alleviating the disorder because of limited efficacy, frequent side effects, and drug interactions.
Botulinum toxin type A is a paralyzing neurotoxin derived from Clostridium bacteria, the same biological agent that causes botulism poisoning. BT inhibits the release of acetylcholine to temporarily relax the target muscle. The exact mode of action of BT for migraine is still unclear. Studies suggest that it also has antinociceptive abilities (blocking the detection of painful stimulus), apart from its neuromuscular activity.
Botox prevents or reduce episodes in chronic migraine. As a prophylactic treatment, it does not treat a migraine episode that has already begun. Patients will need to take their usual pain relievers in such cases. Botox is recommended for patients aged 18 and above, with 15 or more headache days in a month, lasting 4 hours each day. It does not seem to work for episodic migraines and tension headaches. A recent study has reviewed the safety and efficacy of BT for migraine by evaluating current clinical evidence and experience; it has been shown that Botox is well tolerated and is effective in reducing frequency and severity of headaches in patients with chronic migraine.
A retrospective case series using electronic chart reviews from 21 patients showed significant improvement in headache frequency and intensity after Xeomin injection (150 units).
Dysport is a popular alternative for Botox as an off-label treatment for CM. Dysport at 240 units showed significant benefit over placebo at some endpoints.
Dosing, injection sites, and techniques
Dosing, dilution, and site of injection varied widely. Between studies and administrators, the total dosage ranged from 25 to 300 units on several injection sites. The clinical dose commonly used for migraine therapy is between 25–260 units, which is way below the toxic limit.
BT can be administered where the pain or tenderness is felt (follow the pain protocol), at a fixed injection site, or a combination of both. The most common areas injected are the glabellar and frontal regions, temporalis muscle, occipitalis muscle, and cervical paraspinal region.
The whole procedure takes about 15–30 minutes. Symptom relief may take several weeks to reach maximal effect. Advising the patient to keep a “headache diary” documenting the time, duration, severity, and frequency of attacks will help the physician in assessing the patient’s condition and modifying future injection dosages. Repeat injections are often necessary to gauge if Botox is working or not. It is sometimes necessary to retrain the muscles to relax. Relief from Botox injection is reported to last up to 6 months.
Botox has fewer side effects compared to oral medications such as Topamax and Elavil. Most published trials have reported mild and transient adverse events. Higher doses seem to cause increased side effects, such as a sore or painful neck, muscle weakness, and ptosis.
On average, 1 Botox vial containing 100 units costs about $500 and above. The administrator may include other fees that may cost an additional $500–$1,000.
Should you get treatment with botulinum toxin
Good candidates for this treatment are those experiencing headaches for 15 days or more each month. At least half of these episodes must have migrainous features (heightened sensitivity to light, sound, and odors). Patients must be advised of other available treatments for their headache problems. This treatment has not been tested on CM patients under the age of 18.
- It prevents up to 9 headache days per month that lasts approximately 24 weeks.
- The physician will use a tiny needle for injection that is reported to feel like tiny pinpricks.
- It can only be injected by certified Botox specialists.
- This in-office treatment only takes about 15 minutes.
- Subsequent injections must be scheduled every 12 weeks to get the full benefit of Botox.
Clinical evidence and patients’ reviews suggest that botulinum toxin A is an effective, well-tolerated preventative treatment for chronic migraine, who are not responding well to other prophylactic headache treatments. Assessing the frequency of migraine episodes is a good measure of efficacy in this patient population. A dose as low as 25 units is effective and adverse events are mild and self-limiting.