Prevalence of migraines
The prevalence of migraine headaches in the United States is 11.7% or approximately 30 million people, affecting mostly women (17.1% of women, compared to 5.6% of men). Migraine headaches also affect adolescents.The annual cost of treatment and medications for migraine headaches in the U.S. is $13-$17 billion and the annual cost of work days lost (112 million days per year) is $14 billion.
Approximately ten million Americans suffer from medically refractory migraine headaches. Migraine headache patients who have persistent symptoms after medical management or those who cannot tolerate the side effects of medical therapy may be candidates for surgical decompression.
Getting a migraine diagnosis
The diagnosis of chronic migraine headaches should be performed first by a neurologist or other migraine headache specialist, based on the most up to date criteria of the International Headache Society. Next, a migraine headache journal kept for at least one month, documenting the frequency, severity, and potential sites of the head and neck where their migraine headache pain may have originated from is key to identifying surgical candidates.
Frequent identification of specific site(s) of pain belies “trigger sites” that may benefit from migraine surgery. Diagnostic procedures such as nerve blocks, botulinum toxin injection, or Doppler ultrasound may be useful to confirm trigger sites. At the time of a developing migraine headache, patients may be able to point to one or more sites of tenderness where the pain started or is developing from – if a local nerve block performed at these site(s) improves symptoms, the patient would likely benefit from surgery at these site(s).
For patients who present without a migraine attack, they are often able to recall and point to trigger sites based on memory. If injecting botulinum toxin into the muscles surrounding these specific site(s) causes significant improvement of symptoms over the next couple months, the patient would likely benefit from surgery at these site(s). On the other hand, patients with vague, diffuse areas of pain at the start of a migraine attack or ocular migraine headaches are not surgical candidates.
Treatment for migraines
The initial surgical treatment for migraine headaches involves thorough decompression of the affected nerves at the identified trigger site(s). Decompression primarily involves performing myectomies and fasciectomies surrounding the involved trigeminal or cervical nerve branch at the identified trigger site(s). Doppler ultrasound at trigger sites is performed to help identify arterial branches that may be irritating a nerve, where arterectomy should be performed.
Analysis of computed tomographic images is useful in identifying supraorbital foramen or notches, where osteotomies and fasciotomies, respectively are performed to release the nerve. After decompression, placing fat grafts beneath or around the freed up nerve is performed at frontal and occipital trigger sites to pad the nerve from cicatricial changes and manage dead space after myectomy.
Neurectomy of a nerve branch is occasionally performed as a last resort during revision surgery in patients with persistent migraine headache symptoms after initial decompression – some improvement is obtained at the expense of temporary or permanent numbness in the dermatome for that nerve branch. Fat injection may be used as an adjunct at the time of initial surgical decompression, or at a later treatment date for patients with recalcitrant migraine headache symptoms following surgical decompression.
Traditionally, 73% of migraine headache patients treated with surgical decompression need multiple trigger sites (average of 2.6 sites) decompressed at the time of surgery.21 With fat injection, most patients (76%) need only one site to be injected (mean of 1.28 sites injected per patient). Generally these procedures are well tolerated with minimal morbidity. Incisions are small and placed in well-hidden areas to minimize scar burden, seromas or hematomas are rare, and numbness following surgery is almost always temporary unless neurectomy is performed. The most common complaint is worsening of migraine headaches symptoms in the acute postoperative inflammatory period, which generally improves after a few weeks.
Occasionally, successful migraine surgery may “unmask” secondary site(s) that patients describe are new sources of their migraine headaches. In these cases, patients should maintain a new headache journal and be evaluated for surgery at these secondary trigger sites. The success rate of migraine surgical decompression ranges from 79-90%.
Factors associated with surgical failure are younger age of migraine onset, intraoperative complications, and two or fewer surgical sites. Factors associated with surgical success are surgery at a frontal or zygomaticotemporal site or at multiple trigger sites. Secondary fat injection has been shown to significantly improve or completely abate symptoms in 69% of patients with migraine headaches persisting after surgical decompression. These procedures improve symptoms likely due to the fact that trigeminal nerve branches in migraine patients are abnormal and surgical decompression or fat grafting reduces nerve irritation that may otherwise trigger a migraine headache.
Successful migraine headache surgery requires working closely with neurologists or migraine headache specialists for appropriate patient diagnosis and medical management. Careful patient selection and thorough analysis of long term symptoms to determine an appropriate surgical candidate and operative plan also cannot be understated.