Migraine Surgery for Chronic Headache Relief - Types, Uses, and Risks

Introduction

Migraine is a neurologic (origin related to the nervous system) headache that affects about 10 percent of the population. Females are more affected than males. It mostly affects students and the urban population. It can result in nausea, vomiting, vertigo, and extreme sensitivity to light or sound, among other issues. Migraine may or may not present with an aura (flashing light, blind spot, or tingling sensation of face).

In most cases, migraines are associated with triggers like loud noise, bright light, and so on. Migraine can be acute or chronic. The medical treatment options include beta-blockers, anticonvulsants, antidepressants, calcium channel blockers, NSAIDs (Non-steroidal anti-inflammatory drugs), and other drugs. But studies show, these treatment options do not help one-third of those affected. So surgical options are considered in chronic cases where the condition is unmanageable by conventional drugs and behavioral therapy.

Pathophysiology of Migraine

There are several studies associated with the pathophysiology of migraine. The earliest studies showed dilatation of cerebral vessels as a possible cause. But later, researchers found that drugs that precipitate migraine, like sildenafil, do not cause vascular changes. Most studies show the peripheral origin of migraine, further supported by the positive effect of Botulinum toxin treatment and peripheral neurolysis, which are explained below.

When Does a Migraine Become Chronic?

As per the International Headache Society, if a headache occurs for 15 or more days for more than three months with features of migraine for eight days or more, the condition can be categorized as chronic migraine.

When to Consider Surgery, and When Not?

Migraine surgery is indicated in cases where the patient's condition is unmanageable by medical treatment and behavioral therapy. A patient with a history of psychiatric disease is contraindicated for migraine surgery. Surgery should not be carried out in confirmed psychiatric patients.

How to Assess the Severity of a Migraine?

The severity of the migraine is assessed through Migraine Disability Assessment Questionaire. MIDAS (Migraine Disability Assessment) score classifies the severity of the condition as below:

• Score 0 to 5 - MIDAS grade Ⅰ - Little or no disability.

• Score 6 to 10 - MIDAS grade Ⅱ - Mild disability.

• Score 11 to 20 - MIAS grade Ⅲ - Moderate disability.

• Score 21 or higher-grade Ⅳ - Severe disability.

What Are the Different Surgical Techniques?

Mainly surgical interventions focus on four regions, namely:

• Frontal or forehead region.

• Temporal region.

• Nasal.

• Occipital.

1. Botox (Botulinum Toxin):

The safe and effective dose used is 25 units. It is gradually injected into the pericranial muscles at multiple locations based on pain. The toxin enters the nerve ending and blocks the release of substances that transmit pain to the brain.

• For the temporalis site - 3 units on each side (six units).

• For the frontalis site (4 sites) - 2.5 units on each side (total ten units).

• Three units for a corrugator (muscle in the eyebrow region) - 3 units on each side.

• 3 units for procerus (muscle in the region between eyebrows) in the midline.

For occipital headaches, 12.5 to 50 units are applied on each side of the midline in the occipital nerve region. If pain is relieved for 6 to 12 weeks with botox injection, the person is considered ideal for surgery. It can be used for short-term relief and as preventive measures in acute cases. However, it is not recommended for long-term therapy due to the development of resistance. Primarily, it is used as a screening tool for neurolysis.

2. Peripheral Neurolysis:

• Neurolysis of sensory branches of the Trigeminal and Occipital nerve (nerves that supply the face and back of the head) is done.

• These nerve branches include - supraorbital, supratrochlear, zygomaticotemporal, auriculotemporal, and greater and lesser occipital nerves.

• Nerve decompression or nerve liberation is a technique in which the surgeon removes a small part of the tissue, muscle, blood vessel, or bone to relieve the nerve. The nerve decompression occurs in the trigger target regions(frontal, occipital, and temporal regions).

3. Septoplasty:

Septoplasty is a surgery to correct a deviated septum (the bone wall that separates our nostrils).

• A deviated septum blocks the airway and may lead to headaches.

• Septoplasty corrects the deviated septum and restores the airway, thus relieving pressure and correcting headaches in some cases.

• However, the use of septoplasty for relieving headaches is questionable as researchers have different opinions on the same.

4. Turbinectomy:

• This surgery removes turbinates (tiny structures inside our nose that humidify the breath).

• When turbinates grow larger, they can cause breathing problems and headaches.

• Some studies show turbinectomy can help in cases of severe headaches.

• However, more studies are needed to confirm the effectiveness in this case.

5. Neuromodulation:

It is done in cases of failure of medical management or failure of peripheral neurolysis or in those cases where Peripheral nuerolysis cannot be done.

• Occipital Nerve Stimulation (ONS) is done.

• Electrodes are placed around the dorsal cervical nerve in the sub-occipital region.

• Firstly connection is made to a trial stimulator, and if found successful, it is replaced with the permanent implantable pulse generator.

• Alternative treatment options include sphenopalatine ganglion stimulation and supraorbital or vagus nerve stimulation.

What Are the Risks Associated With Migraine Surgery?

1. Botox Complications:

• The transient hollowness of muscle (at the injection site).

• Transient eyelid ptosis (drooping of the eyelid).

• Neck muscle weakness.

2. Peripheral Neurolysis Complications:

• Risk for neuroma (nerve tissue tumor at the injury site) formation.

• Temporary paresthesia (feeling of numbness or abnormal skin sensation).

• Itching at the area of surgery.

• Associated hemorrhage (low incidence).

• Associated infection (low incidence).

3. Turbinectomy Complications:

• Postoperative epistaxis (bleeding from the nose).

• Sinusitis.

• Nasal dryness.

• Septal deviation.

4. Neuromodulation Complications:

• If not anchored properly, lead migration (electrode migration or electrode displacement) may occur.

• Associated infection may occur, which mostly subside with antibiotics, but is severe as, in some rare cases, may require implant removal.

How Reliable Are Migraine Surgeries?

The American Headache Society (AHS) does not recommend surgical treatment for migraine except in cases of clinical trial participation due to the following reasons.

• Extensive research is required on the subject (large multicentral studies should be done).

• Unknown long-term complications.

Conclusion

Migraine is a neurogenic headache that can significantly affect one's quality of life due to associated pain and other symptoms, especially in chronic cases. Most physicians and researchers recommend that one should always opt for medical management and behavioral therapy first, as surgical options still require extensive research on large control groups and possess risks. Therefore, migraine surgery should only be considered for intractable chronic migraine on recommendation by the physician and surgeon.