MIGRAINE

Migraine is the second most common cause of headache, after tension headache. It is described as a severe pulsating or throbbing pain on one side of the head. 

TYPES:

Migraine can be divided into 2 types:

1) Migraine with aura

2) Migraine without aura

AURA - Sensations include the feeling of seeing zigzag lines, dark spots in the visual field, paralysis, tingling, and numbness. 

EPIDEMIOLOGY:

It is the most common headache-related or neurological cause of disability around the world. Migraine more commonly affects the female (15%) population than the male (6%) population. The onset of migraine is common during puberty, however, children as young as 2 years of age may be affected. In women, it is generally associated with menses. 1-2% of cases of migraine are chronic.

CAUSES:

The causes of migraine are not clearly known. Various triggers are recognized, which include stress, hunger, disturbance of sleep, and various types of food, such as aged cheese and Mono-Sodium Glutamate(MSG). 

The causes may be also genetic, however genetic causes are more common for migraine with aura, as compared to migraine without aura. One of the forms of genetic migraine is Familial Hemiplegic Migraine. Mutations involving the Cav 2.1 (P/Q)–type voltage-gated calcium channel CACNA1A gene are now known to cause FHM 1; this mutation is responsible for about 50% of FHMs. Mutations in the Na+-K+ATPase ATP1A2 gene, designated FHM 2, are responsible for about 20% of FHMs. Mutations in the neuronal voltage-gated sodium channel SCN1A cause FHM 3.

SYMPTOMS:

Symptoms include poor concentration, sweating, hot or cold intolerance.

The development of migraine is explained by 5 stages, each of which is characterized by its symptoms:
The 5 stages include - 

1) PRODROMAL STAGE - Changes in appetite, behavior, and mood.

2) AURA

3) HEADACHE - severe pulsating or throbbing pain on one side of the head, accompanied by nausea, vomiting, phono- or photophobia. Can last anywhere between 2 - 72 hours. 

4) RESOLUTION 

5) RECOVERY

DIAGNOSIS: 

The diagnosis of migraine is based on the signs and symptoms of the patient, and imaging tests are used only for differential diagnosis.

Simplified Diagnostic Criteria for Migraine, according to International Headache Society Classification (Headache Classification Committee of the International Headache Society, 2013).

Repeated attacks of headache lasting 4–72 h in patients with a normal physical examination, no other reasonable cause for the headache, and:

At Least 2 of the Following Features: Unilateral pain, Throbbing pain, Aggravation by movement Moderate or severe intensity

Plus at least 1 of the Following Features: Nausea/vomiting, Photophobia, and phonophobia 

MANAGEMENT:

Patient education is an important aspect of migraine management. Information for patients is available at sites such as www.achenet.org, the website of the American Council for Headache Education (ACHE).

NON-PHARMACOLOGIC MANAGEMENT:

Most patients benefit from the identification and avoidance of specific headache triggers. A regulated lifestyle is helpful, including a healthy diet, regular exercise, regular sleep patterns, avoidance of excess caffeine and alcohol, and avoidance of acute changes in stress levels, being particularly wary of the let-down effect. Patients with migraine do not encounter more stress than headache-free individuals; over-responsiveness to changes in stress appears to be the issue.

PHARMACOLOGIC MANAGEMENT:

1) Non-Steroidal Anti Inflammatory Drugs - They affect the severity and duration of the migraine attacks. The combination of acetaminophen, aspirin, and caffeine has been approved for use by the U.S. Food and Drug Administration (FDA) for the treatment of mild to moderate migraine.

2) 5-HT1B/1D RECEPTOR AGONISTS- Oral Stimulation of 5-HT1B/1D receptors can stop an acute migraine attack. Ergotamine and dihydroergotamine are nonselective receptor agonists, whereas the triptans are selective 5-HT1B/1D receptor agonists. Rizatriptan and eletriptan are the most efficacious of the triptans currently available in the United States.  Triptans are generally not effective in migraine with aura unless given after the aura is completed and the headache initiated.

Nasal formulations of dihydroergotamine (Migranal), zolmitriptan (Zomig nasal), or sumatriptan can be useful in patients requiring a nonoral route of administration.

Parenteral administration of drugs by injection, such as dihydroergotamine and sumatriptan, is approved by the FDA for the rapid relief of a migraine attack.

PREVENTION OF MIGRAINE:

• Avoid triggers such as dietary as well as environmental triggers

• Exercise regularly as it helps in managing stress and thus can help prevent migraines

• If a woman has a migraine and estrogen seems to trigger or make the headache worse, then medication containing estrogen should be avoided.

• In general, a preventive medication should be considered in the subset of patients with four or more attacks a month.

REFERENCES:

1) Nhp.gov.in. 2022. Migraine | National Health Portal Of India. [online] Available at: <https://www.nhp.gov.in/disease/neurological/migraine> [Accessed 7 January 2022].
2) Loscalzo, J., Fauci, A., Kasper, D., Hauser, S., Longo, D. and Jameson, J., n.d. Harrison's principles of internal medicine.