WHAT IS A MIGRAINE?
Migraine is a chronic neurologic disease characterized by 4 different stages:
Stage 1: Prodromal stage
Stage 2: Aura
Stage 3: Headache
Stage 4: Postdrome
Migraine is more than just a headache. Various other associated symptoms make this disorder a complex problem.
EPIDEMIOLOGY
About 12% of the general population suffers from migraines. Women suffer from it 2-3 times more than men, and it is usually genetic. The most common type is migraine is that without aura, seen in about 75% of patients. A migraine usually affects people aged 30 to 39 years.
STAGES OF MIGRAINE
Stage 1 or prodromal stage:
Symptoms include constipation, depression, diarrhea, drowsiness, food cravings, or hyperactivity/irritability 1-2 days before the headache.
A migraine sufferer can take treatment before the full-blown attack begins once he/she recognizes the pattern of these symptoms.
Stage 2: Aura:
Aura is present in about 1/3 of migraine sufferers. Individuals suffering from migraines most commonly experience visual auras which include flashes, dots, shimmers, or zig-zag bright lights.
Other auras include sensory aura or tingling sensations on the body or face, motor aura or weakness on one side of the body, and learning or speech difficulty.
The occurrence of eye floaters is also more common among migraine sufferers.
Aura is a reversible neurologic symptom that usually resolves within 10-30 minutes.
It is also possible to experience a migraine aura without symptoms of headaches.
Stage 3 Headache:
The headache associated with migraine is often unilateral, throbbing in nature, and exacerbated by physical activity. It often causes photophobia, phonophobia, nausea, vomiting, and cutaneous allodynia or sensitivity to touch.
A migraine attack occurs when the 5th cranial nerve, also known as the trigeminal nerve, becomes activated and causes pain in the structures it supplies. These structures include the eye muscles, the face, and the dura matter that surrounds the brain.
Moreover, the 5th nerve is sensitized to stimuli that normally do not cause pain, like sneezing, laughing, or touching.
The headache can last from 4 hours to days.
Stage 4: Postdrome:
Patients in this phase can experience transient headaches upon sudden head movements. Exhaustion and fatigue are also common symptoms. During this phase, the person feels depleted or worn out.
WHAT CAUSES MIGRAINE?
An array of factors can cause migraine, which is a brain dysfunction:
1. Cortical spreading depression:
Migraine visual aura is caused by prolonged activation of brain cells starting in the visual cortex and spreading throughout the cerebral cortex.
2. Trigeminovascular system
The trigeminovascular system is also believed to play a role in migraine pathophysiology. The trigeminal nerve (5th CN) has three main branches, the ophthalmic which supplies the ocular structure, maxillary and mandibular which supply the middle and lower face respectively. The trigeminal nerve also supplies the dura mater which is the connective tissue surrounding the brain.
Activation of the 5th cranial nerve leads to release of inflammatory mediators and CGRP causing headache, nausea, vomiting etc.
3. Genetics:
There is a complex genetic basis for migraines. There are migraine disorders caused by mutations in a single gene, while others are caused by polymorphisms in multiple genes.
About 70% of migraine sufferers has a positive family history.
4. CGRP (Calcitonin gene-related peptide):
The CGRP neuropeptide has vasodilator effects on the cerebral and dural vessels. From the intracranial vessels, it transmits pain to the central nervous system.
A recent study found that injecting CGRP can precipitate migraine attacks in migraine sufferers.
Blocking these neuropeptide receptors with monoclonal antibodies has been proven to be an effective strategy for preventing attacks.
TRIGGERING FACTORS:
There is an extensive list of triggering factors that can precipitate a migraine attack.
- Milk products, sugary food, food additives like monosodium glutamate (MSG).
- High stress levels and anxiety
- Caffeine: High intake of coffee or withdrawal from coffee can precipitate migraines.
- Weather changes
- An irregular sleep schedule or too much sleep can lead to migraines.
- The menstrual period can trigger migraine attacks in many women who are otherwise symptom-free. It can even occur after menopause for some women.
- Environmental factors: bright lights, loud noise, or strong odors
- Dehydration
- There is a link between dry eye syndrome and migraine. Therefore, treating dry eyes may also reduce migraine attacks.
HOW IS MIGRAINE DIAGnOSEd:
Most migraines are diagnosed by exclusion and are characterized by:
- Frequent or infrequent recurrent headaches
- Lasting from 4-72 hours without medication
- And have 2 of the following 4
- Moderate to severe intensity
- More intense on one side
- Throbbing in nature
- Getting worse with activity
WHEN SHOULD YOU SEE A DOCTOR?
1. Any visual loss:
2. Aura lasting more than 60 min
Retinal migraine:
In this migraine, the vision is lost intermittently, typically in only one eye, for brief periods of time. Unilateral vision loss can last up to 20 minutes before gradually returning. However, any case of vision loss must be evaluated.
Patients with retinal migraine must be checked for more serious eye conditions such as stroke (due to decreased blood flow), retinal detachment, or even tumors.
The tests that the doctor may perform are:
- Visual acuity test
- Pupillary reaction to light
- Eye movements
- Peripheral vision testing
- Visual field testing
- Retina examination
WHAT SHOULD YOU DO IF YOU HAVE A MIGRAINE?
- Do not drive if you are having throbbing pain and/or visual aura
- Avoid the triggers such as precipitating food and sensations
- Sleep well
- Remain hydrated
- Use sunglasses when stepping out in sun
- The anti-inflammatory properties of fruits, vegetables, and rice make them safe to consume during migraine attacks
- Over the counter pain relief medication
- Lubricating eye drops in case of eye discomfort
TREATMENT
The treatment of migraine involves both abortive and prophylactic measures.
An abortive treatment prevents a headache from progressing further after it has already begun.
While the goal of prophylactic therapy is to reduce the frequency or severity of headaches, thereby improving patient quality of life.
| SEVERITY | NAUSEA/VOMITING | TREATMENT |
| MILD-MODERATE | NO | Non-steroidal anti-inflammatory drugs (NSAIDs): aspirin, naproxen, ibuprofen, or diclofenac. |
| MODERATE-SEVERE | NO | Triptans or with the combination of triptans with NSAIDs |
| SEVERE | YES | Sumatriptan Antiemetics/dopamine receptor blockers like metoclopramide, prochlorperazine, or chlorpromazine Dihydroergotamine with metoclopramide Ketorolac |
Prophylactic Therapy
- Patients who suffer from frequent migraine headaches or headaches that have an impact on their quality of life should receive preventative therapy if acute treatment has failed or caused severe side effects.
- The drugs for prophylactic therapy are usually started at a low dose and gradually titrated up until the patient gets the therapeutic benefit.
- Some of the agents used in prophylactic therapy are:
- Beta-blockers like metoprolol or propranolol
- Antidepressants like amitriptyline or venlafaxine
- CGRP antagonist (monoclonal antibodies) injections: these injections can be on monthly basis to prevent the attacks of migraine in those individuals who regularly suffer from it.
As a final note, a migraine is more than a headache. This is a complex neurological disorder that causes chemical and electrical imbalances in the brain. To lead a quality life, it is crucial to have a proper diagnosis and management. If you notice any blind spot or visual loss, consult your doctor immediately.