Migraine is characterized by periodic headaches, typically unilateral, often associated with visual disturbances and vomiting
Classification
• Classical migraine: visual and sensory symptoms precede or accompany the headache
• Common migraine: no visual or sensory features; headache, nausea, photophobia occur
• Basilar migraine: occipital headache, preceded by vertigo, diplopia, dysarthria, without or without visual and sensory symptoms(brain stem symptoms)
• Hemiplegic migraine: prolonged headache lasting for hours and days; aura consisting of fully reversible hemiparesis and at least one of the following fully reversible visual symptoms, fully reversible sensory symptoms, fully reversible dysphasic speech disturbance
• Typical aura without headache: presence of migraine aura without headache (visual aura most common)
• Retinal migraine: repeated attacks of monocular visual disturbance, including scintillations, scotomata or blindness associated with migraine headache
Pathogenesis:
• Multiple environmental and genetic factors combine to induce cerebral electrical and vascular changes. Many neurotransmitters seem to be involved (eg. Serotonin, noradrenaline, substance
• It is initiated by spreading waves of depolarization from either cortex or brainstem. These central processes generate meningeal neurogenic inflammation (which in includes release of a potent vasodilator calcitonin gene related peptides CGRP and initiation of arachidonic acid cascade) and vasodilation which in turn activates nociceptive afferents that carry the pain signals through the trigeminal ganglion to the trigeminal nucleus caudalis in the trigemino-cervical complex.
• Aura is also thought to be caused by cortical spreading depression and is associated with a localized reduction in the blood flow followed by an increase in blood flow and characteristically affects the parieto occipital complex.
Precipitating factors:
Each person has his own triggering factors. Some common precipitants are stress, exposure to bright light, loud noises, smoke, strong scents, menstruation, contraceptive pills, lack or excess of sleep, chocolates, cheese, caffeine, citrus fruits, strong additives such as MSG, vasodilators
General features:
• Attacks are episodic and start at the puberty and continue tillage middle life with variable degree of spontaneous remissions.
• Frequency, duration and severity of attack vary in same individual.
• Headache us typically hemicranial, throbbing in character, associated with nausea and vomiting
• Allodynia (production of pain from normally a non painful stimuli)
• Attacks spontaneously terminate after few hours or after sleep
Diagnostic criteria:
Common migraine:
Repeated attacks (at least five attacks) of headache lasting 4-72 hours that have following features:
• Normal physical examinations
• No other reasonable cause for headaches
• Headache has at least 2 of the following:
- Unilateral pain
- Throbbing or pulsatile in nature
- Aggravation of the pain by movement
- Moderate or severe intensity of pain
• At least 1 of the following during the headaches: - Nausea or vomiting
- Photophobia or phonophobia
Classical migraine:
Repeated attacks (at least 2 attacks) of headache lasting 4-72 hours that have the following features:
• Normal physical examination
• No other reasonable cause for the headache
• Aura consisting of at least one of the following , but no motor weakness:
- Fully reversible visual symptoms including positive features (eg. Flickering lights, spots or lines) and/or negative features (eg. Numbness)
- Fully reversible dysphasic speech disturbance
- Least two of the following:
- Homonymous visual symptoms and/or unilateral sensory symptoms
- At least one aura symptom developing gradually over >/= 5 minutes and/or different aura symptoms occurring in succession over >/=5 minutes
- Each symptom lasting >5 minutes ans </= 60 minutes
Headache begins during aura or follows aura within 60 minutes
Dangerous features of headache in a patient known to have migraine (red flags)
• Rapidly increasing frequency of headache
• Abrupt onset of severe headache
• Marked change in headache pattern from sleep
• Triggered by valsalva maneuver, cough, exertion or sexual activity
• Associated incoordination
• Presence of focal neurologic signs or symptoms
• Associated fever, neck stiffness
• Associated with tenderness over temporal artery
• Associated with altered sensorium, seizures
Treatment
Drugs that are useful in acute migraine are:
• NSAIDS (Aspirin/ Ibuprofen/Ketorolac)
• Acetaminophens (Paracetamol)
• Ergot alkaloids (Ergotamine, dihydroergotamine)
• D2 receptor blockers (Metaclopramide, Prochlorperazine)
• Triptans ( Sumatriptan, Rizatriptan)
• Dexamethhasoneo
• Magnesium
Drug prophylaxis
Indications:
• Recurring migraine that significantly interferes with a patient’s quality of life and daily routine despite acute treatment
• Four or more attacks per month
• Failure of, contraindication to, troublesome side effects from acute medications
• Frequent, extremely long or uncomfortable auras
Prophylaxis can be attempted with any of the following drugs:
• Propanol
• Pizotifen
• Amitriptyline
• Flunarazine
• Gabapentine
• Valproate
• Topiramate
• Methysergide
Contributor – Dr. Bidhata Rayamajhi
