Migraine - Definition

“Migraine is a familial disorder characterized by recurrent attacks of headache widely variable in intensity, frequency and duration. Attacks are commonly unilateral and are usually associated with anorexia, nausea and vomiting”

-World Federation of Neurology

Migraine Facts

•Migraine is one of the common causes of recurrent headaches

•According to IHS, migraine constitutes 16% of primary headaches

•Migraine afflicts 10-20% of the general population

•More than 2/3 of migraine sufferers either have never consulted a doctor or have stopped doing so

•Migraine is underdiagnosed and undertreated

•Migraine greatly affects quality of life. The WHO ranks migraine among the world’s most disabling medical illnesses

Burden Of Migraine

•World - 15-20% of women and 10-15% of men suffer from migraine

•In India, 15-20% of people suffer from migraine

•Adults – Female: Male ratio is 2 : 1

•In childhood migraine, boys and girls are affected equally until puberty, when the predominance shifts to girls.

Migraine Triggers

•Diet Precipitants-Cheese,chocolate,Red wine

•Disturbed sleep pattern

•Hormonal changes

•Drugs

•Physical exertion

•Visual stimuli

•Auditory stimuli

•Olfactory stimuli

•Weather changes

•Hunger

•Psychological factors

Phases of Acute Migraine

•Prodrome

•Aura

•Headache

•Postdrome

PRODROME

•Vague premonitory symptoms that begin from 12 to 36 hours before the aura and headache

•Symptoms include

–Yawning

–Excitation

–Depression

–Lethargy

–Craving or distaste for various foods

Duration – 15 to 20 min

AURA

Aura is a warning or signal before

onset of headache

Symptoms

•Flashing of lights

•Zig-zag lines

•Difficulty in focussing

Duration : 15-30 min

HEADACHE

•Headache is generally unilateral and is associated with symptoms like:

ØAnorexia

ØNausea

ØVomiting

ØPhotophobia

Ø Phonophobia

ØTinnitus

•Duration is 4-72 hrs

POSTDROME (RESOLUTION PHASE)

Following headache, patient complains of

•Fatigue

•Depression

•Severe exhaustion

•Some patients feel unusually fresh

Duration: Few hours or up to 2 days

MIGRAINE – CLASSIFICATION

According to Headache Classification

Committee of the International

Headache Society, Migraine has been

classified as:

•Migraine without aura (common migraine)

•Migraine with aura (classic migraine)

•Complicated migraine

MIGRAINE: CLINICAL FEATURES

Migraine Without Aura	Migraine With Aura
No aura or Prodrome	Aura or prodrome is present
Unilateral throbbing headache may be accompanied by nausea and vomiting	Unilateral throbbing headache and later becomes generalised
During headache, patient complains of phonophobia and photophobia	Patient complains of visual disturbances and may have mood variations

MIGRAINE-
PATHOPHYSIOLOGY

VASCULAR THEORY

•Intracerebral blood vessel vasoconstriction – aura

• Intracranial/Extracranial blood vessel vasodilation – headache

VASCULAR THEORY

•In Classic Migraine cortical hypoperfusion that begins in visual cortex and spreads forward at rate of 2to 3mm/min

•The decrease in blood flow avg 25-30%and progress anteriorly in a wave like fashion independent of topography of cerebral arteries

•The wave of perfusion persist for 4-6hr,follows convolutions of cortex to frontal lobe via insula

•Perfusion of sub cortical structure is normal

•During common migraine no flow abnormalities are usually seen

Cortical hypoperfusion begins in visual cortex and progress anteriorly to frontal lobe independent of topography of cerebral artereies

Serotonin theory

Electrical stimulation ofserotonergic dorsal raphe neuron can result in migraine like headache

•There are projections from dorsal raphe that terminate on cerberal arteries altering blood flow

•There are projections from dorsal raphe to visual centers like LGB, Superior colliculus,retina,visual cortex

•Specific serotonin receptors are found in blood vessels of brain

•These represent neural substrate for circulatory and visual characteristics of migraine

TRIGEMINAL-VASCULAR THEORY

• Neurovascular process, in which neural events result in activation of blood vessels, which in turn results in pain and further nerve activation

•Activation of cells in trigeminal nucleus caudalis in the medulla results in the release of vasoactive neuropeptides including substance-P and calcitonin gene-like peptide

•These neuropeptide induce a sterile inflammation that activates nociceptive afferents originating on the vessel wall, further contributing to pain

MIGRAINE: DIAGNOSIS

•Medical History

•Headache diary

•Migraine triggers

•Investigations (only to exclude secondary causes)

üEEG

üCT Brain

üMRI