Migraine - ‘a common and distressing disorder’
'Migraine is a common and distressing disorder. It is not likely to take life but can destroy the quality of life at what might have been its most rewarding moments1.'
Studies have shown the incidence of migraine to be 9-10%, about 17% of the female population and 6% of the male population. So, about 2 million Australians can be expected to suffer from migraine, about 1.5 million women and about 500,000 men. It is thought that more women suffer migraine than men due to hormonal factors.
'Onset of migraine is from childhood onwards but most commonly in the 20s and 30s and relatively infrequently after the age of 40; therefore, prevalence increases from the first to fourth decades and thereafter declines. Migraine may nevertheless be a significant health issue among children2.'
Symptoms
The International Headache Society classifies a headache as a migraine when:
(a) the pain can be classified by at least two of the following;
one sided
moderate to severe
throbbing
aggravated by movement
(b) there is at least one of the following associated symptoms:
nausea
vomiting
photophobia (sensitivity to light)
phonophobia (sensitivity to noise)
(c) the headache lasts for between 4 and 72 hours.
Other symptoms that may be experienced include
- osmophobia (sensitivity to smell)
- aura (visual disturbances such as bright zigzag lines, flashing lights, difficulty in focusing or blind spots lasting 20-45 minutes)
- difficulty in concentrating, confusion
- a feeling of being generally extremely unwell
- problems with articulation or co-ordination
- diarrhoea
- stiffness of the neck and shoulders
- tingling, pins and needles or numbness or even one-sided limb weakness
- speech disturbance
- paralysis or loss of consciousness (rare).
Migraine may occur recurrently over many years or even decades. Frequency may vary greatly in the same person over time, from a few a year up to several a week.
Stages of Migraine
Migraine can be divided into five distinct phases:
1. Early Warning Symptoms (prodromol)
A significant number of migraineurs experience warning symptoms for up to 24 hours before the attacks start but may not recognise these signs until they know what to look for. These symptoms include:
- changes in mood, varying from feeling elated, on top of the world and full of energy, flying through the day’s work and accomplishing twice as much as usual, to feeling depressed and irritable
- gut symptoms, nausea, changes in appetite (intense hunger or sugar craving: may consume a whole packet of biscuits or chocolates), lack of appetite, constipation, diarrhoea
- neurological changes, drowsiness, incessant yawning, difficulty finding the right words (dysphasia), dislike of light and sound, difficulty in eye focus
- changes in behaviour, hyperactive, obsessional, clumsy, lethargic
- muscular symptoms, general aches and pains
- fluid balance changes, thirst, passing more fluid, fluid retention.
All these symptoms arise in the hypothalamus, the deep-seated part of the brain.
2. Aura
Aura accompanies migraine attacks for about 20 – 30% of migraineurs. The most common aura symptoms are visual disturbances such as bright zigzag lines, flashing lights, difficulty in focusing or blind spots. Aura affects the visual field of both eyes despite often seeming to affect one only and lasts 5-60 minutes then the vision normally restores itself. Less commonly aura affects sensation or speech. When several aura symptoms are present, they usually follow in succession.
3. Headache
Those experiencing classical migraine (migraine with aura) may or may not have a gap of up to an hour between the end of the aura and the onset of the head pain and may feel a bit ‘spaced out’ during the gap. Regardless of whether one experiences migraine with aura, or common migraine (migraine without aura), the headaches are similar. The headache phase can last up to three days. It is often throbbing and on one side of the head, but can affect both. It can be on the same or opposite side to the aura. Movement makes it worse. The most common accompanying symptoms in this phase are nausea, vomiting and sensitivity to light, sound and smell. Eating can help especially starchy foods. The symptoms can be more distressing than the headache itself.
4. Resolution
The way an attack ends varies greatly. Sleep is restorative for some. Being sick can make children feel much better. For others effective medication can improve attacks. For a few nothing works except the headache burning itself out.
5. Recovery (postdromol)
A feeling of being drained may exist for about 24 hours, others may feel energetic or even euphoric.
What causes migraine?
‘Susceptibility to migraine is normally inherited. Certain parts of the brain employing monoamines, such as serotonin and noradrenaline, appear to be in a hypersensitive state, reacting promptly and excessively to stimuli such as emotion, bombardment with sensory impulses, or any sudden change in the internal or external environment. If the brainstem systems controlling the cerebral cortex become active, the brain starts to shut down, a process starting at the back of the brain in the visual cortex and working slowly forward. The pain nucleus of the trigeminal nerve becomes spontaneously active; pain is felt in the head or upper neck and blood flow in the face and scalp increases reflexly. Noradrenaline is released from the adrenal gland and causes the platelets to release serotonin. Serotonin in the circulation is thought to reflect levels of this neurotransmitter in the brain.
The brainstem nuclei of one side have a reciprocal effect on those of the other side; their effects may alternate, causing cortical changes on one side and headache on the other, or causing the headache itself to change from side to side.
Essentially, migraine is caused by the interaction between the brain and the cranial blood vessels. Treatment can be aimed at constriction of dilated arteries to abort each headache as it comes or at the brain itself in an attempt to prevent the headaches altogether.
This is the present hypothesis for the mechanism by which migrainous symptoms are produced3.
Types of Migraine
Apart from common migraine and migraine with aura, other types of migraine are:
Lower-half Headache or Facial Migraine
The term applies to common migraine that covers one-half of the face involving the nostril, cheek and jaw.
Migraine Aura without Headache
Where the headache of migraine with aura may become less severe over the years or may not occur at all, the attacks are referred to as migraine aura without headache. It is rare for attacks to have always occurred without a headache and a doctor should be consulted if this develops for the first time when over 50.
Status Migrainosus
This term describes migraine that may last longer than 72 hours. Symptoms of nausea and light sensitivity resolve after a couple of days but the headache persists.
Abdominal Migraine (recurrent stomach pains in childhood)
Symptoms are periodic abdominal pains (experienced by about 20% of migrainous children compared with about 4% of children who do not suffer from headache).
Rare types of migraine include:
Basilar Artery Migraine (with loss of balance and fainting)
Symptoms include visual disturbances, giddiness, loss of balance, slurred speech followed by aching mainly in the back of the head. Fainting can occur at the height of the attack.
Hemiplegic Migraine (with weakness on one side of the body)
Symptoms resemble a stroke and may progress until the arm and leg on one side are completely paralysed for a few hours. Repeated attacks may leave a residual weakness. Familial hemiplegic migraine occurs where there is a family history of hemiplegic migraine.
Ophthalmoplegic Migraine (with double vision)
Symptom is paralysis of one or more of the muscles moving the eyes resulting in the eyes moving out of alignment and the person seeing double.
Retinal Migraine (with loss of vision in one eye)
Symptom is loss of sight in one eye and normal vision in the other. The sight clears leaving an ache behind the eye or a generalised headache.
Migrainous Infarction
Symptoms range from permanent blind spots to a full stroke occurring during a typical migraine attack. An infarct is the death of tissue due to an inadequate blood supply.
Triggers
See also: Management of Headache / Precipitating factors
Triggers are many and varied, not the same for everyone and not necessarily the same for different attacks in the same person. Identifying triggers may be complicated by the fact that it often takes a combination of triggers to set off a headache.
Dietary Triggers
Common, well-recognised dietary triggers include:
- missed, delayed or inadequate meals
- caffeine (coffee and tea) withdrawal
- certain wines, beers and spirits
- chocolate, citrus fruits, aged cheeses and cultured products (chocolate and other sugar cravings may be prodomal not triggers)
- monosodium glutamate (MSG)
- dehydration.
Environmental Triggers
Environmental triggers include:
- bright or flickering lights, bright sunlight
- strong smells, e.g. perfume, gasoline, chemicals, smoke-filled rooms, various food odours
- travel, travel-related stress, high altitude, flying
- weather changes, changes in barometric pressure (likewise, decompression after deep-sea diving)
- loud sounds
- going to the movies
- computers (overuse, incorrect use).
Hormonal Triggers
Hormonal fluctuations are implicated as a significant trigger for women as three times as many women suffer from migraine headaches as men, this difference being most apparent during the reproductive years,. Hormonal triggers may be:
- Climacteric (final menstrual period)
- Menstruation (a UK study found 50% of women more likely to have migraine around menstruation)
- Ovulation
- Oral contraceptives
- Pregnancy (may worsen for first few months but in two thirds of women improves in latter part)
- Hormone replacement therapy (HRT)
- Menopause.
Physical and Emotional Triggers
Physical and emotional factors include:
- lack of sleep or oversleeping (even as little as half hour difference in routine, e.g. sleeping in on weekends)
- illness such as a viral infection or a cold (if taken cold and migraine medication, remember that many cold remedies contain pain-killers)
- back and neck pain, stiff and painful muscles, especially in scalp, jaw, neck, shoulders, and upper back
- sudden, excessive or vigorous exercise (regular exercise can however prevent migraine, if migraine is triggered by a blow to the head a doctor should be consulted)
- emotional triggers such as arguments, excitement, stress and muscle tension
- relaxation after stress (weekend headache).
Treatment of Migraine
Much can be done about migraine. Treatment is not just a matter of taking a tablet but a case of each individual developing a migraine management plan that will probably involve lifestyle modifications, medication and complementary therapies.
See: Management of Headache
Medication
Some people can manage their migraines with medications available from a pharmacy. For many others, these are not sufficiently effective. If this is the case, or you are unsure about the cause or nature of your headache, or if your headaches change, it is important you consult a doctor. Studies show that 50% of migraine sufferers have not been diagnosed. Even if you have previously consulted a doctor and the prescribed treatment has not been successful it is worth going again. Migraines can be managed, effective migraine management involves a partnership between you and your doctor. Some medications are given once the headache has begun (acute treatment) and others taken daily to reduce the frequency of attacks (preventative treatment).
Acute Treatment
Infrequent, less severe migraine may respond to over-the counter medications such as
- aspirin (not recommended for young children, some adults respond well to three tablets)
- paracetamol
- non-steroidal anti-inflammatory drugs such as ibuprofen (Nurofen, Brufen), naproxen (Naprosyn).
Medications that may be prescribed for more severe migraine include
- triptans such as sumatriptan (Imigran), naratriptan (Naramig), zolmitriptan (Zomig) that are based on the serotonin molecule
- ergotamine compounds (Cafergot) that appear to provide relief by constricting cranial blood vessels
- stronger non-steroidal anti-inflammatory drugs
- stronger narcotic-type analgesics.
Anti-emetic medications often prescribed with other forms of acute therapy to minimise the nausea that often accompanies migraine include
- metoclopramide (Maxolon), prochlorperazine (Stemetil) or domperidone (Motilium) to increase absorption and reduce nausea.
Preventative Treatment
Prophylactic/preventative medication is taken daily, regardless or whether a headache is present, to reduce the incidence of severe or frequent headaches. These include:
- beta blockers such as propranolol (Inderal), timolol (Blocadren), atenolol (Tenormin) and metoprolol (Lopresor, Betaloc) that block the beta-receptors on which adrenaline works in the nervous system as well as on blood vessels
- serotonin antagonists such as methysergide (Deseril), pizotifen (Sandomigran) and cyproheptadine (Periactin)
- sodium valproate or valproic acid (eg Epilim), an anti-epileptic drug shown to reduce the intensity of migraine
- calcium-channel blockers such as verapamil (Isoptin) that stop the constriction of blood vessels by preventing the use of calcium necessary for this reaction
- antidepressants such as amitriptyline (eg. Tryptanol) have an action on headache that is independent of their antidepressant action
- feverfew, a herbal remedy
- riboflavin 200mgm twice daily has been reported as useful.
All are effective. All have side effects and, except feverfew and riboflavin, are prescription drugs. Many were initially introduced for some other problem and were also observed to reduce headache.
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