What is a migraine?
Migraine is a complex neurobiological disorder that has been recognized since antiquity. The core features of migraine are headache, which is usually throbbing and often unilateral, and associated features of nausea, sensitivity to light, sound, and exacerbation with head movement.
Migraine has long been regarded as a vascular disorder because of the throbbing nature of the pain. However, as we shall explore here, vascular changes do not provide sufficient explanation of the pathophysiology of migraine. Up to one-third of patients do not have throbbing pain. Modern imaging has demonstrated that vascular changes are not linked to pain and diameter changes are not linked with treatment.
Migraines are severe headaches that usually begin on one side of the head (often behind the eye) and spread to the whole head. Migraines can last from two hours to a few days.
A migraine is a relatively common medical condition that can severely affect the quality of life of the sufferer and his or her family and friends.1 Almost 8% of Canadians over the age of 12 have been diagnosed with migraine, of which 75% are women and 25% are men. Migraine is most commonly experienced by both men and women between the ages of 25 and 39.2
There are two different types of migraines: migraines without aura and migraines with aura.
A migraine without aura is a condition characterized by moderate to severe throbbing and unilateral pain. The pain is worsened by movement and accompanied by at least one of the following symptoms:
- Nausea, loss of appetite, and/or vomiting
- Photophobia (increased sensitivity to light)
- Phonophobia (increased sensitivity to sound)
Migraines without aura are characterized by a sudden onset and can have a major impact on the sufferer’s daily life.6 On average, untreated migraine episodes last from 4 to 72 hours. A migraine with aura involves any number of different sensations that range from visual disturbances to physical sensations.3 The aura symptoms usually occur in alternating body sites during different attacks. Almost always preceding the headache, the aura symptoms can last between 5 and 60 minutes.3 Some people report having a prodrome, a feeling of strangeness a day or two before the attack begins. Prodromes are characterized by mood changes, food cravings, feeling tired or hyperactive, or excessive yawning. Some people may also experience fatigue, stiffness in the neck, and difficulty concentrating.
What causes migraines?
The cause of migraines is unclear. No one knows exactly why migraines happen. For many years it was believed that migraine attacks arose consequent to changes in the blood vessels which supply the head and brain; aura (when it occurred) was attributed to constriction of arteries, with neurological symptoms resulting from impaired blood ﬂow and the “throbbing, sickening” pain of migraine attributed a compensatory dilation of those and other vessels.
There are many theories that discuss the causes of migraine. The cortical spreading depression (CSD) theory suggests that migraine is a disease of the brain such as angina is a disease of the heart. Disruption of normal brain functioning is believed to be the underlying cause of migraine pain and aura. Another theory is the vascular theory which suggests that migraines result from the widening of blood vessels surrounding the brain. The chemical serotonin is also thought to play an important role in migraine development.8 While the precise cause of migraines remains unknown, a number of potential migraine triggers (habits or conditions associated with the onset of a migraine) have been identified.
Doctors believe there are ‘triggers’ that bring on a migraine, although finding out an individual’s trigger is not always easy. Some common triggers include:
- alcohol, especially red wine
- flickering lights from a TV or computer screen
- heat, light (glare), or noise • chemicals, such as those found in petrol and perfume
- cheese, coffee, nuts, chocolate, oranges, tomatoes, some food additives, and preservatives
- hormonal changes – periods, hormone pills, and menopause
- emotions – stress, excitement, or fatigue
- relaxation – after a stressful working week, you relax and a migraine attack occurs.
- Diet (foods such as cheese, coffee, tea, alcoholic beverages, or nuts)
- Strong odors such as perfumes
- Bright lights
- Loud noises
- Changes in the weather
- Sleeping more or less than usual
- Certain medications
What are the symptoms?
The symptoms of the migrainous aura are spectacular and sometimes frightening. Although most migraine patients will never have an aura, much attention has been focused on the phenomenon. The classical, slow progression of symptoms is experienced by only 15%, whereas less specific disturbances cover the whole visual field in about 25% of patients.
Migraine pain can be throbbing, pulsing, or squeezing and it gets worse with movement and normal activities. Other symptoms include:
- a warning sign (aura) such as blurred vision, flashing lights, numbness, tingling, and funny smells
- nausea and vomiting
- a dislike for bright lights
- a dislike for loud noises.
The attacks may be few and far between, or frequent and severe. Migraines are often unpredictable.
Migraine and stroke
The relationship between migraine and stroke is complex. The symptoms can sometimes seem similar (see How do I tell the difference between migraine and stroke later in this guide), and they may share some underlying risk factors.
Stroke and migraine both happen in the brain, and sometimes the symptoms of a migraine can mimic a stroke. However, the causes of the symptoms are different. A stroke is due to damage to the blood supply inside the brain, but a migraine is thought to be due to problems with the way brain cells work. In a stroke, the blood supply to part of the brain is cut off, killing brain cells. This causes permanent damage to the brain and can have long-lasting physical, cognitive, and emotional effects. A migraine causes pain and sensory disturbances, but the changes inside the brain are usually temporary.
Migraine is diagnosed by piecing together information about your symptoms and identifying patterns over time. Your GP will do a number of tests checking your vision, reflexes, coordination, and sensations. They will ask you to keep a diary of your migraine symptoms and factors such as what you ate and how you slept leading up to them. This may help you identify and avoid your triggers. You should also record any medicines you are already taking. Painkiller over-use makes migraines difficult to treat.
The first step in managing your migraines is to identify your triggers so that you can avoid them in the future. You may find it helpful to keep a migraine diary to track details of your attacks.
There are many different migraine medications on the market. Which medications you take depends on many factors—the time of day or night that the attack occurs, how bad your migraine is, and any other health issues you may have, such as heart disease, asthma, high blood pressure, or pregnancy.
Basically, migraine medication involves three different types of treatment:
- Treating migraine attacks
- Rescue medications
- Preventing migraine headaches
But, there are various things you can do to help reduce the risk of an attack:
Follow a regular sleep routine: try going to bed and awakening at the same time each day. Get enough sleep–but don’t oversleep.
- Exercise: go jogging or join a gym. Keeping your body healthy and fit is a great way to reduce migraines
- Reduce stress: regular exercise, deep breathing exercises, yoga, and transcendental meditation can be good stress relievers for many.
- Avoid overstimulation of senses: avoid using fluorescent lights. Have your sunglasses handy on sunning days. Steer clear of fragranced soaps and beauty products.
- Stop smoking: smoking is a migraine risk factor. One-third of smokers complain that smoking initiates or exacerbates their migraines. The odor of cigarette smoke can also trigger attacks.
- Behavioral techniques: relaxation techniques, thermal and electrical stimulation of the head, and management skill programs have all been effective in reducing attacks.
- Psychological support: cognitive behavioral therapy (stress coping) teaches sufferers problem-solving and coping skills that can be used to handle their migraine triggers.
- Physical therapy: for some sufferers, migraines are induced by physical trauma. Hot packs, ultrasound, and therapeutic massage can help diminish pain.
Remember that some migraine triggers are unavoidable