Posted by Brigham and Women's Hospital March 18, 2014
What causes a migraine?
Although migraines are extremely common, their exact cause remains unknown. It appears likely that the visual aura relates to a phenomenon called “cortical spreading depression,” which temporarily affects electrical impulses in the brain. The pain of a migraine headache probably relates to spasm or irritability of blood vessels in the brain, which are sensitive to pain (unlike the brain tissue itself, which does not have pain receptors).
It is often possible to identify certain risk factors that increase the chance of having migraines. These include:
- Family history – Migraines often run in the family.
- Gender – Overall, migraines are more common in women than in men.
- Hormonal status – It is natural for a woman to notice a change in headaches and other migraine symptoms in adolescence or around the time of menopause.
Many individuals can identify specific triggers for their migraines, such as: lack of sleep, skipping meals, caffeine withdrawal, emotional or physical stress, and certain foods or drinks (including red wine, chocolate, or aged cheese). For many patients with isolated migraines, however, it’s difficult to pinpoint specific triggers. Furthermore, trigger avoidance alone may not be enough to control headaches.
What are the signs that my visual symptoms aren’t due to a migraine?
The typical visual symptoms of a migraine are “positive,” meaning that something shimmering or sparkling is disrupting the vision. Migraines are less likely to cause “negative” symptoms of pure visual darkness. An episode of visual darkness typically requires additional evaluation for other conditions, including a transient ischemic attack (ministroke).
Can I have a migraine without a headache?
It is quite common to have a migraine without any headache. The medical term for this is “acephalgic migraine.” Except for the absence of a headache, the visual symptoms in this type of migraine are identical to the episodes that accompany a classic migraine aura.
What are the acute (short-term) migraine treatments?
An isolated migraine without a headache typically does not require any acute treatment. The first few times someone experiences a visual migraine it usually causes a lot of anxiety. That anxiety, however, usually subsides once they become familiar with the symptoms.
Some patients are able to tell when a headache is beginning. They may find that early use of simple strategies can nip a mild headache in the bud. These simple strategies include such things as eating, having caffeine, meditating or taking an over-the-counter medication such as acetaminophen or ibuprofen.
When headaches are moderate or severe, additional treatment may be needed. Most headache medications work best when they are taken in time to stop the headache before it becomes too severe. If vomiting is a problem, patients may require non-oral medicines such as injections or rectal suppositories. Some patients find over-the-counter combinations of simple analgesics in combination with caffeine to be helpful. Other patients try a class of prescription medications known as “triptans.”
Triptans are specially designed to work on receptors on blood vessels and brain cells in order to halt a migraine at an early stage. Although there are a number of different triptans, made by several different pharmaceutical companies, each of these is similarly effective. They’re often taken orally, but also come as injections and nasal sprays. These medicines are generally not considered safe in patients with a history of strokes, heart attacks, or other vascular diseases.
What are the preventive migraine treatments?
Many patients who experience isolated migraines without severe headaches don’t require specific preventive treatments. If a patient is aware of the particular triggers that seem to bring on an episode, however, then those triggers can be avoided.
For patients whose migraine pattern includes frequent, severe headaches, it is very reasonable to consider additional preventive treatments. The main goal for any of these strategies is to reduce the overall frequency and severity of the headaches. No preventive treatment, however, is 100 percent effective. For example, it would be considered successful if a preventive treatment helped reduce the number of severe headaches from eight per month to two-four per month.
There are numerous medications that can be used as a preventive treatment for migraine. Medications used as preventive treatments can cause side effects, but starting with a low dose and then increasing the dose very slowly is usually a helpful strategy. Some commonly tried medications include amitriptyline, and topiramate. Less commonly, medications such as propranolol or valproic acid are used. For some patients, botulinum injections (in the forehead and scalp) can help reduce headaches. Certain vitamins, minerals and herbal preparations are also used to help prevent migraines.
How can I prevent migraines without using medicines?
Some preventive migraine treatments do not require medication. Many people find that regular exercise makes them feel better. Other strategies include improving sleep habits or learning to cope more effectively with stress by learning relaxation techniques such as biofeedback or meditation.
Printable version of Dr. Prasad’s migraine information: