Article on Relationship of Migraine and Seizure

Migraine & Coexisting Illness
reprinted with permission by Ache Newsletter Winter/1999



Migraine is relatively common. About 18% of U.S. women and 6% of men develop migraine at some point in their lives. So, it's not surprising that some people with migraine also have other medical problems, such as diabetes, heart disease, rheumatoid arthritis, or depression. Identifying and treating these coexisting conditions can be quite important in managing the migraine headaches. For example, many effective headache medications must be avoided by people who have heart or blood vessel disease in addition to migraine. Likewise, some medications can cause headache as a side effect, so it's important to review medications taken for other health problems to see if they might be contributing to the headaches.

Many of these coexisting illnesses are coincidental; a person happens to have diabetes and migraine because both are common. In some situations, there is more than coincidence involved. While many people with migraine enjoy perfect health except for their headaches, migraine sufferers do have increased rates of specific comorbid disorders (two disorders that occur together too frequently to be coincidence), including depression, seizures, and Raynaud's disease. The reverse is also true; people who already have depression, epilepsy or Raynaud's disease are at an increased risk of migraine.

This increased risk is not "one more thing to worry about". The majority of headache sufferers do not have a serious comorbid health problem. The fact that these disease associations do occur gives us some important clues to underlying mechanisms that help to explain the cause of migraine. Just as important, many of our current headache prevention medications were first identified when drugs prescribed for other conditions were found to be effective for migraines as well.

Migraine & Epilepsy

Epileptic seizures occur when a group of nerve cells in the brain become activated and discharged all at once. Depending on their location in the brain, this burst of hyperactivity can have a wide range of effects, from momentary confusion to muscle spasms, to loss of consciousness. These attacks may be the result of actual damage to the nerve cells (following a head injury, for example) or to some recurrent imbalance in the brain's chemistry. Some evidence suggests that abnormalities in the brain serotonin system may have a role in seizures, and serotonin is also known to be involved in migraine.

Migraine and epilepsy frequently occur together, and the association between these two conditions is more than coincidental. Epilepsy is relatively rare compared to migraine, affecting only 0.5% of the population, or one in 200 people. However, several studies of migraine patients have shown the rate of epilepsy to be much higher, about 6%. In other words, epilepsy is about 12 times more common among people with migraine than it is in the general population.

In addition, people with epilepsy appear to have higher risk of developing migraine at some point in their lives. Researchers have examined possible genetic links between migraine and epilepsy by studying the families of people with epilepsy. This study found that individuals with epilepsy had nearly a one-in-four chance of developing migraine. Within a given family, relatives without epilepsy had a one-in-seven chance (15%) of developing migraine, compared to a one-in-four risk (26%) for family members with epilepsy. The risk of migraine was elevated both before and after the onset of seizures. Shared genes cannot account for the increased co-occurrence of migraine and epilepsy, nor can environmental factors. Perhaps it can be attributed to an unknown altered brain state.

Both migraine and epilepsy are characterized by episodes of hyperactivity in the brain and nervous system.

Both can sometimes be triggered by strong sensations, such as bright light or noise. Given the overlap between the two disorders, some experts have theorized that the underlying mechanisms that produce migraine and seizure attacks may be similar.

Knowing that a person has both migraine and epilepsy is important to selecting the optimal treatment. For example, tricyclic antidepressants are often effective for migraine prevention but these drugs may lower the seizure threshold and so would not be appropriate choices. On the other hand divalproex (Depakote) was first approved

as a treatment for epilepsy and other seizure disorders and later shown to be effective for migraine prevention. Use of a single medication to treat both conditions helps in avoiding side effects or complications, and is generally more convenient for the individual.

Migraine & Raynaud's phenomenon

Raynaud's phenomenon or Raynaud's disease refers to a spastic condition affecting the small arteries of the toes and fingers. Cold, stress or intense emotion can cause the vessels to constrict, temporarily cutting off circulation, so that the skin appears pale or yellow, then reddened when circulation is restored. This condition is called Raynaud' phenomenon when it is a symptom of an underlying disorder such as lupus, scleroderma, rhematoid arthritis, or hardening of the arteries. Raynaud's disease is a benign primary disorder, like migraine itself. Milder cases can be managed by avoiding cold exposure, caffeine and nicotine, which can all act to bring on symptoms. More severe cases can be helped by biofeedback and medication.

Several studies have suggested that a relationship exists between Raynaud's and migraine. Migraine is more common in patients with Raynaud's disease, chest pain (angina), and connective tissue disorders like lupus or scleroderma. These studies involved people who have already been diagnosed for one or the other disorder. Given that only a minority of migraine sufferers ever see a doctor for their headaches, these types of studies may overestimate the number of headache sufferers who have other conditions such as Raynaud's.

A study in the general population, using a standardized interview and color charts, was used to diagnose Raynaud's phenomenon. People with migraine more often reported cold sensitivity or unusual color changes in their fingers (39%) compared to individuals without migraine (24%). Identification of severe color changes in the hands (from photographs illustrating Raynaud's attacks) was relatively uncommon, but 7% of study participants with migraine met criteria for Raynaud's compared to 2% of participants without migraine. Since migraine headache is known to involve constriction in the blood vessels of the head there may be some common factors causing blood vessel spasm in people with migraine and Raynaud's phenomenon. Alternatively, people with these two conditions may have a heightened sensitivity to changing sensations such as physical and emotional stress and environmental conditions such as cold.

Headache sufferers who have symptoms of Raynaud's disease should be careful to discuss these with their doctor, since several common migraine medications can bring on or intensify Raynaud's attacks. If the Raynaud's disease needs treatment, then it is sometimes possible to choose an option, such as biofeedback, that may also be helpful in preventing migraine attacks.



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