What is a Migraine and Why Does Sumatriptan Relieve Pain?
What is a Migraine?
A migraine is often defined as a severe, throbbing headache, but it's actually a collection of symptoms which may appear in several stages and last for hours or days. The headache may be accompanied by nausea, sensitivity to light and sound and other problems. It may be preceded or followed by unpleasant symptoms as well. Frequent and long-lasting migraines are disabling and seriously interfere with the sufferer's life.
There are treatments available for migraines, although trial and error may be needed to find a helpful treatment for a particular person. Some people experience more benefit from the current treatments than others.
Sumatriptan is a medication that helps to reduce or relieve migraine symptoms in many people. It joins to receptors that normally bind to a chemical called serotonin and constricts dilated blood vessels. A common brand of the medication is Imitrex. Imitrex doesn't work for all migraine sufferers and it doesn't reduce the frequency of migraines. Nevertheless, Imitrex or another brand of sumatriptan is often helpful and in some cases is a very effective treatment for migraines.
A Migraine Headache Versus a Tension Headache
A migraine is not simply a bad headache, as some people imagine. It consists of a collection of symptoms known as a syndrome. Some people experience these symptoms without a headache.
Stages and Symptoms of a Migraine
A migraine is a complex phenomenon. There may be four stages to a migraine, although not every migraine sufferer experiences every stage.
- Prodromal Phase: Several hours to two days before a migraine attack begins, a person may experience unusual sensations such as food cravings, excess energy, irritability, tiredness, depression, a stiff neck or gastrointestinal disturbances.
- Aura Phase: This phase takes place five minutes to an hour before a headache begins. A person may see flashing or colored lights in the form of zigzag lines and there may be blind spots in the field of vision. The person may also experience a pins-and-needles sensation, numbness, confusion or concentration problems. Understanding and communicating with others may become difficult. About thirty percent of people who suffer from migraines experience an aura.
- Attack Phase: The headache originates on one side of the head and produces an intense, throbbing pain. The pain is worse if the person moves. The person often experiences nausea and may vomit. They may also be very sensitive to light, sound, or sometimes smell. There may be other symptoms during the attack phase, such as a feeling of being excessively hot or cold. The symptoms may not be the same during each attack. The attack phase generally lasts from four to seventy-two hours. While most people experience a headache during a migraine, not everybody does.
- Postdromal Phase: Once the headache or most severe symptoms have disappeared, a person may not feel completely well for a day or longer. They are often tired and may be confused. They may still have a background headache, which gradually fades.
The Meninges - Membranes on the Surface of the Brain
There is no definite answer to the puzzle of how a migraine develops. The process appears to be complex and is proving difficult to decipher. It is known that during a migraine attack there are major changes in the chemical and electrical activity in the brain.
The Meninges and the Trigeminal Nerve
According to one theory for migraine creation, increased electrical activity in the cortex of the brain stimulates the meninges. The cortex is the outer layer of the brain. The meninges are three membranes that cover the brain. They contain pain-sensitive nerves as well as blood vessels.
The theory says that migraine pain arises due to inflammation of the meninges and dilation of blood vessels in the area. The expanded blood vessels irritate nerves. Branches of the trigeminal nerve conduct nerve impulses from the meninges to the brain stem at the bottom of the brain. The brain stem then sends signals up to the rest of the brain, include the parts that generate the sensation of pain.
The meninges, trigeminal nerve and brain stem may play a role in the creation of a migraine. Recent theories suggest that the generation of a migraine lies mainly within the brain instead of in the meninges, however.
The Trigeminal Nerve, The Brain Stem and Migraine Headaches
Cortical Spreading Depression
Cortical spreading depression is a phenomenon observed in the brains of some people who get an aura before a migraine attack. It may play a role in the creation of the headache as well as the aura, although this is by no means certain. It's believed to operate by the following process.
- At the start of the migraine, a wave of abnormal neural events and the electrical activity that they generate appears in the brain. The wave often starts in the vision area at the back of the brain and slowly moves forward through the cortex.
- The leading edge of the wave involves excitation of nerves and increased electrical activity. Behind this leading edge is a zone of depressed electrical activity.
- The area of excitation may cause the jagged lights seen by people during an aura as well as the pins and needle sensation. The zone of depression that follows is thought to correlate with blind areas in the visual field.
When the area of excitation reaches the meninges, it may cause the release of chemicals that inflame the meninges and irritate nerves. This in turn may cause a signal to be sent along the trigeminal nerve to the brain stem. The brain stem may then transmit signals up to the section of the brain that creates the sensation of pain.
Changes in the Brain During a Migraine
Calcitonin Gene-Related Peptide, or CGRP
Another theory for migraIne creation states that a trigger causes nerves to release an excessive amount of a substance called CGRP (calcitonin gene-related peptide). CGRP is a neurotransmitter - a chemical that transmits nerve impulses between neurons, or nerve cells. Researchers have found that the level of CGRP is elevated during a migraine attack. They suspect that the chemical is a major contributor to migraine pain.
CGRP causes inflammation and stimulates dilation of blood vessels. New medications that either attack CGRP molecules or block their receptors have been created. It's exciting to note that these medications have helped migraine sufferers in clinical trials. The medications stop vessel dilation without causing their constriction. Sumatriptan also stops the dilation of blood vessels, but it does this by causing vessel constriction, which is undesirable.
Different people have different triggers for their migraines. A person must have a sensitive nervous system and be predisposed to migraine attacks in order for a trigger to cause a migraine. In addition, a trigger may not cause a migraine in a person every time.
Common triggers include specific foods and drinks (such as alcohol, chocolate, caffeine, food preservatives and MSG), certain medications, smoke, changes in eating patterns, changes in sleep patterns, hormonal changes, stress, overexertion, barometric pressure changes and visual triggers such as bright or flashing lights.
Doctors say that a migraine sufferer should keep a daily headache diary. A note should be made of any aspect of a person's life that may trigger a migraine. For example, a person should note their diet and the time they ate the food, their medication and when they take it, the length and time of exercise, the time when they went to bed and the time when they got up, and the weather. A woman should also record the stage in her menstrual cycle, which may be significant.
Keeping a headache diary may be time consuming, but it's a very valuable strategy. Preventing a migraine attack is a much better approach than trying to treat it once it occurs.
The tendency to experience migraines when exposed to certain triggers seems to be inherited. In my family both my sister and I suffer from migraines, although I experience them much less often than she does. We also have different triggers and slightly different symptoms.
Migraine Symptoms, Causes and Treatment
Anyone who thinks that they are experiencing migraines should visit a doctor. A correct diagnosis is essential, since recurring headaches are symptoms of other disorders besides migraines. In addition, patients need to work with their doctor to find a medication or treatment plan that helps them.
What are Sumatriptan and Imitrex?
Sumatriptan is a medication used to relieve migraine pain. It was approved for migraine treatment by the FDA (Food and Drug Administration) in 1992. Imitrex is a popular brand of sumatriptan. Treximet is a brand that contains both sumatriptan and naproxen sodium, a nonsteroidal anti-inflammatory drug (NSAID). Combination drugs work well for some people.
Sumatriptan is a member of the triptan family of chemicals. It's administered as a tablet, an injection or an oral spray. There are other triptans available, so if sumatriptan doesn't help a person's migraines another one can be tried. It's known that triptans constrict or narrow blood vessels and relieve swelling in tissues, but they may also help to relieve migraine pain in other ways.
How Does Sumatriptan or Imitrex Work?
Sumatriptan is believed to help migraines by mimicking the action of a natural chemical called serotonin. Serotonin is a neurotransmitter. It constricts blood vessels and also has other functions. The serotonin level seems to decrease during a migraine.
Serotonin joins to specific receptors on cell membranes in order to do its job. Sumatriptan binds to these receptors. Once it's attached to the receptors, sumatriptan is thought to have several effects. It may block inflammation in the meninges, constrict the meningeal blood vessels, inhibit pain impulses in the brain stem and/or block the creation of pain sensation in the brain. Sumatriptan has also been found to lower the CGRP level in migraine patients.
Many people with a migraine headache need to lie motionless in a dark, quiet room to allow their headache to subside. Cooling pads or ice packs on the forehead reduce pain for some people. In addition, most people need to take some form of medication to treat their headache.
Non-prescription painkillers, anti-inflammatory medications or anti-nausea medications are sometimes helpful. A medicine that contains a combination of a painkiller and an anti-nausea drug may also work. If over-the-counter remedies don't relieve the pain, a doctor may prescribe a triptan or another medication. Botox injections help some patients significantly, although repeated injections over time may be needed to provide benefits.
In March 2014, the Food and Drug Administration in the United States approved the medical use of a device called Cefaly. This device may prevent a migraine attack. It's worn like a headband and administers a weak electric current to the skin and underlying tissues, stimulating branches of the trigeminal nerve. These branches travel to the forehead and face as well as the meninges. Cefaly is available by prescription only.
It may take some time to find an effective medication or treatment regime for a person's individual situation. This reflects the fact that we don't yet understand the generation of migraines and that different mechanisms may operate in different people.
Medication should be taken at the first sign of symptoms if someone recognizes that a migraine attack is approaching. Once the symptoms have fully developed it may be impossible to block them and the person may have to wait until they subside on their own.
The Future For Migraine Sufferers
Migraines affect about ten percent of the world's population, making them a public health problem. For some people, migraines are only an occasional problem. For others they occur much more frequently. In the worst cases the disorder is an almost daily occurrence.
Migraines often disrupt a person's life, preventing them from going to work or school regularly or from taking care of their family and enjoying social activities. New treatments are being created and tested, however. Reducing CGRP levels sounds especially promising. Hopefully, the recently discovered treatments will provide the relief that some people need.
© 2013 Linda Crampton
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