Migraine Headaches Introduction
Experts do not agree about what causes headaches, but they agree that more studies are needed. Headaches are hard to study because of the following reasons:
- People experience pain differently (in other words, a headache one person rates as a 10 on a scale of 10 might be rated as a 5 by another person).
- Measuring headache pain in a standard way that accounts for the personal way people feel pain is almost impossible.
- Studies are limited to human subjects.
Several observations support this idea. When exposed to very high or low temperatures, people sometimes develop a migrainelike headache. (Migraine headaches are sometimes called vascular headaches. Vascular means having to do with the blood vessels.) These headaches can also suddenly arise in some people when they do not get enough sleep or food.
Common triggers of migraine headaches include heat, stress, and lack of sleep or food. Not every headache sufferer is sensitive to these triggers, but virtually all persons with migraine headaches (called migraineurs) have some environmental trigger. About 70% of migraineurs have a first-degree relative (parent, brother, sister, or child) with a history of migraine. People with an inherited tendency for headaches may respond more easily than others to these external stress factors. Some experts have therefore thought that headache is an adaptive and developed response. Most primary headaches slowly develop over minutes to hours. The pain experienced in headache is transmitted by the slowest of all unmyelinated nerves. Unmyelinated nerves lack a myelin sheath, or covering, and send impulses slowly.
Migraine Headaches
In the United States, white women have the highest frequency of migraine, while Asian women have the lowest. The female-to-male ratio increases from 2.5:1 at puberty to 3.5:1 at age 40 years, after which it declines. The rate of migraine headaches in females of reproductive age has increased over the last 20 years.
Migraine Headaches, Causes
The causes of migraine headaches are not clearly understood. In the 1940s, it was proposed that a migraine begins with a spasm, or partial closing, of the arteries leading to the main part of the brain (called the cerebrum). The first spasm decreases blood supply to part of the brain, which causes the aura (lights, haze, zig-zag lines, or other symptoms) that some people experience. These same arteries then become too relaxed, which increases blood flow and causes pain.
About 30 years later, the chemicals dopamine and serotonin were found to play a role in migraine headaches. (These chemicals are called neurotransmitters.) Dopamine and serotonin are normally found in the brain, but they can cause blood vessels to act in uncharacteristic ways if they are present in abnormal amounts or if the blood vessels are unusually sensitive to them.
Together, these 2 theories have come to be known as the neurovascular theory of migraine, and it is presently believed that both theories provide insight into the causes of headache.
Various triggers are thought to initiate migraine headaches in people who are prone to developing them. Different people may have different triggers.
- Smoking has been identified as a trigger for many people.
- Certain foods, especially chocolate, cheese, nuts, alcohol, and monosodium glutamate (MSG), may trigger migraine headaches. (MSG is a flavor enhancer used in many foods, including Chinese dishes.)
- Missing a meal or changing sleep patterns may bring on a headache.
- Stress and tension are also risk factors. People often have migraines during times of increased emotional or physical stress.
- Contraceptives (birth control pills) are a common trigger. Women may have migraines at the end of the pill cycle as the estrogen component of the pill is stopped. This is called an estrogen-withdrawal headache.
- Epilepsy
- Familial dyslipoproteinemias (abnormal cholesterol levels)
- Hereditary hemorrhagic telangiectasia
- Tourette syndrome
- Hereditary essential tremor
- Hereditary cerebral amyloid angiopathy
- Ischemic stroke: Migraine with aura is a risk factor (odds ratio, 6:1).
- Depression and anxiety
Nausea, vomiting, photophobia (sensitivity to light), phonophobia (sensitivity to sound), irritability, and malaise (general discomfort or uneasiness, an “out-of-sorts” feeling) are common. The headache usually lasts for 6-24 hours. Migraineurs generally prefer to lie quietly in a dark room.
Sometimes, a history of certain triggers can be identified. Common associations in migraine include head injury, physical exertion, fatigue, drugs (nitroglycerine [Nitrostat], histamine, reserpine [Serpasil], hydralazine [Apresoline], ranitidine [Zantac], estrogen), and stress.
If the headache is always on one side, the doctor must look for a structural lesion by using imaging studies like magnetic resonance imaging (MRI). Having a history of migraine attacks and determining what brings them on are important, because a secondary headache can mimic a migraine headache and thus mask a new medical problem.
Migraine Headaches, Variants
- Migraine without aura (common migraine) is a throbbing headache without the early visual symptoms.
- Ophthalmic migraine is a type of migraine associated with eye problems. This variant is sometimes called retinal migraine or ocular migraine.
- Abdominal migraine is the term used to describe periodic abdominal pain in children that is not accompanied by headache.
- Complicated migraine is a type of migraine in which migraine attacks are accompanied by permanent problems like paralysis.
- Vertebrobasilar migraine manifests without headaches but with symptoms like vertigo, dizziness, confusion, speech disturbances, tingling of extremities, and clumsiness.
- Status migrainosus is the term used to describe migraine attacks that persist for days. These attacks may result in complications such as dehydration.
- Avoid factors that cause a migraine attack (for example, lack of sleep, fatigue, stress, certain foods, vasodilators).
- Treat accompanying conditions (for example, anxiety, depression).
- Oral birth control agents (contraceptives) may increase the
frequency of headaches in females. Women may be advised to discontinue
oral contraceptives (or to use a different form) for a trial period to
see if they are a factor.
- Sumatriptan (Imitrex, Imigran)
- Zolmitriptan (Zomig, Zomig-ZMT)
- Naratriptan (Amerge, Naramig)
- Rizatriptan (Maxalt, Maxalt-MLT)
- Almotriptan (Axert)
- Frovatriptan (Frova)
- Eletriptan (Relpax)
- Ergotamine tartrate (Cafergot)
- Dihydroergotamine (D.H.E. 45 Injection, Migranal Nasal Spray)
- Acetaminophen-isometheptene-dichloralphenazone (Midrin)
- Prochlorperazine (Compazine)
- Promethazine (Phenergan)
Treatment strategies are more successful if they are tailored to the individual patient and are initiated early in the headache.
Patients with severe nausea and vomiting at the onset of an attack may at first respond best to intravenous prochlorperazine. These patients may be dehydrated; adequate fluid intake is necessary.
Vasoconstrictors (agents that narrow the blood vessels), such as ergotamines or triptans, should not be given to patients with known complicated migraine without the advice of a headache specialist. Instead, acute attacks should be treated with one of the other available agents, such as nonsteroidal anti-inflammatory drugs (NSAIDs) or prochlorperazine.
Mild and infrequent attacks may not always require the use of ergotamines or triptans and may be adequately treated with acetaminophen (Tylenol), NSAIDs, propoxyphene (Darvon, Darvocet), or a combination of these.
About 40% of all attacks do not respond to triptans or any other substance. If all else fails, migraineurs with an attack lasting more than 72 hours (status migrainous) can be treated with intravenous medications. Brief hospitalization may be needed.
Migraine Headaches, Preventive treatment
Patients who have frequent acute migraine attacks and report that the attacks affect their quality of life should consider preventive therapy as a supplement to the specific headache-stopping drugs (abortive treatments) they use.
The goals of preventive therapy include decreasing the frequency and severity of acute attacks and improving quality of life.
Patients with complicated migraine headaches who have a history of neurological symptoms associated with their attacks are definite candidates for preventive therapy. For these patients, even a single previous complicated migraine episode qualifies them for long-term preventive therapy.
The choice of preventive medication should be tailored to the individual's profile, taking into account comorbidities (concurrent medical conditions) such as depression, weight gain issues, exercise tolerance, asthma, and pregnancy plans. All medications have side effects; therefore, selection must be individualized.
Preventive drugs include beta-blockers, tricyclic antidepressants, some anticonvulsants, calcium channel blockers, cyproheptadine (Periactin), and NSAIDs such as naproxen (Naprosyn). Unlike the specific headache-stopping drugs (abortive drugs), most of these were developed for other conditions and have been coincidentally found to have headache preventive effects. The following drugs also have preventive effects; unfortunately, they also have more side effects:
- Methysergide maleate (Sansert): This drug has many side effects.
- Lithium (Eskalith, Lithobid): This drug has many side effects.
- Indomethacin (Indocin): This drug can cause psychosis in some people with cluster headaches.
- Steroids: Prednisone (Deltasone, Meticorten) works extremely well for some people and should be tried if other therapies fail.
Cluster Headaches
Cluster headaches have been called histamine cephalalgia, Horton neuralgia, and erythromelalgia. The causes of cluster headaches are not known with certainty. The mechanisms by which the body produces cluster headache pain and other symptoms are also not known for sure.Cluster Headaches, Prevalence
Cluster headaches are rare. (Less than 1% of the population experience them.) People who do have such headaches usually start to have them when aged 20-40 years. Males get them more often than females (by a ratio of 5-8:1). Usually, no family history of cluster headaches is noted.
Cluster Headaches, Clinical features
Typically, cluster headaches come on with no warning. The signs and symptoms may include intense burning or penetrating pain, often described as a stabbing or hot poker sensation, in or around one eye or temple, occasionally spreading to the forehead, nose, cheek, or upper gum and jaw.
Cluster headaches usually occur on one side of the head. Pain is often penetrating and lasts from 15 minutes to 4 hours. Cluster headaches often cause people to awaken in the middle of the night. During a cluster headache, people are restless and may find relief in pacing or crying. Cluster headaches start rapidly over a few minutes. Periodicity (occurring at regular intervals) is characteristic of cluster headaches. Clusters of headaches are experienced, each cluster lasting as long as several months, once or twice a year. Using alcohol, histamines, or nitroglycerine during a cluster headache may worsen the attack.
Certain personality and physical characteristics have been associated with cluster headaches. A leonine (lionlike) appearance is one of them. Strong associations with smoking, alcohol use, and previous head and face trauma have been noted.
Cluster Headaches, Abortive treatment
Most of the headache-stopping drugs (abortive drugs) effective in treating migraine headaches are also effective in stopping cluster headaches, suggesting that the two types are related.
- Oxygen therapy: This is the treatment of choice and is very safe and
effective. Early in an attack, oxygen delivered through a face mask has
been known to either stop an attack or diminish its intensity. Why this
works is unknown.
- Occipital nerve steroid injection (methylprednisolone acetate [Depo-Medrol]): An injection of this drug may stop a cluster headache attack.
As with the abortive drugs, most of the preventive drugs effective in treating migraine headaches are also effective in preventing cluster headaches, again suggesting that the two types are related.
Daily Chronic Headache
Chronic tension-type headache
Chronic tension-type headache, Treatment
Patients who are less responsive to previous treatment and those with conditions like depression and stress may be good candidates for psychological treatments. Biofeedback has been successful in patients with tension headache. They are taught how to relax their tense muscles. Thermal biofeedback, in which patients are taught to increase their body temperatures to improve their headaches, has also worked. Other less conventional treatments, such as relaxation training and stress-coping training, may be helpful in the long term.
Transformed migraine
Transformed migraine, Treatment
- Detoxification
- Stopping all analgesics and headache-related medications is best done in an inpatient setting.
- Doctors may prescribe a clonidine (Catapres) patch to lessen withdrawal symptoms if narcotic analgesics are involved.
- Stopping all analgesics and headache-related medications is best done in an inpatient setting.
- Preventive: Preventive treatments for transformed migraine headaches are identical to those used for the other types of migraine headache.
Hemicrania continua and chronic paroxysmal hemicrania are uncommon forms of chronic headache. Chronic paroxysmal hemicrania is a severe chronic headache similar to cluster headache. It has a male predominance. The headaches are paroxysmal (pulsing), with pain in the temple/eye region lasting 20-30 minutes. The paroxysms occur several times a day. This type of headache can last several years. Treatment with indomethacin (Indocin) results in a dramatic response.
Secondary Headaches
- Space-occupying intracranial (inside the head) lesions: The headaches associated with intracranial tumors are initially paroxysmal. Classic headaches of this type wake a person from sleep at night and are associated with projectile vomiting. With time, the headaches may become continuous and intensify with activities that increase intracranial pressure (for example, coughing, sneezing).
- Meningeal irritation: Meningitis, especially the chronic forms (tuberculous, fungal), can irritate the meninges (membrane covering the brain and spinal cord) and result in chronic headaches. The headaches are often diffuse (spread out).
- Posttraumatic headache: Headache can be part of a postconcussion syndrome. Patients may report vague headaches, fatigue, memory problems, and irritability for months or years after the traumatic event.
- Temporal arteritis: This is an inflammation of some of the arteries of the extracranial (outside the skull) arteries. The headache is generally localized to the affected side and may be worsened by chewing.
- Post-lumbar puncture (spinal tap) headache: Lumbar puncture can cause a headache that is worsened by sitting up from a lying position. It usually goes away by itself after the person drinks fluids and has caffeine in some form.
- Referred pain: Headache may be a form of referred pain from neighboring structures. Dental disease can cause chronic headaches. Upper neck diseases or arthritis can also cause headaches. People with acute sinus or jaw problems can experience headaches; however, uncomplicated chronic sinusitis does not cause headaches.
- Idiopathic intracranial hypertension (benign intracranial hypertension, pseudotumor cerebri): This disorder, most common in young women, is due to increased intracranial (within the head) pressure in the absence of any structural central nervous system abnormality or obstruction to the flow of cerebrospinal fluid.
Synonyms and Keywords
