Migraine can present in a variety of ways. A hemiplegic migraine is a rare form of migraine where people experience weakness on one side of their body (hemiplegia) in addition to the migraine headache attack.
Like other migraines, hemiplegic migraine causes intense and throbbing pain, nausea, and sensitivity to light and sound. But in addition it also causes temporary weakness, numbness and tingling, and paralysis on one side of the body. These symptoms start before the headache. “Hemiplegia “literally means paralysis on one side of the body. It's incredibly scary he first time a migraine sufferer experiences a hemiplegic migraine, as most assume they are having a stroke.
Hemiplegic migraine, thankfully, only affects a small number of people who get migraines with aura. Aura is a broad term that includes visual symptoms, like flashes of light and zigzag patterns that happen before or during a migraine. Aura also includes other sensory problems and trouble speaking, or weird sensations anywhere in the body. In people with hemiplegic migraines, weakness or paralysis happens as part of the aura.
There are two types of hemiplegic migraine. Which type you have is based on your family history of migraines:
- Familial hemiplegic migraine (FHM)- affects at least two close relatives in the same family. If you have FHM, each of your children will have a 50 percent chance of inheriting the condition.
- Sporadic hemiplegic migraine (SHM) - affects people who don’t have any family history of the condition.
- Subdivisions of Hemiplegic Migraine
- familial hemiplegic migraine type 1
- familial hemiplegic migraine type 2
- familial hemiplegic migraine type 3
This is a very rare migraine-type so if you ever experience new or never-evaluated weakness with your headache, you should seek immediate medical evaluation and not assume you have a hemiplegic migraine.
Both familial and sporadic hemiplegic migraines often begin in childhood.
Sometimes, before the actual headache pain, you'll get other symptoms, that tell you the migraine is coming. These early symptoms, called auras, can include short-term trouble with muscle control and sensation: Symptoms include:
- Severe, throbbing pain, often on one side of your head
- A pins-and-needles feeling, often moving from your hand up your arm
- Numbness on one side of your body, which can include your arm, leg, and half of your face
- Weakness or paralysis on one side of your body
- Loss of balance and coordination
- Dizziness or vertigo
- Nausea and vomiting
These attacks can range from about one a day to fewer than five in a lifetime. There can often be long episode-free periods during life. Generally, episodes become less frequent with time. Individual episodes can vary in severity and duration. Hemiplegic migraine is a chronic disorder and can be extremely painful and debilitating.
Individuals with hemiplegic migraine experience weakness on one side of the body during the aura (hemiplegia), either just before or during the migraine headache. The degree of weakness can vary from mild to severe. Hemiplegia may affect only part of one side of the body, such as just the hand or the hands and arms, or the face. A weakness of the entire side of the body can occur.
In hemiplegic migraine, the weakness is most often associated with at least one other aura symptom. Vision is usually affected temporarily, and symptoms can include a sudden appearance of a bright light in the center of the field of vision causing blind spots (scintillating scotoma), double vision, flashing lights (photopsia), and bright, shimmering, jagged lines (fortification spectra). Visual symptoms can also include a foggy vision or a loss of vision of one half of the visual field. Additional symptoms include numbness or a prickly sensation of the face or arms and legs (paresthesia), fever, imbalance, drowsiness or lethargy, and an inability to understand or express speech (aphasia). The specific aura symptoms that develop during a migraine attack can vary from one attack to another. Some individuals with hemiplegic migraine may also have attacks with a so-called typical aura, including visual, sensory and speech troubles but no weakness.
During an attack of hemiplegic migraine, a headache might start shortly before, during or after the aura. Migraine headaches cause throbbing, intense, sometimes debilitating pain and are notably stronger than regular headaches. The pain can cause nausea or vomiting, and affected individuals may be extremely sensitive to light (photophobia) and to sound (phonophobia).
In severe instances, affected individuals may experience prolonged weakness, seizures, confusion, memory loss, and personality or behavioral changes. Although uncommon, hemiplegic migraine attacks can be severe enough to cause coma.
During such severe hemiplegic migraine attacks, weakness and speech troubles can last for several days or weeks but usually fully recover. In rare instances, permanent complications can develop including intellectual disability.
A minority of individuals with hemiplegic migraine may develop signs or symptoms of involvement of the cerebellum, the area of the brain that controls coordination and balance and is also involved in cognition and behavior. These signs or symptoms can include uncontrolled, repetitive movements of the eyes (nystagmus), slurred speech (dysarthria), and a lack of coordination of voluntary movements (ataxia).
A minority of individuals with hemiplegic migraine may develop epileptic seizures outside of hemiplegic migraine attacks.
The symptoms can last for hours to days, or rarely weeks, but mostly resolve completely.
A hemiplegic migraine causes symptoms like confusion and trouble speaking, which are similar to those of a stroke. Seeing a neurologist or headache specialist for tests can help you get the right diagnosis and treatment.
Abnormal variations in three genes have been identified as causing familial hemiplegic migraine. Genes provide instructions for creating proteins that play a critical role in many functions of the body. When a mutation of a gene occurs, the protein product may be faulty, inefficient, absent, or overproduced. Depending upon the functions of the particular protein, this can affect many organ systems of the body, including the brain.
Variations in the CACNA1A gene cause familial hemiplegic migraine type 1. Variations in the ATP1A2 gene cause familial hemiplegic migraine type 2. Variations in the SCN1A gene cause familial hemiplegic migraine type 3. Some individuals have familial hemiplegic migraines but do not have variations in these genes. Researchers believe that there are additional gene or genes that cause this disorder, but that has yet to be identified.
The three genes are known to cause a hemiplegic migraine to produce proteins that are required for the normal function of nerve cells of the brain (neurons). These proteins play a role in the transport of electrically charged particles called ions across a channel that connects nerve cells (neurons), helping to regulate brain activity. Consequently, familial hemiplegic migraine can be classified as a channelopathy, a group of disorders characterized by abnormalities in the flow of ions, such as sodium and calcium ions, through pores in cell membranes (ion channels). The proteins produced by these three genes may also be involved in other areas or functions of the body as well.
Some researchers have shown that nerve cells are overactive (hyperexcitability) in hemiplegic migraine. This hyperexcitability may be associated with a phenomenon called cortical spreading depression that may play a role in the development of hemiplegic migraine. Cortical spreading depression is a slow wave of depolarization of nerve cells that spreads over the hemispheres of the brain. Depolarization refers to a change in the charge between the outside and inside of the membrane of nerve cells, which affects how or if ions can pass through the membrane. These theories are not proven as definitively playing a role in the development of hemiplegic migraine and more research is necessary to determine the complex, underlying factors that cause the signs and symptoms of this disorder.
Familial hemiplegic migraine is inherited in an autosomal dominant pattern. Genetic diseases are determined by the combination of genes for a particular trait that is on the chromosomes received from the father and the mother. Disorders inherited in a dominant pattern occur when only a single copy of an altered gene is necessary for the appearance of the disorder. The altered gene can be inherited from either parent or can be the result of a new mutation (gene change) in the affected individual. The risk of passing the altered gene from affected parent to offspring is 50% for each pregnancy. The risk is the same for males and females.
Like common migraines, there are a variety of ‘triggers’ that can cause a migraine attack. Triggers that can cause an episode of hemiplegic migraine include certain foods, certain odors, bright light, too little or too much sleep, physical exertion, stress, or minor head trauma. Cerebral angiography can also trigger an episode. This is a type of x-ray exam that is used to assess the health and function of blood vessels in the brain. Sometimes, there are no identifiable triggers when an episode occurs.
Common triggers of hemiplegic migraines include:
- bright lights
- intense emotions
- too little or too much sleep
Other migraine triggers include:
- foods like processed foods, aged cheeses, salty foods, and the additive MSG
- alcohol and caffeine
- skipping meals
- weather changes
Your doctor might prescribe drugs to prevent hemiplegic migraine, to stop them once they've started, and to relieve your symptoms. Your doctor will discuss the best options for you.
Many of the same drugs used to treat regular migraines also work for hemiplegic migraines. A few medications may prevent these headaches before they start:
- High blood pressure medications may reduce the number of migraines you get and make these headaches less severe.
- Anti-seizure drugs might also help with this type of headache.
Drugs called triptans are one of the main treatments for regular migraines. However, they’re not recommended for people with hemiplegic migraines. They could make hemiplegic migraine symptoms worse or cause permanent damage.
CGRP inhibitors are a new class of preventive medicine for treating most common migraines, but indications suggest this treatment would not be effective for hemiplegic migraines.
The treatment of hemiplegic migraine is directed toward the specific symptoms that are apparent in each individual. Treatment may require the coordinated efforts of a team of specialists. Physicians who specialize in diagnosing and treating disorders of the brain and central nervous system in children (pediatric neurologists), neurologists, physicians who specialized in treating headaches or migraines, pain specialists, physicians who specialize in diagnosing and treating eye disorders (ophthalmologists), social workers, and other healthcare professionals may need to systematically and comprehensively plan treatment. Psychosocial support for the entire family may be beneficial as well. Genetic counseling may be of benefit for affected individuals and their families.
There are no standardized treatment protocols or guidelines for affected individuals. Due to the rarity of the disease, there are no treatment trials that have been tested on a large group of patients. Various treatments have been reported in the medical literature as part of single case reports or small series of patients. Treatment trials would be very helpful to determine the long-term safety and effectiveness of specific medications and treatments for individuals with hemiplegic migraine. As in other common varieties of migraine, treatment is divided into acute treatment taken during the attack in order to reduce the severity of the various attack’s symptoms and preventive treatment that is taken every day during some months to reduce the frequency of attacks.
Standard preventive medications used to treat regular migraines can be tried for individuals with all types of hemiplegic migraine, in order to reduce the frequency of attacks. These drugs include tricyclic antidepressants, beta-blockers, calcium channel blockers, and anti-seizure (anti-convulsant or anti-epileptic) medications.
Individuals who experience a severe migraine episode may require hospitalization, particularly for high fever, depressed consciousness, or seizures.
Anti-seizures medications may be used to treat seizures such as those seen in familial hemiplegic type 2.
Given the severity of the symptoms and the contraindication of certain acute medications (triptans and ergotamines), preventive regimens (medications are taken daily to prevent the attacks whether you have a headache or not) are considered especially important in the treatment of hemiplegic migraine.
Since hemiplegic migraine is a subset of migraine with aura, certain preventive medications commonly used to treat typical migraine with aura, including amitriptyline, topiramate, and valproic acid may be beneficial. Beta-blockers are generally avoided for people with hemiplegic migraine out of theoretical concern that it may affect the ability of vessels to dilate.
How is it diagnosed?
A diagnosis of hemiplegic migraine is based upon identification of characteristic symptoms, a detailed patient history, a thorough clinical evaluation and a variety of specialized tests. Two proposed diagnostic criteria have been published (The International Classification of Headache Disorders, 3rd edition and a population-based study of familial hemiplegic migraine suggests revised diagnostic criteria, Thomsen et al. 2002) to help physicians diagnose hemiplegic migraine.
Generally, affected individuals must have two episodes of migraine with aura that exhibit specific signs or symptoms. By definition, fully reversible muscle weakness on one side of the body (hemiplegia) that occurs with at least one other type of aura symptom (vision, sensory, speech or brainstem) must be present for a diagnosis. For the familial form, at least one first- or second-degree relative must also have the disorder.
Doctors diagnose hemiplegic migraines based on their symptoms. You’ll be diagnosed with this type of headache if you’ve had at least two attacks of migraine with aura, weakness, and vision, speech, or language symptoms. These symptoms should go away after your headache improves.
Hemiplegic migraine can be hard to tell apart from other conditions, like stroke or mini-stroke (also called transient ischemic attack). Its symptoms can also be similar to diseases like multiple sclerosis or epilepsy.
To rule out conditions with similar symptoms, your doctor will do tests like these:
- A CT scan uses X-rays to take pictures inside your body.
- An MRI uses strong magnets and radio waves to take pictures inside your body.
- An electroencephalogram measures the electrical activity in your brain.
- An echocardiogram uses sound waves to create pictures of your heart.
If you have one or more family members with this type of migraine, you might want to have genetic testing. However, most people with FHA will not test positive. Researchers have not yet found all the genes linked to this condition.
Prevention and risk factors
Attacks of hemiplegic migraines often start in childhood or young adulthood. You’re more likely to have this type of headache if it runs in your family. If one of your parents has hemiplegic migraine, you have a 50% chance of also getting these headaches.
You may not be able to prevent hemiplegic headaches if they run in your family.
However, you can take medicine to cut down on the number of headaches you get.
Another way to prevent these migraines is to avoid any factors that trigger your headaches.
The number of newly affected individuals within a year (incidence) and prevalence (the overall number of people with a disorder at a given time (prevalence) of hemiplegic migraine is unknown. Studies in a population of Denmark placed the prevalence at 1 in 10,000 individuals in the general population. The prevalence was the same for the familial and sporadic forms. Rare disorders often go misdiagnosed or undiagnosed making it difficult to determine the true frequency of disorders like a hemiplegic migraine in the general population.
Hemiplegic migraine affects more females than males. The onset of the disorder is usually within the first or second decade of life but has ranged from early infancy to the elderly.
Because symptoms of hemiplegic migraine are also symptoms of other conditions such as stroke and epilepsy—a hemiplegic migraine attack can be quite frightening, both to the migraineur and to those witnessing the attacks. Proper diagnosis and treatment are especially essential with this form of migraine. Imaging studies and another testing should be performed to rule out other causes of the symptoms. It is important that people with hemiplegic migraine understand their migraines as well as possible. With continuing research, especially genetic research, more is being learned about hemiplegic migraines. As this research continues, living with hemiplegic migraine will become easier.
Compiled using information from the following sources: