Hemiplegic Migraine

Hemiplegic migraine is a rare subtype of migraine with aura that includes muscle weakness along with other forms of aura. It may occur randomly or it can run in families. When a person has no family history, it is called sporadic hemiplegic migraine. When more than 1 member of the family has this disorder it is called familial hemiplegic migraine.¹

What does plegic mean?

The term plegic means paralysis, but most people with hemiplegic migraine have muscle weakness that lasts hours or days. In rare cases, muscle weakness may last up to 4 weeks. The amount of muscle weakness can be mild to severe. Paralysis and coma are very rare.²

Average number of attacks

On average, a person with hemiplegic migraine has 3 attacks per year and attacks begin between ages 12 and 17. However, there is a wide range, and people may have only a few attacks over their lifetime or up to 250 a year. The number of attacks tends to fall after age 50.³

Symptoms of hemiplegic migraine

Hemiplegic migraine shares many of the same symptoms as other forms of migraine with aura. The aura symptoms begin gradually over 5 minutes or longer, and the aura symptoms occur 1 after another. Symptoms usually last for 20 to 30 minutes, but in rare cases they may last for a few hours to days or even weeks. Overall symptoms may include:^2,3

• Muscle weakness that goes away after the migraine attack and often occurs on 1 side of the body. (This is the key symptom of hemiplegic migraine.)
• Vision changes, such as seeing flickering lights, spots, or lines
• Part or full loss of eyesight
• Trouble speaking that goes away after the migraine attack

The main difference between a hemiplegic migraine and other types of migraine is the muscle weakness that completely disappears after the attack ends. This is called motor aura.

What causes hemiplegic migraine?

Doctors know that hemiplegic migraine that runs in families is caused by mutations in the CACNA1A, ATP1A2, and SCN1A genes. These mutations cause cortical spreading depression, which is abnormal electrical activity in the brain that leads to migraine symptoms.³

More study needs to be done to confirm what causes sporadic hemiplegic migraine. “Sporadic” means the person does not have a close relative with the same condition. There is some evidence that the same genetic mutations involved in the familial type cause many sporadic hemiplegic migraine.³

Diagnosing hemiplegic migraine

A physical exam, medical history, family medical history, and a migraine diary help your doctor diagnose hemiplegic migraine. Blood and imaging tests may be ordered to rule out other health conditions, such as stroke, epilepsy, meningitis, or brain tumors. Genetic testing may help reach a diagnosis if there is a family history of hemiplegic migraines.³

Because muscle weakness, vision changes, difficulty speaking, and head pain are also signs of a stroke, the first time someone experiences these symptoms they must seek immediate medical attention. Some people are also misdiagnosed with epilepsy or stroke.

Treating hemiplegic migraine

The treatment for hemiplegic migraine generally follows the same guidelines for preventive and acute drugs as other migraine types. However, some doctors avoid prescribing abortive or preventive drugs that cause the blood vessels to narrow. Triptans are an example of this type of drug.^1,3

Identifying and avoiding triggers

Next, the person’s migraine triggers must be identified and avoided. Each person may have a different combination of triggers. A migraine journal can be used to record your migraine symptoms, what time of day you have them, what occurred before the symptoms began, how long they last, and the severity. This will help you identify and later avoid your migraine triggers and your doctor accurately diagnose what type of migraine you have.