An Overview of Hemiplegic Migraines
When Migraine Symptoms Resemble a Stroke
Hemiplegic migraines are a rare form of migraine that causes temporary motor problems, including weakness on one side of the body (hemiplegia). These symptoms are a form of migraine aura—known as "motor aura"—and occur with typical manifestations, such as changes in vision, speech, or sensation. Because hemiplegic migraine symptoms are similar to symptoms of a stroke, it is critical to identify and treat these migraines as quickly as possible.
Symptoms
A person undergoing a hemiplegic migraine attack may initially experience a visual aura followed by a sensory aura, and lastly, a motor aura.
In addition to the aura symptoms, the duration of a hemiplegic migraine aura is different from that of a typical migraine with aura. In fact, the aura of a hemiplegic migraine attack often lasts more than one hour; in around 5 percent of people, it lasts more than 24 hours.
Symptoms of a hemiplegic migraine can include:
Weakness on one side of your body, including your face, arm, and leg (motor aura)
Numbness or tingling in the affected side of your face or limb (sensory aura)
Flashes of light, double vision, or other vision disturbances (visual aura)
Trouble speaking or slurred speech
Drowsiness
Dizziness
Loss of coordination
Rarely, people with hemiplegic migraines have more serious symptoms, such as:
Confusion
Loss of control over movement
Decreased consciousness
Memory loss
The symptoms can last from a few hours to a few days. Memory loss can sometimes continue for months.
Related:What Is Your Migraine Profile?
Causes
There are two types of hemiplegic migraine. They share the same symptoms and are both caused by gene mutations.
Familial hemiplegic migraine (FHM) is inherited. Gene mutations associated with familial hemiplegic migraine include:
FHM1, caused by mutations in the CACNA1A gene located on chromosome 19
FHM2, caused by mutations in the ATP1A2 gene located on chromosome 1
FHM3, caused by mutations in the SCN1A gene located on chromosome 2
As research evolves on hemiplegic migraine, more genetic mutations are being discovered. For example, mutations in the PRRT2 gene have also been linked to familial hemiplegic migraine.
If you have one parent with familial hemiplegic migraine, you have a 50 percent of inheriting the condition.
Sporadic hemiplegic migraine (SHM) is less common than familial hemiplegic migraine and is not inherited, which means that a person will not have a family history of the condition. Instead, the genetic mutations of a person with sporadic hemiplegic migraine occur spontaneously.
Mutations in the ATP1A2 and CACNA1A genes have been found to cause sporadic hemiplegic migraine.
Diagnosis
As with all forms of migraine, diagnosis is based on the presence of specific symptoms, frequency of attacks, and the ruling out of other possible causes.
A diagnosis of hemiplegic migraine requires having had at least two attacks that included aura accompanied by fully reversible motor weakness and fully reversible visual, sensory, and/or speech/language symptoms.
The migraines must also have at least two of the following four characteristics:
At least one aura symptom that spreads gradually over five or more minutes and/or two or more symptoms that occur in succession
Individual non-motor aura symptoms lasting five to 60 minutes and motor symptoms lasting for less than 72 hours
At least one unilateral (one-sided) aura symptom
Aura that is accompanied by headache or followed one within an hour
Imaging tests, such as magnetic resonance imaging (MRI) or a computed tomography (CT) scan, as well as neurological tests, may also be performed to rule out other potential causes (such as transient ischemic attack and stroke).
A diagnosis of familial hemiplegic migraine also requires that at least one first- or second- degree relative has had attacks that meet the diagnostic criteria.
Conversely, a diagnosis of sporadic hemiplegic migraine requires that no first- or second-degree relative has had attacks that meet the above criteria.
Treatment
Certain preventive medications commonly used to treat typical migraine with aura can be effective in treating hemiplegic migraines as well. These include:
Amitriptyline
Topamax (topiramate)
Depakote (valproic acid)
Zavzpret (zavegepant)
To prevent hemiplegic migraine attacks, the following drugs may be prescribed for daily use:
Acetazolamide
Verapamil
Drugs that should not be used to manage hemiplegic migraines, because they can increase the risk of a stroke, include:
Ergotamine derivatives
Beta-blockers
Typically, nonsteroidal anti-inflammatories (NSAIDs), anti-nausea drugs, or opioids are used to ease the immediate symptoms of a hemiplegic migraine.
Related:Migraine Treatments on the Horizon
A Word From Verywell
Symptoms of hemiplegic migraine can mimic symptoms of other conditions such as stroke and epilepsy, so there's no doubt that experiencing one of these episodes can be frightening. Getting a proper diagnosis and treatment is especially important with this form of migraine, so make sure to see a specialist who has experience with this rare condition. Research, including identifying more genes associated with hemiplegic migraine, is ongoing and will hopefully make it easier to identify and manage these migraines in the future.