Hemiplegic migraine is a rare type of migraine attack. The word ‘hemiplegia’ means paralysis of one side of the body. The defining symptom that distinguishes hemiplegic migraine from other types is muscle weakness.
Like other migraine types, hemiplegic migraine can cause intense and throbbing pain, nausea, and sensitivity to light, sound and smell. The hemiplegic aura causes temporary weakness, numbness and tingling, other sensory disturbances, and/or paralysis on one side of the body. The paralysis can be partial, such as a facial droop, or affect the entire side. You may also experience confusion, difficulty speaking, or vision problems. These symptoms start before any headache, during the aura phase of the attack. Some people do not get any headache at all.
Because a hemiplegic attack looks very much like a stroke, people living with hemiplegic migraine are frequent visitors to emergency. You will learn what is ‘normal for you’ and when you don’t need to go to hospital, but it is always important not to get too complacent and have a stroke ruled out by doctors anytime you are experiencing anything unusual or are concerned.
Hemiplegic attacks can be very scary, and it’s ok to be worried. They’re often more scary for those around you, who are looking at your droopy face or can’t understand what you are saying. If you are having frequent or unpredictable attacks, it can be helpful to carry a letter or card with you that explains your condition, and asks the reader to call an ambulance.
What causes Hemiplegic Migraine?
Hemiplegic migraine is clearly genetic. Four different specific chromosomal defects have been attributed to hemiplegic migraine, although there are more not yet discovered. Most types of migraine are poly-genetic (multiple genes), hemiplegic migraine is one of the few where a single gene defect can cause the condition. On average 50% of children who have a parent with hemiplegic migraine will develop this disorder.
The genes which have been linked to hemiplegic migraine are:
These genes are related to channels on nerve membranes that control the movement of substances like sodium, calcium and potassium across the nerve. Mutations of these genes result in over-excitability of nerves. Genetic testing is available but not necessary for all people. Genetic testing may be of highest value for people with early-onset hemiplegic migraine associated with seizures or other persistent neurologic symptoms (e.g. ataxia).
You may hear the terms Familial Hemiplegic Migraine (FHM) or Sporadic Hemiplegic Migraine (SHM). The only real difference is that people with FHM have one other identified family member with similar symptoms, and people with SHM have no known family history. There is some evidence that people with SHM will experience more other symptoms of migraine (sensitivity to light, sound, smell and nausea) and will have a headache more often than people with FHM. However, as more evidence comes to light about all migraine being genetic, these terms are likely to be reviewed.
Symptoms of Hemiplegic Migraine
- Motor weakness on one side of the body (Hemiplegia)
- Pounding or throbbing headache, often on the opposite side to the side which is weak
- Nausea and/or vomiting
- Sensitivity to light, sound or smell
- Other typical aura symptoms – vision problems, numbness, tingling, trouble speaking
- Impaired consciousness ranging from confusion to profound coma
- Ataxia (defective muscle coordination)
The symptoms can last for hours to days, or rarely weeks, but most resolve completely.
Please refer to the International Classification of Headache Disorders 3rd edition (beta version) website for more information on the criteria used to diagnose hemiplegic migraine: https://www.ichd-3.org/1-migraine/1-2-migraine-with-aura/1-2-3-hemiplegic-migraine/
Treatment for Hemiplegic Migraine
Management of hemiplegic migraine can be challenging. The care of a migraine specialist neurologist is often required, as many other doctors may never have treated a case of hemiplegic migraine.
Triptans are currently contraindicated (not recommended) in the treatment of hemiplegic migraine because of their vasoconstrictive properties (risk of vessel spasm) and concerns about stroke. Some small studies have safely used triptans with patients with hemiplegic migraine, so your doctor may be ok with prescribing them, but it is important to talk about the stroke risk and make sure you understand them.
The new abortive medication Reyvow, which is not yet available in Australia, works like triptans but does not have the same vasoconstrictive properties. Other common treatments such as NSAIDs and antiemetics may be used to relieve some symptoms.
Given the severity of the symptoms and the contraindication of certain acute medications (triptans), preventive medications are considered especially important in the treatment of hemiplegic migraine. There are small studies reporting use of verapamil, acetazolamide, flunarizine, ketamine, lamotrigine and naloxone for 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. The new CGRP treatments hold particular promise for the treatment of hemiplegic migraine, but more studies are required before we can say for sure how effective they are for this particular subtype.