EAN 2023 | Hemiplegic migraine: causes, symptoms, and treatment

Hemiplegic migraine is a form of migraine with aura, and a migraine with aura what you often have is the migraine headache, but also aura symptoms, which are transient neurological symptoms that go away after a short time. The thing that makes hemiplegic migraine different from common migraine with aura is that you have also a motor aura, which means you have paralysis or other weakness of the limbs, which makes it hemiplegic migraine.

In most patients’ hemiplegic migraine, you don’t have one gene that makes the disorder happen, but in some of them you do and then we call it monogenic hemiplegic migraine. And these monogenic hemiplegic migraine cases, it’s caused by mutation in one of the three known hemiplegic migraine genes, which are CACNA1A, ATP1A2 and SCN1A. If the mutation is there, then they can get a hemiplegic migraine. There are other genes that are also suspected of being involved in hemiplegic migraine, but currently it’s not proven that they can cause the disorder in a monogenic way, as these three other genes can do. We know that all these genes, the proteins that they make, they are located at the synaptic cleft. And there, they can cause hyperexcitability because they lead to an increase in potassium and an increase of glutamate, and together this leads to brain that is hyperexcitable, and this leads to the hemiplegic migraine.

Well, this is something that’s a bit more complex than common migraine, because when you have common migraine and you have patients that have questions about genetics, you can be very clear about that. You can say, well, “there is an increase that your children will also have migraine because you have migraine.” But it’s not in a way that people with hemiplegic migraine can get an increase of risk, because if it’s a monogenic hemiplegic migraine, so if there’s a mutation in one of these three genes, that means that your children will have 50% chance of developing the disorder. This is something that’s important for these patients to realize and also for their children and other relatives to know. So, in their counseling, it’s a bit different.

And if you move on from that, the treatment is also different. In common migraine there are several steps that you can take, and these are not necessarily the same when you think about hemiplegic migraine. So, what we have for these patients we have acute treatment, which is the same as in common migraine. Often you need a triptan and in the beginning when the triptans were first being used, people were kind of scared to give them to people with hemiplegic migraine because they thought they might lead to stroke or other horrible outcomes. But now we know, or at least it is expert opinion, that they can be prescribed safely to these patients because we do not see these kind of side effects. So that’s something that’s important, especially because these patients deserve the treatment they need. But it’s important to realize that these triptans they’re aimed at treating the migraine attack but especially the headache, so they don’t actually treat the aura. And this is important because the hemiplegic migraine patient often come to you with questions “how do I not have this aura?” “How do I make the aura go away?” Because they have a lot of paralysis and these are the complaints that they come to you about. This is something that requires attention and you can’t do this with acute treatment. So then you move on to the preventive treatment, and preventive treatment is aimed at decreasing the severity of the attack and the frequency of the attack. For that there are a lot of different migraine drugs available, but we do use different ones that are usually used in common migraine. For instance, lamotrigine is one of our first choices of treatment because we know it’s very effective for hemiplegic migraine, and acetazolamide and valproate are other drugs that we are frequently using with hemiplegic migraine patients.