How to Know When It's Autoimmune Epilepsy

Andrew N. Wilner, MD

Disclosures

December 06, 2018

Andrew N. Wilner, MD: Welcome to Medscape. I'm Dr Andrew Wilner.

Today, I have the pleasure of speaking with Dr Batool Kirmani, medical co-director of neurosciences and medical director of the Epilepsy Center at Centra Health, Lynchburg, Virginia. Dr Kirmani recently served as the lead author of a paper entitled "Management of Autoimmune Status Epilepticus,"[1] which is a really hot topic. Welcome, Dr Kirmani.

Batool F. Kirmani, MD

Batool F. Kirmani, MD: Thank you.

Wilner: We've been hearing more and more about autoimmune epilepsy. I'm an epileptologist myself and I'm not even sure when I've seen it. How common is this?

Kirmani: The annual incidence of status epilepticus itself is only 12.6 per 100,000 worldwide and 11.7 per 100,000 in developed countries.[2]

For autoimmune epilepsy, sometimes we see maybe one or two cases or more a month, and other months we don't see any. It's there, but it's not that common.

Red Flags for Autoimmune Epilepsy

Wilner: What are the signs that I'm looking for in autoimmune epilepsy?

Kirmani: There are certain red flags that give you an indication that it is autoimmune epilepsy, or autoimmune status epilepticus. Most of these patients don't have any prior history.

The patient's classic clinical presentation is also important, especially when you look at the brain wave studies. What I've noticed, which is not something that's been published, is that these patients have multiple focal seizures as compared to what you see in normal status epilepticus. They have seizures coming from several areas of the brain, which also can be a red flag that this may be autoimmune status epilepticus.

Whenever we come across a case, it takes a long time to treat it and keep them under control like we would regularly be able to do. It is pretty refractory, especially the autoimmune status epilepticus. These cases are nonresponsive to antiepileptic drugs (AEDs). Their seizures keep on happening no matter what you do.

Wilner: It's a difficult case. It's de novo. They're seizing often in status. You're trying this drug and that drug, but nothing works. Does testing their cerebrospinal fluid (CSF) get you anywhere?

Kirmani: It does, and we do send CSF for analysis. However, when it comes to autoimmune epilepsy, the goal is start the treatment right away rather than waiting for the results to come back. By the time the CSF results come back, it may be too late.

Mainly, we initiate AEDs. You start one drug that fails, then a second, and by the third, that's likely too late. At that point, you want to consider immunomodulatory therapies to treat the refractory status epilepticus.

Ruling Out Malignancy

Wilner: We've known for a long time that autoimmune encephalitis is sometimes associated with malignancy. Is what we're talking about here associated with malignancy as well?

Kirmani: It can be, but not always. It's kind of a subset.

We do all the necessary workup for malignancy just to rule out everything, since that can be one of the reasons.

Wilner: What do you do if you don't have any idea where the malignancy is?

Kirmani: Sometimes, the patients present with poor histories and other times they are just healthy people. We perform a whole-body scan depending upon what we find from the history. We'll start with an MRI in the brain and then go further and look for malignancy.

Wilner: Do you see anything on the MRI of the brain?

Kirmani: With status epilepticus, you can see edema, but otherwise no. It's very difficult to see the initial stages of anything on the MRI of the brain.

After Traditional Therapies Fail

Wilner: Let's say you're convinced you have a status case, and you do all the usual things but nothing works. It's multifocal on the EEG and you've sent off your lab studies from the panel. We get those back in about 3 weeks, which, as you say, doesn't help too much.

Kirmani: That's the thing. We don't wait for those studies. We have to start the high-dose steroids or plasmapheresis. Those are the ways we want to go. Really, if you see the EEG not getting anywhere, you are having multifocal seizures, after two medicine failures, that's really when you start thinking about whether there's something more to do than just using the traditional seizure medications. I would go through the immunotherapy rather than just trying traditional AEDs.

Wilner: Teach me about immunotherapy. If we're convinced or have a good idea that it's autoimmune, what do we do?

Kirmani: The high-dose steroids are usually the first line of treatment. I think they should improve on that, but if that doesn't work then we do intravenous immunoglobulin and then maybe end with the plasmapheresis.

Know Your Antibodies

Wilner: Every time I read about this in terms of all the different antibodies, they always seem to add a new one. How do I know which ones to order?

Kirmani: That's a difficult question because we send the whole panel. The most common ones are NMDA (N-methyl-D-aspartate), anti-GAD (anti-glutamic acid decarboxylase), voltage-gated potassium channel, Rasmussen's encephalitis, or herpes simplex. These are the ones we usually send.

Wilner: You mentioned the patient presentation. Apart from a malignancy, are there any risk factors or patient profile that makes you think about autoimmune status?

Kirmani: There are some symptoms which you can look for in the ICU. We look to exclude all the other things like stroke, infection, noncompliant medication, and then progressive encephalopathy. We try to rule out the most common causes of why this happened.

Wilner: Are they likely to have other autoimmune diseases? Is that a risk factor?

Kirmani: It can be, but I'm not seeing much of this. Like I said, autoimmune encephalitis and others can result in autoimmune status epilepticus.

Role of the Clinician

Wilner: You really have to use your clinical judgment and rule out other causes.

Kirmani: It's mainly a typical judgment. You get a good history, look for some failure of conventional anticonvulsants, rule out prior history of stroke or noncompliance, and then look at patient presentation.

The typical such patient I see in the ICU is normal and healthy, with no other problems. Then, all of a sudden they will start to have seizures. When you look at the EEG, those are the ones that are having multifocal seizures. There, I suspect autoimmune status epilepticus right away, although we do try some conventional AEDs at first.

Wilner: We're going to keep an eye out for that. At our hospital, we have a lot of alcohol-related seizures and noncompliance-related seizures. If we get a young, healthy person in status, I think autoimmune is going to be high on the list.

Kirmani: Even in the older population, I've seen otherwise healthy patients who have had no problems before all of a sudden start having multifocal seizures. They're very refractory, and then you suspect whether they're autoimmune or not then.

Wilner: Dr Kirmani, I want to thank you very much for speaking with me today about autoimmune status epilepticus and sharing your experience and insight with Medscape.

Kirmani: Thank you so much for having me.

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