Brain, Skull, And Neck Implants For Epilepsy?! - Anna Bochenek
What's the epilepsy treatment called VNS? Or DBS? Or RNS?! Learn about these cool neuromodulation treatments that can help to prevent and/or control epileptic seizures (!) with star epileptologist Anna Bochenek.
Reported by Torie Robinson | Edited and produced by Pete Allen
Podcast
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00:00 Anna Bochenek
“It's estimated that, like, a six month seizure-freedom can be achieved in 8% of patients with VNS, 18% of patients with DBS, and about 28% of patients with RNS. “00:15 Torie Robinson
Fellow homo sapiens! Welcome back to Epilepsy Sparks Insights. Now, we have heaps of neuromodulation devices on the market to treat the epilepsies right now - but, keeping up with developments is pretty hard work! So, I’m really happy to introduce to you this week, rising star, neurologist and epileptologist Anna Bochenek who gives us the professional low-down on Vagus Nerve Stimulation), Deep Brain Stimulation, and Responsive Neurostimulation, some statistics, plus new ideas/devices that are kind-of in the pipeline or being researched right now as well.Please don’t forget to like, comment and subscribe. Your comment and like will help spread awareness and understanding of the epilepsies around the world.
And now, onto that star of the week, Anna Bochenek.
01:02 Anna Bochenek
Hi Torie, thanks for having me. My name is Anna Bochenek, I'm an adult neurologist and epileptologist. I work at a centre for neurology, epilepsy, and psychiatry: Neurosphera in Warsaw, Poland.01:16 Torie Robinson
And what got you into this specifically? And why adults rather than children?01:20 Anna Bochenek
Children, I think it's too difficult emotionally for me, so I chose adults, and, specifically epilepsy, well I was kind of torn between movement disorders and epilepsy(!), because I considered that like the “meat” of neurology. And both of them actually have a lot of neurostimulation/ neuromodulation devices as a treatment option. So that's something that drew me into that. And in the end, I chose epilepsy.01:49 Torie Robinson
So, what's the difference between - for people who aren't aware - and I get confused too - between neurostimulation and neuromodulation?01:57 Anna Bochenek
It's a difference in naming, mostly. So, there’s….used to we called them neurostimulation device: because you use electric stimulation to affect the brain, right? But, the more we've learned about this method, the more we found that it's not just the stimulation that happens in the moment, it's more than that. It's a “neuromodulation” effect. So, something that's a bit of, like, a disease-modifying effect of those devices on epilepsy. There's this, like, whole area of electroceuticals - so there are different names we can use for those devices! Like, in contrast to pharmaceuticals - so drugs and medications - you have electroceuticals now - so, devices that use electric stimulation to affect a body. So you have pacemakers, cochlear implants, things like that, right? And neurostimulation and epilepsy is the same idea; so, using electric stimulation to affect the brain with the aim to reduce seizures. And you do that through this, like, modulation process that takes time. So, I know you've talked recently with Dr. [Luke] Tomycz about epilepsy surgery - so I think that's [about] expecting, managing expectations as well. I think that's one of the things that's important to mention with the whole neuromodulation idea versus brain surgery. There's a big difference here: 1: It’s considered palliative treatment: so, we don't aim for seizure freedom with neuromodulation. 2: Whereas brain surgery gives you, like, immediate results; with neuromodulation, the effects are much slower. It’s a long game we play! So the effects are gonna improve over the course of [a] few years. So, I think that's something important to mention. And that happens due to this modulation effect. So, we don't fully know how it works(!), but it appears to have effect on both receptors, synapses, gene expression, neuronal growth, neurotransmitters... So, there's many, many things how it happens, but it takes time. So. it's like neuroplasticity, neuromodulation [is] a process that takes quite some time. So, we prefer to use the “neuromodulation” name right now because it kind of underscores this mechanism of action behind.04:44 Torie Robinson
And what are the different types, then, of neurostimulation through neuromodulation?04:47 Anna Bochenek
Okay, so currently we have 3 devices that are approved for epilepsy treatment. So, we have VNS (Vagus Nerve Stimulation), DBS (Deep Brain Stimulation), and RNS (Responsive Neurostimulation). And each one has its own, it has its own advantages, disadvantages. There are quite few similarities between them, but there are also differences. So, when it comes to VNS (I know you had an episode on that before!) - so it's the one we've used for the longest - for more than 25 years now. There's probably more than 100,000 patients implanted with this device worldwide. And each of those devices is built in a, you could say, similar way. So, you have some components that each of them needs to have. So, you have a pulse generator, which is a device that is implanted either under skin on your chest (under your collarbone), or in [the] case of RNS (so the Responsive Neurostimulation) it's implanted under your scalp, within the skull.05:59 Torie Robinson
So you say “within the skull”, are you talking about, like, on top of the brain rather than within the bone?06:05 Anna Bochenek
No, it's within the bone.06:06 Torie Robinson
Really?!06:07 Anna Bochenek
Yeah, that's why it's approved only for adults, because you need to have a certain skull thickness, so a certain bone…06:13 Torie Robinson
Yeah!06:14 Anna Bochenek
…thickness to be able to attach that device.06:18 Torie Robinson
Gosh, how embarrassing, I didn't know that. That's like, wow, that's interesting. I want to see a video on that! Sorry, carry on!06:25 Anna Bochenek
So, so, that's the, that's the generator, then you have electrodes. And in the case of VNS, the electrode is connected to your vagus nerve - so in your neck. And in case of DBS and RNS, there are electrodes that are implanted in your brain. And then you have, like, the programming system; so, something that your doctor is using to program your device. So, that's how it's built.
When it comes to differences between the devices, there are quite a few, and we try to pick the device that's best for a specific patient. So, there are some things we need to consider. If you have a patient who wants to avoid invasive brain surgery (so, implanting the electrodes into your brain) then you're left with VNS (so Vagus Nerve Stimulation), right. If you have a patient who wants to avoid a presurgical evaluation, which is required for RNS (so the Responsive Neurostimulation), you're going to be left with either VNS or DBS. The RNS (so the Responsive Neurostimulation) is different in this sense and it requires this presurgical workup because you need to have a seizure-focus localised because you need to know where you want to implant the electrodes, right? And then that device relies on, like, a real-time EEG data, and delivers responsive stimulation to a patient's EEG recording. What's cool about it [is] it also allows long-term recording, right? So you have like a EEG recording going on constantly in your brain, which might be important for some patients, especially patients with bitemporal epilepsies.08:16 Torie Robinson
Mmm.08:16 Anna Bochenek
So, you've probably heard about that, read about that. That can be quite tricky how to treat that, right? Whether to operate, when to operate. So, if we have a patient like that and we have this access to long-term recording, then we can actually see whether one of those temporal lobes is actually dominant/more active - it's the seizure focus. And then it might allow patients to go through surgery in the end, which is like a curative treatment.08:45 Torie Robinson
Well, fingers crossed curative, not always, right?08:47 Anna Bochenek
Yeah, yeah, that's the thing. In case of brain surgery if you have a well selected patient, your chance of seizure freedom can be between 50 - 80%. I’d say. Depending on the patient, depending upon the type of surgery, of course. With a neural modulation, those numbers are lower. So you can achieve some longer periods of seizure freedom; it's estimated that, like, a six month seizure-freedom can be achieved in 8% of patients with VNS, 18% of patients with DBS, and about 28% of patients with RNS. So, it seems much lower than the surgery. But, if we look at Anti-Seizure Medications in drug-resistant patients (so if you're on your 3rd , 4th, and subsequent medications); your chance of seizure freedom on each of those is about, like, 5%. You can have seizure reduction, but your chance of seizure freedom is quite low…09:51 Torie Robinson
Or even less, right? I mean, I've heard other numbers that…09:54 Anna Bochenek
Even less, even less. Yeah, so some studies say between 1 and 4% like…So less than 5%. Yeah. So those 8%, 20%, it's still much higher, much higher numbers, so it's something that's definitely worth considering as a treatment option.
When it comes to further differences. So, like I said, it's a long game, right? So, unfortunately, we need to educate our patients and manage their expectations. And that's very important because I've had some patients that were not pleased with the results because they didn't have the education beforehand, what…10:35 Torie Robinson
Right.10:36 Anna Bochenek
…to expect, right? So, in general, the seizure reduction is quite similar between different methods. DBS and RNS seem to be a little bit more effective, but, like, [it] might be negligible. So, in the first year of your treatment, you can expect to have about 40% of seizure reduction.10:58 Torie Robinson
Mm-hmm.11:00 Anna Bochenek
And that number goes up in the year 5 or 7, up to, like, 75%!11:06 Torie Robinson
So, it's like, as your brain almost, like, “learns” to make the changes incurred by these treatments.
11:11 Anna Bochenek
Yeah, that's the plasticity, that's the plasticity and the changes that are going on there. And that's like the disease-modifying effect that we see. We don't have, unfortunately, any, like, biomarkers… anything we can look for in the patient that's going to tell us “Oh, you're going to respond better to this.” or “You're going to be [a] non-responder” - because there are some people that are non-responders. About, like, ⅓ of patients will not respond to neuromodulation and there's no way for us to predict that this is what's going to happen. There are many, many studies going on to define those biomarkers, so [as] to improve the whole process of picking the right neuromodulation for specific patients.
So, a VNS procedure is considered quite simple. It takes about 1-2 hours. DBS and RNS are more invasive so the procedure is going to be longer: it's going to be, on average, more than 4 hours. Most devices have non-rechargeable batteries. So, if you get a device like that, you need to know that in 3-5 years you're going to have to have your battery replaced (depending on your settings). There are some rechargeable devices with DBS, so then you have to charge your battery every week or 2 weeks for 30-60 minutes. But you still need to have your battery replaced, but in like 9-15 years instead of, like, 3-5 years. There are some cool new options as well, so, some non-invasive devices that are currently under research. There is Transcranial Magnetic Stimulation, which is already approved for drug-resistant depression. So it's a device that's just placed against your scalp, it sends magnetic pulses, and the session usually lasts between, like, 30-60 minutes. You do it 5 days a week over the course of, like, 4-6 weeks (this is like, [the] initial therapy). And then you have, like, a more of a “maintenance” stage when that's, like, less frequent. It looks promising for depression, for now. There are no recommendations, specific recommendations for epilepsy just yet, but it might be something that we might use in the future. And VNS also has a variation, which is a Transcutaneous VNS [(t-VNS)]. So, you don't need to have to have electrodes implanted. You can just place it [(the device)] over your skin. So, it stimulates one of the vagus nerve branches. It's usually around the ear, so it's like an auricular branch of the vagus nerve. And you can stimulate [it for], like, 15 minutes a day. You can stimulate [it for] a few hours a day. But it's considered, for now, like, less “potent” than the traditional implantable VNS.14:10 Torie Robinson
And what's interesting is that, well, obviously depending… we have to manage our expectations here, but if you improve the mental health of somebody with an epilepsy, you often, indirectly, you can, reduce their seizure frequency.14:10 Anna Bochenek
Yeah, because what we've talked so far is just like seizure reduction, right? And seizure control and those devices have other benefits as well. [They can] improve mood, sometimes improve cognition. They can also decrease the risk of SUDEP, which is also quite a big thing.14:44 Torie Robinson
Massive thing, yeah.14:46 Anna Bochenek
It's more than just seizures! So, let's hope that, like, in the future, we're going to have better tools to pick the right device and the right type of stimulation for specific patients, for specific patients so the numbers we have can go higher and the other benefits are also going to be noticeable.15:08 Torie Robinson
A huge thanks to Anna for providing us with so much useful information on neuromodulation device options, plus some excitement for the future!
Again, if you haven’t already, don’t forget to like, comment, and subscribe, and see you next time! -
Anna Bochenek is an adult epileptologist and neurologist with a special interest in epilepsy, electroencephalography and the treatment of movement disorders, including Parkinson's disease.
Anna graduated summa cum laude from the Medical University of Silesia and has experience in Poland and other countries. In the United States Anna completed an internship in EEG with Prof. Hans Lüders, and in the Netherlands completed an internship in movement disorders at the University Medical Centre Groningen.
Anna was awarded a scholarship from the Supreme Medical Council and is a member of the Polish Neurological Society, the European Academy of Neurology, and the International Parkinson and Movement Disorder Society. Anna also participates in clinical trials of new drugs in Parkinson’s disease. -
LinkedIn: anna-bochenek
Instagram: annabochenekmd
Neurosphera: anna-bochenek
European Academy of Neurology: scientific-panels/epilepsy