What is a responsive neurostimulator? (A.K.A. Why I have a computer in my head)
“My mommy has a computer in her head,” I heard my oldest son brag to his friends. As I think this gave him some street cred, I didn’t correct him. Two years later, I think they still believe I’m some sort of cyborg because I catch them giving me suspicious looks every once in awhile.
I don’t have a computer in my head. I have a responsive neurostimulator - more commonly known as an RNS. It’s one of a few devices out there that helps treat drug-resistant seizures (seizures that aren’t controlled by medication). There’s the vagus nerve stimulator, deep brain stimulation, and the RNS. I might be missing a few, but those are the big three. And, seeing I just ran a mile last week - something I haven’t been able to do without having a seizure for over a decade - I think the RNS deserves a little attention.
1. What is an RNS? The RNS is a medical device that constantly monitors your brainwaves. It has two leads - little wires with electrodes at the end - that the doctor will place at the seizure focus or foci to monitor your brain waves at that site. The medical device itself is smaller than a phone, curved, very light, and lays flush with your skull. No one can tell that you have anything there. The device and leads are constantly monitoring your brain waves - it’s like a never-ending EEG - but you don’t feel it or have to think about it, and it learns what normal brain waves look like for you and what abnormal electrical activity looks like. When the device senses abnormal electrical activity, the RNS sends a little pulse to interrupt the potentially seizure-building communication in your brain, and the idea is that it stops the seizures before they can begin by interrupting the seizure activity as it starts.
If you aren’t having abnormal electrical activity - or something that the RNS recognizes or thinks is abnormal - it’s quiet. The leads and device just hang out, monitor what’s going on, and wait.
2. Do you feel the pulses? No. The device can be altered by your neurologist to deliver stronger pulses, weaker pulses, pulses in different rythyms (short, short, short, or long, short, short, or long, long, short - you get the idea), but you don’t feel it when it is actively delivering pulses. And, as we aren’t have seizures all the time, it’s pretty neat that you have something in there monitoring your brain, tracking your brainwaves, but not adjusting them unless they need to be adjusted.
3. So, what’s the downside? The downside of an RNS? First of all, if your doctors don’t already have an exact location of where your seizures start, you’ll have to go through brain mapping, which means surgery and a stay in the EMU. And, the mapping itself. Why? Because there is no point in placing leads if they aren’t exactly where your seizure foci are - then the RNS would never detect abnormal electrical activity, and your seizures wouldn’t improve.
Also, the device has to learn what is normal and abnormal for your brain. It’s smart, but every brain is different, so it needs time. And you and your doctor have to figure out what strength of pulse (between 1-12) works for you, and what rhythm works for your brain. Too little stimulation, and there’s no point. Wrong rhythm of pulses probably won’t help very much. Last year, a computer program was able to read the information I had downloaded, recommend the exact strength and rhythm that would be helpful, my neurologist and I tried it, and it’s actually working. (I say ‘actually’ because it took 2 years for me to really trust that this device would hold up and make a significant change.)
Third, you have to “download your brain waves” almost every day with the trusty little laptop and wand that you are given, and then - not every day, but semi-frequently - transfer the data to the main system for your doctor to look at and evaluate. Not a big deal, but it takes a few minutes. My kids love watching the data transfer from my device to the laptop.
And finally, you can’t change the settings without going to see your doctor. For something this advanced where you have a laptop and the wand, you’d think that there would be a way to change through a virtual visit, but, no - not yet at least.
I will tell you that, after meeting with my neurologist last May and getting the computer-recommended settings, my quality of life has improved dramatically. I don’t worry as much about seizures. My “big” seizures are much less frequent. It’s a pretty cool feeling. I don’t have daily auras, I feel that I can begin to trust my brain.
Takeaway: If you have failed more than 2 seizure meds, you should begin talking about other options - including surgery and devices. If your seizures start in an area that can’t be resected or the doctors can’t find the exact margins, the RNS is a good alternative and could give you the increased quality of life that we all desperately want, need, and deserve.
Resources:
Neuropace: Currently the company making the RNS. https://www.neuropace.com
