So You Want to Rewire Brains

There’s a lot to like about brain-computer interfaces, those sci-fi-sounding devices that jack into your skull and turn neural signals into software commands. Experimental BCIs help paralyzed people communicate, use the internet, and move prosthetic limbs. In recent years, the devices have even gone wireless. If mind-reading computers become part of everyday life, we’ll need doctors to install the tiny electrodes and transmitters that make them work. So if you have steady hands and don’t mind a little blood, being a BCI surgeon might be a job for you.

Shahram Majidi, a neurosurgeon at Mount Sinai Hospital in New York, began operating in clinical trials for a BCI called the Stentrode in 2022. (That’s “stent” as in a tube that often sits inside a vein or artery.) Here he talks about a not-too-distant future where he’s performing hundreds of similar procedures a year.

Brain-computer interfaces have been around for a few decades, and there are different kinds of implants now. Some have electrodes attached to your brain with wires sticking out of your head and connecting to a computer. I think that’s great as a proof of concept, but it requires an engineer sitting there and a big computer next to you all the time. You can’t just use it in your bedroom. The beauty of a BCI like the Stentrode, which is what I’ve worked with, is that nothing is sticking out of your brain. The electrodes are in blood vessels next to the brain, and you get there by going through the patient’s jugular. The receiver is underneath the skin in their chest and connected to a device that decodes the brain signals via Bluetooth. I think that’s the future.

It’s a minimally invasive surgery. You don’t have to open the skull. You don’t have to violate the anatomy of the brain. Deploying a stent into a blood vessel in the brain is something I’ve done thousands of times for other procedures, but this time I’m deploying a device that will record specific signals coming from a very specific location of the brain. For it to work correctly, I’ll have to make the most precise delivery of an implant I’ve ever learned to do. From the time we enter the room to when we have finished surgery and checked the device, it’s usually less than three hours.

The patients we enroll in these trials are severely disabled. They’re paralyzed from diseases like ALS. They’re bedbound; even bringing them to the hospital could be a monumental task. So I’ve been able to visit all my BCI patients in their homes to talk about the device and how it works. It’s an exciting moment for the patients and their families, but you also have to set expectations.

The surgical planning that goes into a BCI implant is very sophisticated compared to other daily procedures that I do as a neurosurgeon. Before the surgery, my team and I practice on a model to make sure we understand all the steps and protocols. Literally, the room for mistakes is very, very narrow. (Neuralink is building robots to install their BCIs, but I’m not worried about robots coming for my job. You’re always going to need human surgeons and scientists to advance the field and do precise procedures.)