Paralysis: Brain-Computer Interfaces and Spinal Cord Stimulation Guide

Brain implants that turn thoughts into words and spinal stimulation that strengthens hands are real, but only one is available outside trials. Here is what is approved, what is experimental and how to take part.

The problem today: paralysis

Paralysis means losing the ability to move part of the body, and often to feel it too. One of the most common causes is a spinal cord injury, damage to the bundle of nerves inside the spine that carries messages between the brain and the body. The World Health Organization estimates that about 15.4 million people worldwide were living with a spinal cord injury in 2021. Most are caused by falls, road accidents and violence.

Paralysis can also come from diseases of the nerves. ALS (amyotrophic lateral sclerosis, also called motor neurone disease) slowly destroys the nerve cells that control muscles, and many people with ALS eventually lose the ability to move, swallow and speak. A brainstem stroke, a stroke in the part of the brain that connects to the spinal cord, can have a similar effect.

Today, care focuses on surgery to stabilise the spine, months of rehabilitation and lifelong management of bladder, bowel, skin and blood pressure problems. Rehabilitation can bring real gains, especially when some nerve fibres survived the injury. But for many people progress slows after the first year or two. The damaged spinal cord does not heal itself, and there is still no medicine that repairs it. For people with ALS, current treatments can slow the disease a little but cannot restore lost movement or speech.

This is the gap that two families of new technology are trying to fill. Spinal cord stimulation uses small electrical currents to "wake up" nerve circuits below the injury. Brain-computer interfaces (BCIs) read signals directly from the brain and turn them into commands for a computer, a robotic arm or a stimulator. Artificial intelligence (AI) sits at the heart of BCIs, because software has to learn what each pattern of brain activity means.

How brain-computer interfaces and spinal stimulation work

When the spinal cord is injured, the brain usually still knows how to plan a movement. The problem is that the message cannot get through, or arrives too weakly to move a muscle. Below the injury, the nerve circuits that control the legs, arms, bladder and blood pressure are often still alive, just disconnected. New devices try to either boost the weak signals that still get through, or build an electronic detour around the damage.

Non-invasive spinal cord stimulation (through the skin)

In this approach, sticky electrode pads are placed on the skin over the neck or back. A small external machine sends a carefully shaped electrical current through the skin towards the spinal cord. The current does not move the muscles by itself. Instead, it makes the spinal nerve circuits more "ready to fire". When the person then tries hard to move, for example to pinch or grip, the weak signals from the brain that still cross the injury are more likely to produce a movement. That is why stimulation is always combined with intensive exercise. No surgery is needed.

Implanted spinal cord stimulation

Here a surgeon places a thin, flat strip of electrodes (a paddle lead) on the surface of the spinal cord coverings, inside the spine, and connects it to a battery-powered stimulator under the skin, much like a heart pacemaker. Research systems, such as ONWARD Medical's ARC-IM, can send precisely timed bursts of current to different spinal nerve roots in the order needed for stepping or standing. This allows more targeted control than skin electrodes, but it requires an operation.

Brain-computer interfaces that sit in or on the brain

A BCI has three parts: sensors that pick up brain activity, a decoder (AI software that learns which patterns mean "move the cursor left" or "say the word water"), and an output, such as a computer screen, a voice synthesiser or a robotic arm. There are three main ways to place the sensors:

• Inside the brain tissue (intracortical): tiny needles or threads go a millimetre or two into the brain's movement or speech areas and record individual nerve cells. This gives the richest signal but needs open brain surgery. Examples are the Utah array used in the BrainGate studies, Neuralink's N1 and Paradromics' Connexus.
• On the brain surface: a thin film of electrodes lies on top of the brain without piercing it. Precision Neuroscience's Layer 7 and the WIMAGINE implants used by the Swiss NeuroRestore team work this way.
• Inside a blood vessel (endovascular): Synchron's Stentrode is a small mesh tube, like a heart stent, guided through a vein in the neck into a large vein next to the brain's movement area. It records through the vessel wall, so no opening of the skull is needed, but the signal is less detailed.

The "digital bridge": linking brain and spine

The most ambitious approach connects a brain implant to an implanted spinal stimulator. The brain implant detects that the person wants to lift a leg, the software turns that into a stimulation pattern, and the spinal stimulator activates the right muscles a fraction of a second later. Researchers in Lausanne, Switzerland, call this a brain-spine interface or digital bridge. It remains purely experimental.

The main tools and where they stand

Headlines often call these devices "approved" when they are not. Three regulatory terms come up often:

• FDA Breakthrough Device Designation means the US regulator will give a company faster feedback during development. It is not an approval and says nothing final about safety or benefit.
• Investigational Device Exemption (IDE) means the US regulator allows the device to be tested in a specific clinical trial, nothing more.
• Clearance, De Novo authorisation or CE marking means the device may legally be sold for a stated purpose in the US or EU.

ARC-EX (ONWARD Medical)

A non-invasive spinal stimulator with skin electrodes on the back of the neck, used together with hand and arm exercises. It is meant for adults with a long-term, incomplete spinal cord injury at neck level (C2 to C8) who still have some movement or feeling below the injury. The US FDA authorised it through the De Novo route on 19 December 2024 for use in clinics, and ONWARD announced an expanded US clearance for home use in November 2025. The company announced the EU CE mark, covering clinic and home use, on 8 September 2025, with a phased European rollout starting in Germany.

ARC-IM and ARC-BCI (ONWARD Medical with NeuroRestore)

ARC-IM is an implanted spinal stimulator. ARC-BCI pairs it with a brain implant to form a digital bridge. Both are investigational. ONWARD reported that the first implant in its Empower BP pivotal study, which tests ARC-IM for dangerous drops in blood pressure after spinal cord injury, took place in the first quarter of 2026 in the United States.

N1 implant (Neuralink)

A coin-sized wireless implant with 1,024 electrodes spread over very thin flexible threads, inserted by a surgical robot. In trials it lets people with severe paralysis control a computer cursor or, in a separate study, a robotic arm. It is investigational in every country. Neuralink told Reuters in January 2026 that it had 21 participants enrolled in trials worldwide; higher figures circulating online come from unofficial sources.

Stentrode (Synchron)

The blood-vessel BCI described above. It is designed for people who cannot use their hands, to send "clicks" to a phone, tablet or computer. It is investigational and has been tested in small early studies in Australia and the United States.

Utah array and MoveAgain (Blackrock Neurotech)

The Utah array is a tiny grid of needle electrodes that academic teams have used in research for many years, including the BrainGate studies. Blackrock's MoveAgain system for home use received FDA Breakthrough Device Designation in November 2021 but is not approved.

Connexus (Paradromics)

A fully implanted, high-channel BCI aimed mainly at restoring speech for people who cannot talk. The FDA granted an IDE in November 2025, and Paradromics announced the first implant in its Connect-One study at the University of Michigan in June 2026.

Layer 7 Cortical Interface (Precision Neuroscience)

A film thinner than a hair with 1,024 electrodes that rests on the brain surface. In April 2025 the company announced FDA 510(k) clearance, but only for temporary use of up to 30 days, for example to map the brain during surgery. It is not cleared as a permanent BCI for paralysis.

Standard implanted spinal cord stimulators made for chronic pain are widely approved for pain. Using them to treat paralysis is "off-label", meaning outside the approved purpose, and is not backed by approval for that use.

What the evidence shows for BCI and spinal stimulation

The research is genuinely exciting, but most of it involves very small numbers of people. Here are the key studies.

Up-LIFT: non-invasive stimulation for hands and arms

Published in Nature Medicine in May 2024, Up-LIFT (NCT04697472) enrolled 65 adults with long-term neck-level spinal cord injury at 14 centres in the US, Canada, the UK and the Netherlands. Each person first did two months of intensive rehabilitation alone, then two months of rehabilitation with ARC-EX stimulation. Of the 60 people who completed the study, 43 (72%) improved enough in both strength and everyday hand function to count as responders, and 54 (90%) improved in at least one measure. Touch sensation and some quality-of-life scores also improved. There were no serious side effects linked to the device, although 17 people (27%) had milder device-related problems.

Limitations: there was no separate control group receiving fake (sham) stimulation, and people knew when they were being stimulated. Independent researchers have argued that this makes it harder to know how much of the gain came from the stimulation and how much from the extra therapy. The trial was funded by ONWARD.

Walking again with a brain-spine interface

In May 2023, the Swiss NeuroRestore team (EPFL and Lausanne University Hospital) reported in Nature on one man with a long-standing incomplete neck-level injury. Implants on the surface of his brain were wirelessly linked to an implanted spinal stimulator. He was able to stand, walk over ground and climb stairs with natural control of his legs, using a walker or crutches. After rehabilitation, some improvement remained even when the system was switched off. This is a single-person study and cannot tell us how well it would work for others.

Speech from brain signals

• A Stanford team reported in Nature in August 2023 that a woman with ALS who could no longer speak clearly could produce text from attempted speech at about 62 words per minute. Errors were about 9% with a 50-word vocabulary and about 24% with a 125,000-word vocabulary.
• A BrainGate team reported in the New England Journal of Medicine in August 2024 on a man with ALS who used four implanted arrays. With a 125,000-word vocabulary, the system was about 97.5% accurate at around 32 words per minute, and it spoke in a voice built from old recordings of his own voice.

Synchron COMMAND

This early US study (NCT05035823) implanted the Stentrode in six people with severe paralysis of both arms. Results presented in 2024 showed that all six met the main safety goal: no device-related serious side effects causing death or lasting extra disability in the first year. Participants used the system to control digital devices. Six people is far too few to judge long-term safety or benefit.

Neuralink PRIME and related studies

Neuralink's first participant was implanted in January 2024. In May 2024 the company reported that some electrode threads had pulled back out of his brain in the weeks after surgery, reducing performance, and that software changes recovered much of it. Full peer-reviewed trial results have not yet been published.

Who can benefit from BCI and spinal stimulation

Non-invasive stimulation (ARC-EX) is authorised for adults with a chronic (long-standing), non-progressive, incomplete spinal cord injury at neck level, C2 to C8. "Incomplete" means some messages still get through: you have at least a little feeling or movement below the injury. In Up-LIFT, participants had to be at least a year past their injury, and some were more than 30 years past it.

It is generally not for:

• people whose injury is still recent and who are still recovering on their own;
• people with injuries only in the mid or lower back, since the authorised use is for the neck and arms;
• people with progressive diseases such as ALS, for whom it is not authorised;
• people with medical conditions or implants that make electrical stimulation unsafe, which your team will check.

Implanted BCI trials each set their own rules. The Neuralink PRIME study, for example, lists adults aged 22 to 75 with severe paralysis of both arms and hands from neck-level spinal cord injury or ALS, at least a year after injury or diagnosis without ongoing recovery, and with a caregiver able to support frequent study visits. Trials usually exclude people with other active implants such as pacemakers or deep brain stimulators, people who need regular MRI scans, and people with poorly controlled seizures. Always read the specific trial listing.

What to expect as a patient

If you are considering ARC-EX therapy

1. Referral: ask your spinal cord injury doctor or a specialist rehabilitation centre whether it offers the therapy.
2. Assessment: the team examines your strength and sensation using the standard international spinal cord injury exam and checks your medical history and medicines.
3. Set-up: a therapist places electrodes on the back of your neck and adjusts the stimulation level until you feel it but it is comfortable.
4. Sessions: you do hand and arm tasks, such as gripping, pinching and lifting objects, while stimulation is on. In Up-LIFT, stimulation was given alongside intensive therapy over two months.
5. Home use: where home use is offered, you continue exercises with the device under your clinic's guidance.
6. Follow-up: regular re-testing shows whether gains are continuing. Benefits depend on keeping up the practice.

If you join a BCI trial

1. Register on the developer's or hospital's official trial page, or find the study on ClinicalTrials.gov.
2. Screening: phone or video interviews, then visits for brain scans, medical checks, memory and thinking tests and a talk with the study team about risks.
3. Informed consent: you receive a detailed document explaining risks, time commitments and what happens if you leave the study.
4. Surgery: brain implant surgery is done under general anaesthetic in a specialist neurosurgery centre. The Stentrode is placed through a vein by a specialist using X-ray guidance.
5. Calibration and training: over weeks and months you work with engineers who train the software on your brain signals.
6. Long-term follow-up: studies run for years. Paradromics, for example, plans to follow its first participant for six years. Expect frequent sessions, sometimes several per week.

BCI and spinal stimulation: access and cost in the US, UK and EU

United States

ARC-EX is commercially available in the US for clinic use and, since the home-use clearance announced in November 2025, for use at home under clinical supervision. ONWARD said it was available in more than 100 clinics across the US and Europe by the end of March 2026, and that some of the first home systems went to patients of the US Department of Veterans Affairs. There is no official data on standard insurance coverage or patient prices, so ask your clinic and insurer directly. Implanted BCIs are only available in trials at a limited number of academic centres. In properly approved trials, the device and study procedures are usually provided without charge, but check what travel and accommodation support is offered.

United Kingdom

There is no official data on ARC-EX being offered in the NHS or privately in the UK. UK rules currently allow CE-marked devices to be placed on the Great Britain market until 30 June 2030, so availability depends on the company and on providers. For BCIs, Neuralink's GB-PRIME study, approved by the MHRA and UK ethics bodies, began implanting at University College London Hospitals' National Hospital for Neurology and Neurosurgery in October 2025, with Newcastle Hospitals as a second site and up to seven participants planned.

European Union

ARC-EX has a CE mark covering clinic and home use, and ONWARD announced a phased rollout beginning in Germany. Availability and reimbursement vary by country, and there is no official data on public insurance coverage. Implanted spinal and brain-spine systems are only available in research studies, including the NeuroRestore programme in Lausanne, Switzerland (outside the EU but within Europe).

Elsewhere and for international patients

Neuralink runs feasibility studies in Canada (CAN-PRIME, NCT06700304, at the University Health Network in Toronto) and the United Arab Emirates (UAE-PRIME, NCT06992596, at Cleveland Clinic Abu Dhabi). Synchron carried out its earliest human studies in Australia. Trials usually need participants to live near the study site for years.

If you are thinking of travelling for treatment, check:

• Approval: is the exact device approved for paralysis in that country, or is it an off-label use of a pain stimulator?
• Centre experience: how many patients with your type of injury has the team treated, and do they publish results?
• Records to bring: your injury and surgery reports, recent spinal cord injury exam sheets, MRI scans on disc, a medication list and any implant cards.
• Follow-up at home: who will adjust, repair or remove the device after you return? Is there a local doctor willing to take over?
• Insurance: does your health or travel insurance cover complications that happen abroad or after you return?

Risks, limits and realistic expectations

None of these devices repair the spinal cord or stop ALS. They are tools that help the body and brain work around damage.

• Non-invasive stimulation: in Up-LIFT, about a quarter of participants had milder device-related problems. Possible issues include skin irritation under the pads, changes in muscle stiffness (spasticity) and, in people with high injuries, sudden blood pressure reactions (autonomic dysreflexia), so therapy is supervised.
• Implanted spinal stimulators: spinal surgery carries risks of bleeding, infection, fluid leakage around the spinal cord and device problems needing another operation.
• Brain implants: brain surgery carries risks of bleeding, infection and seizures. Over time, the body can form scar tissue around electrodes, which may weaken the signal. Removing electrodes that sit inside brain tissue can itself be risky.
• Blood-vessel implants: avoid opening the skull but carry vessel-related risks such as clots; long-term data are limited to small numbers.
• Effort and time: stimulation only works alongside hard exercise, and BCIs need regular recalibration and years of commitment.
• Unknown future: trial devices may never become products. Ask what happens to support if a company changes plans.

A realistic hope today is a meaningful gain in hand function, independence on a computer or phone, or a faster way to communicate. Walking without help, or a cure, is not a realistic expectation from any currently available device.

Clinical trials and what is next for paralysis

• Neuralink: PRIME (NCT06429735) in the US, CONVOY (NCT06710626) adding robotic arm control, CAN-PRIME (NCT06700304) in Canada, UAE-PRIME (NCT06992596) and GB-PRIME in the UK.
• BrainGate2 (NCT00912041): a long-running academic study at US centres including Massachusetts General Hospital, Brown, Stanford and Emory, for people with spinal cord injury, brainstem stroke, ALS and related conditions.
• Paradromics Connect-One: an early feasibility study of speech restoration, with Michigan Medicine among three enrolling sites.
• ONWARD Empower BP: a pivotal study of the implanted ARC-IM for blood pressure instability after spinal cord injury, with 12 US sites active in early 2026 and further sites planned in Canada, France, Germany, Spain and the UK. ONWARD also reported two more ARC-BCI participants in early 2026.

To search yourself, use ClinicalTrials.gov with terms such as "brain-computer interface" or "tetraplegia", and only apply through official study pages or hospitals.

Questions to ask your doctor about BCI and spinal stimulation

Bring these questions to your spinal cord injury specialist, neurologist or rehabilitation physician:

1. Is my injury complete or incomplete, and at what level? Does that make me a possible candidate for non-invasive spinal stimulation?
2. Is ARC-EX or a similar authorised therapy offered near me, and will my insurance or health service pay for it?
3. How much therapy time would I need each week, and for how long?
4. What improvement could I realistically expect in my hands or arms?
5. Are there side effects I am at higher risk of, such as autonomic dysreflexia?
6. Are there clinical trials, including BCI trials, that I might qualify for? Can you help me read the eligibility rules?
7. Would joining a trial affect my current care, MRI scans or future treatment options?
8. If a clinic offers me a paid implant, what is its approved purpose and what evidence supports it?
9. Who will look after any device long term if I move or travel?

Questions patients ask