For decades, stroke survivors have been told the same thing: Whatever function you haven’t recovered in six months, you likely never will. That assumption is now being dismantled. The American Stroke Association estimates that 1 in 4 American adults will experience stroke in their lifetime, often with devastating consequences. The 2011-2018 National Health and Nutrition Examination Survey estimated approximately 5.7 million U.S. adults living with at least one disability due to stroke, many of whom require assistance for mobility, activities of daily living (ADLs), and employment.
Post-acute care for stroke survivors has historically been fragmented and limited in duration, with many survivors being told not to expect any further recovery beyond what they accomplish in the initial six months. With traditional therapy, most functional gains occur within the first several weeks, slowing markedly after three months. By six months, survivors enter what is clinically defined as the chronic stroke stage, a period marked by a plateau in spontaneous biological recovery, where functional impairments can become permanent without targeted rehabilitation designed to re-engage cortical and motor pathways.
Further complicating recovery, many patients do not receive traditional therapies in the early windows during which they are most effective, leaving them with few options as they age into the chronic time period. As an example, nearly half of stroke survivors with a persistent deficit in hand and arm function never receive any outpatient therapy once they return home.
The significant gap between stroke survival and meaningful recovery highlights the need for new neurorehabilitation approaches such as brain-computer interfaces (BCIs). Evidence continues to emerge supporting BCI therapy as an effective rehabilitation strategy, even for those well beyond the traditional post-stroke recovery window.
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Understanding BCI technology
Brain-computer interface technology translates brain signals (an individual’s thought) into commands that can control external devices, creating a direct communication pathway between the brain and the outside world. BCIs can be used either to bypass a damaged motor pathway from the brain to accomplish a basic need (for example, communication with a speech-generating device) or as therapy to help improve function by promoting neural recovery. For stroke survivors, this therapeutic application shows increasing promise, helping retrain the brain to control lost abilities.
A typical BCI system consists of three main parts:
- A sensor that records brain activity
- Software that interprets those signals and decodes the individual’s intent of what they are thinking and trying to do
- An external output, such as a wearable that assists the movement of an impaired hand
Together, these three parts form a complete brain-computer interface, capturing neural activity, translating it into intent, and converting that intent into real-world action.
Therapeutic non-invasive BCI
Therapeutic BCI devices help stroke patients recover lost abilities by activating healthy brain areas to take over functions that damaged areas can no longer perform. Unlike compensatory BCIs, where the device permanently substitutes for lost brain function, the therapeutic approach aims to rebuild it. This works through neuroplasticity, the brain’s natural ability to rewire itself, which underlies all stroke recovery.
During therapy, the device first identifies a brain signal produced when a patient thinks about performing a movement. Tuned to that signal, the system relays the intent to an output device, which executes the movement almost instantly in response to the thought. Repeated across multiple sessions each week, this process trains the brain to connect the intention to move with the sensation of movement, gradually forming new neural pathways, a mechanism known as Hebbian learning. Patients use the BCI only during therapy, not as a day-to-day assistive device.
As the brain rewires through therapy, outcomes improve further when BCI is part of a holistic care model. Stroke survivors often need physical and occupational therapy to stretch and strengthen affected areas and relearn daily tasks like eating, dressing, and grooming. They may also need help navigating health care or disability benefits, mental health support, or community connection for motivation. For patients with limited mobility or those in underserved areas, telehealth access to stroke specialists can be a critical lifeline to these services.
Real-world studies of BCI and stroke survivors
Evidence from our own clinical work and the broader field continues to mount. Here are summaries of three studies that have demonstrated BCI’s ability to improve stroke therapy:
In one study, 26 chronic hemiparetic stroke patients received 12 weeks of BCI therapy, with the upper-extremity motor function as the primary outcome measure. At the study’s completion, 100 percent of patients showed measured improvements in motor function, with 69 percent experiencing clinically meaningful improvements.
In another study, 78 stroke survivors with chronic upper-extremity impairment were prescribed BCI as part of routine care. The results showed that 70 percent achieved clinically meaningful improvement over the observation period, 33 percent of patients with severe baseline impairment transitioned to lower severity categories, and 50 percent of patients who began below the functional eligibility threshold for other advanced neurorehabilitation interventions crossed clinically relevant motor benchmarks. The study highlights the potential of long-term BCI therapy to result in clinically meaningful upper-extremity recovery in chronic stroke survivors, including those with severe impairment.
A third study compared an at-home BCI therapy system versus an at-home exercise program for improving upper-extremity motor function. The study examined adults aged between 18 and 85 years old, at 6 months or more post-stroke, with limited functionality in upper extremities. The intervention group received BCI therapy to be completed 5 times per week over 12 weeks, while the control group participated in a standard at-home upper-extremity exercise program over the same time period. The results showed that at-home BCI therapy produced significantly greater and clinically meaningful improvements in upper-extremity motor function compared with standard at-home exercise in patients with chronic stroke.
BCI technology has the potential to establish a new standard of care for post-stroke recovery by extending rehabilitation beyond traditional limits. By combining advanced neurorehabilitation with coordinated support services, this approach helps ensure that stroke survivors, clinicians, and care partners remain connected, supported, and equipped with the resources they need throughout the recovery journey. Equally important, these solutions can be delivered in the home, making it easier for patients to stay engaged in therapy without the burden of frequent in-person visits.
Together, these innovations point toward a future where stroke recovery is not defined by a fixed timeline, but by ongoing opportunity, offering patients a higher level of care and support during one of the most vulnerable periods of their lives.
Leo Petrossian is the chief executive officer of Kandu Inc., a neurotechnology company formed from the merger of Neurolutions and Kandu Health. He is a seasoned health care executive and entrepreneur with deep expertise in bringing transformative medical devices from early development to commercialization.
Under his leadership, Neurolutions pioneered the IpsiHand, the first FDA-cleared, non-invasive brain-computer interface (BCI) for stroke rehabilitation and the first BCI to receive a Medicare reimbursement code. The company maintains resources for clinicians, a library of device tutorials, and a guide to getting started with IpsiHand. His work also appears in peer-reviewed research. Dr. Petrossian is passionate about advancing technologies that expand access, improve outcomes, and reshape standards of care in neurology and beyond.
He earned his MBA from the UCLA Anderson School of Management in 2014 and his PhD and MS in biomolecular nanotechnology and solid-state device physics as a National Science Foundation IGERT fellow at Arizona State University in 2007. He also holds a double BS in electrical engineering and biomedical engineering from California State University, Long Beach, and shares updates on LinkedIn.
