The World Health Organization (WHO) reports that approximately 15 million people worldwide suffer a stroke each year. Of these, 5 million are left permanently disabled.
Now, for the first time, researchers have suggested a breakthrough drug that could fully replicate the benefits of physical stroke rehabilitation, recently demonstrated in mice, which builds on earlier human research.
The study tested two potential drugs based on research into how rehabilitation affects the brain. One of them significantly improved movement control after a stroke in mice. Currently, only two drugs exist in the field of stroke recovery, and patients must still undergo physical rehabilitation, which has limited effectiveness.
“The goal is to have a medicine that stroke patients can take that produces the effects of rehabilitation,” said Dr. S. Thomas Carmichael, the study’s lead author and professor and chair of UCLA Neurology. “Rehabilitation after stroke is limited in its actual effects because most patients cannot sustain the rehab intensity needed for stroke recovery.”
Understanding that stroke can severely impact the brain and that physical rehabilitation is often necessary, the UCLA team sought to determine how rehabilitation improves brain function and whether a drug could produce similar effects.
“Further, stroke recovery is not like most other fields of medicine, where drugs are available that treat the disease—such as cardiology, infectious disease or cancer,” says Carmichael. “Rehabilitation is a physical medicine approach that has been around for decades; we need to move rehabilitation into an era of molecular medicine.”
By working with both stroke patients and mice, the researchers investigated how stroke affects brain connections that send signals from the damaged area. They discovered that brain cells become disconnected from other neurons, preventing the brain network from working together for movement-related actions such as walking.
The team found that immediately after a stroke, the brain loses connections in a specific type of cell called parvalbumin neurons. These neurons help create a brain rhythm known as gamma oscillations, which are essential for coordinating brain activity and controlling movement. When a stroke occurs, these gamma oscillations are disrupted. However, rehabilitation in both mice and humans helped restore these neural pathways.
Could this drug potentially improve recovery for stroke patients across different severity levels, and how might it be tailored to individual needs? Carmichael addressed this in an email to The Debrief, explaining, “The initial scope of therapy would be for moderately impaired individuals after stroke.”
“This is because this group of patients has a very variable recovery pattern. Some will show good recovery, but still with limiting function, and some will show minimal recovery. Mildly affected patients will show substantial spontaneous recovery by themselves. This makes it difficult to show the effect of an initial clinical trial. Severely affected patients have mostly poor recovery. There is a small subset that do recover, but to date, there is no reliable biomarker or indicator of this population.”
This drug has the potential to either supplement physical rehabilitation or, in some cases, replace the need for rehab altogether. “The standard of care for roughly 2 to 3 of the patients after stroke is physical rehabilitation. We anticipate that this drug would be added to that standard of care,” Carmichael explains.
The research team emphasizes that further studies are needed to evaluate the drug’s safety and effectiveness before it can be considered for human trials.
The recent study was published in Nature Communications.
Chrissy Newton is a PR professional and founder of VOCAB Communications. She currently appears on The Discovery Channel and Max and hosts the Rebelliously Curious podcast, which can be found on The Debrief’s YouTube Channel on all audio podcast streaming platforms. Follow her on X: @ChrissyNewton and at chrissynewton.com.