Stroke is a leading cause of long-term disability in the US, affecting more than 795,000 Americans every year. But according to a new study, a drug already approved to treat epilepsy may also be effective in reducing brain damage for individuals who have ischemic stroke – the most common form of stroke.
The research team, led by Dr. Sonya Bierbower of the School of Medicine at the University of Texas (UT) Health Science Center at San Antonio, publishes its findings in The Journal of Neuroscience.
Ischemic stroke accounts for around 87% of all strokes in the US. It is caused by a blockage in the artery that supplies the brain with oxygen-rich blood.
Ischemic stroke causes death of nerve cells, or neurons, in the brain. As a result, many patients may experience partial or full paralysis, problems with memory and thinking, trouble with forming or understanding speech, balance and mobility problems, and problems expressing or controlling emotions.
While speech, physical and occupational therapy can aid recovery after stroke, the only medication approved by the Food and Drug Administration (FDA) to reduce ischemic stroke-induced brain damage is tissue plasminogen activator (tPA). This is an intravenous drug that dissolves blood clots and improves blood flow to the brain.
But according to Dr. Bierbower and her team, many stroke patients are unable to receive tPA; it is a strong blood thinner that can cause severe side effects.
As such, the researchers investigated alternative ways to reduce brain damage following ischemic stroke. Specifically, they looked to a drug called retigabine (brand name Ezogabine) – an anticonvulsant already approved by the FDA to treat epilepsy.
Retigabine works by opening the brain’s potassium ion channels, which halts the electrical activity of nerve cells.
“We thought if we could stop the neurons from firing, thus stopping their electrical activity, we could conserve their resources until their blood supply was restored,” explains senior author Dr. Mark Shapiro, also of the School of Medicine at the UT Health Science Center at San Antonio.
For their study, the researchers tested the effects of retigabine in mice that experienced ischemic stroke.
In a balance beam test, the team found that mice treated with the drug had no problems with balance or mobility, compared with untreated mice. “You couldn’t even tell they had a stroke,” says Dr. Shapiro. “They ran across the balance beam like gymnasts.”
The video below shows the difference in balance between the treated and untreated mice:
The researchers note that because retigabine is approved by the FDA as an anticonvulsant, clinicians can use it off-label for the treatment of stroke patients.
However, a clinical trial is needed before the drug can be approved specifically for stroke therapy. This is something the team says is underway.
Commenting on the team’s findings, Dr. David F. Jimenez, professor and chairman of the Department of Neurosurgery at the UT Health Science Center, says:
“As a leading cause of death and disability, stroke poses a major risk to our society. It is very exciting to see that our collaborative work with our colleagues in physiology could provide a superb way to ameliorate the harmful effects of stroke on our patients.”
This research was funded by the National Institute of Neurological Disorders and Stroke, a part of the National Institutes of health.
Medical News Today recently reported on a study published in the New England Journal of Medicine, in which researchers claim it is feasible for paramedics to administer life-saving drugs to stroke patients before they reach the hospital.