A revolutionary new technique, which involves jump-starting the growth of nerve fibers to compensate for brain cells destroyed by the stroke, may be capable of restoring functions to a stroke patient weeks, and even months after the attack, according to a recent report.
“In the best-case scenario, this would open up the window of time that people could recover and go back to normal functional status,” said Gwendolyn Kartje, MD, Ph.D., a professor in the department of cell biology, neurobiology and anatomy and department of neurology at Loyola University Chicago Stritch School of Medicine.
The experimental approach is described by Kartje and colleagues in the journal Topics in Stroke Rehabilitation. Called anti-nogo-A immunotherapy, anti-nogo has dramatically improved functions in lab animals that have experienced strokes. Anti-nogo is also the subject of an ongoing clinical trial in Europe and Canada to test the technique in patients with spinal chord injuries.
Most strokes are caused by clots that block blood flow to one part of the brain, killing brain cells within hours. The drug TPA can minimize damage by dissolving the clot. But TPA is safe and effective only when given within about three hours of the onset of symptoms. Most patients don’t receive treatment within that brief window. Patients typically arrive at the hospital too late, or hospitals do not begin administering TPA soon enough.
Nogo-A is a protein that inhibits the growth of nerve fibers called axons, and checks uncontrolled nerve growth causing excessive sensitivity to pain, or involuntary movements.In anti nogo immunotherapy, an antibody disables the nogo protein.
The left side of the brain controls movements on the right side of the body, and vice versa. Thus, a stroke on the left side of the brain can cause paralysis on the right side of the body. In such a patient, anti-nogo would, it’s hoped, spur the growth of axons from the healthy right side of the brain. These axons would then grow into the right side of the body and restore functions lost by the stroke.
Rats that have undergone strokes in old age have been tested with anti nogo. After anti nogo function in the front paw of the affected side was almost completely restored in some rats. The Novartis company is sponsoring a phase 1 clinical trial of anti-nogo for patients paralyzed by spinal cord injuries, and a clinical trial for stroke [patients could begin by 2012, according to Kartje, who believes anti-nogo has great potential for stroke patients.
Anti nogo “offers the potential for stroke patients to recover, return to nearly normal functional status, and stay out of nursing homes,” Kartje said. “Theoretically, there’s no reason why this should not happen.”
Source: Loyola University Health System