Stem cell injections into the brain may improve some cognitive functions in people who haven’t recovered months or years after a clot-caused stroke, according to a study presented at the American Stroke Association’s International Stroke Conference 2015.
In a preliminary study, 18 patients who had sustained moderate or severe ischemic strokes and remained paralyzed on one side six to 60 months later (average 22 months) received stem cell injections. Patients received 2.5, 5 or 10 million adult bone marrow cells engineered to secrete factors previously shown to protect neurons in animal models.
In tests performed six and 12 months after the injections, some patients showed improvement in some verbal learning tasks. Results differed depending on the location of the stroke. These results should prompt further investigations of cognitive function in studies of stem cell therapy for stroke recovery, researchers said.
Cynthia Kenmuir, M.D., Ph.D., University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania. Abstract 34
Natural brain-repair substance may improve stroke outcome
Supplementing a natural substance that protects nerve cells and encourages new blood vessel formation may aid in new neural growth after stroke when started a week later, according to a mouse study presented at the American Stroke Association’s International Stroke Conference 2015.
Currently, the only FDA-approved drug, tPA, which dissolves clots to restore blood flow, must be given within hours after stroke.
Previously, researchers found that after an experimentally induced stroke (with temporary or permanent blockage of the middle cerebral artery), functional outcomes in rodents improved if they received the bioactive protein fragment perlecan domain V (DV) within six-24 hours.
In the new study, 3-month-old mice received DV or an inactive substance seven days after stroke and every three days thereafter. After 21 days, more new neurons had reached the area of brain damage and survived in mice receiving DV.
Aileen Marcelo-McCabe, Ph.D., University of Kentucky, Lexington, Kentucky. Abstract 163
Spleen may be key target for successful cell therapy after stroke
The spleen — not the brain — may be the key target in successful cell therapy after a stroke, according to a study in mice presented at the American Stroke Association’s International Stroke Conference 2015.
After a stroke, the spleen seems to contribute to ongoing inflammation and brain damage.
Researchers compared the outcome of stroke and cell therapy with autologous bone marrow mononuclear cells (MNCs) in mice with intact spleens and those with spleens removed two weeks before an experimentally induced stroke. After stroke, the size of brain injury was smaller and neurological problems were less severe in mice without spleens. MNCs treatment improved functional recovery in mice with spleens but was no better than a placebo in mice without spleens.
Bing Yang, M.D., University of Texas Medical School at Houston, TX. Abstract T MP22