SAN DIEGO – The healthy brain is a master of autoregulation, continuously adjusting blood flow to meet metabolic demand.
But in traumatic brain injury, cerebrovascular reactivity (CVR) breaks down; blood vessels don’t dilate as they should to deliver nutrients and oxygen, leading to progressive neurologic decline.
Sildenafil (Viagra) – a vasodilator in injured blood vessels – might help, according to ongoing research at the University of Pennsylvania, Philadelphia.
Researchers there gave sildenafil to inpatients with persistent symptoms at least 6 months after traumatic brain injury and measured CVR by a novel MRI technique an hour later. “Sildenafil was able to correct the deficit in CVR in many cases. We are hopeful this could be a useful therapy,” said principal investigator Ramon Diaz-Arrastia, MD, a professor of neurology at the university.
He explained the work in an interview at annual meeting of the American Neurological Association. The next step is to see if sildenafil helps CVR in acute traumatic brain injury, and in people who have had multiple, mild brain traumas, including professional athletes.