DANVILLE — Bruno Cafiso is alive today because his wife, Bonna, recognized the early warning signs of a stroke.

A stroke occurs when there is a sudden interruption of blood to the brain, most often caused by a blockage of one of the arteries leading to the brain.

According to neuroradiologist Dr. David Carrington, the early warning signs of a stroke are many, and include changes in sensation, weakness on one or both sides, absence of speech, drooping of the face or a massive headache.

Though Bruno says there is no history of stroke in his family, he does suffer from arterial fibrillation, a form of heart arrhythmia that also is a risk factor for stroke.

Other risk factors include smoking, poor diet or leading a sedentary lifestyle. Carrington said patients who suffer from high cholesterol, high blood pressure and diabetes also have higher incidence of stroke.

“Notifying EMS would be the first thing to do (if a stroke occurs),” Carrington said, hopefully immediately after the stroke has been suffered.

That’s because doctors work in a strict time frame when it comes to treating stroke, Carrington said.

If given promptly, the intravenous clot-busting therapy known as tPA, or tissue plasminogen activator, can significantly reduce the effects of stroke and reduce permanent disability.

If that therapy does not work, or, in the case of Bruno, a patient has been diagnosed as having a large stroke, the MERCI retriever can be used.

In use since 2002, MERCI is short for Mechanical Embolus Retrieval in Cerebral Ischemia. The device is inserted through an incision in the groin and threaded through arteries on a micocatheter to the brain to either apply medication directly to the clot to break it up, or remove the clot from the brain, immediately restoring blood flow.

The device has been considered a breakthrough, as tPA, though proven successful in treating stroke, has only a short window for application — about three to four hours, Carrington said, while the MERCI retriever can be used up to 8 hours after the onset of a stroke.

“The idea is within that time window anyone at risk for dying does not die,” Carrington said. “Blood flow is restored, then we can save the brain.”