Young. Unsuspecting. Stroke Victim.

Joe Miller had just eaten a sandwich in his kitchen when he was suddenly overcome by dizziness. “My head was spinning, my limbs wouldn’t move, and I couldn’t coordinate a sentence,” the 46-year-old recalls about his experience a year and a half ago. For several hours, he sat on the floor of his Bloomington home, immobilized. Eventually, he was able to pull himself to a chair and call his girlfriend. That evening in the emergency room, a doctor told Miller he’d had a stroke.

Miller had suffered an ischemic, or blockage, stroke. Tissue had separated from the wall of one of the two vertebral arteries at the base of his head, a spontaneous “dissection” that caused blood to clot there. Sometimes dissection happens after a minor head or neck injury. Miller may have strained his neck and had a small stroke a week earlier, while helping his brother move; he suffered a shorter dizzy spell then. But he also had chronic risk factors associated with artery dissection—a history of migraines and elevated blood pressure.

“The doctor said more often than not, it’s a genetic time bomb just waiting for the perfect conditions,” Miller says. Having taken a high-stress finance job three years earlier, Miller had stopped running, was eating a lot of Big Macs, and had gained 40 pounds. Luckily for him, the dissection healed itself and his stroke caused no brain damage. “That’s the miracle of the deal,” he says. “They said, ‘Typically with cases like this, we find out what happened to you in the autopsy.’”

Blocked or Bleeding?

At least 80 percent of strokes are ischemic. Often, doctors can administer clot-busting drugs with good success rates—few brain cells destroyed by lack of oxygen, low incidence of impaired functioning—if patients come for treatment within three hours of a stroke. Another option is surgery via catheter with a clot retrieval device called the Merci Retriever. In Miller’s case, where the clot was caused by a tear in his artery, doctors could give him blood-thinning drugs, but had to wait for the tear to heal itself. The artery was permanently damaged, but “the good news is you can live on one,” Miller says.

Less common but often more deadly is hemorrhagic stroke, or bleeding in the brain. “The blood goes into the brain, which is the consistency of loose meatloaf,” says Dr. Bruce Idelkope, a co-director of the stroke program at Fairview Southdale Hospital and a physician at the Minneapolis Clinic of Neurology in Golden Valley (Miller is one of his patients). The bleeding kills brain cells where it occurs and raises pressure inside the skull, which further damages the brain or causes death, Idelkope explains.

A frequent cause of hemorrhagic stroke is a ruptured aneurysm, a weak spot in a blood vessel that has ballooned out and finally burst. Even absent an aneurysm, blood vessels can be weak and rupture. When that happens, doctors drain blood from the brain in surgery and sometimes “clip” an aneurysm shut to prevent another rupture. But clipping requires opening up the skull and spreading open brain tissue to get to the problem. A less-invasive surgical procedure is becoming more common. In “endovascular coiling,” doctors fill the aneurysm with highly pliable platinum coils that are threaded up into the brain through the femoral artery and an incision in the groin.