Michelle Nimmerrichter was only 20 years old when she suffered a stroke that left her in a coma and on a ventilator.

She appears to be part of a trend -- a recent study found that strokes are affecting people at younger ages.

Nimmerrichter was paralyzed on one side and unresponsive when she arrived at Loyola University Medical Center on May 13th, 2011.

"She was very critically ill," said Dr. Jose Biller, a neurologist who directed her care. Biller is an internationally known expert on strokes in young people, and chair of Loyola's Department of Neurology.

Nimmerrichter has made a remarkable recovery and has returned to college. The main lingering effect is minor dystonia (involuntary muscle contraction) in her right hand. It doesn't stop her from eating her favorite food (cupcakes) or holding her cat, Cupcake.

Biller determined that Nimmerrichter suffered an unusual type of stroke that was triggered by a blood clot in the deep veins in her brain, leading to massive brain swelling. The clot was likely due to two factors: Nimmerrichter's blood has a genetic abnormality that makes it more prone to clotting, and she was taking a hormonal contraceptive, which increases the risk of blood clots.

Biller treated Nimmerrichter with a blood thinner, and medications to relieve pressure in her brain caused by the swelling. She spent two weeks at Loyola and nearly three weeks at a rehabilitation hospital.

Biller said Nimmerrichter's case illustrates the benefits of treating each patient as an individual. "At Loyola, we treat individual patients with stroke, rather than strokes generically," Biller said. "We avoid the temptation of the one-size-fits-all approach, so pervasive with cookbook medicine."

Nimmerrichter's stroke occurred just after she finished her sophomore year at Loyola University Chicago. It was Friday the 13th, and she was home alone at her mother's house in Brookfield. She was discovered by her boyfriend, who came to see her after she failed to respond to a text. He found her laying in bed, staring blankly at the wall.

Her mother, Mari Nimmerrichter, was shocked when she was told her daughter had suffered a stroke. "Most people equate strokes with people who are 50 or 60 or older," she said. But a recent University of Cincinnati College of Medicine study found that strokes among people under age 55 in the greater Cincinnati area increased from 13 percent of all strokes in 1993-94 to 19 percent in 2005. The study was published in Neurology®, the journal of the American Academy of Neurology.

"Strokes can occur at any age," Biller said. "The impact of strokes can be devastating to young adults, their families and society."

Biller is author of the textbook, "Stroke in Children and Young Adults," and a co-author of the American Heart Association's guidelines for management of stroke in infants and children.

The quicker a patient is diagnosed and treated, the better the outcome. "But people don't think that children and young adults can get strokes," Biller said. "So family members often are slow to recognize strokes."

Warning signs of stroke include sudden: Weakness of the face, arm or leg, especially on one side of the body. Numbness or tingling of the face or one side of the body. Confusion or trouble understanding. Trouble speaking. Trouble seeing in one or both eyes. Trouble walking; dizziness; loss of balance or coordination. Severe, unusual headaches.

A stroke kills 32,000 brain cells each second. So if you or a family member experience stroke symptoms, Biller advises, call 911 immediately.

"Every second counts," Biller said. "Time is brain."