Former Republican Gov. George Pataki’s son-in-law remains under treatment for a severe stroke, a condition that is on the increase in young people, a top cardiology expert says.

“We are seeing more people suffering stroke at an early age due to factors like untreated high blood pressure, diabetes and poor diet, although there are other reasons for such a stroke to happen as well,” Chauncey Crandall, M.D. tells Newsmax Health.

Allison Pataki and her husband, David Levy, 30, were on a flight en route to Chicago when the plane was diverted to Fargo, N.D., when he suffered a life-threatening stroke last week. Pataki, who is running for president, put his campaigning on hold while he went to join is family.

Although a vast majority of strokes occur in people over age 65 (the risk is 30 to 50 per 1,000 in this age group), 10 percent to 15 percent affect people age 45 and younger (a risk of 1 in 1,000), studies find.

A few years ago, the Centers for Disease Control and Prevention cited an increase in such strokes, blaming them on lifestyle factors that include untreated hypertension, obesity, diabetes and other lifestyle factors.

But another cause of stroke in younger people is the problem of undetected heart problems, particularly atrial septal defect, which is a congenital problem known also as a “hole in the heart,” said Dr. Crandall, author of the Heart Health Report.

As a baby develops in the womb, a wall (called the interatrial septum) forms that divides the upper chamber into a left and right atrium. An abnormal formation of this wall can result in a hole that remains after birth.

If untreated, a stroke can occur if a blood clot passes to the left side of the heart and travels to the brain. Under normal circumstances, such a blood clot would be filtered out from the lungs.

In other stroke news, researchers have discovered that intensive therapy can help stroke victims regain use of their arms, even after as much time as a year has passed.

Researchers know that people who suffer strokes can regain at least some use of their limbs after six months, but this study at University of Florida Health found that extensive physical therapy helped them recover motor function, even though they began the study treatment a year or more later.

The researchers compared the motor learning rehabilitation to learning a beginner learning a new sport move, and said that patients must concentrate on performing a movement as deliberately as possible, with as much normal movement as possible, and must practice the task repetitively.