Word that champion speed skater Denny Morrison had suffered a stroke may have stunned many of us who assume it’s an affliction of the old.

But a Canadian neurologist says the condition is not as rare among the young as one might think.

The 30-year-old Morrison tweeted Saturday night that he was in hospital in Utah, recovering from a stroke. In a statement, Speed Skating Canada explained that Morrison had been spending free time in Salt Lake City when a fellow competitor noticed Morrison showing odd symptoms and drove him to hospital where doctors diagnosed a stroke.

Dr. Richard Swartz, a stroke neurologist at Sunnybrook Health Sciences Centre in Toronto, says while many of us think of strokes as a disease of the aged, they can affect anyone at any age, even infants.

“Stroke is actually a fairly common disease among young adults,” Swartz told CTV’s Canada AM on Monday.

Stroke affects one in 10,000 people between the ages of 14 and 45, making it more common than multiple sclerosis among young adults, said Swartz.

The risk and incidence of stroke certainly increase with age. That’s when the effects of the key risk factors for stroke -- high blood pressure, high cholesterol and obesity -- can cause narrowed blood vessels.

When a blood vessel leading into the brain becomes completely blocked, it can trigger what’s known as an ischemic stroke.

Yet Morrison is an elite-level athlete and likely to be in excellent cardiovascular condition.

Swartz doesn’t know the particulars of Morrison’s case, but says it’s possible that the injuries Morrison sustained in a motorcycle accident 11 months ago played a role in his stroke.

He notes that Speed Skating Canada said in its announcement that brain and neck scans had confirmed the presence of a blood clot in Morrison’s brain as well as a dissection, or a tear, in his carotid artery, which is a major blood vessel in the neck supplying blood to the brain.

Swartz said arterial dissections are “actually the most common identifiable cause” of stroke in young adults.

Any kind of physical trauma can lead to a tear in a blood vessel that fails to heal, he said.

“Usually, a stroke associated with trauma happens quite quickly after a trauma, but it can happen in a delayed fashion. So it may be related in his case,” he said.

Morrison did not undergo surgery and did not need blood thinners, Speed Skating Canada said, but they added that he remains in hospital.

Following the motorcycle accident, the Olympic medallist returned to competition earlier this year and recently completed a full month of bike touring on the Arizona Trail.

Swartz says it’s difficult to know whether intense exercise might have sparked Morrison’s stroke.

“Exercise tends to be a great prescription against stroke. So most times, it’s actually protective,” he said.

“But at the extremes, exercise can put a strain on the heart. So if someone is predisposed to a heart condition, extreme exercise or dehydration can put a strain on the heart. So it depends a little bit on the cause whether intense exercise is beneficial or harmful.”

Swartz adds that strokes can have a range of outcomes. About 15 per cent – “and this includes young adults” – may not survive their stroke, he says. Another 20 to 25 per cent recover fully with no lasting effects. The rest experience lasting deficits that can range from mild to severe.

But Swartz says it’s heartening to see Morrison tweeting from his hospital bed just hours after the stroke.

“That’s a good sign,” he said.