A recent incident involving an American yoga and fitness model shows that even young, healthy, active people can suffer strokes, challenging the conventional wisdom that strokes are exclusively caused by age, poor diet and smoking.
An injury called a carotid artery dissection, which can sometimes occur while people are engaged in physical activity or suffer a major trauma, can sometimes result in stroke.
The injury made headlines this week when the Instagram model shared her story of suffering a stroke after practicing handstands and headstands as part of her regular yoga routine. She was told that it was because she had torn an artery in her neck.
While only about two per cent of all strokes are caused by a torn neck artery, according to an article in the New England Journal of Medicine, this injury accounts for 10 to 25 per cent of all strokes in young and middle-aged people.
Here’s what to know about the condition:
A carotid artery dissection, as it’s formally known, is essentially a tear in the inner lining of one of the major arteries in your neck, said Dr. Michael Hill, director of the stroke unit at Calgary’s Foothills Hospital and a spokesperson for Heart & Stroke.
The other major arteries in your neck, the vertebral arteries, can also suffer the same kind of tears.
While, depending on the exact nature and location of the tear, it might not cause any symptoms, it’s a known cause of stroke, he said.
“It’s something that we see frequently and look for and deal with probably on a weekly basis,” said Hill.
When the artery tears, “the first thing the body does is it forms a clot over where the spot of the tear is,” he added. “If a piece of clot breaks free and travels up into the brain, blocks an artery in the brain, then you have a stroke.”
In some cases, the entire carotid artery might get blocked, which would also cause a stroke, he said.
What causes it
Young people who suffer these strokes might say: “‘What’s going on? I eat properly, I live well, I don’t smoke, I exercise. What’s going on?’” Hill said.
None of those risk factors are related to the stroke in this case.
Most often, the artery tears due to major trauma like a car accident, he said.
But smaller trauma might also be linked to these tears.
“There’s all kinds of associations reported: hanging your head over the sink to get your hair washed at the hairdresser, playing golf, chiropractic manipulation of the neck, yoga — all this kind of stuff has been potentially implicated as a cause,” said Hill.
In these cases, though, Hill said it’s hard to prove that the activity actually caused the injury. In the absence of a major trauma, doctors don’t usually know exactly what happened.
“These are just associations, and no one really knows,” he said.
WATCH: Younger people being treated at Calgary comprehensive stroke centre
It’s plausible that someone could injure their neck arteries doing a yoga pose, he said, but he also thinks it’s likely that there is some underlying risk factor in such cases that predisposes people to this kind of injury.
“Lots of people play hockey or play golf or get their hair washed or go to a chiropractor, and nothing happens to them. They’re fine,” he said.
Some connective tissue disorders and genetic factors have been associated with the injury, as have recent respiratory infections. Many cases are also thought to arise spontaneously with no known cause.
Can it be prevented?
People take risks when they do sports or other activities, said Hill, and they decide what level of risk they are comfortable taking.
“In general, your neck is a pretty vulnerable part of your anatomy, right? There’s a lot of critical structures that go in through your neck,” he said.
“I think it’s generally true that doing crazy things that will put your neck at risk is a bad idea.”
How to recognize when something is wrong
Knowing the symptoms of stroke can ensure that you get the help that you or someone else needs as soon as possible. The Heart & Stroke Foundation suggests remembering the acronym FAST, which stands for:
Face — Is it drooping?
Arms — Can you raise both?
Speech — Is it slurred?
Time — To call 911 right away.
WATCH: What a stroke is and how to spot the signs
Specifically with carotid artery dissection, even if they’re not having a stroke, people can sometimes have a very severe headache on one side, Hill said.
“The carotid artery, when you injure it, actually hurts,” he explained.
The headache would be unlike any headache that person has felt before, he said. According to a literature review, neck pain on one side is also a common symptom.
Often, people will also have one pupil that’s much larger than the other, along with a drooping eyelid, as a symptom of a carotid artery injury, he said.
“That’s a warning that something has happened and you need to be checked out and have artery imaging and try to make a diagnosis so that you can be protected from stroke,” he explained.