February 14, 2014
News Review From Harvard Medical School -- Injury May Increase Strokes among the Young
Having a head or neck injury may triple the chance of stroke in the next month for people under age 50, a study finds. Strokes are most common among adults over 65. They occur less often in young adults and children, but they are not rare. The new study looked at medical records of 1.3 million people younger than 50. All of them had received emergency treatment for head or neck injuries. Within the next four weeks, 48 out of every 100,000 young adults had an ischemic stroke. This is the most common type of stroke. It is caused by a clot that blocks a blood vessel in the brain. Strokes also occurred in 11 of every 100,000 children treated for a head or neck injury. Researchers said they were unsure why the stroke rate increased so sharply after these injuries. Study findings were presented February 13 at a conference. HealthDay News wrote about the study.
By Howard LeWine, M.D.
Harvard Medical School
What Is the Doctor's Reaction?
We usually think of stroke as something that happens to older people. In fact, the risk of stroke does increase with age, especially in people 65 and older.
But the number of strokes occurring in younger people is rising. A recent study estimated that 19% of strokes today happen in adults younger than age 55.
Experts aren't exactly sure why stroke risk is increasing at younger ages. Some suggest that it's just because strokes can be more accurately diagnosed now. Brain MRI is very good at diagnosing a stroke. Other experts believe it's because of the dramatic rise in obesity and type 2 diabetes.
This report highlights another factor that increases the risk of stroke in younger people -- a head or neck injury. Admittedly, the risk of stroke from this type of injury is very small. Fewer than 5 strokes occur after every 10,000 emergency department visits by young adults for head or neck injury.
The authors were not able to determine the exact causes for these strokes. But it's reasonable to assume that a major cause was an artery tear.
Injury to the head or neck can transmit sudden force to the major arteries in the neck. This can result in a tear to an artery. Doctors call it a dissection. It can happen in one of the carotid arteries (in the front of the neck) or one of the vertebral arteries (in the back of the neck).
The tear in the artery allows blood to flow into the artery wall. This narrows the artery. Blood flow slows through that area. A damaged artery with slow blood flow will have a high risk of a blood clot that can completely block blood flow to the brain. This is one type of stroke.
What Changes Can I Make Now?
Ideally, if you could predict who would have a carotid or vertebral artery tear after a head or neck injury, you would tell them to take a daily aspirin. Or you might even consider having them get blood-thinning heparin shots.
However, head and neck injury rarely results in a stroke from a carotid or vertebral artery dissection. And treating everyone with either aspirin or a blood thinner is not an option. Preventing even one stroke could lead to more people having side effects, potentially serious ones.
The important message is to be aware of the symptoms of neck artery dissection. A severe headache on one side of the neck, face and head can be the only symptom. And a dissection can happen even without known head or neck trauma. In that case, aspirin or a blood thinner can help prevent a stroke.
With or without a headache, symptoms that suggest you may be having a stroke always require immediate action.
If you suspect that you or someone you are with is having a stroke, think FAST:
- Face: Ask the person to smile. Is one side drooping?
- Arms: Ask the person to lift both arms. Does one drift back down?
- Speech: Ask the person to repeat a simple sentence. Is it slurred or incomplete?
- Time: If one or more stroke signs are present, act quickly. Call 911, and get the person to the nearest hospital with an emergency department. If possible, it should be a hospital with a stroke center.
What Can I Expect Looking to the Future?
This study won't lead to any changes in the guidelines for prevention and treatment of stroke.
Even in younger people, most strokes are still related to the usual risk factors. To help decrease your risk:
- Know your blood pressure, and lower it if it's high.
- Don't smoke.
- Lose excess weight.
- Become more active.
- Control your blood sugar and cholesterol levels.
- If you drink alcohol, do so in moderation.
- Adopt a healthy diet, such as a Mediterranean-style diet.