If you've had shingles, you may be at higher risk of having a stroke. That report comes from a new study published in the online issue of the American Academy of Neurology’s medical journal Neurology®.
After adjusting for other risk factors, the study shows people ages 18-40 are more likely to have a stroke, heart attack or transient ischemic attack (TIA) if they have ever had shingles, than people of the same age who never had shingles.
Shingles is a painful skin rash caused by the same virus that causes chickenpox. After chickenpox, the virus becomes dormant or inactive in some nerves in the body.
Shingles develops if that virus becomes active again, which can occur many years after chickenpox. People over age 60 or those with a weakened immune system are at higher risk of developing shingles. But anyone who had chickenpox can develop shingles.
Stroke is the fourth leading cause of death, and the leading cause of disability, in the United States. A stroke occurs when a blood clot blocks the flow of blood in an artery in the brain, or when a brain artery ruptures. This prevents nutrients and oxygen from reaching part of the brain, which causes brain cells in that area to die.
A TIA, sometimes referred to as a mini-stroke, is also caused by a blood clot in an artery in the brain. The difference between a TIA and a stroke is that the TIA blockage is temporary. Most TIA clots dissolve in about a minute, without causing permanent damage to the brain.
TIAs are serious conditions better categorized as warning strokes because there is no way to tell whether any blood clot will dissolve before the brain is permanently injured. Both strokes and TIAs are considered to be medical emergencies.
According to the study, people under age 40 are 74 percent more likely to have a stroke if they have ever had shingles. People over 40 who had shingles are more likely to have a heart attack or TIA, but showed little increased risk of stroke compared to people of the same age who had not had shingles. People over 40 showed significantly less risk.