Over 90% of the world population has the virus that causes chickenpox lying dormant in their nervous system. Most people contract the varicella zoster virus, or VZV, when they get chickenpox as children. For around a third of these people, this same virus will reactivate years later and cause shingles, also called herpes zoster.
While most people are familiar with the painful rash that VZV causes for shingles, a wide spectrum of other complications can also occur even without visible skin symptoms. Among the most severe is stroke, in particular ischemic stroke, which occurs when the blood supply to the brain is restricted by narrowing arteries or blocked by a clot.
