The relationship between herpes zoster and stroke.

Varicella zoster virus (VZV) infects >95 % of the world population. Typically, varicella (chickenpox) results from primary infection. The virus then becomes latent in ganglionic neurons along the entire neuraxis. In immunocompromised individuals, VZV reactivates and causes herpes zoster (shingles), pain, and rash in 1-2 dermatomes. Multiple case reports showed a link between stroke and zoster, and recent studies have emerged which reveal that VZV infection of the cerebral arteries directly causes pathological vascular remodeling and stroke (VZV vasculopathy). In the past few years, several large epidemiological studies in Taiwan, Denmark, and the U.K. demonstrated that zoster is a risk factor for stroke and that antiviral therapy may reduce this risk. Herein, the history, clinical features, and putative mechanisms of VZV vasculopathy, as well as recent epidemiological studies demonstrating that zoster increases the risk of stroke, are discussed.