Varicella zoster virus is the only human virus known to replicate in cerebral arteries, Dr. Herng-Ching Lin, from Taipei Medical University, and associates note in the November issue of the journal Stroke, published online on October 8. “It is hypothesized to spread along the nerve fibers to the blood vessels where it induces further inflammatory and thrombotic responses.”
Their population-based cohort study included 7760 patients treated for herpes zoster between 1997 and 2001 and 23,280 randomly selected control subjects.
Within a year after their first ambulatory care visit for shingles, 133 patients (1.71%) in the study cohort developed first-time strokes. There was a 1.31% 1-year incidence of stroke in the 306 (1.31%) control subjects.
Adjusted hazard ratios for stroke after herpes zoster and herpes zoster ophthalmicus were 1.31 (p < 0.050) and 4.28 (p < 0.001), respectively, compared with controls. The zoster patients also had adjusted hazard ratios of 2.79 (p < 0.001) for intracerebral or subarachnoid hemorrhage and 1.31 (p = 0.009) for ischemic stroke compared to controls.
“Although varicella zoster virus vasculopathy is a well documented complication that may induce a stroke (after) herpes zoster attack, it does not fully account for the unexpectedly high risk of stroke in these patients,” the authors conclude.
They call for further studies “to explore the underlying pathomechanisms and intervention strategies for patients experiencing herpes zoster attacks.”