Introduction: Central nervous system infection by the varicella-zoster virus (VZV) can be responsible for myelitis, meningitis, ventriculitis and large and small-vessels encephalitis.
Case report: We report the case of a 57-year-old-man hospitalized for deteriorating general health. Physical examination revealed likely encephalitis associated with headache without meningeal syndrome. Successive cerebral MRIs showed bilateral necrosis of the amygdaloid bodies and multiple deep and sub-cortical infarcts suggestive of vasculitis. Cerebral arteriography was normal. Three cerebral fluid examinations disclosed mononuclear pleiocytosis with few red blood cells. PCR analysis for VZV was only positive at the third time.
Discussion: The diagnosis of VZV encephalitis is difficult without the rash typical of zoster and because of the low sensitivity of PCR VZV in comparison with PCR HSV.
Conclusion: In active viral disease, where the prognosis depends on early treatment, we highlight the usefulness of repeated PCR analysis and the search for antibodies in blood and cerebrospinal fluid.