[Myelitis and optic neuritis caused by varicella].

INTRODUCTION: Varicella mainly affects children between 1 and 14 years old. It is the initial infection caused by the Varicella-Zoster virus. It is characterized by a vesicular cutaneous eruption, fever and generally good prognosis. The neurological complications caused by the Varicella-Zoster virus are infrequent and include: meningitis, encephalitis, cerebellar ataxia, Reye's syndrome, myelitis, optic neuritis, mononeuropathy, polyneuropathy, necrosis of the retina and cerebral arteritis. CLINICAL CASE: We present the unusual case of a woman patient aged 18 who presented with myelitis 15 days after having a varicella rash. Analysis of the cerebrospinal fluid showed intrathecal production of antibodies against the Varicella-Zoster virus. Fourteen days after resolution of the myelitis, she presented with unilateral optic neuritis which remitted without sequelae, (as did the myelitis). Cerebral and medullary MR showed no alterations.
CONCLUSIONS: The pathogenesis leading to involvement of the nervous system is still not well defined. Direct invasion by the virus has been postulated, particularly in Herpes-Zoster (reinfection by Varicella-Zoster), as immunological phenomena which may be more frequent with Varicella (initial infection by Varicella-Zoster virus). In our case there were two short episodes of neurological involvement: optic neuritis and myelitis, with a satisfactory clinical course after giving corticosteroids. This makes one think of immunological mechanisms rather than direct invasion of the central nervous system by the Varicella-Zoster virus.