VARICELLA-ZOSTER VIRUS-INFECTION OF THE CENTRAL-NERVOUS-SYSTEM IN THEACQUIRED-IMMUNE-DEFICIENCY-SYNDROME

Productive varicella-zoster virus (VZV) infection of the central nervo us system (CNS) was demonstrated in II acquired immune deficiency synd rome (AIDS) patients using immunocytochemistry and in situ hybridizati on. A characteristic zoster skin eruption was seen in only four cases. From our own series and II other cases in the literature, we identifi ed five clinico-pathological patterns of VZV infection of the CNS in A IDS patients which could occur simultaneously. (i) Multifocal encephal itis predominantly involving the white matter likely to be due to haem atogenous spread of the infection was found in four cases. (ii) Ventri culitis was found in three cases. In two cases there was complete acut e or chronic necrosis of the ventricular wall with marked vasculitis; in the third, the ependymal lining appeared irregular with foci of VZV -infected ependymal cells, some of which protruded into the ventricula r lumen. (iii) Acute haemorrhagic meningo-myeloradiculitis with necrot izing vasculitis was observed in two cases. In one, this was associate d with ventriculitis and was possibly due to shedding of infected epen dymal cells into the ventricular lumen and secondary seeding of the CS F: (iv) Focal necrotizing myelitis was seen in one case. It followed c utaneous herpes zoster and was considered to result from neural spread from the diseased dorsal root ganglion similar to cases previously de scribed of encephalitis limited to the visual system following VZV oph thalamicus, or bulbar encephalitis following a trigeminal zoster (v) V asculopathy involving leptomeningeal arteries and causing cerebral inf arcts was seen in four cases, it was associated with meningitis in mos t cases. These findings ave in keeping with the observation in non-AID S patients that VZV spread to the CNS may follow different routes. Our study tends to show that VZV infection of the CNS occurs move frequen tly in AIDS than previously suspected and suggests that it must be con sidered as a diagnosis in cases of encephalitis, ventriculitis, focal myelitis, acute myeloradiculitis and cerebral infarcts in these patien ts.