Varicella zoster virus infection of the central nervous system – 10 year experience from a tertiary hospital in South India

Introduction: Varicella zoster virus is an exclusively human neurotrophic virus. The primary infection with the virus causes varicella. The virus remains latent in nervous tissue and upon secondary activation causes a variety of syndromes involving the central nervous system (CNS) including meningoencephalitis and cerebellitis. Materials and Methods: In this study, we looked at the epidemiology, clinical and laboratory features, and outcomes of patients who were admitted with varicella zoster of the CNS from 2005 to 2014. Results: There were 17 patients. Fever was present in 13 patients, seizures in 9 patients and headache and vomiting in 4 patients each. A generalized varicella rash was present in 8 out of 17 patients. A single dermatomal herpes zoster was present in seven patients. Two patients had no rash. Varicella zoster polymerase chain reaction (PCR) in cerebrospinal fluid (CSF) was done in 5 patients of which 4 were positive and 1 was negative. Nine patients had diabetes with an average glycated hemoglobin of 8.6%. Total number of deaths was five. Conclusions: Patients with diabetes who develop varicella or herpes zoster may be at risk for CNS complications. The diagnosis of varicella encephalitis has to rest on a combination of clinical findings and CSF PCR, as neither the rash nor the PCR is sensitive enough to diagnose all the cases with varicella encephalitis.