Department of Neurology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India.
Abstracts of the papers presented at the International Conference of Indian Virological Society on “Emerging and Re-emerging viral Diseases of the Tropics and Subtropics” at Indian Agricultural Research Institute, New Delhi, India, December 11–14, 2007.
More than 200 viruses produce various types of neurological diseases including encephalitis, meningitis, encephalo-myelitis, radiculitis and even stroke due to vasculitis especially with herpes zoster. The tenets of management of viral encephalitis include administration of antiviral drugs, control of seizure, attention to respiration, cardiac rhythm, nutrition, fluid and electrolyte balance, prevention of deep venous thrombosis, aspiration pneumonia, bedsore, secondary infections and finally rehabilitation. Specific antiviral drug is available only to herpes and enterovirus group of infections. In herpes simplex encephalitis (HSE) intravenous acyclovir has been proved to be efficacious than placebo and vidarabine in a dose of 10 mg/8 hrly IV for 14 days. Outcome is better if started early before the patient is deeply comatose. Acyclovir is also effective against herpes zoster and Epstein Barr virus encephalitis. Empirical acyclovir is not indicated as 80–90% encephalitis is not due to herpes even in developed nations. However acyclovir should be started in a clinically suspected patient whose MRI reveals bilateral temporal involvement and EEG reveals PLEDs pending the CSF PCR results. Decision about continuation of acyclovir should be taken after PCR results. Acyclovir resistance may occur in immunocompromised patients with HSE and in them treatment should be continued for 3 weeks followed by valacyclovir or famciclovir. In HSV 6 and 7 which manifest with febrile convulsion with maculopapular rash may be treated with ganciclovir, valganciclovir, foscarnet or cidofovin. Same antiviral drugs may be used against cytomegalovirus encephalitis; however response is not as good as acyclovir in HSE. Various drugs have been used to treat flavivirus infections but none is found to be effective. Ribavarin and interferon á 2a have been used in Japanese encephalitis and West Nile but not found to be effective. Pleconaril has come out to be an effective treatment option for enterovirus infection. Dengue infection although does not have specific treatment but attention to intravenous fluid and correction of bleeding and coagulation factors need special attention especially in dengue hemorrhagic and shock syndrome. Corticosteroid has not been found to be effective in Japanese and herpes simplex encephalitis. Antiepileptic drug should be started in patients with seizure and prophylaxis antiepileptic drug in those who has highly epileptogenic area (frontotemporal) involvement. In 90% patients with viral encephalitis however treatment is supportive which is life saving.
