Immune-mediated neurological manifestations of dengue virus- a study of clinico-investigational variability, predictors of neuraxial involvement, and outcome with the role of immunomodulation

Abstract

Our aim was to study dengue-related immune-mediated neurological complications (IMNC) during the recent epidemic. This was a cross-sectional observational study of 79 IMNC cases from 1627 laboratory confirmed dengue cases from January 2015 to January 2016 and their follow-up for 3 months. According to the World Health Organization, cases were categorized into those having dengue fever (DF), and those having a severe syndrome that includes dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Laboratory as well as clinicoradiological data, the predictors of outcome, and the role of immunomodulation in determining the final result were analyzed. Out of the 1627 confirmed dengue cases, 14.6% developed neurological complications and only 4.86% cases had IMNC. Among the IMNC seen, the majority of the patients had the onset of their manifestations in the subacute (7-30 days) latency period; however, there was no mortality seen. We found Miller Fisher syndrome (MFS), limbic encephalitis, and immune-mediated cerebellar demyelination (IMCD) as the new findings in the IMNC spectrum. Patients with DF were more prone to developing brachial plexus neuritis and polyneuritis cranialis, whereas those patients with a severe syndrome were more commonly associated with Guillain-Barre syndrome (GBS). Significant (P < 0.001) predictors of central nervous system involvement were anemia, an elevated hematocrit, and the presence of DSS, whereas patients with a higher mean body temperature, DF, and elevated hematocrit were more prone to developing peripheral nervous system manifestations. The platelets counts and the hemoglobin levels had a negative correlation whereas the hematocrit value, the mean body temperature, and the alanine aminotransferase levels had a moderately significant positive correlation for the development of IMNC. The immunomodulatory therapy (IMT), if initiated after fever abatement led to a significant clinically favorable outcome at 3 months, especially in patients with GBS, polyneuritis cranialis, and brachial plexus neuritis. The spectrum of IMNC is vast and may include MFS, limbic encephalitis and IMCD. Early initiation of IMT, in the presence of significant predictors, may reduce the IMNC-related morbidity.