Neurological Manifestations of Zika Virus Infection: An Updated Review of the Existing Literature

Abstract

Zika virus (ZIKV) is a neurotropic virus closely linked to other flaviviruses like dengue virus, West Nile virus, yellow fever, and Japanese encephalitis virus. Though initially considered a mild virus, ZIKV gained everybody's attention when the World Health Organization (WHO) declared it a global public health emergency in February 2016. Being considered an important cause of innumerable neurological manifestations and pediatric modality, we aimed to present a comprehensive overview of the neurological details of ZIKV infection. This study reviews the neurological manifestations of ZIKV infection. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) strategy was employed, along with a combination of keywords, to enlist all articles with data on ZIKV and its neurological manifestations, diagnosis, and treatment. All case reports, case series, and systematic reviews published between 2017 and 2024, focusing on neurological manifestations of ZIKV, were included in this study. Case studies, editorials, letters to the editors, and clinical images were excluded. The search was conducted using Boolean operators "AND" and "OR" on PubMed and Google Scholar. A total of five case reports, one case series, and one systematic review and meta-analysis were included. Out of 603 patients, the study suggested a male preponderance of 366 patients (62.5%) for ZIKV infection. About 258 patients presented with rash (46.1%), 243 with fever (43.8%), and 134 with dysphagia (36.5%). Neurological signs on examination were limb paresis in 545 (91.1%) patients, areflexia in 401 (88.9%) patients, and tetraparesis in 153 (61%) patients. A significant finding on magnetic resonance imaging (MRI) showed enhancement of the distal cord, conus medullaris, and cauda equina in two cases (0.3%). Serological analysis showed a positive plaque reduction neutralization test (PRNT) in 125 (73.5%) patients. Increased protein levels were identified in 240 (78.7%) cases on cerebrospinal fluid (CSF) analysis. The commonest diagnostic modality utilized was polymerase chain reaction (PCR) in 118 (24.3%) cases. Intravenous immunoglobulins (IVIg) were used for the medical management of 442 patients included in this review (77.4%). ZIKV is known to cause insidious detrimental effects on the central nervous system regardless of the age of an individual. Being a cause of extreme sensorimotor disability, various preventive and precautionary measures are being undertaken to ensure early diagnosis and prevent prolonged liability on a patient's health. Effective therapeutics including IVIg have paved the way in bringing down the hurdles in the management and cure of the infection.

Keywords: encephalitis; fetal zika virus syndrome; guillain-barrè syndrome; meningitis; microcephaly; neurological manifestations; zika virus.

Figure 1. PRISMA flowchart for the search strategy and quality assessment of included studies

PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-Analyses

Figure 2. A schematic flowchart for Zika virus infection presenting with neurological manifestations

Image Credit: Author Amna Sohail