Neurological Manifestations in COVID-19 Infection: A Systematic Review and Meta-Analysis

Background: Growing evidence showed that coronavirus disease 2019 (COVID-19) infection may present with neurological manifestations. This review aimed to determine the neurological manifestations and complications in COVID-19. Methods: We conducted a systematic review and meta-analysis that included cohort and case series/reports involving a population of patients confirmed with COVID-19 infection and their neurologic manifestations. We searched the following electronic databases until April 18, 2020: PubMed, Embase, Scopus, and World Health Organization database (PROSPERO registration number: CRD42020180658). Results: From 403 articles identified, 49 studies involving a total of 6,335 confirmed COVID-19 cases were included. The random-effects modeling analysis for each neurological symptom showed the following proportional point estimates with 95% confidence intervals: "headache" (0.12; 0.10-0.14; I-2 = 77%), "dizziness" (0.08; 0.05-0.12; I-2 = 82%), "headache and dizziness" (0.09; 0.06-0.13; I-2 = 0%), "nausea" (0.07; 0.04-0.11; I-2 = 79%), "vomiting" (0.05; 0.03-0.08; I-2 = 74%), "nausea and vomiting" (0.06; 0.03-0.11; I-2 = 83%), "confusion" (0.05; 0.02-0.14; I-2 = 86%), and "myalgia" (0.21; 0.18-0.25; I-2 = 85%). The most common neurological complication associated with COVID-19 infection was vascular disorders (n = 23); other associated conditions were encephalopathy (n = 3), encephalitis (n = 1), oculomotor nerve palsy (n = 1), isolated sudden-onset anosmia (n = 1), Guillain-Barre syndrome (n = 1), and Miller-Fisher syndrome (n = 2). Most patients with neurological complications survived (n = 14); a considerable number of patients died (n = 7); and the rest had unclear outcomes (n = 12). Conclusion: This review revealed that neurologic involvement may manifest in COVID-19 infection. What has initially been thought of as a primarily respiratory illness has evolved into a wide-ranging multi-organ disease.