To gain further insight on the association between human toxocariasis and epilepsy in light of the new evidence in the last years. A systematic review was conducted without date and language restriction in the following electronic databases: MEDLINE (PubMed), Ingenta Connect, Science Direct (Elsevier), RefDoc, Scopus, HighWire, Scielo and the database of the Institute of Neuroepidemiology and Tropical Neurology of the Limoges University (IENT). Two investigators independently conducted the search up to November 2017. A pooled odds ratio (OR) was estimated using a random effects model. Meta-regression was conducted to investigate potential sources of heterogeneity. Database search produced 204 publications. Eleven case-control studies were included that were carried out in 13 countries worldwide. A total number of 4740 subjects were considered (2159 people with epilepsy and 2581 people without epilepsy). The overall pooled OR was 1.69 (95% CI 1.42–2.01) for the association between epilepsy and Toxocara spp. seropositivity. A positive association was constantly reported in the restricted analysis (WB as confirmatory or diagnostic test, younger population, and population–based studies). Meta-regression showed no statistically significant association between covariates and outcome. The updated meta-analysis provides epidemiological evidence of a positive association between Toxocara seropositivity and epilepsy. New surveys supported the association, mainly population-based studies. On this basis, health strategies to reduce the impact of Toxocara spp are strongly advised. Further research should be performed to understand the physiopathological mechanisms of toxocara-associated epileptogenesis. Human toxocariasis is a parasitic zoonosis caused by the larval stages of Toxocara canis (T. canis), the common roundworm of dogs, and by the roundworm of cats, Toxocara cati (T. cati). Toxocariasis is one of the most prevalent helminthiasis worldwide. Humans become infected by the ingestion of contaminated food or soil or by direct contact with dogs and cats. Epilepsy is the most common chronic neurological disorder worldwide with a global estimate of about 70 million cases of lifetime epilepsy. Early studies suggested high rate of toxocara exposure (toxocara seropositivity) among people with epilepsy. Despite several studies support the possible role of toxocariasis in the incidence of epilepsy, this association is still debated. We updated our previous research to gain further insight on the association. This study provides new evidence of a positive association between the two diseases. On this basis, health strategies to reduce the impact of Toxocara spp are strongly advised. Further studies are necessary to clarify the role of certain parasites in epilepsy.

To provide an overall estimate of the prevalence of idiopathic REM Sleep Behavior Disorder (iRBD). Two investigators have independently searched the PubMed and Scopus databases for population-based studies assessing the prevalence of iRBD. Data about type of diagnosis (polysomnographic diagnosis, defined iRBD [dRBD]; clinical diagnosis, probable RBD [pRBD]), continent, age range of the screened population, quality of the studies, sample size, screening questionnaires, and strategies have been gathered. A random-effect model was used to estimate the pooled prevalence. Heterogeneity was investigated with subgroup analysis and meta-regression. From 857 articles found in the databases, 19 articles were selected for the systematic review and meta-analysis. According to the type of diagnosis, five studies identified dRBD cases given a pooled prevalence of 0.68% (95% confidence interval [CI] 0.38–1.05) without significant heterogeneity (Cochran’s Q p = 0.11; I² = 46.43%). Fourteen studies assessed the prevalence of pRBD with a pooled estimate of 5.65% (95% CI 4.29–7.18) and a significant heterogeneity among the studies (Cochran’s Q p < 0.001; I² = 98.21%). At the subgroup analysis, significant differences in terms of prevalence were present according to the quality of the studies and, after removing two outlaying studies, according to the continents and the screening questionnaire used. Meta-regression did not identify any significant effect of the covariates on the pooled estimates. Prevalence estimates of iRBD are significantly impacted by diagnostic level of certainty. Variations in pRBD prevalence are due to methodological differences in study design and screening questionnaires employed.