title: Evaluation of positive and negative predictors of seizure outcomes among patients with immune-mediated epilepsy: a meta-analysis.
abstract: BACKGROUND
  The objective of this study was to analyze published literature on autoimmune epilepsy and assess predictors of seizure outcome.
  
  
  METHODS
  From PubMed and EMBASE databases, two reviewers independently identified publications reporting clinical presentations, management and outcomes of patients with autoimmune epilepsy. A meta-analysis of 46 selected studies was performed. Demographic/clinical variables (sex, age, clinical presentation, epilepsy focus, magnetic resonance imaging [MRI] characteristics, time to diagnosis and initiation of immunomodulatory therapy, and type of immunomodulatory therapy) were compared between two outcome groups (responders and nonresponders). Clinical response was defined as >50% reduction in seizure frequency. Unstandardized effect sizes were collected for the studies for responder and nonresponder groups. Sample size was used as the weight in the meta-analysis. The random effects model was used to account for heterogeneity in the studies.
  
  
  RESULTS
  The 46 reports included 186 and 96 patients in responder and nonresponder groups respectively. Mean age of the responders and nonresponders was 43 and 31 years (p < 0.01). Responders were more likely to have cell-surface antibodies (68% versus 39%, p < 0.05), particularly voltage-gated potassium channel complex antibodies (p < 0.01). Mean duration from symptom onset to diagnosis, and symptom onset to initiation of immunomodulation was significantly lower among the responders (75 versus 431 days, p < 0.05, and 80 versus 554, p < 0.01, respectively). There was no outcome difference based on gender, MRI characteristics, seizure type, type of acute immunomodulatory therapy, or use of chronic immunomodulation.
  
  
  CONCLUSIONS
  Among published cases to date, older age, presence of cell-surface antibodies, early diagnosis and immunomodulatory treatment are associated with better seizure outcomes among patients with autoimmune epilepsy.
authors: Department of Neurology and Neurotherapeutics, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75235, USA.
authors: Divyanshu
authors: D
authors: Dubey
authors: Department of Neurology and Neurotherapeutics, UT Southwestern Medical Center, Dallas, TX, USA.
authors: Zehra
authors: Z
authors: Farzal
authors: Department of Neurology and Neurotherapeutics, UT Southwestern Medical Center, Dallas, TX, USA.
authors: Ryan
authors: R
authors: Hays
authors: Department of Health Systems Research Parkland Health & Hospital System Dallas, TX, USA.
authors: L Steven
authors: LS
authors: Brown
authors: Department of Neurology and Neurotherapeutics, UT Southwestern Medical Center, Dallas, TX, USA.
authors: Steven
authors: S
authors: Vernino
keywords: autoimmune disease; encephalitis; epilepsy; immunotherapy; limbic encephalitis; paraneoplastic