Seizure Occurrence After Solid Organ Transplantation: A Systematic Review and Meta-Analysis

Background/Objectives: Seizures are clinically important neurological complications after solid organ transplantation (SOT), but their reported frequency varies widely. We aimed to estimate the pooled seizure occurrence proportion after SOT and summarize reported seizure-related clinical factors. Methods: PubMed, Embase, and Web of Science were searched on 28 February 2026 for prospective or retrospective observational studies published in 2000–2025 that included SOT recipients and reported post-transplant seizures. No language restrictions were applied. Risk of bias was assessed using the Joanna Briggs Institute critical appraisal checklist for prevalence studies. Study-specific proportions were logit-transformed and pooled using random-effects models. Organ- and age-specific subgroup analyses, prediction intervals, sensitivity analyses, and assessments of small-study effects were performed. Results: Thirty-four reports representing 32 independent cohorts and 8816 recipients were included. The pooled seizure occurrence proportion was 5.3% (95% CI, 3.9–7.1%), with substantial heterogeneity (I2 = 87.0%) and a 95% prediction interval of 1.1–22.8%. Pooled seizure occurrence was higher in pediatric than adult cohorts (10.7% vs. 4.4%; between-group p = 0.011), although this study-level difference should not be interpreted as evidence of an independent effect of pediatric age. Commonly reported clinical contexts included calcineurin inhibitor-related neurotoxicity, metabolic or electrolyte disturbances, posterior reversible encephalopathy syndrome, cerebrovascular or structural brain injury, infection or systemic complications, and pre-existing neurological conditions. The evidence was limited by predominantly retrospective designs and heterogeneous seizure ascertainment and follow-up. Conclusions: The pooled study-specific seizure occurrence proportion after SOT was 5.3%, but occurrence varied substantially across populations and ascertainment periods, as reflected by the wide 95% prediction interval (1.1–22.8%). This estimate should not be interpreted as a uniform individual risk across transplant populations. Post-transplant seizures should prompt evaluation for potentially reversible and treatment-relevant causes. This review received no external funding and was not registered.