To evaluate the diagnostic accuracy of reduced montage electroencephalography (EEG) for seizure detection and provide evidence-based recommendations.

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a diagnostic meta-analysis to assess the sensitivity and specificity of reduced EEG montages in detecting seizure activity. A hierarchical summary receiver operating characteristic curve (HSROC) model was used to estimate the area under the curve (AUC). Subgroup analyses were conducted to identify sources of heterogeneity. Bayesian estimates were used for validation.

Across 8 studies encompassing 3,458 reduced EEG montage samples, all studies used a reduced EEG montage with 7 to 10 electrodes. The pooled sensitivity was 0.75 (95 % CI: 0.68–0.80), and the pooled specificity was 0.97 (95 % CI: 0.95–0.98). The HSROC model had an AUC of 0.96 (95 % CI: 0.93–0.97). Variations in study results were attributed to factors such as the number of electrodes (pooled sensitivity of 0.66 for studies employing <8 leads and 0.77 for studies employing ≥8 leads) and montage design coverage (pooled sensitivity of 0.64 for studies employing subhairline montage and 0.77 for studies employing above-hairline montage). The Bayesian and frequentist findings agreed with each other and had a pooled sensitivity of 0.74 (95 % HPD: 0.65–0.83) and pooled specificity of 0.97 (95 % highest posterior density 0.95–0.98).

Reduced EEG montages with 8 or more electrodes are feasible for seizure detection, especially in emergency settings where rapid detection is crucial.