OBJECTIVE
Subclinical seizures (SCSs) remain an understudied aspect of presurgical evaluation in patients with drug-resistant epilepsy (DRE), with uncertain prevalence, distribution among epilepsy types, and predictive value for surgical outcomes. This systematic review and meta-analysis aims to explore the occurrence of SCSs, their concordance with the seizure-onset zone (SOZ), and their association with postoperative seizure outcomes.
METHODS
A systematic search of Medline, Embase, and Web of Science was performed to identify studies reporting SCSs during scalp electroencephalography (EEG) monitoring or intracranial EEG (iEEG) monitoring in patients with DRE undergoing epilepsy surgery. Data on SCS prevalence, concordance with SOZ, and postoperative outcomes were extracted. Pooled proportions and odds ratios (ORs) were estimated using random-effects generalized linear mixed models. Subgroup analyses evaluated the proportions of SCSs in temporal vs extratemporal epilepsy.
RESULTS
Thirteen studies comprising 1174 patients met the inclusion criteria. The pooled prevalence of SCSs was 32% (95% confidence interval [CI] 8-73) during scalp EEG monitoring and 50% (95% CI 38-62) during iEEG monitoring. Concordant SCSs with SOZ occurred in 37% of patients undergoing iEEG. Non-concordant SCSs were associated with a nearly fivefold higher odds of poor postoperative seizure control (OR 4.82, 95% CI 1.80-12.96; p = 0.002). SCSs were more frequent in temporal lobe epilepsy than in extratemporal epilepsy (57% vs 44%, p = 0.046). Within temporal lobe epilepsy, the highest prevalence was observed in the mesiotemporal region (69%). Overall, the presence of SCSs alone was not associated with a poor outcome, but the spatial non-concordance with the SOZ was highly predictive for poor seizure outcome.
SIGNIFICANCE
SCSs are common in presurgical evaluation, particularly in temporal lobe epilepsy. Although their presence alone is not prognostic, non-concordant SCSs are associated with worse postoperative outcomes. Systematic assessment, especially using iEEG, may improve delineation of the epileptogenic zone and surgical planning in DRE.
P. Bosque-Varela, Panagiota-Eleni Tsalouchidou, Petra Levicka et al.· Epilepsia· 0 citations
Background and Objectives Reliable prediction of short-term mortality in status epilepticus (SE) can contribute to guide clinical decisions. Current prognostic systems achieve only acceptable predictive power and show lack of generalizability or poor calibration. We aimed to identify clinical predictors of short-term mortality in patients with nonhypoxic SE and develop a predictive score. Methods This was a multicenter, multinational cohort study based on registry data. Participants were consecutive episodes of SE in participants aged 14 years or older from Modena (Italy) (derivation cohort) and in participants aged 18 years or older from Salzburg (Austria) (validation cohort). The predefined outcome was 30-day mortality after the onset of SE. Age, sex, level of consciousness before treatment, semiology of SE, level of disability at baseline before SE, etiology, and treatment refractoriness were assessed. Adjusted regression coefficients of each independent predictor were transformed to produce a points-based risk scoring system. Results The Italian cohort included 689 episodes, and the Austrian cohort comprised 569 episodes of SE. In the derivation cohort, the 30-day mortality rate was 27.3%. The independent risk factors were aged 75 years or older (odds ratio [OR] 5.52, 95% CI 3.45–8.83; p < 0.001), consciousness impairment (stuporous or comatose) before SE treatment (OR 1.76, 95% CI 1.09–2.82; p = 0.020), acute etiology due to primary CNS pathology (OR 2.60, 95% CI 1.60–4.23; p < 0.001), refractoriness to treatment (OR 6.40, 95% CI 3.91–10.46; p < 0.001), and disability before SE onset (OR 3.53, 95% CI 2.22–5.61; p < 0.001); remote etiology was independently associated with a lower likelihood of 30-day mortality (OR 0.28, 95% 0.13–0.61; p = 0.001). An integer-based scoring system termed Age, Consciousness, Aetiology, Refractoriness, Disability (ACARD) was developed by combining these independent predictors. In the validation cohort, the 30-day mortality rate was 11.6%. The area under the curve of the ACARD score was 0.864 (95% CI 0.836–0.891) in the derivation cohort and 0.845 (95% CI 0.801–0.888) in the validation cohort. Calibration plot indicated good fit of predicted and observed data in both cohorts. Discussion The ACARD score is a user-friendly tool developed to predict 30-day mortality after nonhypoxic SE. It has the potential to identify participants at high risk of short-term mortality and outperform the performance of other available scoring systems.
Simona Lattanzi, E. Trinka, P. Bosque-Varela et al.· Neurology· 0 citations