- •PGES is common after GCS and the incidence of PGES in GCS varies from 23% to 86%.
- •Longer tonic phase duration in GCS increases the likelihood of having PGES in GCS.
- •Sleep state at GCS onset and age of epilepsy onset show significant association with PGES occurrence in GCS.
- •The presence of postictal immobility and oxygen desaturation nadir are also related to PGES occurrence in GCS.
Background and purpose
Postictal generalized EEG suppression (PGES) has been suggested as a pathophysiological hallmark for sudden unexpected death in epilepsy (SUDEP). We aimed to characterize the clinical determinants for PGES occurrence after generalized convulsive seizures (GCS).
We systematically searched Pubmed, Embase and Medline databases up to 30 August 2021. Eligibility screening, data extraction, and quality assessment of the retrieved articles were conducted by two independent reviewers. Studies reporting potential risk factors of PGES occurrence in GCS were included for subsequent meta-analysis and PGES was defined as a generalized EEG attenuation of any duration >1s below 10μV, immediately or within 30s after an ictal EEG pattern has terminated. A fixed-effects model was applied when the heterogeneity is low (I2 values < 50%). Otherwise, a random-effects model was used (I2 values ≥ 50%). We assessed the odds ratio (OR) as outcome measure for dichotomous variables and the STD Mean Difference (SMD) for continuous variables. The Begg test and the Egger test was applied in the assessment of publication bias.
A total of 15 relevant studies were identified, enrolling 2057 GCSs. The incidence of PGES in GCS from 15 studies varied from 23% to 86%. The longer tonic phase duration (SMD, 0.26; 95%CI, 0.13 to 0.39; p < 0.001), sleep state at GCS onset (OR,1.63; 95%CI, 1.24 to 2.16; p = 0.001), older age of epilepsy onset (SMD, 0.48; 95%CI, 0.21 to 0.75; p = 0.001), the presence of postictal immobility (OR, 78.05; 95%CI, 32.31 to 188.53; p < 0.001) and oxygen desaturation nadir (SMD, -0.54; 95%CI, -0.76 to -0.33; p < 0.001) showed significant association with the likelihood of having PGES in GCS, but not total seizure duration (SMD, -0.06; 95%CI, -0.20 to 0.08; p = 0.385), tonic-clonic duration (SMD, -0.12; 95%CI, -0.26 to 0.01; p = 0.071), clonic phase duration (SMD, -0.09; 95%CI, -0.27 to 0.08; p = 0.293), epilepsy duration of patients (SMD, -0.09; 95%CI, -0.27 to 0.08; p = 0.293) or lack of early O2 administration (OR, 1.59; 95%CI, 0.80 to 3.17; p = 0.184).
The current study informed that PGES is common after GCS. Early identification should be considered among individuals with GCS at high risk of PGES through clinical screening. Further studies with larger sample size are required for individualized evaluation of the risk of PGES in GCS and more effort is needed to further evaluate the risk of SUDEP.
To read this article in full you will need to make a payment
Purchase one-time access:Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
One-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:Subscribe to Seizure - European Journal of Epilepsy
Already a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
- Sudden unexpected death in epilepsy.Lancet. 2011; 378: 2028-2038
- Sudden unexpected death in epilepsy: epidemiology, mechanisms, and prevention.Lancet Neurol. 2016; 15: 1075-1088
- Do antiepileptic drugs or generalized tonic-clonic seizure frequency increase SUDEP risk? A combined analysis.Epilepsia. 2012; 53: 249-252
- An electroclinical case-control study of sudden unexpected death in epilepsy.Ann Neurol. 2010; 68: 787-796
- Incidence and mechanisms of cardiorespiratory arrests in epilepsy monitoring units (MORTEMUS): a retrospective study.Lancet Neurol. 2013; 12: 966-977
- Postconvulsive central apnea as a biomarker for sudden unexpected death in epilepsy (SUDEP).Neurology. 2019; 92: e171-e182
- Postictal generalized EEG suppression and postictal immobility: what do we know?.Epileptic Disord. 2020; 22: 245-251
- Equivocal significance of post-ictal generalized EEG suppression as a marker of SUDEP risk.Seizure. 2017; 48: 28-32
- Postictal generalized electroencephalographic suppression is associated with generalized seizures.Epilepsy Behav. 2011; 21: 271-274
- Postictal generalized EEG suppression: an inconsistent finding in people with multiple seizures.Neurology. 2013; 81: 1252-1256
- Age-specific periictal electroclinical features of generalized tonic-clonic seizures and potential risk of sudden unexpected death in epilepsy (SUDEP).Epilepsy Behav. 2013; 29: 289-294
- Nocturnal seizures are associated with more severe hypoxemia and increased risk of postictal generalized EEG suppression.Epilepsia. 2017; 58: e127-e131
- Risk factors of postictal generalized EEG suppression in generalized convulsive seizures.Neurology. 2015; 85: 1598-1603
- Two predictors of postictal generalized EEG suppression: tonic phase duration and postictal immobility period.Seizure. 2018; 61: 135-138
- Association between semiologic, autonomic, and electrographic seizure characteristics in children with generalized tonic-clonic seizures.Epilepsy Behav. 2021; 122108228
- Postictal immobility and generalized EEG suppression are associated with the severity of respiratory dysfunction.Epilepsia. 2016; 57: 412-417
- Postictal generalized EEG suppression is not associated with periictal cardiac autonomic instability in people with convulsive seizures.Epilepsia. 2013; 54: 523-529
- Autonomic dysregulation in children with epilepsy with postictal generalized EEG suppression following generalized convulsive seizures.Epilepsy Behav. 2020; 102106688
- Postictal generalized EEG suppression and respiratory dysfunction following generalized tonic-clonic seizures in sleep and wakefulness.Epilepsia. 2017; 58: 1409-1414
- Hypoxemia following generalized convulsive seizures: risk factors and effect of oxygen therapy.Neurology. 2019; 92: e183-e193
- Impact of periictal interventions on respiratory dysfunction, postictal EEG suppression, and postictal immobility.Epilepsia. 2013; 54: 377-382
- Periictal electroclinical characteristics of postictal generalized electroencephalographic suppression after generalized convulsive seizures.Medicine. 2020; 99: e19940
- Tonic phase of a generalized convulsive seizure is an independent predictor of postictal generalized EEG suppression.Epilepsia. 2013; 54: 858-865
- Postictal generalized EEG suppression after generalized convulsive seizures: a double-edged sword.Clin Neurophysiol. 2016; 127: 2078-2084
- Automated analysis of risk factors for postictal generalized EEG suppression.Front Neurol. 2021; 12669517
- Prevention of sudden unexpected death in epilepsy: current status and future perspectives.Expert Rev Neurother. 2020; 20: 497-508
- Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement.Ann Int Med. 2009; 151 (W264): 264-269
- Operational classification of seizure types by the International League Against Epilepsy: position paper of the ILAE Commission for Classification and Terminology.Epilepsia. 2017; 58: 522-530
Wells G.A., Shea B., O'Connell D., Peterson J., Losos M., Tugwell P., et al. The Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomised studies in meta-analyses. http://www.ohri.ca/programs/clinical_epidemiology/oxford.asp0 (accessed 15/03/2018).
- A methodological review of how heterogeneity has been examined in systematic reviews of diagnostic test accuracy.Health Technol Assess. 2005; 9 (iii): 1-113
- Trim and fill: a simple funnel-plot-based method of testing and adjusting for publication bias in meta-analysis.Biometrics. 2000; 56: 455-463
- Ictal symmetric tonic extension posturing and postictal generalized EEG suppression arising from sleep in children with epilepsy.Pediatr Neurol. 2017; 76: 54-59
- Postictal generalized EEG suppression is linked to seizure-associated respiratory dysfunction but not postictal apnea.Epilepsia. 2012; 53: 825-831
- Sudden death in epilepsy recorded in ambulatory EEG.J Neurol Neurosurg Psychiatry. 2007; 78: 1395-1397
- Impaired consciousness in epilepsy investigated by a prospective responsiveness in epilepsy scale (RES).Epilepsia. 2012; 53: 437-447
- How do seizures stop?.Epilepsia. 2008; 49: 1651-1664
- Incidence, recurrence, and risk factors for peri-ictal central apnea and sudden unexpected death in epilepsy.Front Neurol. 2019; 10: 166
- Impaired serotonergic brainstem function during and after seizures.J Neurosci. 2016; 36: 2711-2722
- The serotonin axis: shared mechanisms in seizures, depression, and SUDEP.Epilepsia. 2011; 52 (Suppl): 28-38
- The sudden infant death syndrome.N Engl J Med. 2009; 361: 795-805
- Symptomatology of epileptic seizures in the first three years of life.Epilepsia. 1999; 40: 837-844
- Do generalized tonic-clonic seizures in infancy exist?.Neurology. 2005; 65: 1750-1753
- Sudden unexplained death among subjects with refractory epilepsy.Epilepsia. 1996; 37: 931-935
- 3rd Sudden unexplained death in children with epilepsy.Neurology. 2001; 57: 430-434
- Cohort study of incidence of sudden unexplained death in persons with seizure disorder treated with antiepileptic drugs in Saskatchewan, Canada.Epilepsia. 1995; 36: 29-36
- Impact of periictal nurse interventions on postictal generalized EEG suppression in generalized convulsive seizures.Epilepsy Behav. 2016; 58: 22-25
Published online: March 27, 2022
Accepted: March 26, 2022
Received in revised form: March 23, 2022
Received: October 7, 2021
© 2022 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.