Evaluation of EEG Changes in Seizures with Absence to Focal Motor and Bilateral Tonic-Clonic Progression using Amplitude Integrated EEG in Children.
Abstract number :
1.471
Submission category :
3. Neurophysiology / 3A. Video EEG Epilepsy-Monitoring
Year :
2022
Submission ID :
2232870
Source :
www.aesnet.org
Presentation date :
12/3/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:28 AM
Authors :
Juan Toro Perez, MD, MSc – University of ottawa; Erick Sell, MD, – Neurologist, Pediatrics, University of Ottawa; Asif Doja, MD, FRCPC – Neurologist, Pediatrics, University of Ottawa; Katherine Muir, MD, FRCPC – Epileptologist, Pediatrics, University of Ottawa; Sarah Healy, MSc – Research associate, Pediatrics, University of Ottawa; Srinivas Bulusu, MSc – Chief Technologist, Neurology, University of Ottawa; Sharon Whiting, MD, FRCPC – Epileptologist, Pediatrics, University of Ottawa
This is a Late Breaking abstract
Rationale::Idiopathic generalized epilepsy (IGE) and generalized genetic epilepsy (GGE) are subtypes of generalized epilepsy. Generalized epilepsy represents 23-43% of new-onset epilepsy in children and adolescents (1), and 53-58% of them have one of the IGE syndromes. These patients will experience absence, myoclonic, tonic-clonic, myoclonic-tonic-clonic and generalized tonic-clonic seizures. These may have focal or asymmetric features and myoclonic seizures may be focal or asymmetric (3).Terminology for the transition from absence seizure leading to bilateral tonic-clonic seizure was described as “the double generalization phenomenon in juvenile absence epilepsy” or “absence-to-bilateral-tonic-clonic seizure as a generalized seizure type." This could lead to confusion as in some patients, a focal component can be seen after the initial absence seizure followed by bilateral tonic-clonic seizure (absence to focal to bilateral tonic-clonic progression). Using the analysis of this progression using Video-electroencephalography (EEG) analyzed with amplitude integrated EEG. Using complex mathematical algorithms with analysis of specific frequency band, signal complexity, connectivity, and networks, as well as the ILAE seizure classification, we proposed that generalized absence seizures may lead to focal to bilateral tonic-clonic progression._x000D_
Methods: We conducted a retrospective analysis of the patients with epilepsy admitted to the epilepsy monitoring unit (EMU) from 2014 to 2022, whose seizure types included absence and generalized tonic-clonic. Normal brain MRI was required. Patients with developmental epileptic encephalopathy were excluded.
Results: A total of 452 patients were admitted to our EMU between May 2014 and May 2022. 56 had a diagnosis of generalized epilepsy whose seizure types included absence and generalized tonic-clonic. Four patients had absence to focal to bilateral tonic-clonic progression and five seizures were recorded. Two of them had juvenile absence epilepsy (JAE), one had juvenile myoclonic epilepsy (JME) and one had generalized genetic epilepsy (GGE) and mild delay in the context of SLC13A5 mutation. The mean age of the patients at seizure onset was 8 years (range:1-12, SD ±4.9665), at the diagnosis was 8.5 years (range:1-13, SD ± 5.4467). All patients had normal background with the exception of the patient with GGE who had mild slowing. Photic and hyperventilation were noncontributory in patients #2, #3, and #-4. The patient #1 had absence status epilepticus before the bilateral tonic-clonic progression. Quantitative spike detection analysis of all patients showed focal build up after the absence seizures (green bar), with right frontal (dark red bar) or bilateral frontal propagation (dark red and blue bar) following by bilateral hemisphere involvement (light red bar).
Conclusions: Amplitude integrated EEG is an important tool which increases the accuracy to detect focality during the seizure propagation to the frontal cortex through the thalamo-cortical network. With this quantitative analysis we confirmed absence seizures could propagate to focal area in the frontal cortex prior to the bilateral tonic-clonic progression.
Funding: Not applicable
Neurophysiology