Abstracts

Outcome of Absence Epilepsy with Onset at 8 to 11 Years of Age: Watershed Ages When Syndromes Overlap

Abstract number : 1.21
Submission category : 4. Clinical Epilepsy / 4B. Clinical Diagnosis
Year : 2022
Submission ID : 2204825
Source : www.aesnet.org
Presentation date : 12/3/2022 12:00:00 PM
Published date : Nov 22, 2022, 05:26 AM

Authors :
Anita Datta, MD, FRCPC, CSCN Diplomate (EEG) – University of British Columbia; Laura Wallbank, EEG technologist – University of British Columbia; Jacqueline Crawford, EEG technologist – University of British Columbia; Peter Wong, MD, FRCPC – University of British Columbia

Rationale: Absence seizures occur in various epilepsy syndromes, including childhood and juvenile absence epilepsy. When children present with absence seizures at ages when syndromes overlap, initial syndrome designation is not always possible, making prognosis challenging. For these children, the study objective is to determine electro-clinical features associated with seizure prognosis including development of generalized tonic-clonic seizures (GTCs).

Methods: Children with new-onset absence epilepsy between 8-11 years of age with at least 5-years of follow-up data were studied through the review of medical records and initial EEG tracings.

Results: Ninety-nine patient records were reviewed. The median age of absence seizure-onset was 9 years [Interquartile Range (IQR) = 8.00, 10.00] and the median age at follow-up was 15 years [IQR = 13.00, 18.00]. Forty-five percent developed GTCs and 21% developed myoclonic seizures. GTCs were associated with a trial of more anti-seizure medications (ASMs) (p< 0.0009) and a lower likelihood of seizure remission after weaning ASMs [6.7% of patients with GTCs vs. 71.4% without GTCs]. No difference in seizure frequency was observed at follow-up in those with and without GTC. On multivariate analysis, a history of myoclonic seizures, anxiety, as well as bi-frontal slowing and mild background slowing on initial EEG (p< 0.05) were associated with GTCs. Although not significant, shorter bursts were also associated with GTCs. A trial of more anti-seizure medications (ASMs) was associated with a lower likelihood of 1-year seizure-freedom at follow-up (p< 0.006).
Clinical Epilepsy