Delay to Diagnosis in Idiopathic Generalized Epilepsy
Abstract number :
3.529
Submission category :
4. Clinical Epilepsy / 4B. Clinical Diagnosis
Year :
2024
Submission ID :
1615
Source :
www.aesnet.org
Presentation date :
12/9/2024 12:00:00 AM
Published date :
Authors :
Presenting Author: Gabriella Foca, BA – NYU Grossman School of Medicine
Jacqueline French, MD – New York University Comprehensive Epilepsy Center
Orrin Devinsky, MD – NYU Grossman School of Medicine
Rationale: We investigated the delay to diagnosis in patients with Idiopathic Generalized Epilepsy. We also assessed seizure semiologies associated with delayed diagnoses.
Methods: We retrospectively analyzed enrollment data from the Human Epilepsy Project 3, an observational multi-site study of IGE patients from 17 sites in the United States and Australia. All subjects were adjudicated to confirm IGE diagnosis. Participants enrolled into three cohorts: newly diagnosed (enrolled within 12 months of treatment initiation); long-standing treatment responsive ( >2 years of seizure freedom, failed ≤ 2 antiseizure medications (ASMs)); and long-standing treatment resistant ( >2 years of continuous treatment with ASMs with persistent seizures.) At the initial study visit, data was collected on participants’ seizure onset and frequency of each seizure type experienced. Treatment delay was defined as ASM initiation >4 months from initial seizure activity. We analyzed seizure data from 192 participants: 83 participants newly diagnosed, 64 treatment-responsive, and 45 treatment-resistant.
Results: Demographics were similar across study cohorts. 82.3% of all participants experienced > 1 generalized tonic-clonic seizures (GTCS), 19.8% had absence and 20.8% had myoclonic seizures. Among the newly diagnosed, 79.5% reported GTCSs, 20.4% reported absence, and 24.1% reported myoclonic seizures. Among the long-standing treatment-responsive cohort GTCS(s) occurred in 81.3%, absence in 32.8%, and myoclonic seizures in 17.2%. The refractory cohort had the highest rates of absence seizures (37.8%) and GTCS (88.9%); myoclonic seizures occurred in 17.8%. Two thirds (67.7%) of participants began treatment >4 months after first reported seizure activity, with earliest initiation in the newly diagnosed cohort (57.8%). Overall, 30.2% experienced a >12 month delay before initial ASM treatment. The median delay to treatment initiation in this group was 3 years (ranging from 13 months - 22 years). Delay was similar among the 3 cohorts (Well controlled 32.8%, Newly Diagnosed 30.1%, Refractory 26.7%). Among those with >12 months delay to treatment initiation (n=58), the initial seizure type was absence or myoclonic in 70.7%. Of those who later developed GTCSs, 18 (46.2%) had absence, 14 (35.9%) had myoclonic seizures, and 7 (17.9%) had both before their first GTCS. In these cases, diagnosis was delayed until convulsive seizure onset. Only 19 participants had a >12 months delay to initiate ASM and a convulsive seizure before or concurrent with another seizure type.
Conclusions: Diagnosis of epilepsy is often delayed in IGE patients whose initial seizure type is absence or myoclonic. Delay did not seem to impact outcome, as the percentage with delay was similar in treatment sensitive and resistant cohorts. Those with the most significant delays to diagnosis had ongoing absence and/or myoclonic seizures until their first GTCS, which led to diagnosis. Reducing diagnostic delays can reduce morbidity and potentially reduce mortality in IGE patients.
Funding: Supported by: Finding a Cure for Epilepsy and Seizures (FACES), Jazz Pharmaceuticals, One8 Foundation
Clinical Epilepsy