Epilepsy in Neurofibromatosis: Prevalence in Adults, Phenotype, and Genotype
Abstract number :
2.38
Submission category :
16. Epidemiology
Year :
2022
Submission ID :
2205122
Source :
www.aesnet.org
Presentation date :
12/4/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:28 AM
Authors :
Julien Hebert, MDCM, MSc, FRCPC – Columbia University Irving Medical Center; Robert De Santis, MD – University of Toronto; Raymond Kim, Md, PhD, FRCPC – University Health Network; Vera Bril, MD, FRCPC – University Health Network; Aylin Reid, Md, PhD, FRCPC – University Health Network
Rationale: Neurofibromatosis type 1 (NF1) is a rasopathy associated with neurocutaneous, systemic, and neurological manifestations, in particular low-grade glioma (notably optic glioma). There is currently a paucity of data on the prevalence of epilepsy in adult patients with NF1. There is also scant data on the association between genotype and epilepsy in this disorder.
Methods: Patients ≥18 years old seen at the Elisabeth Raab Neurofibromatosis Clinic of the Toronto General Hospital (Toronto, ON, Canada) and meeting diagnostic criteria for either NF1, Neurofibromatosis type 2 (NF2), or Schwannomatosis were prospectively enrolled between January 1, 2017, and December 31, 2020. Patients with NF2 and Schwannomatosis were used as a control, with the main focus of analysis being NF1. Each patient underwent a scalp routine electroencephalogram and, if not already performed, a brain MRI. A diagnosis of epilepsy was established based on the 2014 International League Against Epilepsy (ILAE) operational definition of epilepsy. Genetic sequencing for NF1, NF2, and schwannomatosis was offered to all patients by the clinic’s medical geneticist. Fischer exact test was used to compare categorical variables and Wilcoxon Rank Sum test for continuous variables.
Results: One hundred and twenty eight patients were included in this study: 113 (88%) had NF1, 10 (9%) NF2, and 5 (4%) schwannomatosis. For the main group of interest (NF1), the median age at the time of inclusion in this study was 33 (range 11-71) years. Thirteen patients (12% of NF1) had epilepsy; no patients with NF2 or Schwannomatosis (control group) had epilepsy. Patients with a learning disability were more likely to have seizures than those without (p< 0.01), as were patients with low-grade glioma (not including optic glioma, p=0.05). The presence of Focal Area of High Signal Intensity (FASI) was not associated with epilepsy (p=0.22). Most patients with epilepsy (80%) had focal seizures, with one patient having a Juvenile Myoclonic Epilepsy (JME) phenotype. Of the 12 patients with epilepsy who underwent genetic testing, all had loss-of-function mutations. No missense mutations were noted.
Epidemiology