Clinical Characteristics of Epilepsy and Its Risk Factors in Neurofibromatosis Type 1: A Single-Center Study

Abstract

Purpose This study investigated the clinical characteristics and risk factors of epilepsy in patients with neurofibromatosis type 1 (NF1) at a tertiary center. Methods The medical records of 103 children diagnosed with NF1 from February 2009 to July 2019 were retrospectively reviewed. Demographic features, NF1-related features, seizure characteristics, treatment outcomes, and electroencephalography and brain magnetic resonance imaging (MRI) findings were compared between patients with and without epilepsy. Results Among the 103 patients (median age, 11.5 years; age range, 1.0 to 34.8), 14 (13.6%) had epilepsy. The median age of seizure onset was 5.8 years (range, 1.1 to 18.9). Focal and generalized seizures were observed in nine (64.3%) and six (42.9%) patients, respectively. Five patients (35.7%) had a history of status epilepticus and one of them died of it. Two patients (14.3%) had drug-resistant epilepsy. On brain MRI obtained at the time of seizure onset, seven (50%) patients had unidentified bright objects and three (21.4%) had other structural abnormalities. Learning disability (odds ratio [OR], 4.5; 95% confidence interval [CI], 1.17 to 17.5) and a family history of epilepsy (OR, 39.7; 95% CI, 3.78 to 416.53), but not structural abnormalities, were significant risk factors for epilepsy. Conclusion Epilepsy was more common in NF1 patients than in the general population. NF1 patients with epilepsy had various seizure types, but exhibited relatively good outcomes. The types of brain abnormalities were not significantly different between patients with and without epilepsy. Our results suggest that mechanisms other than structural brain abnormalities should be considered epileptogenic in NF1 patients.

Keywords

• neurofibromatosis 1
• epilepsy
• learning disabilities
• risk factors