Epilepsy in neurofibromatosis type 1

- Epilepsy is common in NF1 and often occurs in patients with brain tumors and mesial temporal sclerosis.
- In NF1 localization-related epilepsy is more common than primary generalized epilepsy.
- In NF1 localization-related epilepsy is usually drug-resistant; primary generalized epilepsy is usually not drug-resistant.
- Patients with mesial temporal sclerosis and NF1 can have coexisting medial temporal lobe cortical dysplasia.
- Patients with mesial temporal sclerosis and NF1 can be good surgical candidates.

ObjectivesTo describe the characteristics of epilepsy in patients with Neurofibromatosis type 1 (NF1).MethodsAnalysis of a cohort of consecutive NF1 patients seen in our NF1 clinic during a three-year period.ResultsOf the 184 NF1 patients seen during that period, 26 had epilepsy and three had febrile seizures. Of the 26, 17 (65%) had localization-related epilepsy, seven of whom (41%) were drug resistant. Six (23%) had apparently primary generalized epilepsy (0/6 drug resistant), two (8%) Lennox-Gastaut syndrome, and one (4%) West syndrome (all three were drug-resistant). As compared to the patients with no epilepsy, those with epilepsy were more likely to have MRI findings of mesial temporal sclerosis (MTS) (23% vs. 5%, p = 0.0064), and cerebral hemisphere tumors (31% vs. 10%, p = 0.0079), but not of the other MRI findings including neurofibromatosis bright objects, or optic gliomas. Three of the six patients with MTS underwent temporal lobectomy with subsequent control of their seizures with confirmation of MTS on pathology in 3/3 and presence of coexisting focal cortical dysplasia (FCD) in 2/3. We also have observed three additional patients outside the above study with the association of NF1, MTS, and intractable epilepsy.SignificanceEpilepsy is relatively common in NF1, often occurs in patients with brain tumors or with MTS which can coexist with FCD, can be associated with multiple types of epilepsy syndromes, and when localization-related is often drug-resistant. Patients with NF1 and MTS can respond to medial temporal lobectomy and may have coexisting medial temporal lobe cortical dysplasia.