Abstracts

Rationale: In this study we sought to describe and characterize the association between neurofibromatosis type 1 (NF1) and focal epilepsy due to medial temporal sclerosis (MTS). Methods: We analyzed the clinical, EEG, video EEG when available, MRI and pathological findings of a cohort of sequential NF1 patients (n = 184) seen in our center during a 3 year period. Results: Of the 184 NF1 patients seen during a 3 year period, 26 had epilepsy. Of the 26, 17 (65%) had localization-related epilepsy, 7 (41%) of whom were drug resistant. As compared to the patients without epilepsy, those with epilepsy were more likely to have MRI findings of MTS (23% vs. 5%, p=0.0064), and cerebral hemisphere tumors (31 % vs. 10%, p=0.0079, Fisher Exact Test).  Only 1 out of the 6 patients with both epilepsy and MTS had been referred for intractable epilepsy to our center; the remaining 5 had originally been referred for their other concerns separate from their epilepsy. Upon eliminating the patient specifically referred for epilepsy from the analysis, repeating the Fisher Exact test still demonstrated a statistical difference (p = 0.019), emphasizing the association of epilepsy in NF1 and MTS. 3 of the 6 patients with MTS underwent temporal lobectomy with subsequent control of their seizures. 3/3 patients who underwent surgery had confirmation of MTS on pathology, and 2/3 patients had coexisting focal cortical dysplasia (FCD). Furthermore, outside of the above study we have also observed 3 additional patients who demonstrate again the association of NF1, MTS, and intractable epilepsy. Conclusions: Epilepsy  in NF1 often occurs in patients with MTS. Patients with NF1 and MTS can respond to medial temporal lobectomy, and may have coexisting focal cortical dysplasia. Funding: No funding was received in support of this abstract.