Abstracts

Rationale: Seizures are reported to complicate Neurofibromatosis 1 (NF1) in 3-6% of patients. Our experience suggests a somewhat higher incidence. Our objective was to examine the incidence and characteristics of seizures in a large group of NF1 patients. Methods: We reviewed medical records from 1287 consecutive patients with NF1 (ages 1 wk to 81 y), evaluated at the University of Chicago over the last 22 years. Results: 15.9% of patients with NF1 had a history of seizures. The age of onset was <1y.o. in 11%, 1-10y.o. in 37%, 11-18 y.o. in 17% and >18y.o. in 20%, with no age of onset recorded in 15%. In only 5% did the seizures occur exclusively with fever. The seizures were described as clonic in 55% and staring or confusional episodes or sleep disturbances in 23%. No description was available in 22%. EEG classification demonstrated that the seizures were partial complex in 37% and primary generalized in 13%. For the remainder, the EEG was either normal (25%) or unavailable. In only 13% of patients, seizures were due to identifiable injuries such as a vascular insult, meningitis, or tumor. Conclusions: Seizures occur frequently in NF1. They have several peak times of onset with a significant percentage occurring in late teenage and adult years. Seizures can be subtle and often overlooked. Prolonged video EEG recording is invaluable in assessing seizures in this population. The etiology of the seizures remains unclear in the vast majority of patients.