Abstracts

Rationale: Although accounting for 1-10% of childhood epilepsies, limited literature exists about Lennox-Gastaut Syndrome (LGS) persisting in adults. International League Against Epilepsy (ILAE) has classified LGS as an epileptic encephalopathy, with initial seizures occurring during 1-8 years of age. It is considered to be one of the most severe and refractory forms of epilepsy with all patients having moderate to severe degree of cognitive deficits. The classic triad for LGS is early onset of multiple seizure types, generalized slow spike-wave pattern on EEG and moderate to severe cognitive deficits. However, not all elements of the triad are present during adulthood and there is no characteristic description of the seizure that prompts the clinician to consider the diagnosis of LGS. Methods: We reviewed the clinical description and EEG records, including video recordings, for a three-year period, of patients that fit the clinical criteria of LGS but did not always have a formal diagnosis of LGS. Patients had long-standing history of poorly controlled seizures and moderate to severe cognitive deficits. Some of the patients had atonic seizures as well as complex partial seizures. All of them were on multiple anti seizure medications and in some cases, had a history of Vagus Nerve Stimulator (VNS) placement and prior surgery for seizures. Results: In our small series of 12 patients, we found certain clinical features during seizures, which appeared to be consistent in all the patients. (We will have a list of semiology of each patient s seizure in the poster as well as a typical representative clinical event on video for presentation) All of these patients exhibited brief episodes (lasting 10-30 seconds) of seizures. The onset was mostly with one or both upper extremity tonic extension and posturing, with flexion at the wrists associated with head turning to one side. Review of EEG in all of these patients showed inter-ictal activity of spike wave discharges which were symmetrical at times and lateralized at other times. Ictal activity showed generalized large amplitude slowing in the delta-theta range, followed by bilateral polyspike activity. Conclusions: The phenomenon of brief unilateral or bilateral upper extremity tonic extension with flexion at wrists and head turning to one side maybe a characteristic phenomenon in adult LGS patients and assist in proper classification of seizures as Lennox-Gastaut Syndrome. This is important as ensuring correct diagnosis has significant therapeutic and prognostic implications.