Long term outcome of Lennox-Gastaut syndrome

Abstract

I performed a long-term follow-up study in patients with Lennox-Gastaut syndrome (LGS). Sixty-eight patients that were more than 18 years of age were included in this study. The type of seizure, seizure frequency, electroencephalography (EEG) characteristics, cognitive function, motor disability, treatment and seizure outcomes were evaluated. Patients were aged 18.7 to 35.8 years (mean 23.0 years) and the follow-up duration ranged from 8.3 to 32.5 years (mean 19.3 years). Seizures and EEGs changed with age. Although the seizure frequency and intensity decreased, 76.5% of the patients sustained seizures, which were mainly generalized tonic, atonic or generalized tonic-clonic seizures. The age at seizure onset, etiology, brain magnetic resonance imaging (MRI) abnormalities and history of infantile spasms were not associated with seizure outcomes. Characteristic EEG features of diffuse slow spike-wave (DSSW) and generalized paroxysmal fast activities (GPFA) disappeared in half of the patients. In regards to cognitive function, 94.7% of the patients exhibited moderate to profound mental retardation that was independent of many clinical factors or seizure outcomes. Only 39.7% of the patients had independent daily living skills and 25.4% could not walk even with support. Although LGS is a form of intractable epilepsy, applying diverse treatments including ketogenic diet and surgeries to the patients that have had other unsuccessful treatments can lead to more successful seizure control.