Abstracts

Rationale: Frequency and epilepsy characteristics including definition of the epileptogenic zone in patients with autism spectrum disorders (“autism”) in a neuropediatric clinic and pediatric epilepsy center.Methods: Retrospective analysis of all patients older than 4 years (about 7000 patients) treated at our center between 1990-2006. Only those patients were included who at a minimum had a wake- and sleep-EEG and a MRI. Autism was diagnosed by a child epileptologist and child psychiatrist. 40 patients with autism underwent presurgical evaluation including video-EEG-monitoring.Results: 101 patients (age range 4-21 years; mean 9.4 years; 66 male, 41 female) had autism. 85% were severe mental retarded, 8.9 % were not able to walk independently. 85/101 patients (84%) had epilepsy, 2 (2.5%) electrial status epilepticus during slow sleep (ESES) without seizures. Most common etiologies were: focal cortical dysplasia (30%), asphyxia / prematurity (12%) and SCN1A-mutation (6%). In 65% of our patients with autism the manifestation of the first seizure was within the first year of life. Classification of epilepsy: 54% symptomatic focal epilepsy, 17% symptomatic generalized, 4% idiopathic focal, 4% idiopathic generalized, 5% Dravet syndrome. Seizure onset zone: 28% bilateral , 19% hemispheric, 17% temporo(-parieto)-ocipital, 11% temporal, 4% frontal, 2% occipital, 18% not classified. In 28% of the patients the epileptogenic zone was within the right and in 20% within the left hemisphere; in 44% the zone could not be defined or seizure onset was bilateral. Epilepsy surgery was performed in 25 patients with a seizure outcome of Engel I in 44%, II in 17 %, III in 9% and IV in 30%.Conclusions: In this highly selected sample, the majority of patients with autism had a symptomatic epilepsy and a severe mental retardation. Most of them were able to walk independently. In accordance with the literature, most of our patients were also characterised by an early manifestation of epilepsy within the first year of life and an involvement of the temporal lobe in the epileptogenic zone. No other specific risk factors were found. A higher rate of autistic children than usual in our center did not get seizure free by epilepsy surgery. Both the early diagnosis of autistic regression in patients with epilepsy and a detailed work up of epilepsy in patients with autism are necessary and have therapeutic implications.