Abteilung Prächirurgische Epilepsiediagnostik – EpilepsiezentrumKlinik für Neurochirurgie

Cognitive outcome after resective epilepsy surgery in children with focal cortical dysplasia

This is a clinical study aimed to find information about factors influencing cognitive outcome after resective epilepsy surgery in more than 100 children with focal cortical dysplasia followed 1.5-17 years after surgery.

One of the major comorbidities of epilepsy in children is the presence of cognitive impairment. Both seizures and cognitive impairment can have an effect on the psychosocial outcome, so both have to be taken into consideration in determining the success of resective epilepsy surgery in children. However, there is still a lack of information about factors influencing cognitive outcome after epilepsy surgery in children, for multiple reasons: many studies comprise of small samples of patients, and these samples are often heterogeneous, mixing not only patients with different etiologies, but also patients with very different clinical situations, i.e. infants or young children with severe epilepsies and older patients, for which surely the concept of "early enough" might not be the same. And, especially in children, there is a need for long-term follow-up studies. This information might help determine whether there is a best time to perform surgery based not only on seizure outcome but on cognitive outcome.

The strengths of the present study are the size of the sample, to our knowledge one of the largest reported - the Freiburg Epilepsy Centre having a large experience in the management of children and adults with focal cortical dysplasia (Fauser et al., 2015) -, the homogeneity of etiology, and the long-term follow-up. Main limitation is the lack of an appropriate control group of non-operated children to determine whether changes over time after surgery are an effect of surgery and/or seizure outcomes.

Patients with structural epilepsy due to FCD undergoing surgical treatment will be identified from electronic charts. Inclusion criteria are: (1) age at surgery younger than 18 years; (2) epilepsy diagnosis confirmed by video-EEG monitoring; (3) surgical treatment at the University Hospital in Freiburg between 1999 and 2015, (4) histological confirmation of FCD, based on resected specimens; and (5) clinical follow-up of at least 18 months.

After informed consent patients’ clinical data will be collected and analyzed, particularly the age at epilepsy onset/surgery, the severity of the epilepsy, the etiology, the site and extent of the lesion/resection and the results from neuropsychological assessment before and after surgery and at last follow-up.