Spikes might precede seizures and predict epilepsy in children with Sturge-Weber syndrome: A pilot study

Sturge-Weber syndrome (SWS) is a neurocutaneous disorder characterized by a facial port-wine stain, a glaucoma, and a leptomeningeal angioma. Epilepsy occurs in more than 75% of affected children, and seizures occurring in the first year of life are associated with a poor neurological prognosis. The aim of this study was to identify possible predictive markers of epilepsy on electroencephalogram (EEG) performed prior to seizure onset in children with SWS.

This study included children with a diagnosis of SWS who had an EEG performed prior to seizure onset. Patients who did not develop epilepsy had a minimum follow-up of 3-years. We compared EEG characteristics of patients who developed epilepsy with patients who did not develop epilepsy by the time of their follow-up.

Eleven children were included in this study. EEG was performed at the median age of 2.1 months (range 1.0-22.1). Six children developed seizures with a time interval between EEG and seizure onset ranging from 2 days to 21 months. EEG background activity was asymmetric in 8 patients, 5 of whom later developed epilepsy. Focal interictal spikes or sharp waves were exclusively recorded in patients who developed later epilepsy (4 out of 6). One of these patients had a supposed false positive EEG as he did not developed epilepsy until 21 months later and one patient had a false negative EEG with seizures occurring 2 days after a normal EEG.

Spikes on EEG might be a useful marker to identify patients with SWS at risk of developing epilepsy. Their predictive value should be assessed in larger prospective studies.