Epilepsy and electroencephalographic abnormalities in SATB2-associated syndrome (SAS)

Objective Seizures are an under-reported feature of the SATB2-associated syndrome (SAS) phenotype. This study aims to describe the electroencephalographic (EEG) findings and seizure semiology and treatment in a population of individuals with SAS. Methods We performed a retrospective review of 101 individuals with SAS who were reported to have had a previous EEG study to identify those that had at least one reported abnormal result. For completeness, a supplemental survey was distributed to the caregivers and input from the treating neurologist was obtained whenever possible. Results Forty-one subjects were identified as having at least one prior abnormal EEG. Thirty-eight individuals (93%) had epileptiform discharges, 28 (74%) with central localization. Sleep stages were included as part of the EEGs performed in 31 individuals (76%) and epileptiform activity was recorded during sleep in all instances (100%). Definite clinical seizures were diagnosed in 17 individuals (42%) with a mean age of onset of 3.2 years (4 months to 6 years) and focal seizures were the most common type of seizure observed (42%). Six subjects with definite clinical seizures needed polytherapy (35%). Delayed myelination and/or abnormal white matter hyperintensities were seen on neuroimaging in 19 individuals (61%). Conclusions Epileptiform abnormalities are commonly seen in individuals with SAS. A baseline EEG that preferably includes sleep stages is recommended during the initial evaluation of all individuals with SAS, regardless of clinical suspicion of epilepsy.