Clinical correlations of occipital epileptiform discharges in children

Objectives: To determine the frequency of different causes of occipital epi leptiform discharges (OEDs) in children and to analyze the EEG features tha t help predict epilepsy type and prognosis. Methods: We identified children with OEDs in the absence of other focal discharges using an EEG database a t our center; the presence of generalized spike-wave discharges (GSW) or sl owing was not an exclusion criterion. Diagnosis, neurologic status, seizure semiology, and seizure remission status were recorded. Results: Of 90 pati ents with OEDs, 50 (56%) had symptomatic seizures (18 with cerebral palsy, 11 with cerebral dysgenesis, 8 with genetic abnormalities); 31 (34%) had id iopathic seizures, including 6 with benign childhood epilepsy with occipita l paroxysms (BCEOP), 8 (9%) had no seizures; and 1 (1%) had febrile seizure s. Only two reported ictal visual symptoms. Eighty-seven percent with backg round slowing had symptomatic seizures, and 87% with normal backgrounds had idiopathic seizures (p < 0.001). Of 72 children with seizures and adequate follow-up, 28 of 45 (62%) with a normal background experienced seizure rem ission compared with 10 of 27 (37%) with background slowing (p = 0.04). Twe nty of 81 patients with epilepsy had GSW. Twelve (60%) of the 20 GSW-positi ve patients had idiopathic epilepsy compared with 19 of 61 (31%) without GS W (p = 0.02). Conclusions: Most epilepsy in referred children with OEDs is symptomatic; syndromes such as BCEOP are rare. Visual ictal symptoms are ra re. The presence of GSW or a normal background rhythm correlates with idiop athic seizures and a better prognosis.