Abstracts

Rationale: Epilepsy in children is common and may be associated with considerable medical and social morbidity. Focal seizures may arise from any region of the brain and accurate identification opens up medical and surgical treatment options that may cure or remit seizures. Occipital spike activity is more common in children compared to adults and may reflect a very heterogeneous group of epilepsies including benign focal epilepsies of childhood (BFEC) which are age dependent electroclinical syndromes. The two most commonly described BFECs of childhood are benign childhood epilepsy with centrotemporal spikes (BCECTS) and benign childhood epilepsy with occipital paroxysms (BEOP). In addition occipital spikes may be seen in symptomatic epilepsies due to brain metabolic disorders or lesions. There are limited detailed studies of seizure semiology, the scalp EEG and MRI imaging to define specific pediatric etiologies in pediatric occipital lobe epilepsy. We aimed to study detailed clinical semiology and scalp EEG findings of both benign and symptomatic variants in children with occipital lobe epilepsy to provide diagnostic and therapeutic approaches. Methods: All pediatric patients (<16 years) with occipital spikes recorded between January 2008 to October 2011 in the neurophysiology department Rainbow Babies and Children's University Hospital were selected. Spikes were analysed according to morphology, localization, changes with eye closure, sleep, photic stimulation. Where available ictal patterns were also analysed. Seizure semiology was analysed with regard to visual auras, lateralizing signs, motor, autonomic and other features. The benign group was defined based on published spike characteristics. The symptomatic group was defined by the presence of MRI pathology. Results: 32 patients were studied, 50% (16/32) were symptomatic, 50% (16/32) had BEOPs studied at age 5.89 (±4.83) and 7.8 (±6.6) years of age retrospectively. Autonomic symptoms were predominantly seen in the benign goup (2/16), versive (7/16) and tonic clonic seizures (6/16) were more frequent in the symptomatic patients. ESES was seen in both symptomatic (4/16) and benign (2/16) patients. MRI pathologies found in the symptomatic ischemic and developmental lesions such as heterotopia, tubers, focal cortical dysplasias Focal slowing (7/16), more extensive spike localization and bilateral spikes (16/16) were frequent in the symptomatic cases. Conclusions: Seizures and EEG findings in children with BEOPs and occipital spikes associated with MRI pathology occured equally in 32 pts studied. ESES was seen in both groups. Motor features and more widespread spike localization and focal dysfunction were more prominent in the symptomatic group suggesting involvement of a more widespread epileptogenic network.