P03-T A review of patients with possible Occipital-lobe-seizures (OLS) seen at University-Hospital-of-Wales (UHW) in 2018

Abstract

Introduction Patients having experienced OLS describe their seizures as featuring bright colours, and severe blurring of their vision, occasionally ictal vomiting, deviation of the eyes, and hypersalivation with or without impairment of consciousness. OLS are thought to account for between 5% and 10% of epilepsies with photo-sensitive epilepsies occurring in 1–5% of epilepsies. Method EEG’s including prolonged, sleep deprived and video monitoring EEG’s including (where appropriate) hyperventilation and photic-stimulation were reviewed in 929 patients referred at the UHW during 2017–2018. Results Four patients were found to have evidence of occipital lobe seizures. One was a juvenile patient with suspected idiopathic occipital lobe epilepsy. One patient was found to have posterior temporal/occipital lobe abnormality on Magnetic Resonance Imaging as a result of childhood injury. MELAs and concordant occipital stroke were thought to be the cause of the third patient. The final patient has been treated intensively because of injury due to collapse. Vomiting was not a feature of any seizure semiology. Hypersalivation and spitting were observed late into the seizure of one patient (spread temporally with secondary generalization). All described visual disturbance ranging from simple colored 2-dimensional shapes in the vision to more complex kaleidoscopic manifestations. Electrographic correlate was similar comprising repetitive sharp wave discharges. Conclusion Although thought to account for 5–10% of epilepsies, we at UHW (the largest teaching hospital in Wales) found OLS accounted for a very small percentage of confirmed epilepsies.