A Comparative Study of EEG Findings of Photosensitive Generalized and Foca/ Epilepsy Syndromes

Abstract

Background: Photosensitivity has been observed in generalized epilepsies, such as Juvenile Myoclonic Epilepsy (JME), as well as focal reflex epilepsies, including newly reported ldiopathic Photosensitive Occipital Lobe Epilepsy (IPOLE). Generalized and focal EEG findings have been reported in both groups, with the varying degrees.Objective: To compare EEG findings in photosensitive generalized and focalepilepsy syndromes.Method: EEG recordings with the standardized intermittant photic stimulation.Findings: Total 47 EEGs of J 5 JME and 10 IPOLE cases were reviewed. Generalized discharges were identified in 66% of JME patients, whereas those were identified in 40% of IPOLE group. Focal discharges were observed 20% in JME and 50% in IPOLE groups. Photoparoxysmal Responses (PPR) were prominent in anterior areas in JME (60%), and in posterior areas in IPOLE patients (90%).Conclusion: Similarities among EEG findings may support common mechanisms in ictogenesis. However, differences in localization and duration, regularity, frequency and morphology, resulting in different clinical pictures, may indicate further mechanisms to be evaluated.