Abstract
Occipital lobe epilepsy (OLE) is one of the symptomatic partial epilepsies (SPE), and is associated with ictal visual symptoms in general. However, it is very difficult to diagnose OLE, because (1) the boundaries of the occipital lobes are vague, (2) epileptic discharges originating from the occipital lobes spread into other lobes easily, (3) seizure manifestations of OLE are complex. We studied about 10 patients who had undergone simultaneous recording of EEG and magnetoencephalography (MEG), and whose dipoles localized in the occipital lobes. They were divided into three groups, the mesial type, the lateral type, and mixed type. We examined the relation between clinical symptoms and dipole localizations in these cases. Mesial type patients had elementary hallucinations such as phosphenes, and the lateral type had complex hallucinations. Visual hallucinations (elementary or complex) may be useful in inferring both localization and extent of epileptogenesis.
