Ipsilateral independent periodic lateralized epileptiform discharges.

We have identified a previously unreported subtype of periodic lateralized epileptiform discharge (PLED) characterized by periodic discharges arising from ipsilateral independent foci. All 4 patients had acute cerebral lesions, and 3 of them had focal motor seizures with secondary generalization. The site of localization of the PLEDs corresponded to the boundaries of the underlying structural lesion or lesions, and this, together with the variable temporal relationship between them, supports a cortical origin for PLEDs associated with underlying lesions. the spatial and temporal independence of these periodic discharges in combination with their association with (1) acute cerebral lesions. (2) altered consciousness and seizures, and (3) resolution with time leads us to propose the term "IpsiIPs" to describe this subtype of PLEDs.