Periodic lateralized epileptiform discharges (PLED's) and nystagmus retractorius

A 57-year-old diabetic woman presented with focal right-sided seizures and hyperglycemia. She later showed periodic lateralized epileptiform discharges (PLEDs), originating in the left hemisphere, which were temporally associated with nystagmus retractorius. It appears that the left hemisphere epileptiform activity diffusely excited brainstem structures via polysynaptic pathways to produce the nystagmus.