Periodic EEG patterns observed in two cases with partial seizures.

Two cases with partial seizure and periodic EEG pattern were reported. Case 1. A 74-year-old woman reveal typical periodic lateralized epileptiform discharges (PLED's) on the right hemisphere. The patient was semicomatous with mild jaundice and epilepsia partialis continua in the left lower limb. Postmortem examination revealed a main metastatic carcinoma of pancreas head origin in the right parietooccipital region. In the right hemisphere, the cortical structures were relatively preserved, but the white matter including the frontal lobe was swollen and its demyelinating changes were observed diffusely. The PLED's might result from an anatomical or functional severance of the cerebral cortex from normal connections with deeper structures. Case 2. A 61-year-old woman, with idiopathic hypoparathyroidism showed partial complex seizure. The EEG revealed an anterior temporal spike focus and slowing in the right hemisphere, corresponding with repetitive seizures of about one minute duration and with several minutes interval. An interictal periodic EEG pattern appeared in the right anterior and mid-temporal region. No cerebral abnormalities were found with other neurological examinations including brain scanning, carotisangiogram, and echoencephalogram. The periodic pattern was assumed as subclinical focal seizure discharges from the right anterior temporal deep structures.