Stimulus aborted periodic epileptiform discharges: A case description and possible relationship with stimulus induced discharges

摘要

An EEG pattern is considered periodic when it consists of discharges recurring at regular or nearly regular interval with an identifiable interdischarge time. If the pattern becomes continuous with no separation between individual discharges, it is considered rhythmic rather than periodic. Ictal discharges are defined as any rhythmic discharges or spike-wave pattern with definite evolution in frequency, location, or morphology. "Epileptiform", a term commonly used in the EEG literature, refers to sharply contoured discharges not necessarily related to seizures (Hirsch et al., 2004). In periodic epileptiform discharges (PEDs) repetitive sharp waves, spikes, or sharply contoured waves are recorded without clear evolution in frequency and location; the abnormalities must recur at regular or nearly regular intervals with an identifiable periodicity. Frequent periodic EEG patterns are classified as: