Retrospective inventory of EEG abnormalities in partial status epilepticus.

In this retrospective study, EEG activity in partial status epilepticus (PSE) was classified into different patterns from analysis of both ictal and interictal discharges. In 64 patients with recorded PSE, continuous seizures and closely spaced seizures interrupted by only brief flat periods were uncommon. PLEDs, defined as classic periodic lateralized epileptiform discharges, and PLEDs Plus, defined as PLEDs associated with stereotyped low amplitude, were the most common abnormalities. PLEDs and PLEDs Plus can each occur alone or sequentially (sequential PLEDs) between consecutive seizures. The quantity of ictal activity was significantly lower with PLEDs, sporadic spikes and with the absence of epileptiform abnormalities than with PLEDs Plus and sequential PLEDs. EEG monitoring is important to gauge the effectiveness of treatment, particularly in patients with patterns associated with a high incidence of seizure activity, namely continuous seizures with or without flat periods, sequential PLEDs and PLEDs Plus. From serial recordings, a sequence was reconstructed which may be relied upon to further assess the need for additional energetic therapeutic measures. The reconstructed sequence differed in patients with chronic lesions since sequential PLEDs and PLEDs Plus were identified exclusively in patients with acute or subacute lesions.