Abstracts

Patients of all ages present with episodes that may or may not be seizures. Diagnosis is further complicated in those with already diagnosed alternate seizure types and those with abnormal EEGs (especially in pediatrics where certain syndromes can be outgrown and where epileptiform activity can be markedly activated by sleep). Prolonged EEG monitoring can be helpful, especially if events are captured. Does ambulatory EEG without video provide adequate information, or should most such patients be admitted to epilepsy monitoring units?, All ambulatory EEG reports (including brief history, medications, clinical question posed, as well as summaries of patient diaries [if returned]) performed at Virginia Commonwealth University during 2005 were reviewed. Patient ages ranged from 4 to 79 years., 122 ambulatory EEG reports were reviewed.
20 of these were for periods of altered responsiveness without unusual movements in patients without confounding features. 14/20 were normal, with 5 recordings that captured the events of suspicion. 1/20 had intermittent slowing. 4/20 had rare generalized spike/wave discharges. 1/20 had possible ictal runs and it was suggested that EMU admission be considered. Of the remaining 102 recordings, 65 were of patients who were already on anti-epileptic drugs (AEDs) for seizures and had non-stereotypic or increasing events.
8 recordings were done to see if medications had altered the density of spike/wave discharges or stopped continuous spike wave of slow wave sleep (CSWS), or if pts had outgrown absence seizures.
In 7 out of the 122 reports, a suggestion for video-EEG monitoring was made. Two were to further elucidate already identified tonic seizures or bursts of generalized repetitive spikes with intermixed slowing (portions with disorganized background could not always be identified as artifactual or ictal). Two were in pts who had had cranial surgery or surgery plus recent stroke with very abnormal baseline recordings where transitions to sleep/arousals were possibly ictal, with significant artifact making interpretation difficult. Two recordings showed possible focal ictal activity, one in a pt with [italic]trouble with eyesight [/italic]over a four hour period, and one with no reported problems during the periods involved. One pt had one second epochs of slowing with intermixed spikes (no seizures were seen; no diary had been returned)., Out of 122 ambulatory recordings, only 5 were considered by the reviewers to be inadequate for accurate evaluation of possible seizure activity. 2 had very abnormal background (s/p cranial damage at more than one site) at the start. Three had suspicious activity that might have been more accurately interpreted if simultaneous video was available. (Others suffered from lack of capture of the events of suspicion, which is a problem in the EMU as well.) Thus, ambulatory EEG does prove to be a valuable tool for identifying ambiguous clinical events as epileptic or not.,