Clinical indications and diagnostic yield of video-electroencephalographic monitoring in patients with seizures and spells.

Video-electroencephalographic (EEG) monitoring is an important neurodiagnostic technique that may be used for selected patients who present with recurrent and unprovoked spells. For most patients who have epilepsy, the "routine" EEG is sufficient for physicians to classify seizure types and initiate medical therapy; however, routine EEG has substantial limitations for approximately 20% of patients who do not have epilepsy but are referred to comprehensive epilepsy programs because of medically refractory "seizures." These patients may have physiological or psychological disorders that may cause diagnostic confusion with epilepsy and result in the patients being treated unnecessarily with antiepileptic drugs. Video-EEG monitoring, ie, ictal EEG monitoring, performed either on an outpatient basis or in an epilepsy monitoring unit, can help physicians identify ictal EEG patterns that may be necessary for classifying seizure types and determining surgical localization. The sensitivity and specificity of EEG recordings during clinical episodes are superior to those of the routine interictal EEG. Video-EEG monitoring may prove to be an essential procedure for helping physicians confirm diagnoses of seizure disorders, classify seizure types, and select surgical candidates who have intractable epilepsy.