[Short sleep on the EEG--a source of otherwise overlooked EEG abnormalities]

A short sleep portion in an otherwise routinely performed EEG evaluation is often highly informative. This is particularly true for epileptological conditions. Several paroxysmal discharges are demonstrable solely in sleep and/or drowsiness; these potentials remain undetected in a waking tracing. Hence the inclusion of a sleep portion may be crucial in the assessment of epileptic seizure disorders but tends to yield less information in non-epileptic conditions. Sedation (Chloral Hydrate) is recommended if sleep does not occur spontaneously.