Ambulatory cassette EEG in epilepsy diagnosis.

The electroencephalographic evaluation of patients with possible or proven epilepsy is no longer limited to routine laboratory EEGs or intensive inpatient monitoring. Expanded temporal sampling of the EEG, which increases the probability of documenting, characterizing, and quantitating the electrographic manifestations of these illnesses, is now available on a portable, outpatient, and less cumbersome inpatient basis by means of ambulatory cassette recordings. The technological advances which have made this technique feasible include small multi-channel tape recorders, miniature preamplifiers, and rapid video/audio playback units. New designs in montages and analysis techniques have made the procedure practical. Clinical series and controlled trials have confirmed the usefulness of cassette EEG monitoring in the evaluation of epilepsy and a wide range of other paroxysmal neurologic disorders. Ambulatory EEG diagnostic yields have been shown to be superior to routine laboratory studies and nearly as good as inpatient telemetry evaluations. The role of cassette recordings in clinical electroencephalography continues to be defined as new applications are established.