RE CULL

SUMMARY The relative merits of 24-hour ambulatory EEG/ECG monitoring and routine EEG recording have been compared in a group of 62 patients attending a neurological clinic because of episodes of loss of consciousness. Overall, ambulatory EEG abnormalities were detected in 21 cases (34%) compared with 16 cases (26%) for routine EEG. Ambulatory EEG mainly improved the detection of generalised paroxysmal activity, but in some cases lateralised abnor-malities were detected which were not present on the routine record. Patients who reported clinical attacks once a week or more frequently showed an improved yield of diagnostic abnor-malities on ambulatory EEG, but the technique did not prove superior to routine EEG if attacks were less frequent. The indications for, and limitations of, ambulatory EEG monitoring are discussed. Over the past 8 years technical equipment has become available for the prolonged monitoring of EEG and ECG in ambulant patients, enabling a continuous 24-hour record of up to four data chan-nels to be stored on a single magnetic tape cas