Monitoring at the Instituut voor Epilepsiebestrijding Meer en Bosch.

A requirement for intensive epilepsy monitoring arose from a demand for ictal EEG registration for diagnostic purposes and in the context of pharmacokinetic research. The monitoring facility developed gradually: first conventional EEG equipment was used on the wards, later miniaturized pre-amplifiers were introduced to allow the patient greater freedom, finally a comprehensive specialized monitoring facility was created with its own accommodation. For most clinical and research applications arising in the Institute intensive observation and video monitoring are necessary. The greater reliability, channel capacity and bandwidth of cable telemetry offer considerable advantages over alternative monitoring techniques as radio telemetry. For recording from patients in locations outside the monitoring unit but where restricted mobility is acceptable a combination of telephone telemetry with a local radio link is used. Synchronization of EEG and video images is achieved by various means, depending on the application: split-screen technique, superimposition of EEG on video images or annotating the paper EEG chart with digital time information derived from the video time-date generator. Buffering of EEG signals is also available by means of a computer disk or a shift register. During the development of the system evaluation studies have been performed showing a progressively increasing yield of clinically useful information. At the most recent assessment, 79% of the investigations answered the clinical question addressed, in 65% of instances the findings had consequences for management and in over 25% the decisions resulting from monitoring had long-term therapeutic benefits for the patient.