MR Imaging–Compatible Electroencephalography Electrode System for an Epilepsy Monitoring Unit

SUMMARY: We studied the usefulness of an MR imaging–compatible electroencephalography (EEG) electrode system for continuous EEG recordings in our epilepsy monitoring unit (EMU) by comparing 100 consecutive patients with MR imaging–compatible and MR imaging–incompatible EEG recording electrodes who underwent MR imaging between 3:00 PM and 7:00 AM. The MR imaging–compatible system captured seizures in 21/50 (42%) patients and clinically valuable new electrographic data in 13/50 (26%) patients during the study interval, whereas possible seizures were lost to recording in 19/50 (38%) patients in the MR imaging–incompatible system. EEG recording was comparable by both systems, but the nurses could disconnect and reconnect the patients to their electrode cables only in the MR imaging–compatible system during the study interval while the EEG technologists were off duty. This study shows that the MR imaging–compatible system could be used routinely for long-term monitoring of the patients in EMUs. Although electroencephalography (EEG) remains the pri-mary tool in the investigation of patients with epilepsy, MR imaging studies are essential for the evaluation of patients with medically intractable epilepsy.1 For patient safety2 and to avoid distortion of the images, EEG electrodes are routinel