A Case of Loss of Consciousness due to Epilepsy Diagnosed Using an Implantable Loop Recorder

We report a case of clonic-tonic seizures diagnosed using an implantable loop recorder, a device for detecting cardiac arrhythmias. A 65-year-old man was referred to our hospital for loss of consciousness with myotonic jerks during sleep. He had experienced several similar episodes. No family history of sudden death was evident, and no structural heart disease was present. Coronary angiography with intracoronary acetylcholine (ACh) showed neither organic stenosis nor vasospastic angina. Ventricular tachyarrhythmias were not induced by programmed electrical stimuli. Sleep electroencephalography, brain magnetic resonance imaging and magnetic resonance angiography revealed no specific findings. We implanted a loop recorder to monitor rhythm abnormalities. One month later, an attack occurred at night. His wife recognized the episode and activated the implantable loop recorder. No arrhythmia was recorded, but myopotentials characteristic of tonic-clonic seizures were detected.