Sudden loss of consciousness is a common presenting symptom in clinical neurology. Differential diagnoses include syncope and epilepsy. Distinguishing the two may be difficult when syncopes are followed by convulsions [1] or when epileptic seizures have vegetative symptoms like ictal asystole [2]. A 55-year-old woman presented to our epilepsy center with persistent spells of loss of consciousness after implantation of a cardiac pacemaker in the previous year. She had had three episodes of sudden loss of consciousness and subsequent falls. After routine cardiological work up, including 24 h ECG, did not reveal any abnormalities, a cardiac event monitor was implanted and documented 12 asystoles of up to 9 s duration, some of them associated with syncope. She was diagnosed with a sick-sinus syndrome, and had a cardiac DDDR-pacemaker implanted. No more falls occurred after that, but the patient had episodes where she would perform inadequate manual automatisms and wander about aimlessly. The patient herself was amnesic for these events. Her past medical history was non contributory. A cranial MRI and a routine EEG had been without abnormal findings. We admitted the patient to our epilepsy monitoring unit for differential diagnosis of her spells. We recorded one seizure, beginning with an unspecific aura followed by loss of responsiveness and manual automatisms. Within 4 s after clinical onset, she was tachycardic at 120 beats/min (bpm). We recorded a right temporal seizure pattern 12 s after clinical onset, which evolved into a left temporal seizure pattern 25 s later. Coinciding with the beginning of the left temporal seizure pattern, the heart rate slowed down to below the pacemaker’s sensing frequency of 60 bpm and the pacemaker started stimulation. Twentyfive seconds after the end of the seizure pattern, the heart regained full sinus node activity (Fig. 1). A high resolution MRI did not reveal any pathology. We diagnosed right temporal lobe epilepsy, and started levetiracetam (2,500 mg daily). She has been seizure free for 12 months now. The cardiac pacemaker was read out and it had not been active during that time. Our patient illustrates the difficulties that may be encountered in the differential diagnosis of syncope and epilepsy. Our patient’s leading symptom was sudden loss of consciousness and falls, which eventually led to the implantation of a cardiac pacemaker. Only then were her epileptic seizures—characterized by loss of responsiveness and mild automatisms—unmasked, because the ictal asystole was averted by the pacemaker, preventing the syncopal fall. Even though the patient has been seizure free for 12 months, and the pacemaker has not been active in that time, we believe that the pacemaker was necessary in any case, because asystoles may not revert on their own and may be associated with sudden unexpected deaths in epilepsy patients [3]. Ictal asystole is mostly associated with left hemispheric seizure activity [4], which was the case in our patient, when the seizure pattern propagated from right to left. She would have become asystolic, which was prevented only by the pacemaker. Ictal tachycardia, when not due to physical exertion or emotional distress, lateralizes to the right hemisphere [5], which was the case in our patient as well. Our patient demonstrates that vegetative symptoms of temporal lobe epilepsy such as syncopal falls due to ictal J. Remi S. Noachtar (&) Epilepsy Center, Department of Neurology, University of Munich, Marchioninistr 15, 81377 Munich, Germany e-mail: noa@med.uni-muenchen.de