An unusual case of loss of consciousness: when an epileptic brain let the heart slow down

The differential diagnosis of an episode of transient loss of consciousness can be sometimes very tricking, in particular when symptoms peculiar of syncope are mixed with focal neurological symptoms. We report the case of a 54-year-old woman who suddenly claimed, during a polygraphic recording (electroencephalography/electrocardiogram), a feeling of fear and tachycardia followed by loss of consciousness and then a tonic posturing of the left limbs. Polygraphic recording showed a critical electroencephalographic pattern starting from left temporo-zygomatic channels followed after few seconds by a sudden slowing of cortical background activity associated with an episode of asystole, as witnessed simultaneously by electrocardiogram. Muscular activity covered electroencephalographic activity of following minutes. This case provides an opportunity to highlight the existence of rare conditions such as ictal arrhythmias which should be considered in the differential diagnosis of episodes of transient loss of consciousness in particular when dysautonomic and neurological symptoms are intermingled. Autonomic symptoms (vomiting, tachycardia, cyanosis, bradycardia and asystole) may be also more frequent in idiopathic (more rarely symptomatic) epilepsies of childhood (Panayiotopoulos syndrome).