A pallid paroxysmal event in children: it is vagal anoxic seizure, it is treatable, and it is not “epilepsy”

Excerpt

There is sometimes diagnostic confusion in children presenting with loss of consciousness, sudden falls, or other paroxysmal motor phenomena. In general, the vagal reactivity has received scarce attention in the pediatric literature. Both neurophysiological mechanism and physiopathological data concerning the vagal effects are almost absent from pediatric, cardiological, and neurological textbooks. However, vagal reactivity is at the crossroads of two major clinical fields: first, neurology, due to the fact that all the chronological sequences are mediated by a nerve and that some of the paroxysmal events related to increase of the vagal reactivity are basically neurological; second, cardiology, since most of the clinical effects of vagal reactions are heart rate mediated. Some authors even use the term of neurocardiology to demonstrate the intrinsic involvement of both systems. Recent investigations established that a third road has to be added to the abovementioned crossroads: the respiratory vagal effect which will probably lead to adjusting the terminology to neuropneumocardiology when considering vagal effects [3, 4]. The vagal reflex that has been the most extensively described in the literature is the “Hering-Breuer reflex”. It is a vagally mediated respiratory reflex. In its initial description it was demonstrated that sustained lung inflation was able to inhibit inspiration in animals and that the reflex could be abolished by vagotomy. The cardiac effects of a vagal stimulation had been extremely well documented in animal experiments: precise cardiac response has been obtained at titrated electrical stimuli of the vagus nerve. The parasympathic system was considered for many years to be of little, if any, importance in the control of cardiac function. …