New light has been thrown on the subject of convulsions and allied conditions in childhood by the study of the electrical reactions. This work was begun and carried out for years by Escherich.1 General convulsions in children, laryngospasm, spasmodic apnea, tetany and similar phenomena have been shown to be but manifestations of an underlying hyperexcitability of the peripheral nervous system, with a tendency to tonic and clonic spasms, the so-called spasmophilic diathesis.
Mechanically the hyperirritability can be shown by tapping over the seventh nerve along its course in the cheek, with a resulting contraction of the muscles around the mouth. Tapping over the upper branches of the same nerve may produce a similar contraction about the eye. The first is known as Chvostek's and the second as Weiss' phenomenon. Constriction of the arm in this condition at times brings on the tetany position of the hand—Trousseau's phenomenon. The Chvostek