These facial spasms are caused by the nerves that control the muscle being easily excited (called hyperexcitability) due to hypocalcemia.
In his professional life, Chvostek devoted himself to the study of etiopathogenesis and to the treatment of neurological disorders, including by means of electrotherapy.
[7] It is frequently seen in alcoholics, persons with diarrhea, patients taking aminoglycosides or diuretics, because hypomagnesemia can cause hypocalcemia.
It can also be found in subjects with respiratory alkalosis, for example as a result of hyperventilation syndrome, which can lead to a drastic reduction of the concentration in serum of calcium ions while at normal levels, for the binding of a significant proportion of ionized calcium (Ca2+) with albumin and globulins.
[11] Due to the combination of poor sensitivity and specificity the clinical utility of this sign is reduced.