True about Chvostek's sign are all of the following except: March 2010, March 2013

Ans. C: Raised calcium levelPTH is essential for life. After parathyroidectomy, there is a steady decline in the plasma Ca2+ level. Signs of neuromuscular hyperexcitability appear, followed by full-blown hypocalcemic tetany.In humans, tetany is most often due to inadveent parathyroidectomy during thyroid surgery. Symptoms usually develop 2-3 days postoperatively but may not appear for several weeks or more. Injections of PTH correct the chemical abnormalities, and the symptoms disappear. Injections of Ca2+ salts give temporary relief.The signs of tetany in humans include Chvostek's sign, a quick contraction of the ipsilateral facial muscles elicited by tapping over the facial nerve at the angle of the jaw; and Trousseau's sign, a spasm of the muscles of the upper extremity that causes flexion of the wrist and thumb with extension of the fingers