Chvostek sign

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The Chvostek sign (also Weiss sign) is one of the signs of tetany seen in hypocalcemia. It refers to an abnormal reaction to the stimulation of the facial nerve. When the facial nerve is tapped at the angle of the jaw, the facial muscles on the same side of the face will contract momentarily (typically a twitch of the nose or lips) because of hypocalcaemia (ie from hypoparathyroidism, pseudohypoparathyroidism, hypovitaminosis D) with resultant hyperexcitability of nerves. Though classically described in hypocalcaemia, this sign may also be encountered in respiratory alkalosis, such as that seen in hyperventilation, which actually causes decreased serum Ca++ with a normal calcium level due to a shift of Ca++ from the blood to albumin which has become more negative in the alkalotic state.

It was first described by František Chvostek, an Austrian physician in 1876, and later independently by Nathan Weiss in 1883.

The Trousseau sign of latent tetany is also often used to detect early tetany.

[edit] References

• Chvostek F. Beitrag zur Tetanie. Wien Med Press 1876;17:1201-3, 1225-7, 1253-8, 1313-16.
• Weiss N. Centralbl Gesammt Ther 1883;1:9.

[edit] External links

• František Chvostek
• Nathan Weiss