Chvostek sign

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 (i.e. masseter muscle), the facial muscles on the same side of the face will contract momentarily (typically a twitch of the nose or lips) because of hypocalcemia (i.e. from hypoparathyroidism, pseudohypoparathyroidism, hypovitaminosis D) with resultant hyperexcitability of nerves. Though classically described in hypocalcemia, this sign may also be encountered in respiratory alkalosis, such as that seen in hyperventilation, which actually causes decreased serum Ca²⁺ with a normal calcium level due to a shift of Ca²⁺ from the blood to albumin which has become more negative in the alkalotic state.

It was first described by František Chvostek, a Czecho-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.

Chvostek's sign may also be present in hypomagnesemia, frequently seen in alcoholics, persons with diarrhea, patients taking aminoglycosides or diuretics, because hypomagnesemia can cause hypocalcemia. Magnesium is a cofactor for Adenylate Cyclase. The reaction that Adenylate Cyclase catalyzes is the conversion of ATP to 3',5'-cyclic AMP. The 3',5'-cyclic AMP (cAMP) is required for Parathyroid hormone activation.

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.
• Weisinger, J. R.; Bellorín-Font, E. (1998). "Magnesium and phosphorus". The Lancet 352 (9125): 391–396. doi:10.1016/S0140-6736(97)10535-9. PMID 9717944.  edit
• Goljan, EF. Rapid Review Pathology. Mosby, Elsevier, 2007; pp. 504.

External links

• František Chvostek
• Nathan Weiss

This medical sign article is a stub. You can help Wikipedia by expanding it.v · Categories: Symptoms and signs: Endocrinology, nutrition, and metabolism Medical sign stubs Wikimedia Foundation. 2010. Игры ⚽ Нужен реферат? Richard A. Muller Michael Heatley Look at other dictionaries: Chvostek sign — Chvostek Weiss sign spasm of the facial muscles elicited by tapping the facial nerve in the region of the parotid gland; seen in tetany. Called also Schultze or Schultze Chvostek s …   Medical dictionary Chvostek sign — Chvos·tek sign (kvosґtək) [Franz Chvostek, Austrian surgeon, 1835–1884] see under sign …   Medical dictionary chvostek sign — noun see chvostek s sign …   Useful english dictionary Chvostek sign — noun One of the signs of tetany seen in hypocalcemia …   Wiktionary Schultze-Chvostek sign — Schult·ze Chvos·tek sign (shooltґsə kvosґtek) [F. Schultze; Franz Chvostek, Austrian surgeon, 1835–1884] Chvostek sign …   Medical dictionary Chvostek-Weiss sign — Chvos·tek Weiss sign (kvosґtək vīsґ) [F. Chvostek; Nathan Weiss, Austrian physician, 1851–1883] Chvostek sign …   Medical dictionary chvostek's sign — (ḵə)ˌvȯsˌtek(s) noun or chvostek sign ˌtek Usage: usually capitalized C Etymology: after Franz Chvostek died 1884 Austrian surgeon : a twitch of the facial muscles following gentle tapping over the facial nerve in front of the ear that… …   Useful english dictionary Sign — Any abnormality that indicates a disease process, such as a change in appearance, sensation, or function, that is observed by a physician when evaluating a patient. * * * 1. Any abnormality indicative of disease, discoverable on examination of… …   Medical dictionary Chvostek's sign — Chvos·tek s sign (kə ).vȯs .tek(s) or Chvos·tek sign (kə ).vȯs .tek n a twitch of the facial muscles following gentle tapping over the facial nerve in front of the ear that indicates hyperirritability of the facial nerve Chvos·tek kvȯs .tek… …   Medical dictionary Chvostek — Franz, Austrian surgeon, 1834–1884. See C. sign …   Medical dictionary 18+ © Academic, 2000-2024 Contact us: Technical Support, Advertising Dictionaries export, created on PHP, Joomla, Drupal, WordPress, MODx. Mark and share Search through all dictionaries Translate… Search Internet Share the article and excerpts Direct link … Do a right-click on the link above and select “Copy Link”