Trousseau sign of latent tetany (not to be confused with Trousseau syndrome) is highly specific for hypocalcaemia 1. It may be elicited by placing a blood pressure cuff over the upper arm and inflating to above systolic pressure for 2-3 minutes. This reduces arterial supply to the forearm. The ischaemia, in the context of hypocalcaemia, and mediated by the mechanism of hypocalcaemic neuronal irritability, leads to muscular spasm of the wrist and hand (carpopedal spasm). The sign is seen in 94% with hypocalcaemia and only 1% of those with normal calcium levels (i.e. 94% sensitivity and 99% specificity)
History and etymology
Armand Trousseau (1801-1867), was a French physician who was the first to describe his eponymous sign 2.
- 1. Jesus JE, Landry A. Chvostek's and Trousseau's Signs. N Engl J Med 2012; 367:e15 DOI: 10.1056/NEJMicm1110569
- 2. Young P, Bravo MA, González MG, Finn BC, Quezel MA, Bruetman JE. [Armand Trousseau (1801-1867), his history and the signs of hypocalcemia]. (2014) Revista medica de Chile. 142 (10): 1341-7. doi:10.4067/S0034-98872014001000017 - Pubmed