Trousseau sign of latent tetany is a

medical sign Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showin ...

observed in patients with low

calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar t ...

. From 1 to 4 percent of normal patients will test positive for Trousseau's sign of latent tetany. This sign may be positive before other manifestations of

hypocalcemia Hypocalcemia is a medical condition characterized by low calcium levels in the blood serum. The normal range of blood calcium is typically between 2.1–2.6 mmol/L (8.8–10.7 mg/dL, 4.3–5.2 mEq/L) while levels less than 2.1 mm ...

such as

hyperreflexia Hyperreflexia is overactive or overresponsive bodily reflexes. Examples of this include twitching and spastic tendencies, which indicate upper disease of the upper motor neurons and the lessening or loss of control ordinarily exerted by higher ...

and

tetany Tetany or tetanic seizure is a medical sign consisting of the involuntary contraction of muscles, which may be caused by disorders that increase the action potential frequency of muscle cells or the nerves that innervate them. Muscle cramps caus ...

, as such it is generally believed to be more sensitive (94%) than the Chvostek sign (29%) for hypocalcemia. To elicit the sign, a

blood pressure cuff A sphygmomanometer ( ), a blood pressure monitor, or blood pressure gauge, is a device used to measure blood pressure, composed of an inflatable cuff to collapse and then release the artery under the cuff in a controlled manner, and a mercury o ...

is placed around the arm and inflated to a pressure greater than the

systolic blood pressure Blood pressure (BP) is the pressure of circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term "blood pressure" r ...

and held in place for 3 minutes. This will occlude the brachial artery. In the absence of blood flow, the patient's hypocalcemia and subsequent neuromuscular irritability will induce spasm of the muscles of the hand and forearm. The wrist and

metacarpophalangeal joint The metacarpophalangeal joints (MCP) are situated between the metacarpal bones and the proximal phalanges of the fingers. These joints are of the condyloid kind, formed by the reception of the rounded heads of the metacarpal bones into shallow ca ...

s flex, the DIP and PIP joints extend, and the fingers

adduct An adduct (from the Latin ''adductus'', "drawn toward" alternatively, a contraction of "addition product") is a product of a direct addition of two or more distinct molecules, resulting in a single reaction product containing all atoms of all co ...

. The sign is also known as ''main d'accoucheur'' ( French for "''hand of the

obstetrician Obstetrics is the field of study concentrated on pregnancy, childbirth and the postpartum period. As a medical specialty, obstetrics is combined with gynecology under the discipline known as obstetrics and gynecology (OB/GYN), which is a surgic ...

''") because it supposedly resembles the position of an obstetrician's hand in delivering a baby. The sign is named after French physician Armand Trousseau, who described the phenomenon in 1861. It is distinct from the

Trousseau sign of malignancy The Trousseau sign of malignancy or Trousseau's syndrome is a medical sign involving episodes of vessel inflammation due to blood clot (thrombophlebitis) which are recurrent or appearing in different locations over time (thrombophlebitis migrans o ...

, which is a type of abnormal blood clot due to certain types of cancer.Trousseau's sign of visceral malignancy
in

GPnotebook GPnotebook is a British medical database for general practitioners (GPs). It is an online encyclopaedia of medicine that provides an immediate reference resource for clinician A clinician is a health care professional typically employed at a s ...

, retrieved May 2022

References

Symptoms and signs: Endocrinology, nutrition, and metabolism {{med-sign-stub