Trousseau sign of latent tetany
A medical sign of latent tetany elicited by arm occlusion.
The Trousseau sign of latent tetany is a clinical indicator of low calcium levels. To test for it, a blood pressure cuff is placed on the arm and inflated above systolic pressure for three minutes, blocking the brachial artery. When blood flow stops, the patient’s low calcium and resulting nerve irritability cause the hand and forearm muscles to spasm. This produces a specific hand posture—flexion at the wrist and knuckles, extension at the finger joints, and fingers drawn together—called *main d’accoucheur* (French for “hand of the obstetrician”), because it resembles how an obstetrician’s hand looks during delivery. The sign can appear before other symptoms of hypocalcemia, such as overactive reflexes or full tetany, and is considered more sensitive (94%) than the Chvostek sign (29%) for detecting low calcium. It may also occur in hyperventilation syndrome, where rapid breathing lowers blood calcium through hypocapnia. Between 1 and 4 percent of people with normal calcium levels will test positive. The sign is named after French physician Armand Trousseau, who described it in 1861, and is distinct from the Trousseau sign of malignancy, which involves abnormal blood clots linked to certain cancers.
- field
- Medicine
- known_for
- Describing the Trousseau sign of latent tetany
- sign_positive_rate_in_normal_patients
- 1 to 4 percent
- sensitivity_for_hypocalcemia
- 94%
- comparison_to_Chvostek_sign_sensitivity
- 29%
Quick Facts
- Test Of
- Hypocalcemia
Facts from the source article.
Lore & Background
The sign is named after French physician Armand Trousseau, who described the phenomenon in 1861. It is distinct from the Trousseau sign of malignancy, which is a type of abnormal blood clot due to certain types of cancer. The sign may be positive before other manifestations of hypocalcemia such as hyperreflexia and tetany, and it is generally believed to be more sensitive (94%) than the Chvostek sign (29%) for hypocalcemia.
Reader's Guide
The Trousseau sign of latent tetany is a clinical test for hypocalcemia, with a reported sensitivity of 94% compared to 29% for the Chvostek sign. It is elicited by inflating a blood pressure cuff above systolic pressure for three minutes, causing carpal spasm in the form of main d'accoucheur. The sign may also be observed in hyperventilation syndrome due to hypocapnia-induced reduction of calcium levels. From 1 to 4 percent of normal patients will test positive, indicating that false positives can occur. Its historical significance lies in its description by Armand Trousseau in 1861, and it remains a standard bedside test for latent tetany. The sign is distinct from the Trousseau sign of malignancy, which involves abnormal blood clotting associated with cancer.
Did You Know?
- The sign is also known as main d'accoucheur, French for 'hand of the obstetrician.'
- From 1 to 4 percent of normal patients will test positive for Trousseau's sign of latent tetany.
- The sign is generally believed to be more sensitive (94%) than the Chvostek sign (29%) for hypocalcemia.
- The sign may also be observed as a symptom of hyperventilation syndrome.
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