Chvostek's Sign: A Clinical Indicator of Calcium Levels

Definition and Elicitation

The Chvostek sign, also referred to as Chvostek-Weiss or Schultze sign, describes an involuntary facial muscle twitch elicited by tapping the facial nerve. This sign is obtained by gently tapping the facial nerve, near the mandible, with a reflex hammer or a finger.

Clinical Significance

Normal Calcium Levels

A positive Chvostek sign indicates elevated neuromuscular excitability, which can be caused by normal or elevated serum calcium levels. In individuals with normal calcium levels, a positive Chvostek sign may be a sign of hypomagnesemia (low magnesium levels).

Increased Calcium Levels

A positive Chvostek sign is more commonly associated with increased serum calcium levels (hypercalcemia). Hypercalcemia can occur due to various medical conditions, such as primary hyperparathyroidism, vitamin D intoxication, or certain cancers.

Other Factors

Besides calcium levels, other factors that can influence the Chvostek sign include:

• Electrolyte imbalances
• Hypothyroidism (underactive thyroid gland)
• Tetany (a condition of muscle spasms and cramps)

Diagnostic Utility

The Chvostek sign is a quick and non-invasive test that can provide a preliminary indication of calcium levels. However, it is important to note that a positive Chvostek sign alone is not diagnostic of hypercalcemia or hypomagnesemia. Further blood tests, such as serum calcium and magnesium levels, are necessary for a definitive diagnosis.

Conclusion

The Chvostek sign is a valuable clinical tool for assessing neuromuscular excitability. A positive sign suggests altered calcium levels or other underlying medical conditions. While it is not diagnostic, its presence can prompt further investigation and appropriate treatment.