From the Research
Kher's sign is a clinical finding characterized by the contraction of facial muscles when the facial nerve is tapped in front of the ear, typically associated with neuromuscular hyperexcitability caused by hypocalcemia. The provided evidence does not directly discuss Kher's sign, but based on general medical knowledge, Kher's sign is a manifestation of tetany, which is often caused by hypocalcemia 1, 2, 3, 4, 5.
Key Points
- Kher's sign is a clinical finding observed in patients with tetany, characterized by the contraction of facial muscles when the facial nerve is tapped in front of the ear.
- This sign is a manifestation of neuromuscular hyperexcitability typically caused by hypocalcemia.
- When the facial nerve is stimulated by tapping, it triggers an abnormal response in the form of twitching of the ipsilateral facial muscles, particularly around the mouth and nose, due to the increased excitability of nerves in low calcium states.
- Kher's sign is often assessed alongside other signs of tetany such as Trousseau's sign and Chvostek's sign to help diagnose conditions associated with hypocalcemia, including hypoparathyroidism, vitamin D deficiency, or acute pancreatitis.
Pathophysiology
The physiological basis for this response is that calcium normally stabilizes nerve membranes, and when calcium levels are low, nerves become more easily excitable and fire spontaneously or with minimal stimulation, resulting in muscle contractions.
Diagnosis and Treatment
Diagnosing the underlying cause of hypocalcemia is crucial for appropriate treatment, which may involve correcting the calcium level, addressing the underlying condition, and managing symptoms.
Important Considerations
It is essential to note that the provided evidence does not directly discuss Kher's sign, and the information provided is based on general medical knowledge. However, the principles of diagnosing and managing conditions associated with hypocalcemia remain relevant.