The Chvostek sign is the exaggerated physical response to stimulation of the facial nerve in patients with hypocalcemia. The maneuver and the sign were described in 1876 by the Czech physician František Chvostek.
The maneuver consists of percussion with a finger on the angle of the jaw, which is the site where the facial nerve is most superficial. In this way, the nerve is stimulated and if there is a movement of the facial muscles on the same side with this stimulation, the sign is positive..
Many functions of the body are regulated by calcium. Some of them are muscle movements, including the heart muscle and brain function. A blood calcium level below 8.8 g / dL is considered hypocalcemia.
Hypocalcemia can have consequences such as arrhythmias and seizures. Another common cause of this condition is accidental removal of the parathyroid glands in thyroidectomy surgery..
The parathyroids are glands that are responsible for releasing parathyroid hormone (PTH) that regulates the level of calcium in the body. When there is no parathyroid hormone, the general consumption of calcium is higher and decreases in a generalized way, leading the patient to a state of calcium deficiency or hypocalcemia.
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Chvostek's sign is a physical manifestation that occurs due to hyperactivity of the facial nerve due to hypocalcemia, in response to an external stimulus. František Chvostek (1835-1884), a physician of Czech origin, was the one who described the maneuver and the sign in 1876.
Based on the evaluation of the history, symptoms and history of a patient, the doctor can guide his diagnosis towards circulating calcium deficiency.
Patients who have undergone total thyroid removal surgery usually develop muscle cramps and hyperexcitability of the muscles with involuntary movements of the mouth within a day or two later. When this occurs, we proceed to a physical examination aimed at hypocalcemia..
The maneuver begins with the patient seated and relaxed. The doctor proceeds to tap a finger gently at the angle of the jaw. The anatomical reason why this point is chosen is because it is there where the facial nerve makes its most superficial route and is easier to stimulate..
If the patient responds to the stimulus with an exaggerated movement of the labial commissure and even the eye on the same side of the stimulation, the Chovstek sign will be positive, being an indicator to request the patient specific laboratory tests to measure the level of calcium in the blood.
An associated sign that can appear in this condition is Trosseau's sign, in which the patient presents hyperflexion of the wrist joint when inflating a blood pressure cuff on the arm on the same side..
Trosseau's sign is more specific than Chovstek's sign when diagnosing hypocalcemia.
The parathyroids are small glands that are located on the back of the thyroid gland in the central part of the neck. Usually there are four, but they can vary in number and find fewer or more.
The main function of these glands is to produce and release parathyroid hormone (PTH) into the blood. This hormone maintains the calcium balance in the body.
When the gland detects low levels of calcium in the blood, it begins the production and secretion of PTH. Likewise, when calcium levels in the blood increase, there are contrary mechanisms that stop the release of PTH.
Parathyroid hormone has a direct effect on the bones, kidneys and small intestine, since these are the sites where the process of absorption and resorption of calcium is regulated. Finally, its action on these sites has an impact on the level of calcium in the blood..
Calcium is an essential element for the proper functioning of the muscles, the heart, the bones, the kidneys and the nervous system..
Inside cells, in the mitochondria, there are calcium channels that regulate their function. When there is an imbalance in the calcium level, a cellular imbalance occurs that leads to organ dysfunction.
Although the pathologies of the parathyroid glands are not very frequent, hyperparathyroidism is a condition that can present in the surgical consultation.
Hyperparathyroidism is defined as an overactive parathyroid. It has several causes, but the most common is the presence of an adenoma. Parathyroid cancer is a very rare pathology but it must be taken into account.
Adenoma is a type of benign tumor that increases the size of the gland making it more active. That is, it leads it to produce and secrete a greater amount of PTH.
Patients with hyperparathyroidism have hypercalcemia, that is, a greater amount of circulating calcium in the blood. Typical symptoms of hypercalcemia are fatigue, depression, bone pain, excessive thirst, and in some cases, kidney stones..
Resolution of a parathyroid adenoma is surgical.
Hypoparathyroidism is a condition in which the activity of the parathyroids is decreased. That is, there is less PTH circulating in the blood.
The most common cause of hypoparathyroidism is accidental excision of the parathyroid glands during surgery that completely removes the thyroid, called a total thyroidectomy..
Other less frequent causes are autoimmune diseases in which the immune system itself destroys parathyroid cells..
Hypoparathyroidism can be temporary or permanent. In any case, therapy with calcium supplements should be started as soon as possible since the biochemical imbalance produced by the decrease in calcium in the body can lead to many complications, including death..
The decrease in the level of calcium in the blood increases the excitability of the muscles and nerves. The patient with hypocalcemia may present symptoms such as involuntary movements of the muscles, commonly of the muscles of the face, called fasciculations..
When the doctor examines, he may notice an increase in the reflex response of the patient. These symptoms, together with an adequate questioning, guide the diagnosis of hypocalcemia..
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