VERIFIED CONTENTAuthor: lek. Katarzyna Banaszczyk
Calcium deficiency in our body can manifest itself both rapidly, i.e. tetany, and have more subtle clinical symptoms that should be properly induced. What is the Chvostek symptom and what does it show?
The Chvostka symptomis characteristic of a calcium deficiency in the body. We speak of a deficiency of this element when its total concentration in the blood serum is lower than 2.25 mmol / l. In medical terms, calcium deficiency is called hypocalcemia.
Chvostek symptom - what is it?
At the outset, it is worth explaining what the Chvostek symptom described in the medical literature is. The Chvostek symptom is caused by hitting the facial nerve with a neurological hammer, i.e. in a place located approximately 2 centimeters forward from the earlobe.
After hitting this place with a hammer, facial muscles contract, visible to the naked eye. This symptom is caused by the doctor when he begins to suspect the so-called latent tetany in the patient.
Calcium and its role in the body
Calcium is a very important element that has many biological functions. The most important of them is the conditioning of the correct course of such phenomena as:
- blood clotting,
- neuromuscular conduction - without calcium, muscle contraction does not run properly,
- secretion of hormones,
- activation of many enzymes.
In our body, calcium is present in both ionized and protein-bound and anions-bound forms. In medical practice, it is common practice to evaluate total serum calcium levels - so this test determines the total amount of calcium in the blood.
Chvostek symptom - causes
What are the most common causes of Chvostek's symptom? These are primarily factors leading to calcium deficiency in the body, which include:
- low intake of calcium in the diet,
- vitamin D deficiency,
- intestinal malabsorption - in this case, less calcium can be absorbed from food,
- excess phosphate in the body - phosphates are chemical compounds capable of binding calcium, which causes its deficiency,
- applicationdrugs that increase the loss of calcium in the urine - these drugs include, among others loop diuretics (i.e. furosemide, torasemide),
- taking medications that inactivate vitamin D - these include anti-epileptic drugs such as hydantoin and barbituric acid derivatives,
- hypoparathyroidism - is associated with the deficiency of parathyroid hormone, a hormone that determines the appropriate concentration of calcium in the serum,
- damage and failure of organs involved in the production of the active form of vitamin D - here we are talking about the liver and kidneys,
- skeletal muscle damage - i.e. rhabdomyolysis. During the breakdown of muscle cells, a large amount of phosphate is released, which, as already mentioned, binds calcium,
- disintegration of neoplastic cells, i.e. the so-called tumor lysis syndrome - the mechanism of hypocalcemia in this case corresponds to the above-described mechanism related to rhabdomyolysis,
- chronic use of bisphosphonates - these are drugs used in the treatment of osteoporosis.
Chvostek symptom, i.e. latent tetany
The Chvostek symptom is considered a so-called latent tetany symptom. In medicine, the term tetany is referred to as muscle resting hyperactivity resulting from electrolyte disturbances, including calcium deficiency.
Such hyperactivity results in symmetrical muscle contractions of our body, which fit into the clinical picture of a tetany attack (such a seizure will be described in the next paragraph).
However, in the case of chronic calcium deficiency, we can deal with the so-called latent tetany, which we unmask by inducing the Chvostek symptom. Latent tetany does not manifest itself in the characteristic contractions of the entire muscle parts, i.e. tetany attack.
It is worth being aware that the Chvostek symptom is not the only symptom of latent tetany. The second symptom of this clinical condition is the Trosseau symptom, the so-called "obstetrician's hand".
This symptom is caused by pressing the arm with the cuff of the blood pressure monitor. For this purpose, it is necessary to inflate the device to 20 mm Hg above the patient's systolic pressure.
Performing such an action causes the palmar bend of two fingers of the hand - the fifth finger and the fourth finger (the first, second and third fingers remain straightened). This arrangement of the fingers resembles a doctor's hand during a obstetric examination, which is why this is the second name of the Trosseau symptom.
Calcium deficiency and tetany attack
The Chvostek symptom, accompanying lowered serum ionized calcium levels, is usually not the only symptom of this disorder.
Other symptoms that contribute to the clinical picture of hypocalcaemia includenumbness as well as muscle spasms in the hands which can spread to the shoulders of the face and lower limbs.
The mouth of a patient with a tetany attack can take on a so-called fish shape. The occurrence of these characteristic muscle contractions of the body is called a tetany attack. During such an attack, despite symmetrically occurring muscle contractions, the patient's awareness is preserved.
Tetany equivalents - what are these symptoms?
Symptoms that indicate a calcium deficiency in the body are also:
- visual disturbance - such as double vision, photophobia,
- bronchospasm (which causes asthma-like symptoms) and laryngospasm,
- spasms of arteries - incl. coronary arteries - which causes typical angina pains, cerebral arteries - which can manifest itself as migraine or even loss of consciousness, as well as abdominal arteries, which causes abdominal pain.
Hypocalcaemia may also be seen on an electrocardiogram (EKG) as a prolongation of the QT interval.
Calcium deficiency and tetany - disease recognition
The basic test for the diagnosis of hypocalcemia is the determination of this element in the blood serum. If the serum total calcium level is below 2.25 mmol / l, it is known as hypocalcaemia. It is also worth doing other laboratory tests that may lead us to the possible cause of calcium deficiency.
These tests include, among others, the designation:
- creatinine concentration- this is a parameter that tells us about the efficiency of the kidneys. As already mentioned, kidney failure may predispose to a deficiency of the active form of vitamin D, which in turn causes a decrease in serum calcium levels,
- phosphates- their excess reduces the concentration of calcium,
- magnesium- a significantly reduced level of this element causes a reduction in parathyroid hormone secretion by the parathyroid glands, which in turn leads to hypocalcemia,
- vitamin D- its deficiency is a common cause of hypocalcemia,
- parathyroid hormone- it is a hormone produced by the parathyroid glands, responsible for the regulation of the body's calcium metabolism - parathyroid hormone deficiency may indicate hypoparathyroidism,
- Daily calcium excretion with urine- allows us to confirm the loss of calcium in this way.
Chvostek symptom - tetany treatment
The basic action in the case of symptomatic tetany is to supplement the missing element. For this purpose, calcium is administered intravenously in the form of compounds:
- calcium gluconolactobionate
- or calcium chloride.
It is recommended to start taking oral supplementation at the same time - with both calcium and vitamin D.
If the cause of the low serum calcium level is excessive loss of calcium in the urine, it is possible to use a thiazide, a diuretic that reduces the loss of calcium in the urine.
To sum up, when we have symptoms that may suggest calcium deficiency, it is definitely worth going to our general practitioner (family doctor), who can measure the level of calcium in the serum. Thanks to this, we can easily rule out hypocalcemia.
It is also worth remembering about vitamin D supplementation in the period from September to April. Most Poles have a deficiency of this important substance, which is responsible, among other things, for regulating the body's calcium balance.