Diffuse toxic goiter
Diffuse toxic goiter is a disease of the thyroid gland that occurs when a function of the immune system is disturbed, characterized by a persistent increase in the production of thyroid hormones, usually a diffusely enlarged thyroid gland with subsequent disruption of the functional state of various organs and systems, primarily the cardiovascular and central nervous systems. The disease affects women 5-10 times more often than men.
The main role in the development of diffuse toxic goiter is assigned to hereditary predisposition, ie, the presence of certain mutant genes in the genetic material. Factors provoking the onset of the disease are stresses, infections, insolation, etc. The presence of the ancestral nature of diffuse toxic goiter is confirmed by the fact that in 15% of cases, people suffering from this disease have relatives with the same.pathology. At 50% of relatives in a blood antibodies to a tissue of a thyroid gland are defined.
The development of the disease is possible if there is a genetic predisposition and the impact of provoking factors that contribute to the realization of information embedded in the mutant genes. It is often noted that diffuse toxic goiter develops in parallel with other autoimmune diseases. It is believed that as a result of a violation of the proper functioning of the immune system, a mutation of T-lymphocytes occurs in the body, and they begin to act on the thyroid tissue, perceiving its structure as foreign. Mutated T-lymphocytes can independently damage the thyroid gland. In this case they have a direct toxic effect. In addition, T-lymphocytes can influence the thyroid tissue indirectly, with the help of B-lymphocytes. B-lymphocytes in this case begin to produce antibodies to the gland tissue. In addition to such a mechanism for the development of diffuse toxic goiter, the function of T-lymphocytes of suppressors is also disturbed under the influence of disruption of the normal functioning of the immune system. In the absence of pathology, T-suppressors control the process of the immune response of the body.
As in the case of diffuse toxic goiter, the production of hormones increases, thyrotoxicosis develops( that is, the excess of hormones has a toxic effect on the human body), the extent of which affects the severity of all possible manifestations of the disease. An increase in the number of thyroid hormones in the blood leads to their pathological effect on many organs and systems of the body. In the first place, the cardiovascular system suffers. Characteristic is the development of the "thyrotoxic" heart, in which its dystrophy occurs. This disorder is manifested by a constant rapid heart rate, a violation of the heart rate, in most cases, an increase in blood pressure. In addition to the cardiovascular system, the central nervous system is also affected. Signs of her defeat are the following: tearfulness, increased excitability, emotional lability, the movements become fussy, the trembling of fingers of elongated hands is noted - a symptom of Marie, as well as the trembling of the whole body. Under the influence of an excess of thyroid hormones in the body, the processes of non-synthesis( anabolism) of substances( which occurs normally in a healthy organism) and the processes of substance disintegration( catabolism) are activated. Manifestations of such a metabolic disorder are a decrease in the body weight of a progressive nature, while the body temperature increases, but does not exceed 38.0 ° C.Appetite is usually elevated, sweating, muscle weakness. In addition, there is a decrease in the mineralization of bones due to the washing out of the bone tissue of calcium, which occurs under the influence of a large number of thyroid hormones( osteopenia).Quite often the streets of this disease appear complaints about increased fragility of nails and hair loss. The digestive system function is disrupted, which is manifested by disorders of the stool, abdominal pain without clear localization. When the disease progresses, characteristic eye symptoms appear: when looking up, the upper eyelid lags behind the iris( Gref's symptom), while looking down the upper eyelid also lags behind the iris( Kocher's symptom), a person can not fix a sight on a nearby object( Mobius symptom), whenlooking up, a man wrinkles his forehead( symptom Geoffrey), a rare blink( Stelvag's symptom), the ocular sheath is widened, a white band of sclera( the symptom of the Dalrymple) is marked between the iris and the upper eyelid, a small tremor of the closed eyes( symptomRosenbach).With expressed diffuse toxic goiter, there is an increase in the size of the thyroid gland, which can be determined either by palpation in the case of a slight increase in it, or by examining the neck region, which is possible with a sufficiently strong increase in its size.
There are two classifications of the degrees of enlargement of the thyroid gland. Classification according to Nikolaev( 1955) includes VI degrees of enlargement of the gland.
0 degree - the thyroid gland is not palpable at all.
I degree - with palpation an enlarged thyroid isthmus is defined.
II degree - an increase in the thyroid gland is noted when feeling and during the act of swallowing.
III - there is an increase in the size of the neck.
IV - goiter is greatly enlarged and changes the shape of the neck.
V - goiter is very large.
There is a classification of WHO( 1994), according to which, III degree of enlargement of the gland is distinguished.
0 degree - goiter is not.
I degree - goiter is not visible on examination, but it is probed.
II degree - goitre is visible on examination.
In addition to the above signs, the function of other endocrine glands in the body is impaired. In women there is a violation of the menstrual cycle. In men, there is an increase in the size of the mammary glands. Also, the adrenal gland function is impaired, which is manifested by a relative adrenal insufficiency.
Diffuse toxic goiter in a number of cases is noted in newborn infants. This is possible if the disease is observed in their mothers. There are two forms of neonatal damage. At the first form, the symptoms of the disease are noted in children at birth: low body weight, increased heart rate, decreased muscle tone, increased body temperature. The development of this form of diffuse toxic goiter is explained by the transfer through the placenta of antibodies to the thyroid gland from mother to child. The second form of diffuse toxic goiter in newborns occurs at the age of 3-6 months. At the same time, the course of the disease is usually very severe and in 20% of cases it ends with the death of the child. If the child survives, then in most cases he has a brain damage.
To confirm diffuse toxic goiter it is necessary to conduct a blood test for thyroid hormones. At the same time there is a decrease in the amount of thyroid-stimulating hormone of the pituitary gland and a simultaneous increase in the amount of thyroxine( T4) and triiodothyronine( T3).The ultrasound of the thyroid gland is performed to determine the presence of a diffuse process and determine its size. If the total volume of the thyroid gland exceeds 45 cm3, then an operative treatment of this disease is necessary. There are three degrees of severity of diffuse toxic goiter: light, medium and heavy. The mild severity of this disease is characterized by the following manifestations: heart rate 80-120 beats / min, pronounced weight loss, hand tremor is weak, a slight decrease in performance. The average severity is characterized by the following criteria: the number of heartbeats is 100-120 beats per minute, pulse pressure is increased, weight loss is more than 10 kg, reduced efficiency. Severe severity of thyrotoxicosis: heart rate more than 120 beats / min, there is an arrhythmia, mental disorders, dystrophy of internal organs, sharply reduced body weight( more than 10 kg), disability. There is another classification of the severity of diffuse toxic goiter. According to this classification, subclinical, manifest and complicated types of the disease course are distinguished. The subclinical course of the disease is characterized by blurred manifestations. Detect such a course of diffuse toxic goiter only on the basis of laboratory methods of examining blood for hormones. With a manifest type of diffuse toxic goiter, all manifestations of the disease can be clearly seen. In blood tests, characteristic changes in the levels of thyroid hormones are determined. The complicated variant of the flow is characterized by the attachment of cardiac rhythm disturbances to the existing manifestations in the form of arrhythmia, there are signs of heart failure, relative adrenal insufficiency, dystrophic changes appear in the internal organs, the psychic state is sharply disturbed, and a pronounced body mass deficiency is noted.
There are medicinal and surgical treatments for diffuse toxic goiter. Medication therapy includes the use of antithyroid drugs, treatment with radioactive iodine. In the case of surgical treatment, preoperative preparation is carried out, consisting in taking thyreostatics. Thyroid medications include mercazolil, thiamazole, carbimazole. Thyreostatic drugs, in particular mercazolil and propylthiouracil, block the formation of thyroid hormones, and also affect the immunity system. Initially, high doses of the drug( 20-40 mg / day) are used. Later on they pass to a maintenance dose( 5-15 mg / day).Thyrostatics are usually prescribed in conjunction with β -adrenoblockers, such as anaprilin( 80-120 mg / day) and atenolol( 50-100 mg / day).The purpose of prescribing this group is to restore normal heart rhythm. After 3-4 weeks from the beginning of such treatment, the level of thyroid hormones in the blood reaches normal values, that is, the state of euthyroidism is formed. After reaching this state, the dose of thyreostatic drugs should decrease gradually. At the same time prescribe the drug L-thyroxine. This drug is prescribed to maintain the state of euthyroidism. Treatment with these drugs in a maintenance dose continues for 1.5-2 years. Then the drug therapy stops completely, and the person should be under the constant supervision of the endocrinologist, since there is a possibility of developing an exacerbation of thyrotoxicosis. Treatment with thyreostatic drugs can give its complications. To prevent complications from the blood, it is necessary to undergo control of blood tests, especially in the first three months from the start of therapy. During this period, blood control should be performed every 7-10 days, and subsequently every 3-4 weeks. Another method of treating the state of thyrotoxicosis is the use of radioactive iodine. Apply local irradiation of the area of the thyroid gland, in which radioactive iodine enters its tissue. There it decomposes to form β -particles, which are able to penetrate the gland thickness by only 2 mm. There is an absolute contraindication for therapy with radioactive iodine. Such a contraindication is pregnancy and the period of feeding. In the event that a woman of reproductive age received this type of treatment, she should use contraceptive methods within one year after her termination. Men of reproductive age should use methods of contraception within 120 days. In the case of diffuse toxic goiter in pregnancy, the dose of thyreostatics should be reduced, since large doses may adversely affect the fetus. Usually, propylthiouracil is prescribed, which in smaller amounts than mercazolil penetrates the placental barrier and practically does not adversely affect the fetus. L-thyroxine in the treatment of diffuse toxic goiter during pregnancy is not prescribed, since its use requires an increase in the dose of thyreostatics, which will have an adverse effect on the fetus. Operative treatment of diffuse toxic goiter during pregnancy is possible only if there are strict indications in the II or III trimester. In some cases, an operative treatment is necessary. Indications for him are frequent exacerbations of thyrotoxicosis against the background of ongoing medical treatment, intolerance to drugs of the thyreostatic group, the presence of a node in the thyroid gland. There are also contraindications to surgical treatment. These are: myocardial infarction during the last two months, stroke, malignant neoplasms localized outside the thyroid gland. During the operation, the thyroid gland is removed, in which a small portion of the gland tissue remains uninstalled. In most cases, the mass of the thyroid tissue left is about 5 g.
Complications of diffuse toxic goiter can be: thyrotoxic crisis, endocrine ophthalmopathy and pretybial myxedema.
Thyrotoxic crisis is a very difficult condition, complicating diffuse toxic goiter, and can be a serious enough threat to human life. The mechanism of development of a thyrotoxic crisis has not yet been fully studied, but there are a number of hypotheses. According to one of them, it is believed that with the development of this complication, there is an increase in the number of free forms of thyroid hormones due to disruption of the binding process. According to another hypothesis, the development of thyrotoxic crisis is associated with an increase in the sensitivity of the organism to these hormones. The provoking factor in this case is an infectious disease, a stressful state of the organism, etc. Characteristic signs appear: the condition worsens sharply, which is associated with an increase in the manifestations of all the symptoms characteristic of the state of thyrotoxicosis. The development of thyrotoxic crisis is necessarily combined with the appearance of a relative insufficiency of the adrenal glands. In most cases, signs of liver failure and pulmonary edema are associated. The thyrotoxic crisis usually develops suddenly. The person becomes excessively mobile, his excitement is noted. He takes a forced position, typical for thyrotoxic crisis: the legs are bent at the knees and are divorced in the sides( "frog pose").A characteristic feature is the decrease in muscle tone( in particular, the muscles of the tongue), which is manifested by a speech disorder. The body temperature rises, and the skin feels hot and wet. There is an increase in the number of heartbeats to 130 beats per minute. The heart rate may be disturbed. Urgent conduct of medical measures is necessary.