TETANY (Greek tetanos a tension, tension, a spasm) — a syndrome of the increased neuromuscular excitability caused, as a rule, by decrease in concentration of the ionized calcium in blood against the background of an alkalosis; it is shown by attacks of tonic spasms of separate muscular groups.
Etiology and pathogeny. Syndrome of T. it is directly caused by decrease in concentration in blood and in intercellular liquid of ionized calcium (see) at reduction of content of the general calcium in blood or owing to disturbance of formation of free calcium ions or their binding at normal concentration of the general calcium (0,085 — 0,12 g/l). The main conditions interfering formation of calcium ions are alkalosis (see), decrease in concentration of magnesium and strengthening of phosphorus in blood.
Emergence of T is the most frequent. it is connected with the general hypocalcemia caused by a hypoparathyrosis (see). Because of a shortcoming parathormone (see) absorption of calcium in intestines and its mobilization from bones decreases, in renal tubules the reabsorption of phosphorus amplifies that conducts to a hyperphosphatemia and decrease in content of the ionized calcium in blood. Increase in neuromuscular excitability comes to light clinically at decrease in concentration of the general calcium in blood to 0,07 g/l, attacks of T. usually arise at even more expressed its decrease (to 0,05 — 0,035 g/l). Other reasons of the hypocalcemia leading to emergence of T., there can be disturbances of absorption of calcium at a hypovitaminosis of D, diseases of the alimentary system which are followed by diarrhea and a steatorrhea including at enterita (see. Enteritis ), Gee's diseases (see), etc. (so-called enterogenous T.); an immobilization of calcium in bones during treatment by vitamin D of rickets or owing to hyper -
products of thyrocalcitonin (see. Kaltsitonin ) at the medullary cancer of a thyroid gland (see) occurring from S-to a letok; insufficient completion of the raised consumption of calcium at pregnant women and at a lactation at nursing mothers that most likely is caused by the hidden relative insufficiency of function of epithelial bodies (insufficient mobilization of parathormone). The last, perhaps, is also the reason of T., observed sometimes at acute inf. diseases and number of exogenous intoxications (morphine, carbon monoxide, chloroform, etc.), T., arising at a respiratory alkalosis in connection with a hyperventilation (see. Hypocapny ), and also idiopathic T., the origin a cut is not studied. Rare reason of T. inborn resistance of renal tubules to regulation of their function is parathormone. Nature of renal T., observed at hron. a renal failure (see), it is insufficiently studied, but it is possible to assume a certain role of decrease in reaction of the struck nephrons to parathormone since nek-ry shifts in concentration of calcium and phosphorus in blood usually come to light (a hypocalcemia, a hyperphosphatemia).
The T also is connected with a hypocalcemia. newborns, quite often proceeding against the background of decrease in concentration of magnesium in blood, and also T. at the inborn changes of phosphoric and calcic exchange which are not connected with a hypoparathyrosis (pseudohypoparathyroidism).
T. in connection with the alkalosis which is the reason of decrease in concentration in blood of the ionized calcium it is observed at considerable losses of chlorine as a result of persistent or pernicious vomiting at heavy early toxicosis of pregnant women, at patients with a pyloric stenosis (gastric T.) and other diseases which are followed by an alkalosis (primary giperal-dosteronizm, etc.), after introduction by the patient of a large amount of hydrosodium carbonate.
T., caused by binding of the ionized calcium in blood, it is possible at poisoning oxalic to - that (formation of insoluble salts of calcium), massive transfusions of a citrated blood.
Decrease in concentration of the ionized calcium in intercellular liquid reduces stability of membranes of nervous cells, increases their permeability for sodium and increases excitability of neurons. In motor-neurons and in system of internuncial neurons of a spinal cord the phenomenon of a post-tetanic potentsiation weakens, carrying out in a reflex arc is facilitated. In some cases moiosinaptichesky answers to irritation completely are absent and the strengthened polisinaptichesky categories come to light. All this leads to substantial increase of reflex sokratitelny reactions of muscles to mechanical and other irritations that finds a wedge, expression in Hvostek's symptoms, Trusso (see. Spasmophilia ), etc. Even weak irritations are capable to cause convulsive reduction of group of the muscles entering a zone of an innervation of the irritated motor nerve. Intravenous administration of calcium chloride promotes recovery of reflex activity.
Clinical picture. Distinguish the explicit and hidden (latent) T. Typical attack of T. begins with harbingers in the form of paresthesias, numbness, a cold snap of extremities, feeling of crawling of goosebumps, there are fibrillar twitchings, and then tonic spasms (see) separate muscular groups. The so-called carpopedal spasm — convulsive reduction of distal muscles of extremities and sgibatel is characteristic: hands are given to a trunk, bent in elbows, brushes are lowered down, the thumb is given to the bent IV and V fingers («obstetrical hand»), feet and fingers of feet — in a condition of bottom bending; the sole takes the form of a trench. At myotonia of the person there is a characteristic look: lips adopt the provision reminding a fish mouth, eyelids of a poluopushchena, eyebrows are cramped, the lockjaw of chewing muscles — a so-called cynic spasm sometimes develops. Convulsively reduced muscles are painful, firm to the touch. In hard cases spread of spasms on a trunk, a diaphragm, development of a bronchospasm (bronkhotetaniye) is possible that results in respiratory insufficiency (see). Frequent dangerous manifestation of T. children have a laryngospasm sometimes leading to a lethal outcome from asphyxia (see). Spasms of smooth muscles of l are less often observed. - kish. a path (a gullet, the gatekeeper, intestines), to-rye are followed by a dysphagia, vomiting, abdominal pains, dysfunction of intestines. The cases of a spasm of coronary arteries which are followed by attacks of stenocardia (see) and a cardiac standstill (cardiotetany) are described.
Latent form of T., proceeding asymptomatically or shown only paresthesias and arching pains in muscles of extremities, it is characterized by lack of spontaneous convulsive attacks.
Parathyroprival option T. has usually hron. current; convulsive attacks recur with various frequency, sometimes spontaneously, sometimes under the influence of such factors as pnterkurrentny infections, physical tension, a psychoinjury, overheating, overcooling, etc. The aggravation of a tetany in spring months is natural.
The diagnosis in the period of a convulsive attack does not represent considerable difficulties. During the mezhpristupny period, and also at the hidden T. conduct the researches directed to identification of symptoms of the increased mechanical and electric excitability of nervous trunks — Hvostek, Weiss, Trusso's symptoms, etc. Hvostek's symptom is caused by easy percussion a finger or a hammer on a trunk of a facial nerve in front from outside acoustical pass. At the same time all muscles innervated by a facial nerve (a symptom of Hvosteka-I), muscles of area of wings of a nose and a corner of a mouth (a symptom of Hvosteka-II) or only a muscle of area of a corner of a mouth (a symptom of Hvosteka-III) can be reduced. Percussion on the course of a malar branch of a facial nerve causes reduction of an orbital part of a circular muscle of an eye and frontal muscle (Weiss's symptom) in the outer edge of an eye-socket. During the crossclamping of a shoulder a plait or a cuff of the device for measurement of the ABP before disappearance of pulse for 2 — 3 min. the tetanic contracture of a brush as «obstetrical hand» (Trusso's symptom) develops. Passive bending in a hip joint of the leg straightened in a knee joint (at the same time the patient lies on spin) causes a convulsive spasm of razgibatel of a hip and supination of foot (Schlesinger's symptom — Poulat). About existence of T. also positive symptom Petenya can testify: at blow convulsive bottom bending of foot arises a hammer on a middle part of a front surface of a shin. The condition of electric excitability is estimated by irritation by a small galvanic current of a median, elbow or fibular nerve (a symptom of Erba). The symptom is considered positive if to a katodozamykatelyyua reduction of a muscle arises at current less than 0,7 ma, an at its further increase develops a katodozamykatelny tetanus.
Nosological accessory of a syndrome of T. is defined with diseases, at to-rykh it it is observed. Parathyroprival T. establish on the basis of data of the anamnesis (operative measures, especially repeated, on a thyroid gland, injuries of a neck, etc.), combinations of a hypocalcemia with hyper-fosfatempey, are given also a spetsi of l of the ygy loading tests which are applied in diagnosis hypoparathyrosis (see). Gastric, enterogenous, renal forms T. are distinguished on the dominating displays of the main pathology (plentiful vomiting, ponosa, a steatorrhea, a renal failure). Enterogenous T., and also T. at a hypovitaminosis of D, it is characterized by decrease in contents not only the general calcium, but also phosphorus of blood, but also, increase in activity of alkaline phosphatase, a cut it is observed also at T. at pregnant women and nursing mothers. At a renal failure the level of phosphorus in blood is increased. At sick T., connected with an alkalosis and a hyperventilation, all specified indicators remain within norm. The pseudohypoparathyroidism is distinguished on the basis of a complex of the signs characteristic of this disease (a growth inhibition and intellectual development, a brachydactyly with shortening of metacarpal and plusnevy bones, formation of hypodermic calcificats, a number of neurologic, endocrine and trophic frustration). Diagnosis is helped by laboratory methods of a research: at a pseudohypoparathyroidism the content of calcium in blood is lowered, the content of phosphorus — is increased, activity of an alkaline phosphatase in blood normal or is increased.
The differential diagnosis at a tetanic attack carry out with convulsive states at organic diseases of a brain, rage (see), tetanus (see), a hypoglycemia (see), poisoning with strychnine (see), hysteria (see), epilepsies (see). Consider characteristic symptoms of these diseases, data of the anamnesis, estimate efficiency of intravenous administration of calcium chloride, to-ry stops an attack of T. Unlike epilepsy at T. it is not observed, as a rule, prikusyvanpya language, a loss of consciousness, however, as V. G. Baranov (1977) specifies, sometimes at a hypoparathyrosis the attack of spasms with typical displays of an epileptic seizure and changes of EEG, characteristic of it, develops. In such cases differential and diagnostic value has a research of content of calcium and phosphorus in blood.
Attack of T. stop slow intravenous administration 10 — 15 ml of 10% of p-pa of chloride of a pla of a gluconate of calcium. Injections are repeated if necessary to 2 — 4 times a day. Intramusculary enter 25% solution of magnesium sulfate; apply Seduxenum. At a laryngospasm if there is no bystry effect of administration of calcium, it is shown tracheotomy (see). Urgent actions for correction of metabolic disturbances with the subsequent operative measure are demanded by gastric T. at a pyloric stenosis. The therapy directed to normalization of calcic exchange and the prevention of tetanic attacks depends on nosological accessory of the disease which caused T. (giioparatpreoz, pseudohypoparathyroidism, rickets, dekompensirovanny pyloric stenosis etc.).
Forecast is defined by character of a basic disease and weight of attacks of T. During an attack poses a direct threat for life of the patient larpn-gospazm. The forecast at T is adverse., connected with hron. renal failure. At T. other etiology, including connected with giio-paratireozy the forecast in general favorable also depends on rational therapy of a basic disease.
Prevention attacks of T. consists in treatment of a basic disease. ensuring the normal content in blood ionized a kalpiya, an exception of the factors provoking an aggravation of T. (hyperventilation, overcooling, mental injuries etc.).
A tetany at children
At children of the first two years of life of T. it is observed more often than at children of more advanced age and at adults. According to M. S. Maslov (I960), it occurs at 3,5 — 4% of children of this age. Reasons of T. at children same as at adults, but among them at children of advanced age diseases of kidneys, cirrhosis, a sprue prevail (a Gee's disease, to a spr), heavy intestinal toxicoses. Great value in an origin of T. at children the pathologies observed during certain age periods have the forms. In this regard allocate T. newborns and rachitogenic T. Except for T., caused by an alkalosis (T. gastric, hyper ventilating, T. after introduction to an organism of excess amount of alkalis), main types of T. at children are connected with a hypocalcemia and in most cases the hyperphosphatemia is defined.
T. newborns on the etiology are not, apparently, homogeneous. As a rule, it proceeds with a hypocalcemia, is frequent with a hyperphosphatemia at normal activity of an alkaline phosphatase; also value of decrease in concentration of magnesium in blood is established. The hypomagnesiemia is most often observed at the end of the first week of life. If concentration of magnesium in blood falls lower than 1 mg / 100 ml (it is normal from 1,7 to 2,8 mg / 100 ml), then there are T. Predpolagayetsya's symptoms that T. newborns it can be connected with the hypoparathyrosis arising, in particular, owing to a hyperparathyreosis and a hypercalcemia at mother that on a feedback mechanism weakens function of epithelial bodies of a fruit. In some cases T. it can be caused by damage at the time of delivery of the nerve centers regulating function of epithelial bodies (the role of such disturbances in emergence of T is known. at patients with hypoparathyroid cretinism). In some cases in epithelial bodies hemorrhages are found. However the steady hypoparathyrosis at chest and early children's age meets seldom — at an aplasia of epithelial bodies or owing to a birth trauma. The hyperphosphatemia caused by limitation of fosfatvydelitelny function of kidneys at newborns, especially at premature children and during the feeding by their cow's milk rich with phosphates can be one of the reasons of decrease in the ionized calcium in blood.
Rachitogenic T., or spasmophilia (see), observed at children at the age of 3 — 12 months, it is caused by insufficient receipt in an organism of calcium because of disturbances of its absorption owing to a D-hypovitaminosis (see. Vitamin deficiency ). Increase in content of phosphorus in blood and transition of calcium from blood in a bone tissue at impact of solar radiation (spring) or under the influence of small doses of vitamin D leads to decrease in amount of the ionized calcium in blood and thereof to a tetany.
Wedge, manifestations of T. at children same as at adults (the carpopedal spasm is typical), but it is more often observed laryngospasm (see) the tendency to development of the general tonic and clonic spasms is also more expressed (see). The laryngospasm develops suddenly: there is a sonorous or hoarse breath during the crying, shout or laughter, during the awakening from a dream, then the apnoea, usually for several seconds follows, but can proceed also up to 1 — 2 min. At the child the scared look, a mouth is open, he convulsively tries to make a breath; skin turns pale, becomes covered cold then, then there is cyanosis, generalized clonic or tonic spasms are possible, quite often comes to light ekstrasistolpya. The attack comes to an end with a deep sonorous breath, later to-rogo the child surely cries, but in a few minutes calms down. Such attacks can repeat several times a day; in an interval between them the child looks quite healthy.
The general toniko-clonic spasms — the most severe form of explicit T. Vnachale are usually noted short-term tonic spasms, and then develop clonic, often proceeding with a loss of consciousness. The attack begins with myotonia of the person, to-rye further extend to extremities. In most cases the general spasms proceed several minutes; they can sometimes be followed by an incontience a calla and urine, release of foam from a mouth, as at an epileptic seizure.
In the periods between attacks of T. and at latent T. at children, as well as at T. at adults, the hyperreflexia, paresthesias, symptoms of the increased neuromuscular excitability come to light: positive symptoms of Hvostek, Trusso, Lyust's phenomenon (at effleurage on a fibular nerve on an outer surface of a shin below a head of a fibular bone there is a bystry assignment and bending of foot), Maslov's symptom (the easy prick of skin in the healthy child causes increase and deepening of respiratory movements, and in the patient with a spasmophilia an apnoea).
T. newborns need to be differentiated with spasms at wet brain as a result of asphyxia, intracraneal hemorrhages, a hypoxia, a hypoglycemia, bilirubinovy encephalopathy, malformations of a brain. Quite often children of chest age the reason of spasms have a fever at any disease proceeding with temperature increase (an acute respiratory disease, flu, intestinal infections, vaccination, an infection of urinary tract, etc.). The attack of spasms appears at high (apprx. the 39th a hail) temperature, in most cases in the first day of fever, during an initial stage inf. diseases. Peculiar tetanic spasms are noted at newborns at tetanus (see), inborn toxoplasmosis (see), purulent meningitis (see). The differential diagnosis of a laringosiazm is carried out with different types of a croup (see), and also with inborn stridor (see).
Treatment of T. at children same, as at adults. For stopping of an attack by the newborn enter 2 — 3 ml of 10% of solution of chloride or a gluconate of calcium, to babies — 3 — 4 ml. Intramuscular introduction of 25% of solution of magnesium sulfate is carried out at the rate of 0,8 ml/kg, but by no more than 8 ml. From food of sick T. children exclude cow's milk, to babies appoint an early vegetable feeding up.
The forecast and prevention — same, as at adults.
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V. K. Velikov; L. M. Golber (stalemate. physical.), V. A. Tabolin (ped.).