Tonic convulsions are sharp and prolonged muscle contractions, in which the limb or the whole body freezes in a forced position. They are local and generalized, accompanied by pain, dysfunction of other systems. Convulsions manifest infectious diseases, metabolic disorders, intoxications, etc. Neurological examination, laboratory tests (general, biochemical, molecular genetic), functional methods help to find out the cause. Treatment is aimed at relieving symptoms and correcting the underlying pathology.
In preschool children, diseases with a febrile syndrome can provoke febrile convulsions. Their development is due to the action of pro-inflammatory cytokines (especially interleukin-1β), increased sensitivity to hyperthermia of some ion channels. Common causes of febrile seizures are acute infections:
Tonic spasms in tetanus are caused by an exotoxin that inhibits the release of inhibitory mediators. Attacks include trismus of mastication, sardonic smile, rigidity, and opisthotonos. Convulsions in rabies are explained by degenerative changes in the pyramidal tract, cerebellum, and brain stem. Muscles reduce from loud sounds, movement of air, water.
Seizures are caused by fluid and electrolyte disorders, which may be due to malabsorption of certain substances (malabsorption, vitamin D deficiency), endocrinopathies (hypoparathyroidism, hyperaldosteronism, diabetes insipidus), kidney pathology and other conditions. Tonic convulsions are included in the picture of numerous electrolyte imbalances:
Tonic convulsions are accompanied by severe hypoglycemia with energy starvation of the brain. In diabetes, it is provoked by an overdose of drugs, physical activity, alcohol intake. In other situations, insulinoma must be ruled out. In addition to convulsive seizures, neuroglycopenic syndrome is manifested by impaired consciousness up to coma, weakness, visual impairment.
Convulsive activity is also present in the clinic of hyperglycemic conditions, especially diabetic hyperosmolar coma. Already at an early stage, consciousness is disturbed due to an increase in the osmolarity of the plasma. Local or generalized tonic convulsions can be supplemented by symptoms of focal CNS lesions: aphasia, paresis, sensory deficit. Patients are disturbed by intense thirst and polyuria.
Many metabolic disorders are characterized by damage to the brain tissue and tonic convulsions. The picture of hereditary metabolic diseases is due to the accumulation in the body of certain substances or a deficiency in the products of their enzymatic cleavage. Attacks of tonic convulsions can manifest various monogenic defects:
Transient blood flow deficiency and cerebral ischemia explain tonic convulsions in cardiovascular diseases. Complete atrioventricular block with bradycardia and periods of asystole is manifested by Morgagni-Adams-Stokes syndrome - loss of consciousness, tonic and clonic spasms. Similar changes can occur in deep syncope due to acute arterial hypotension.
Uremic convulsions occur against the background of chronic renal pathology (nephritis, polycystic, nephrosclerosis), potentiated by the action of nitrogenous substances. Characterized by tonic spasms of the muscles of the extremities, widespread myoclonus, fibrillar or fascicular twitching. In the interictal period, muscle excitability increases, pathological reflexes appear.
Hepatic encephalopathy is associated with the cerebrotoxic effect of various metabolites (ammonia, mercaptan, short-chain fatty acids), manifested by tonic convulsions of the arms and legs, rigidity, twitching of individual muscles. Flapping tremor (asterixis), impaired consciousness are typical. Against the background of a reduction in the size of the organ, jaundice sharply increases, a "liver" smell from the mouth is noted.
Sharp contractions of the muscles of the back, neck, trunk and limbs are characteristic of epilepsy in children. In patients up to a year, flexion, extensor, mixed paroxysms of the tonic or clonic type may be observed. Other epileptic syndromes are associated with them - Vesta, Otahara, Lennox-Gastaut. Pathology is manifested by frequent convulsions, often refractory to anticonvulsants, mental retardation of the child.
Non-epileptic paroxysms include dissociative convulsions that occur against the background of mental disorders, psychological conflict, and the action of strong stressors. Usually we are talking about hysteria, which is accompanied by a seizure with arching "arc", reminiscent of an epileptic seizure. Unlike the latter, such a seizure has a clear demonstrative character, occurs in the presence of other persons, and is not accompanied by injuries.
An increase in neuromuscular excitability forms the basis of neurogenic respiratory disorders, in particular, hyperventilation syndrome. In his picture there are tonic convulsions in the extremities of the type of "obstetrician's hand" or carpopedal spasm, symptoms of Trousseau and Khvostek, paresthesia. The development of such conditions is associated with hypocapnic alkalosis, electrolyte imbalance.
Heat cramps are caused by the loss of sodium and chlorides with sweat, are painful tonic muscle contractions lasting from several minutes to an hour that occur during exercise. With a local decrease in temperature, spasms of the extremities are observed. With severe general hypothermia, trismus, the position of the embryo, and tension in the muscles of the abdominal press are detected.
With electrical injury, convulsions cover areas of the body through which the current discharge has passed. Severe muscle spasm can lead to contractures, dislocations and fractures. As an element of cerebral disorders, convulsions accompany radiation injuries in the primary reaction phase in the cerebral form of radiation sickness. Neurological symptoms are supported by encephalomyelopathy, focal infarcts.
A common cause of seizures is the toxic effect of various chemical compounds on the central nervous system. Usually, the conscious use of psychoactive substances (alcohol), carbon monoxide poisoning, strychnine poisoning, or an overdose of drugs are ascertained. The tension of striated muscles is caused by the action of a number of drugs:
The origin of tonic seizures is determined by the results of a comprehensive examination. An important role in the diagnosis of pathological conditions is assigned to anamnestic data and a thorough neurological examination. Additional methods are used to verify structural, functional and metabolic disorders:
Hereditary pathology is detected by molecular genetic tests, by prenatal diagnosis. The presence of symptoms from the internal organs requires an ultrasound scan of the kidneys, liver, and an ECG is prescribed for cardiovascular diseases. A neurologist should distinguish convulsions from hyperkinesis and other paroxysmal conditions.
At the pre-hospital stage, with local spasms, it is recommended to rub and massage the affected area, stretch the muscles contracted by a tonic cramp. In the case of a generalized attack, it is necessary to protect the patient from possible injuries, to provide access to fresh air. The emergency medical team that arrived on call conducts symptomatic correction with anticonvulsants.
The basis of the traditional treatment of tonic seizures is drug therapy, the purpose of which is to eliminate symptoms, influence the causes and mechanisms of the development of the underlying disease. Given the extensive etiological structure of the convulsive syndrome, various drugs may be present in its correction schemes:
Some drug-resistant seizures may benefit from a ketogenic diet. The nature of nutrition occupies an important place in the treatment of hereditary fermentopathy, electrolyte disorders. From non-drug methods, massage, exercise therapy, psychotherapy are also used. Severe poisonings require extracorporeal detoxification.