Clonic convulsive syndrome (myoclonia) is characterized by short-term spasms and relaxation of the muscles, quickly following one after another, which leads to stereotyped motions having a different amplitude. They arise when excessive stimulation of the cerebral cortex and is accompanied by somatotypic spreading of the muscles according to the position of the motor cortical centers: starting from the face, fingers, hands, forearms, shoulder, then legs are sequentially seized.
There may be localized clonic convulsions: chorea with rhythmic contraction of the muscles - occiput, shoulders, shoulder blades (convulsive syndrome of Bergeron), bilateral myoclonies of the face, neck, chest, shoulder girdle and upper extremities (convulsive syndrome of Bergeron-Henoch), with cortical genesis - in the form of kozhevnikovskoy epilepsy (arrhythmic convulsions of certain body groups) or Jackson epilepsy (spasmodic contractions of the limbs on the side opposite to brain damage), with stem lesions - convulsions of the eye, soft not ba, tongue, mimic muscles of the face, neck (nodding cramp), etc. A distinctive feature of them (for differentiation with convulsions in tetanus) is painlessness or a feeling of fatigue.
Generalized myoclonias in the form of chaotic twitching of the muscles of the body and limbs are called convulsions, which are also characteristic of lesions of the cerebral cortex in trauma, tumors, meningitis, hypoxia, diabetic coma, high temperature, etc.
Tonic convulsive syndrome is accompanied by a long (up to 3 minutes or more) muscle contraction. They arise both in the stimulation of the subcortical structures of the brain and in the peripheral nerves, as well as in disorders of neurohumoral regulation, in particular / parathyroid function, metabolic disorders, especially calcium and phosphorus, hypoxia, etc. Common tonic convulsions (opisthotonus) are rare. More often local convulsions occur, when stiffness occurs, the "hardening" of individual muscle fibers, for example, faces, it takes the form of a "fish mouth" - a symptom of Khvostek, gastrocnemius or back with osteochondrosis (Korneev's symptom), fingers ("spasm" ), brushes (the "hand of an obstetrician" is a symptom of Tissaur), the thumb and index finger (dactylospasm) - in tailors, musicians and others, whose work is associated with irritation of the nerves that innervate these muscles. Diagnosis of pronounced myospasm does not cause difficulties, during the interictal period and with a latent form, a series of provocative techniques are performed to detect increased excitability of nerve trunks.
Tapping with a hammer along the trunk of the facial nerve in front of the auricle can cause spasm of all muscles innervated by the facial nerve (the symptom of Khvostek I), the region of the wings of the nose and the corner of the mouth (the symptom of Khvostek II), only the corner of the mouth (the symptom of Khvostek III). Tapping at the outer edge of the orbit along the zygomatic branch of the facial nerve causes a reduction in the circular and frontal muscles of the eye (Weiss's symptom). The clamping of the arm with the cuff of the apparatus for measuring blood pressure after 2-3 minutes causes a spasmodic contraction of the hand like the "hand of an obstetrician" (a symptom of Tussaud).
Passive flexion in the hip joint with a straightened knee in the position of the patient on the back causes myopathy of the thigh extensors and foot supination (Stelsinger-Poole symptom). Tapping along the middle part of the front surface of the shin causes a salvage plantar flexion of the foot (Peten's symptom). Irritation with a weak galvanic current of less than 0.7 mA of the median, ulnar or peroneal nerves causes a spastic contraction, innervated by these nerves (Erb's symptom).
Characteristic is convulsive syndrome in tetanus - wound infection caused by the toxin of the absolute anaerobic sporebearing rod Clostridium tetani, characterized by the defeat of the nervous system with attacks of tonic and clonic seizures. With a long incubation period (sometimes up to a month) convulsive syndrome can develop already with healing wounds. The convulsive syndrome and its severity depend on the amount of toxin.
With a very small amount of toxin, it spreads along local tissues (muscles) with damage to the nerve endings of these muscles and regional nerve trunks. The process develops locally, most often causing a non-abstinent reduction, and fibrillation.
With a small amount of toxin, it spreads through the muscle fibers and perineurally, including nerve endings, nerves to the synapses and roots of the spinal cord. The process is of an easy ascending form with the development of tonic and clonic convulsions in the limb segment.
With a moderate and significant amount of toxin, the spread occurs peri- and endoneurally, as well as intraconsularly, affecting the anterior and posterior horns of the spinal cord, synapses and neurons, as well as the motor nuclei of the spinal cord and cranial nerves with the development of a heavy ascending form of tetanus. It is accompanied by the development of common tonic seizures, against which there are also clonic.
When a toxin enters the blood and lymph, the descending form of tetanus develops, in which its spread occurs throughout the body, affecting all groups of muscle fibers and nerve trunks and arriving from the neuron intra-axially to various motor centers. The rate of spread depends on the length of each neural path.
The shortest neural path in the facial nerves, therefore the convulsive syndrome in them develops, first of all, affecting the musculature of the face and chewing muscles with the formation of three pathognomonic symptoms: trismus caused by tonic contraction of the chewing muscles, as a result of which the patient can not open the mouth, sardonic mocking, snide) smile caused by convulsions of facial muscles (forehead in wrinkles, eye slits narrowed, lips stretched and corners of mouth lowered down); Dysphagia due to spasm involved in the act of swallowing. Then the centers of the muscles of the neck and back, later the limbs, are affected. At the same time a typical picture of opisthenus develops, the patient flexes his arch due to a sharp contraction of the muscles, supported by the back of the head, heels and elbows "
Unlike hysteria and catalepsy, convulsive syndrome increases with sound (enough to clap hands) or light (turn on the light) irritation. In addition, in tetanus, only the large muscle fibers of the hand are involved in the process, and the feet retain mobility, which is never the case with hysteria and catalepsy; on the contrary, the hands are compressed into a fist, the feet are stretched out. With tetanic contractions of the face and neck, the tongue moves forward and the patient usually bites it, which does not happen with epilepsy, meningitis and head injury, which is characterized by tongue twisting. Lastly, the respiratory muscles of the thorax and the diaphragm are involved in the process. The brain is tetanus toxin is not affected, so patients even in the most severe cases remain conscious.
Currently, all patients who have a convulsive syndrome, including tetanus, are referred to specialized hospitals with a neurological and resuscitation department.