Spasticity

Definition

Spasticity is a type of paralysis. Unlike flaccid paralysis, in which the affected limbs hang down from the body, spastic paralysis is characterized by greatly increased muscle tension. In spasticity, the muscles are in a kind of permanent excitation, which is due to the disorder causing it. This is located in the area of the central nervous system, i.e. in the brain or spinal cord.

What is damaged in spasticity?

If the nerve tracts that control movement in the brain or spinal cord are damaged, two pathological mechanisms are the result. On the one hand, the so-called pyramidal tract, which in healthy people establishes the connection between the brain (more precisely: motor cortex) and the nerves that supply the muscles, is interrupted. Since the nerve that mediates between the pyramidal tract and the muscle no longer receives any stimuli from the brain, its excitability increases, which then leads to increased reflexes, for example – a diagnostic feature of spasticity.

On the other hand, the extrapyramidal system that opposes the pyramidal tract is affected. The extrapyramidal system normally has an inhibitory effect on muscle excitation. If this function is lost, hyperexcitability occurs with increasing muscle tension up to the spasmodic muscle status of spasticity. In this sense, spasticity is not a disease in itself, but the symptom of nerve damage. The causes of spasticity are many and varied, but are always due to damage to the movement-mediated nerve pathways in the brain or spinal cord.

Causes of spasticity

Spasticity most often occurs as a result of a stroke (cerebral infarction). In this case, an area of the brain is no longer sufficiently supplied with blood due to a vascular occlusion or bleeding, which causes an oxygen deficiency. Without oxygen, the sensitive nerve cells (neurons) quickly break down and die.

This can result in movement disorders such as spastic paralysis, although this often only occurs as the disease progresses. The aforementioned lack of oxygen, which can lead to the massive destruction of nerve cells and to various deficits as well as spasticity, may also occur in a way other than a stroke. One example of this is early childhood brain damage.

Children who are exposed to an excessive lack of oxygen during pregnancy or at birth may suffer temporary, but also permanent damage such as spastic paralysis. Accident-related changes in the structures of the brain and spinal cord can also interrupt the movement-controlling nerve tracts and trigger spasticity. The most common accident-related injury is the craniocerebral trauma, which is particularly common after traffic accidents.

Another possibility is the underlying chronic disease. Multiple sclerosis (MS) or amyotrophic lateral sclerosis (ALS), for example, are classic triggers for spasticity, even though the diseases themselves are far less common than a stroke. Inflammatory diseases of the nervous system (meningitis, encephalitis or myelitis) rarely leave behind corresponding damage.

Spasticity of the lungs or bronchial tubes has only one thing in common with spasticity as such or spastic paralysis – the spasmodic process. A so-called bronchospasm results in increased muscle tension in the respiratory muscles. As a result, the airways become narrower, the breathing resistance increases: the patient can no longer exhale well.

The cause of bronchospasm is often found at the bottom of a chronic lung disease. A special group of these diseases – obstructive lung diseases – classically cause narrowing of the airways. Examples are bronchial asthma and COPD (the most common smoker’s disease).

An acute inflammatory disease of the respiratory tract, such as bronchitis, can also cause bronchospasm under certain circumstances. However, this often happens if the patient already suffers from a chronic lung disease. If no disease is the cause of the spasticity of the respiratory muscles, there may be poisoning with chemical vapors or smoke.

The treatment of acute bronchospasm is usually carried out with inhalation sprays. A distinction is made between short-acting drugs for acute respiratory distress and long-acting drugs for existing chronic lung disease. Spasticity in the intestine leads to a defective function of the intestine.Only a part of the intestine or in very rare cases the whole intestine can be affected.

The spastic cramping of the intestinal wall alternately leads to longer lasting constipation and diarrhea. This is due to the disturbance of the so-called peristalsis. This is the movement of the bowel to allow food to pass through the intestine.

Spasticity in the bowel is often accompanied by severe abdominal pain and sudden cramps. Spasticity in the bowel can also occur in the context of multiple sclerosis, where there is a disturbance in the transmission of nerves. For the treatment of spasticity in the bowel, antispasmodic drugs are available.

The best known representative of this group of drugs is Buscopan (also known as Spasman, spelled Butylscopalamin). Painkillers such as ibuprofen or diclofenac are also used to treat pain. Multiple sclerosis (MS) is a chronic, inflammatory disease of the central nervous system, i.e. the spinal cord and the brain.

The disease most frequently occurs for the first time between the ages of 20 and 30 and is characterized by symptoms such as cerebellar dysfunction, spastic paralysis, sensitivity disorders and other deficits. Since MS is a disease in which the course is often relapsing-remitting, the symptoms can occur with varying degrees of severity. Both the severity of symptoms may vary among different patients, as well as among a patient at different times.

Spasticity occurs in about 30% of all patients at the beginning of the disease and in over 80% during the course of multiple sclerosis. Spasticity, which is caused by inflammation of the nervous system, is variable in its severity. Only the hands can be spastically paralyzed, while the arm can be moved completely normally.

Spasticity can also be more extensive, affecting entire limbs or one half of the body (e.g. left arm and left leg). In some cases, paraplegia may also be a cross-sectional symptom. For example, both legs are paralyzed, as may be the case after an accident involving the spine.

Although the exact cause of MS is not yet known, the mechanism leading to spasticity must be the same as for other causative diseases. The pyramidal tracts and the extrapyramidal system (see “Definition”) are damaged by the inflammation, which leads to an overactivation of the muscle controlling nerve cords. A stroke, also known as a cerebral infarction or apoplexy, refers to the massive and sudden undersupply of blood to an area of the brain caused by the occlusion of the supplying vessel or by a bleeding.

After a stroke, movement is often restricted, usually affecting the arms or hands, but more rarely the lower limbs. These restrictions are due to damage to the brain, or more precisely to the areas that control movement. While the acute paralysis symptoms tend to be of a flaccid nature, there are several possibilities for further development.

The deficits can heal completely, the flaccid paralysis can persist or transform into spastic paralysis over weeks or months. Since the damage is in the brain, the direct control center of motor function (movement) is affected. Once the nervous system has overcome the shock of the undersupply, there is a gradual increase in muscle tension, which can turn into spastic paralysis of a permanent nature.

In babies, oxygen deficiency can cause damage to the brain, which can result in spasticity. This oxygen deficiency can occur during pregnancy, but also at birth or later. During pregnancy, for example, there is the possibility that the umbilical cord may be broken and thus the supply to the fetus may be interrupted.

Complications can occur during birth, such as the baby lying in the birth canal for a long time without a functioning oxygen supply, or the umbilical cord wrapping itself around the baby’s neck. A common cause of oxygen deficiency during birth is bathing accidents, in which the life of the child, but not all areas of the brain can be saved. This damage, known as infantile central paresis, is caused by the death of nerve cells (neurons) in the brain.Neurons are very sensitive cells and cannot survive long without a functioning supply of oxygen.

They are particularly vulnerable in infancy. Since the brain is still developing, the failure of a group of neurons can cause worse consequential damage than in adults. The resulting spasticity can be satisfactorily adjusted under good therapy and sometimes make a life without a wheelchair possible.

Various drugs and novel surgical techniques are used. The prognosis of such spasticity caused by early brain damage in children is highly dependent on the degree of damage. Are you more interested in this topic?spasticity is caused by an incorrect regulation of the activation of muscles by the nerve cells.

This is always caused by damage to various nerve tracts in the back. One important pathway is the so-called pyramidal pathway, which conducts commands to activate the muscles from the brain via the spinal cord to the respective muscles. The other important pathways are the so-called extrapyramidal pathways.

These mainly transmit signals to the muscles, which have a calming effect to prevent excessive activation of the muscles. If these pathways are damaged, the muscle lacks the command to reduce its tension. Accordingly, the tension of the muscle is increased. Now, the information or impulses that cause the muscle to execute uncontrolled twitches also predominate. This results in a twitch, which is spastic, i.e. convulsive, due to the lack of control over the nerve tracts.