Controlling muscle activity throughout the body is a function of the human nervous system. When the parts of the spinal cord and brain (the two major organs of the nervous system) that are involved in muscle activity become diseased, the corresponding muscle activity becomes completely different. The same thing happens when the nerve connections between the muscles and the core nervous system are affected. In either case, the type of alteration in muscle activity provides a sense of the nature of the disorder.
Symptoms caused by nervous disorders include emotional abnormalities. The five movement abnormalities most common with nervous disorders are gait disturbance, involuntary movements, muscular hypertonicity, paralysis and tetany. Let’s discuss the motion abnormalities here in detail.
Movement is also related to difficulty walking. Many types of nervous system disorders can interfere with the normal development of walking; which is so, because walking is such a complicated function. Such disorders, which can alter gait, include spasticity or stiffness, weakness, and paralysis.
Involuntary or uncontrollable movements involving muscles or groups of muscles can develop in certain nerve disorders. Athetosis (slow, tortuous, twitching, usually of the hands and feet) and chorea (rapid, jerky movements, usually of the head and limbs) are two examples of nervous disorders in which spontaneous, involuntary movements are developed.
Muscular hypertonia – also called spasticity – is another one of those movement abnormalities that is associated with certain nervous disorders. Some important processes in the body cause the major muscles to remain firm. This is clearly proved by the ability of each person to maintain his position without giving thought to the continuous movements of his body. Once each uses the same muscles in some rapid movement, the very process or mechanism that makes them stay. The firm is automatically offset to move the muscles quickly. In some nervous disorders, this ability to release the muscles is lost, so that those muscles remain firm even when the individual desires move quickly.
Paralysis means the absolute (not merely reduced) inability of a muscle or group of muscles to respond to voluntary commands. The only cause is damage to the nerve or nerve tract that usually controls the muscles. Damage deprives a nerve or nerve tract of its ability to import or transmit nerve impulses.
Tetany is a tonic condition characterized by muscle spasms. In this condition, the muscles respond abnormally to stimulation. Tetany occurs in three conditions: tetanus (an acute infectious disease caused by tonic spasm of voluntary muscles, especially the jaws), alkalosis (an abnormal condition of increased alkalinity of the blood and tissues), and hypoparathyroidism (deficiency of parathyroid hormone in the body, such that when serum calcium drops to low levels ). But tetany can also occur in certain nervous disorders, in which brain cells respond abnormally to normal stimuli.
In fact, each of these five abnormalities causes a general weakness of movement, although weakness in itself is considered a sign of nervous disorders. In weakness combined with nervous disorders, the ability to use the muscles in the usual way is diminished; the causes may be certain nervous diseases that destroy the nerve centers of the muscles or the nerve fibers that lead to these muscles.
As with all types of nervous disorders, the treatment of any of these five movement abnormalities must be carefully managed and monitored by a physician.
Sources:
1. “Movement Disorders” from the Mayo Clinic – http://www.mayoclinic.org/movement-disorders/ types.html
2. “Movement Disorders” from the Neurology Channel – http://www.neurologychannel.com/movementdisorders/index.shtml
