A spasm is a pathological contraction of the muscles associated with an increase in their tone . A spasm is a reflex reaction, depending on the state of the pyramidal system . Active mobility during a spasm is sharply limited, passive is also difficult, and with passive movements of the limbs there is an increased resistance, which has a springy character. With minor movements, muscle hypertension may not be caught; in these cases, it becomes noticeable with sharper movements.
Clinical manifestations of skeletal muscle spasm are an increase in muscle tone, tactile tension of the muscles and a visual change in their configuration. A characteristic picture of a spasm is an electromyogram, on which an increase in the amplitude of potential fluctuations and other signs are detected. Spasm of the muscles of the limbs are observed in childhood paralysis , lesions of the brain and spinal cord .
In the clinic, spasm of blood vessels , respiratory tract, and digestive tract are of great importance in addition to spasm of the skeletal muscles. These spasms are also most often reflex and are caused by these or other stimuli indirectly through the central nervous system, although the source of irritation itself may be localized in the spasm organ. So, bronchospasm can be the result of a foreign body in the respiratory tract; vasospasm may occur as a result of local cooling or under the influence of only emotional influences.
In the case of skeletal muscle spasm, various relaxants are prescribed to relax it (see muscle relaxants ), and in the case of smooth muscle spasm vasodilator, bronchodilator drugs, spasmolytic agents (see), etc.