Spasm

SPASM (from Greek spasmos—cramp), prolonged contractions of muscles associated with an increase in their tone and usually caused by a defect in the pyramidal system. Spasm is characterized by a decrease in passive mobility and an increase in the resistance offered during passive movements (hypertonia). Unlike rigidity in S., the resistance is elastic (it springs back). Usually, hypertonia is already present at rest; during active and especially passive movements, it is reflexively increased to a very varying degree. During rapid movements in these cases, a very significant but quickly decreasing muscle tension is found in the first moment, which is significantly reduced or may even completely disappear with cautious and slow movements. Therefore, to reveal beginning reflex S., it is sometimes necessary to resort to more vigorous movements and to pay attention to the resistance of the muscles when approaching physiological end points of movement. If, during the performance of a passive movement, the patient is asked to increase it at a certain moment by a voluntary movement, the muscle resistance immediately decreases significantly, although only temporarily. In spasm, the resistance offered to a movement in a certain direction is usually greater than in the antagonist. A tendency for the spastic limb to return to its original position is also observed, especially with more significant S. Spasms significantly hinder movements, because in this case, to achieve the same external effects, motor impulses must be increased, all the more so because in these cases the physiological decrease in tension in the antagonists that normally occurs with voluntary movements is disrupted. Signs of increased tone are the strengthening of tendon reflexes, muscle tension, and a change in the contour of the muscles upon inspection and palpation. In the lower extremities, S. in spinal diseases usually occurs earlier and is more severely expressed in the proximal parts than in the distal parts. Individual muscle groups are affected differently in this case, usually the flexors are more affected than the extensors. Spasm is usually most pronounced in the adductors. Adductor spasms are especially frequently observed in cerebral infantile paralysis and lead to a peculiar position of the legs when standing and walking (see Infantile Paralysis). Reflex intensification of spasm is often detected only in the lower extremities during standing and walking, during which the legs become immobile! Thermal influences have a great effect on the state of tone. Thus, prolonged warm baths significantly reduce it. -- By intentional S. is meant S. occurring during the performance of voluntary movements, by protospasm—the first twitching in individual muscle groups before general convulsions, corresponding to the focus of damage in the cortex, for example in Jacksonian epilepsy. Myospasm is the convulsion of muscles in general, monospasm is the convulsion of individual muscles or limbs.

and. Receiving.