ASYNERGIA

ASYNERGIA (from the Greek a- negative part, syn - with and ergon - work), disorder of a complex motor act due to the violation of the ability to associate individual elementary movements into a complex movement. The patient becomes unable to combine a series of movements that in any complex movement must be performed simultaneously in different segments of the body. Because of this, the complex movement is composed of sequential simple movements rather than from the simultaneous combination of the same movements. Tests for A.: 1) the patient stands; he is asked to throw his head back and arch his torso backward. A normal subject at the same time bends the knees and extends the feet, maintaining body balance. The asynergic person is unable to combine the arching of the torso backward with bending of the knees and extension of the feet, loses balance and falls backward. 2) The patient sits. He is given the task to touch the object in front of him at the level of his knees with the tip of his foot. The asynergic person first bends the thigh and raises the leg high, and only then extends the knee and strikes with the foot tip at the target. 3) To the patient lying horizontally, it is proposed to assume a sitting position without using hands. The asynergic person cannot do this, because, instead of raising the torso, he raises the legs, due to the violation of the synergy of contractions of the t. ilio-psoatis and t. glutei maximi. - In asynergia, the amplitude of movements is also disrupted: they become disproportionate to the goal, hence another name for this disorder - dysmetria. When drawing a straight line on paper, the asynergic person does not stop at the set goal but goes beyond it. When trying to take a glass in hand, he excessively opens his palm and then bends his fingers, etc. In A., the ability to quickly alternate repeated movements is also impaired (see Adiadokhokinesis). A. was first described by Babinski (Babinski, 1909) in diseases of the cerebellum, but it can also be observed in lesions of the striatal body system.