Dysmetria

DYSMETRIA, lack of measure in movement both in spatial and temporal relations: movement goes beyond the set goal, stops too late, is performed jerkily, with excessive

Excessive opening of the right and left hand when grasping a glass.

speed. D. is revealed by a series of experiments. - Grasping experiment: the patient is asked to take a glass - he opens his hand too widely and closes it later than he should (see figure). - Experiment with forearm rotation: the upper limbs are extended forward with palms up, on command the patient rotates them inward - on the affected side the rotation is excessive, more than on the healthy side. - Experiment with drawing: the patient is asked to draw a horizontal line to a set point - the line goes beyond this point; he is asked to draw a series of vertical strokes between two horizontal lines - the drawn' strokes go above and beyond these horizontal lines. The classic experiment - hitting the tip of the nose, the ear with the index finger. Dysmetria plays a large part in the formation of adiadokokinesia. On the lower limbs D. is especially manifested in gait - excessive flexion in the joints, throwing the affected lower limb to the side. A characteristic distinguishing feature of D. from spinal ataxia - complete independence from closing the eyes (A. Thomas). D. is a symptom of cerebellar damage and its connections. In a less pure form, it can be observed with cortical, thalamic, pontine and bulbar lesions. Instruments for registering dysmetria were proposed by Rossolimo.