Deco Test

The deco test is a method for identifying paresis of the hand muscles innervated by the median nerve. This test is based on the fact that when a patient tries to take a piece of paper with fingers I and II, he involuntarily brings the first finger towards the palm. This occurs due to paresis of the muscle that is innervated by the median nerve and is responsible for adducting the thumb. If an involuntary lifting of the first finger is observed during the deco test, this may indicate median nerve palsy.

To conduct a deco test, you need to ask the patient to take a piece of paper in his hand and try to squeeze it between fingers I and II. Normally, during this movement the first finger should rise towards the palm. If the patient cannot lift the first finger, or it rises only partially, then this may indicate the presence of median nerve paresis.