Girliha Phenomenon

Gierlich phenomenon is an involuntary pronator movement of the arm on the side of paresis or ataxia when it is extended. This phenomenon was first described in 1875 by the French neurologist and physiologist Hippolyte Dejerine.

The Gierlich phenomenon manifests itself in the fact that when the arm is extended on the side of paralysis or ataxia, the hand and fingers turn inward and the pronator muscle contracts, which leads to flexion of the arm. This movement can be caused either by passive extension of the arm or by active movement.

The mechanism of this phenomenon is due to the fact that on the side of paralysis or ataxia there is a decrease in the tone of the pronator muscles, which allows the arm to stretch without resistance. As a result, the hand and fingers rotate inward, which leads to contraction of the pronator muscle and flexion of the arm.

This phenomenon has important clinical significance because it can help in the diagnosis of paralysis and ataxia, as well as in assessing the condition of the pronator muscles. In addition, the Gierlich phenomenon can be used to assess the effectiveness of treatment and rehabilitation of patients with neurological diseases.