Anterior interosseous nerve syndrome following supracondylar lesions of the median nerve: clinical findings and electrophysiological investigations.

Lesions at the volar aspect of the forearm may lead to isolated paralysis of the anterior interosseous nerve, which is a purely motor branch of the median nerve. The same syndrome may result from circumscribed damage at the level of the upper arm. Two patients are reported with the typical anterior interosseous nerve syndrome following supracondylar lesions of the median nerve and the literature is reviewed. In most cases this syndrome is a complication of supracondylar fractures of the humerus in children. A simple clinical test for the diagnosis, the pinch test, and the typical electromyographic findings are described. Whereas electroneurography has been considered to provide little help in diagnosis, a significantly lower nerve conduction velocity was found in the median nerve between the medial intermuscular spatium and the cubital fossa compared to the normal arm, and a prolonged response latency of the pronator quadratus of the injured arm following stimulation of the median nerve in the intermuscular medial spatium and the cubital fossa.