Nontraumatic, progressive paralysis of the deep radial (posterior interosseous) nerve.

Abstract

Isolated paralysis of the deep radial nerve is relatively infrequent and is usually secondary to acute trauma. A few cases have accumulated in the literature in which weakness was insidious at the onset but progressed slowly to complete paralysis. Since the etiologic factors remain obscure in the majority of these cases, it is our purpose to present 2 cases in which pathologically proved neoplasms were found in association with alterations in the deep radial nerve adjacent to the tumors, and to review 16 additional cases reported in the literature. Anatomically,1the deep radial nerve arises as a terminal branch of the radial nerve near the lateral epicondyle of the humerus, where it contains motor fibers only (Figs. 1 and 2). It descends just medial and anterior to the lateral epicondyle, crossing the anterolateral aspect of the elbow joint in a cleft between the brachialis and the brachioradialis muscle. Just