Several syndromes of median nerve entrapment proximal to the carpal tunnel have been described. These include entrapment at the ligament of Struthers (LS), lacertus fibrosis, heads of the pronator teres (PT) muscle, sublimis bridge of the flexor digitorum sublimis muscle, and of the anterior interosseous nerve (AION). These proximal median nerve (PMN) syndromes appear in the literature of several medical and surgical specialties, but our experience suggests that true neurologic lesions are relatively uncommon. Because these syndromes are rare and often confused with radiculopathy or carpal tunnel syndrome (CTS), it is important for clinicians to keep a high index of suspicion so that proper diagnosis and treatment are ensured when they evaluate upper extremity pain and sensory loss. Table 1 provides a summary of the common entrapment syndromes of the median nerve.

Some median nerve compression neuropathies occur in the proximal arm.<sup>12 Gessini L., Iandolo B., Pietiangeli A. Entrapment neuropathies of the median nerve at or above the elbow Surg Neurol 1983 ;  19 : 112-116  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti, 21 Kaufman M. Differential diagnosis and pitfalls in electrodiagnostic studies and special tests for diagnosing compressive neuropathies Orthop Clin North Am 1996 ;  27 : 245-252

Cliccare qui per andare alla sezione Riferimenti, 47 Sunderland S. The median nerve: Anatomical and physiological features Nerves and Nerve Injury Edenburgh: Churchill Livingston (1978).  672-677 691–727.

Cliccare qui per andare alla sezione Riferimenti</sup> These syndromes are not discussed in detail because they are not true entrapments but rather compressive injury to the nerve from an identifiable cause (i.e., crutch palsy, humeral fracture, trauma and so forth).

The median nerve, like most nerves, has an internal architecture: nerve fibers are not randomly distributed but tend to cluster in groups that eventually branch off from the main trunk of the nerve.<sup>47 Sunderland S. The median nerve: Anatomical and physiological features Nerves and Nerve Injury Edenburgh: Churchill Livingston (1978).  672-677 691–727.

Cliccare qui per andare alla sezione Riferimenti</sup> This is clinically important because a compressive force may be unequal and may disproportionately damage fibers destined to become one branch of the median nerve.<sup>17 Jabaley M.E., Wallace W.H., Heckler F.R. Internal topography of major nerves of the forearm and hand: A Current View Am J Hand Surg 1980 ;  5 : 1-18

Cliccare qui per andare alla sezione Riferimenti, 52 Weitsch J.J., Sanger J.R., Matloub H.S. Pseudo-Anterior Interosseous Nerve Syndrome Muscle Nerve 1985 ;  8 : 68-70

Cliccare qui per andare alla sezione Riferimenti</sup>