[Anterior interosseous nerve lesions revisited in 2004].

[neuralgic amyotrophy]

When the anterior interosseous nerve (AIN ) is involved , a motor deficit of the distal pinch appears . It usually occurred suddenly , with or without pain and the deficit may be complete or partial . Other nerve lesions and some precipitating conditions can be noticed and are important to assess the exact mechanism of the nerve lesion . Partial AIN lesion is frequently misdiagnosed as tendon rupture . The electrodiagnostic examination should always study the pronator quadratus or another muscle innervated by the AIN , the AIN conduction and the motor and sensory median nerve conduction . Thus electrodiagnosis will always assess the AIN lesion and precise its axonal or compressive mechanism . Mononeuritis as neuralgic amyotrophy is the most frequent cause of AIN palsy and never requires surgery . Traumatic lesions are less frequent and usually recover spontaneously . Thus , surgery is rarely required before 12 to 18 months except when no recovery occurs after trauma .