Evaluation of peripheral nerve injury

Common etiologies of peripheral nerve injury include penetrating injury, crush, stretch, and ischemia. Management of nerve injury requires familiarity with the relevant anatomy, pathology, pathophysiology, and the surgical principles, approaches and concerns. Surgical repair is done at varying time intervals after the injury, and there are a number of considerations in deciding whether and when to operate. In neurapraxia, the compound muscle action and nerve action potentials on stimulating distal to the lesion are maintained indefinitely; stimulation above the lesion reveals partial or complete conduction block. The picture in axonotmesis and neurotmesis depends on the time since injury. The optimal timing for an electrodiagnostic study depends upon the clinical question being asked. Proximal nerve injuries are problematic because the long distance makes it difficult to reinnervate distal muscles before irreversible changes occur. In the early management of peripheral nerve injury, control of pain is often the most pressing consideration and a number of approaches may be used to bring relief.