Post-traumatic distal nerve entrapment syndrome.

Eleven patients with paralysis of muscle groups in the upper or lower extremity were clinically diagnosed after previous proximal direct trauma to the corresponding peripheral nerves, without complete nerve disruption. Patients were seen within an average of 8 months after trauma (minimum 3 months and maximum 2 years after). Nerve lesions were caused either by gunshot, motor-vehicle accident, and other direct trauma or, in one case, after tumor excision. All patients presented with complete sensory and motor loss distal to the trauma site, but demonstrated a positive Tinel sign and pain on testing over the "classic" (distal) anatomic nerve entrapment sites only. After surgical release through decompression of the nerve compression site distal to the trauma, a recovery of sensory function was achieved after surgery in all cases. Good-to-excellent restoration of motor function (M4/M5) was achieved in 63 percent of all cases. Twenty-five percent had no or only poor improvement in motor function, despite a good sensory recovery. Those patients in whom nerve compression sites were surgically released before 6 months after trauma had an improvement in almost all neural functions, compared to those patients who underwent surgery later than 9 months post trauma. A possible explanation of traumatically caused neurogenic paralysis with subsequent distal nerve compressions is provided, using the "double crush syndrome" hypothesis.