Peripheral Nerve Injuries

Diagnosis

A detailed neurologic examination will be performed to evaluate motor, sensory and autonomic loss. If the examination indicates signs and symptoms of a nerve injury, the doctor may recommend the following diagnostic tests to determine if a nerve is working normally.

Electromyogram (EMG or Electromyography)

This test measures how the muscles supplied by a specific nerve are working. A thin-needle electrode is inserted into the muscles that appear to be affected by a nerve injury. An instrument records the electrical activity in the muscle at rest, and as the muscle is moved or contracted.

Nerve Conduction Study

Similar to electromyography, this test measures how well electrical signals are transmitted through the nerves. The nerve is stimulated by electrodes placed at two different points in the affected area. Nerve conduction is measured by dividing the distance between the two points by the difference in time it takes for the impulse to travel between them. This yields a "meters per second" speed of nerve conduction.

Magnetic Resonance Imaging (MRI)

This test uses magnetic waves to produce a detailed, three-dimensional view of the affected body area, including the nerve.