The nerve root is a peripheral extension of the central nervous system (CNS) that exits the spinal canal and terminates in the extremities. Its purpose is to transmit sensory information from the extremity to the brain and motor commands from the brain to the extremity.

Nerve root irritation occurs when some structure puts pressure upon the nerve root either in the form of a tumor, a fracture, arthritis, a congenital deformation, or herniated disc, a stenotic canal (narrowed spinal canal) or several other diagnoses.

Compression of a nerve(s) in the cervical spine (neck) can cause a radiating pain in the arm or shoulder, making shoulder motion painful. It is uncommon for shoulder pain to be caused by nerve irritation. However, a suprascapular nerve can become entrapped and can cause weakness or an inability to flex, abduct and externally rotate the shoulder.

Minor cases of nerve entrapment may respond to a course of physical therapy and anti-inflammatory medication. Patients generally respond well to moist heat on the affected area. If symptoms persist or worsen, a physician may order electromyography (EMG) or a magnetic resonance image (MRI) of the cervical spine. The EMG will help assess neuromuscular activity.

Symptoms
Symptoms include pain, numbness, tingling and weakness.

Diagnosis
The diagnosis is made through a neurologic exam and confirmed through the use of an MRI (magnetic resonance image), EMG (electromyography), a discogram (when normal saline is injected into a disc to expand it and determine if this recreates pain) or CT myelogram. An EMG is an electrical test which determines the ability of a nerve to conduct an electrical charge. A myelogram is an injection of contrast material (dye) into the cerebral spinal fluid (CSF) which occurs in the sac surrounding the spinal cord.

Treatment
Treatment may include a short period of rest (24-72 hours), anti-inflammatory medications, bracing and a gradual return to exercise. Steroid injections into the spinal canal may be helpful. Often, a back stabilization exercise program is extremely helpful to the patient.