There are many causes for arm pain but only a small percentage of arm pain originates from pinched nerves in the neck. Nonetheless, the pain resulting from cervical radiculopathy, pinched or damaged nerves, can be severe. Frequently, arm pain starts at the base of the neck or near the scapula (shoulder blade). The pain commonly is constant and little can relieve it. At times, placing the hand on top of the head can help as that decreases the stretch occurring on the pinched nerve. Most cases of radiating arm pain resolve spontaneously, but medications and epidural injections can be quite helpful in decreasing pain while the body heals itself. If non-operative treatments fail there are multiple surgical options including a foraminotomy (enlarging the space for the nerve), fusion, and disc replacement. Progressive weakness in an arm is concerning and frequently an indication for surgery.
Cervical discs, like discs throughout the spine, consist of a strong outer ring of collagen (the annulus) that holds a softer, spongier portion of the inner disc (the nucleus). In cervical radiculopathies, a portion of the outer annulus tears, and some of the inner nucleus herniates or pushes out. When a disc herniates it can place pressure on a nerve or the spinal cord, which can cause the pinched nerves typical of cervical radiculopathy.
Most cervical radiculopathies occur without a precipitating cause. A blow to the head, a motor vehicle accident, or a rapid twisting injury can also cause cervical radiculopathy.
Most cervical radiculopathies present initially with neck pain that resolves over days to a few weeks. If a nerve is pinched, however, pain near the scapula or shoulder blade is common. Numbness, tingling, or pain in the arm or hand can occur. Occasionally, patients will experience weakness. Symptoms are frequently worse during neck extension and head tilt toward the painful arm. Patients may find relief by raising the arm and placing one's hand on the head because the stretch on the nerve is minimized.
If the disc radiculopathy stems from an issue that compresses the spinal cord, myelopathy can result. Symptoms may include arm or leg weakness or numbness, bowel or bladder incontinence, difficulty using the hands, and trouble with balance.
Most cervical radiculopathy pain will resolve spontaneously over two to six weeks. In cases involving herniated discs, the herniated piece of the disc will often begin to shrink and the nerve is no longer irritated. Early treatment involves heat or ice, anti-inflammatory medicines (such as ibuprofen or steroids), muscle relaxant medicines, and narcotics. Physical therapy, including cervical traction, can help reduce pain.
If more conservative treatments fail, epidural injections are a minimally invasive way to help with arm pain. Steroids are injected around the irritated nerve under x-ray guidance.
Finally, surgical intervention is considered when symptoms last for several weeks without improvement, there is weakness in the arm that does not improve, or the spinal cord is compressed (myelopathy). If the disc is herniated to the side of the spinal cord, surgery may be performed through the back of the neck. The surgeon removes only the herniated fragment of the disc (posterior cervical foraminotomy). Surgery is more commonly performed from the front or anterior approach. This operation involves removing the entire disc and performing a cervical fusion or disc replacement. Overall, surgery is highly effective in relieving scapular and arm pain, with success rates above 85%.