Nerve Compression
By Roger C. Sohn, MD
What is Suprascapular Nerve Compression?
Suprascapular nerve compression is a syndrome of pain in the back of the shoulder. This condition can vary in severity from mild in some cases to severe in others. The suprascapular nerve is a very important nerve of the shoulder, giving power to the rotator cuff muscles. This deep layer of shoulder muscles allows the shoulder to have strength and stability through a range of positions. The suprascapular nerve passes over the top of the shoulder blade in an area called the suprascapular notch. The nerve passes under the transverse scapular ligament which can place pressure or abrasive force on the nerve. This can lead to irritation and inflammation of the nerve.
What are the symptoms of Suprascapular Nerve Compression?
Patients often describe the symptoms as a pain in the back of the shoulder. It tends to radiate down from the top of the shoulder and down to the middle of the shoulder blade. The symptoms can be worsened by certain positions or activities such as working out or rotating the shoulder outward. In some cases, avoidance of those activities can relieve the nerve pain, but in some cases, the nerve can remain inflamed, leading to an increase in pain in the posterior shoulder. In longstanding cases, the nerve can also become damaged, leading to weakness of the rotator cuff muscles. This can result in difficulty when externally rotating the shoulder.
How is Suprascapular Nerve Compression Diagnosed?
A shoulder specialist can make the diagnosis by asking about the location of your symptoms. The doctor will also examine the shoulder and look for other possible causes of the pain. Imaging tests such as X-rays and MRIs can give additional information. In some severe cases, a nerve conduction test can detect the loss of normal innervation to the rotator cuff muscles. However, the most reliable way to diagnose the problem is by doing a diagnostic injection. During a diagnostic injection, the doctor places an ultrasound probe over the suprascapular nerve. The doctor then injects a mixture of lidocaine and cortisone into the area of around nerve. After a few minutes, the doctor will ask the patient to try to put their shoulder in the positions that cause pain. If the pain is gone after the injection, this confirms the diagnosis.
The pain relief from a shot typically follows a "double dip" pattern if the nerve is indeed the problem. The first dip in pain relief happens within minutes due to the fast-acting lidocaine in the injection. The lidocaine wears off after about 1 hour at which point the pain will return. However, the pain will start to improve again as the cortisone starts working 2-3 days after the injection. If the pain relief follows the “double dip” pattern, the diagnosis is reinforced.
What are the treatments for Suprascapular Nerve Compression?
In some cases, the diagnostic injection can also be the cure for the problem. It can be helpful to add a moderately gentle course of physical therapy to eliminate any bad scapular mechanics. If the shoulder remains stable, any compression on the nerve may be relieved. However, if the symptoms persist, surgery can be very helpful. The surgery is a minimally invasive arthroscopy of the shoulder. During the procedure, the surgeon places a camera called an arthroscope in the shoulder. The nerve is identified and protected with retractors. Then the overlying ligament is cut, removing pressure from the nerve. If there are additional problems with the shoulder they can be addressed at the same time as needed.
What are the risks of surgery?
Any surgery carries risks such as infections, anesthesia risks, bleeding, and postoperative pain. The nerve may also become temporarily bruised from the placement of retractors during surgery. The nerves in the area may also become irritated in a condition known as complex regional pain syndrome. The pain may not be completely relieved by the surgery.
What are the restrictions after surgery?
The restrictions depend on whether there are other procedures done at the same time as the suprascapular nerve release. If the nerve release is done alone, there is usually about a week of restricted motion and sling use. After that, patients are encouraged to use the shoulder as pain allows. If there are other repaired structures at the time of surgery, this may increase the length of restrictions. In many cases, the pain in the back of the shoulder is relieved within the first few days after surgery.