Medial nerves, or medial branch nerves, carry pain signals to the facet joints of the spinal column. From there, those pain signals are relayed to the brain, which in turn makes the body aware of the pain. Facet joints link each vertebra in the spine and also determine the range of motion of one’s neck. The medial branch nerves originate with the cervical nerves that supply impulses to muscles and skin, particularly in the forearms and hands. There are also medial plantar nerves located in the foot.
Properly functioning medial nerves can lead to debilitating pain, such as lower back pain, simply by being the source by which the brain is informed of the pain impulse. This has led to a pain treatment known as a medial branch block. Doctors performing such a block inject medicine into an area of the spine outside a joint but near the nerve or nerves controlling the area’s pain impulses. It doesn’t necessarily resolve the underlying medical condition but it does block the medial nerve from forwarding the pain signals to the spine for relay to the brain, leaving the body unaware that it should be hurting.
A medial nerve block that fails to relieve the pain is considered a therapeutic failure but serves as a diagnostic tool for doctors, who use the ongoing pain to determine that the joint is not the problem. Pain that goes away for a short while before returning tells doctors that the joint is the problem but the medicine used, sometimes steroids, was ineffective. Pain that goes away, returns, and goes away again tells doctors that the block had therapeutic value and can be repeated as necessary. Medial nerve blocks may last only a short while, but such effective short-term therapy can lead doctors to perform another procedure that has similar but longer-lasting effects.
Improperly functioning medial nerves also can be a problem, though many related conditions are easily treated without surgery. Undue pressure on the medial nerve can lead to such conditions as medial epicondylitis, or golfer’s elbow. The condition is a form of tendinitis caused by stress on the muscles that bend the wrists forward. Surgery is rarely necessary in treating golfer’s elbow, because the pain usually subsides when the affected muscles are allowed to rest. Strengthening and stretching exercises after pain has subsided can help prevent the condition from returning.