Causes include severe atherosclerosis, inflammation of blood vessels, blood clots, and sometimes procedures that involve the abdominal aorta.
Sudden back pain with pain radiating from the affected area is followed by muscle weakness and inability to feel heat, cold, or pain in the affected areas and sometimes paralysis.
Magnetic resonance imaging or myelography with computed tomography is usually done.
Treatment focuses on correcting the cause if possible or relieving symptoms.
Spinal cord dysfunction and paralysis are usually permanent.
(See also Overview of Spinal Cord Disorders.)
Like all tissues in the body, the spinal cord requires a constant supply of oxygenated blood. Only a few arteries, which are branches of the aorta, supply blood to the front part of the spinal cord. But this blood accounts for three fourths of the blood the spinal cord receives. Thus, blockage of any one of these arteries can be disastrous. Such a blockage occasionally results from the following:
Severe atherosclerosis of the aorta (deposits of fatty material in the aorta's wall)
Separation of the layers of the aorta's wall (aortic dissection)
Procedures that involve the abdominal aorta, such as surgery to repair a bulge (aneurysm) there
A blood clot that breaks off from the wall of the heart and travels through the bloodstream (becoming an embolus)—an uncommon cause
The first symptoms of a blocked spinal cord artery are usually
The pain is followed by muscle weakness, and people cannot feel heat, cold, or pain in areas controlled by the part of the spinal cord below the level of the blockage. People immediately notice symptoms, which may lessen slightly over time.
If the blood supply to the front of the spinal cord is greatly reduced, the legs are numb and paralyzed. But sensations transmitted through the back of the cord—including touch, the ability to feel vibration, and the ability to sense where the limbs are without looking at them (position sense)— remain intact because the back of the cord receives blood from other sources. Problems may partly resolve after the first few days.
Weakness and paralysis can lead to the development of pressure sores and breathing difficulties. Bladder and bowel function may be impaired, as may sexual function.
Blockage of the spinal cord’s blood supply is usually suspected based on symptoms.
Magnetic resonance imaging (MRI) usually enables doctors to diagnose such a blockage. If MRI is unavailable, myelography with CT, is done. These tests can help doctors rule out other disorders that cause similar symptoms.
Angiography can confirm that an artery to the front of the spinal cord is blocked, but it is usually unnecessary.
When possible, the cause (such as aortic dissection or polyarteritis nodosa) is treated, but otherwise, treatment focuses on relieving symptoms and managing complications, especially when paralysis and spinal cord dysfunction do not resolve in the first few days and become permanent.
Because some sensations are lost and paralysis may develop, preventing pressure sores from forming is important.
Because breathing can be affected, therapy to help prevent pneumonia from developing may be necessary. Such therapy includes deep breathing exercises, postural drainage (positioning the person so that gravity helps drain secretions from the lungs), and suctioning (inserting a small plastic tube through the nose and into the windpipe to gently suck out secretions).
Because bladder function is usually impaired, a catheter is needed to drain urine. This treatment prevents the bladder from enlarging and being damaged.