Section 6. Brain, Spinal Cord, and Nerve Disorders

Chapter 93. Spinal Cord Disorders

Topics: Introduction | Accident-Related Injuries | Spinal Cord Compression | Cervical Spondylosis | Spinal Hematoma | Syrinx | Hereditary Spastic Paraparesis | Acute Transverse Myelitis | Blockage of the Blood Supply | Subacute Combined Degeneration of the Spinal Cord

Blockage of the Blood Supply

Like all tissues in the body, the spinal cord requires a constant supply of oxygenated blood. Branches of the aorta supply most of the blood to the front part of the spinal cord. Blockage of any one of these arteries may be disastrous. Such a blockage occasionally results from severe atherosclerosis of the aorta, separation of the layers of the aorta's wall (aortic dissection), or a blood clot that breaks off from the wall of the heart and travels through the bloodstream (becoming an embolus). Occasionally, surgery to repair a bulge (aneurysm) in the abdominal aorta results in a blockage of an artery supplying the spinal cord.

Symptoms

The first symptoms are usually sudden back pain and pain in the areas supplied by the nerves branching from the affected area of the spinal cord. The pain is followed by weakness and an inability to feel heat, cold, or pain in areas below the level where the blood supply has been blocked. Symptoms are most noticeable during the first few days and may resolve, at least partially, over time. The blood supply to the front of the spinal cord is greatly reduced, but the back of the cord is unaffected because it receives blood from other sources. Therefore, the legs, which are controlled by the front part of the cord, are numb and paralyzed, but sensations transmitted in 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.

Weakness and paralysis can lead to the development of bedsores and breathing difficulties. Bladder and bowel function may be impaired as may sexual function.

Diagnosis and Treatment

The diagnosis is usually based on symptoms. Magnetic resonance imaging (MRI) or myelography (see Section 6, Chapter 77) can help doctors rule out other disorders that cause similar symptoms. A spinal tap (see Section 6, Chapter 77) may be performed to rule out transverse myelitis as the cause of the symptoms. Angiography can confirm that the artery to the front of the spinal cord is blocked, but it is usually unnecessary.

Treatment is aimed at relieving symptoms. Because some sensations are lost and paralysis may develop, preventing bedsores (pressure sores) from forming is important. Therapy to help fluids drain from the lungs (such as deep breathing exercises, postural drainage, and suctioning may be necessary. Physical and occupational therapy (see Section 1, Chapter 7) may be needed to help preserve muscle function. If bladder function is impaired, a catheter to drain urine from the bladder may be needed.