SPINAL CORD COMPRESSION – Causes and Risk Factors, Clinical Manifestations, Diagnostic Evaluations and Treatment

Injuries and disorders can put pressure on the spinal cord, causing back pain, tingling, and muscle weakness and other symptoms. The spinal cord may be compressed suddenly, causing symptoms in minutes or over a few hours or days, or slowly, causing symptoms that worsen over many weeks or months.

Normally, the spinal cord is protected by the spine, but certain injuries and disorders may put pressure (compress) on the spinal cord, disrupting its normal function. These injuries and disorders may also compress the roots of spinal nerves, which pass through the spaces between the back bones (vertebrae) or the bundle of nerves that extend downward from the spinal cord (cauda equine)

 

CAUSES AND RISK FACTORS

The spinal cord may be compressed by the following:

• Bone: If the back bones (vertebrae) are broken (fractured) are dislocated, or grow abnormally (as occurs in cervical spondylosis), they may compress the spinal cord. Vertebrae that are weakened by cancer or osteoporosis may break after a slight or even no injury.
• Connective tissue: Connective tissue, such as ligaments, can compress the spinal cord after a severe spinal injury
  
• An accumulation of blood (hematoma): Blood may accumulate in or around the spinal cord. The most common cause of spinal hematoma is an injury, but many other conditions can cause hematomas.
  
• Tumors: Cancer that has spread (metastasized) to the spine or the space around the spinal cord is a common cause of compression. Rarely, a tumor within the spine causes compression
  
• A localized collection of pus (abscess): Less commonly, pus accumulates in or around the spinal cord and compresses it
  
• A ruptured or herniated disk: A herniated disk can compress spinal nerve roots (part of spinal nerves next to the spinal cord) and occasionally spinal cord itself. Sometimes the cauda equine syndrome results in compression of the spinal cord.
  

 

Sudden compression usually results from an injury which often causes a fracture or dislocation of a vertebra. Gradual compression may result from cancer or cervical spondylosis, but bones weakened gradually (for example, by cancer or osteoporosis) may suddenly fracture, which can suddenly worsen compression. Hematomas, abscesses, and ruptured disks can cause sudden compression but often cause compression gradually over days to weeks. The most common cause of slowly developing compression (over months to years) is cervical spondylosis.

 

CLINICAL MANIFESTATIONS

Slight compression may cause mild symptoms if it disrupts only some nerve impulses going up and down the spinal cord. These symptoms may include discomfort or pain in the back, slight muscle weakness, tingling, other changes in sensation, and in men, difficulty initiating and maintaining an erection (erectile dysfunction). Pain may radiate down a leg, sometimes to the foot. If the cause is cancer, an abscess, or a hematoma, the back may be tender to the touch in the affected area. Sometimes sensation is lost. Reflexes, including the urge to urinate, may be exaggerated, sometimes causing muscle spasms and increased sweating. If compression increases, symptoms may worsen.

Substantial compression may block most nerve impulses, causing severe muscle weakness, numbness, retention of urine, and loss of bladder and bowel control. If all nerve impulses are blocked, paralysis and complete loss of sensation result. A bet like band of discomfort may be felt at the level of spinal cord compression. Once compression begins to cause symptoms, the damage usually worsens from minimal to substantial unpredictably but rapidly in a few hours to a few days.

 

DIAGNOSTIC EVALUATIONS

People with symptoms suggesting spinal cord compression require immediate medical attention because prompt diagnosis and treatment may reverse or lessen loss of function.

Because the spinal cord is organized in a specific way, doctors can determine which part of the spinal cord is affected based on the symptoms and results of a physical examination. For example, if the legs (but not the arms) are weak and numb and bladder and bowel functions are impaired, the spine may be damaged at the midchest (thoracic) level. The location of pain or tenderness along the spine also helps doctors determine the site of the damage.

Magnetic resonance imaging (MRI) is done immediately. Or if MRI is unavailable, myelography (x-ray  of the spinal column after injection of a radiopaque dye) with computed  tomography (CT) is done. These tests usually show where the spinal cord is compressed and may indicate the cause, MRI or myelography with CT can detect a fracture or dislocation of a vertebra, a herniated disk, an abnormal bone growth, an area of bleeding, an abscess, or a tumor. During myelography, a spinal tap (lumbar puncture) is done to inject a small amount of radiopaque dye into the space around the cord. Thus, doctors can determine whether compression completely blocks the normal flow of cerebrospinal fluid through this space.

If the cause is thought to be a fracture or dislocation due to injury, x-rays may also be taken. They provide information quickly, enabling doctors to quickly evaluate the problem.

The cause of the compression is confirmed during surgery to relieve the pressure on the spinal cord.

If surgery is not done immediately and if MRI or myelography with CT detects an unidentifiable abnormal mass causing compression, a biopsy is done instead of surgery to identify it. Guided by CT, doctors insert a needle into the abnormal mass.

 

TREATMENT

If loss of function is partial or very recent (usually when compression occurs suddenly), the compression must be relieved immediately. When compression is detected and treated quickly, before nerve pathways are destroyed, treatment can prevent permanent damage to the spinal cord, and function is usually completely recovered. Surgery is typically needed to relieve compression. Surgery may also be needed to insert steel rods and thus stabilize the spine.

Other treatment varies depending on the cause. For certain disorders, high doses of corticosteroids, such as dexamethasone or methylprednisolone are given intravenously as soon as possible. These disorders include tumors if the cause is unknown and possibly blunt injuries. Corticosteroids can reduce swelling in or around the spinal cord, which may be contributing to compression. If an abscess causes symptoms of spinal cord dysfunction (such as paralysis and loss of bowel or bladder control), a neurosurgeon surgically removes the abscess as soon as possible. Antibiotics are also given. If symptoms of spinal cord dysfunction have not developed, drawing the pus out through a needle, giving antibiotics, or both may be all that is needed.

If the cause is a hematoma, the accumulated blood is surgically drained immediately. People who have a bleeding disorder or who are taking anticoagulants are given injections of vitamin K and transfusions of plasma to eliminate or reduce the tendency to bleed. If the cause is cancer, treatment usually includes surgery, radiation therapy, or both. 

SPINAL CORD COMPRESSION – Causes and Risk Factors, Clinical Manifestations, Diagnostic Evaluations and Treatment