Herniated disks: When back pain becomes dangerous

Feb 05, 2017 Dr Zulfikar Bux, Features / Columnists

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By Dr Zulfikar Bux

Assistant Professor of Emergency Medicine

A while back I had written about cauda equine syndrome. Since then, quite a few persons have been

asking me about their back pain and have some difficulty understanding the term “pinched nerve”. A “pinched nerve” occurs from a herniated disk and today we will shed some light on this worrying condition.

 

WHAT IS A HERNIATED DISK?

The disks in your spine, called intervertebral disks, are thin, oblong structures that serve as cushions between the bones of your back (vertebrae). Each disk is made of a soft gel core surrounded by a tough outer shell. This structure allows the disk to be firm enough to maintain the space between the vertebrae, but soft enough to compress when the spine flexes during bending, leaning and turning sideways.

In some people, mostly middle-aged adults, a disk’s tough outer shell develops an area of weakness or a small tear. When this happens, part of the disk’s soft inner core can bulge out of its normal position (herniate), producing a condition called a herniated disk.

If the herniated disk presses on nerves in the nearby spinal canal (pinched nerve), this can cause variety of nerve-related symptoms, including pain, numbness and muscle weakness. In the most severe cases, a herniated disk can compress nerves that control the bowel and bladder, causing loss of urinary and bowel control.

 

WHY DO DISKS HERNIATE?

Scientists do not fully understand why disks herniate. Most theories attribute this condition to a combination of the following factors:

• Disk aging– Herniated disks are rare in young people, but common among people aged 35 to 55. Of all the factors responsible for herniated disks, aging is probably the most important. With age, the disk’s outer shell appears to degenerate slowly, possibly because of decades of upright posture and back flexion.
• Genetic factors– In some families, several close relatives suffer from herniated disks, whereas other families are not affected at all. If the condition runs in a family, it may have an unusually early onset, even striking people younger than 21. Studies are beginning to identify specific genes linked to inherited forms of disk disease.
• Individual risk factors– You may be at increased risk of a herniated disk if you work at a job or participate in a sport that involves heavy lifting or excessive twisting or bending.

There are three distinct areas of the vertebral column where a herniated disk may occur:

• The cervical area between the vertebrae in the neck
• The thoracic area between the vertebrae in the upper back, near the ribs
• The lumbar region between the vertebrae in the lower back, above the pelvis

Herniated disks are most common in the lumbar region (lower back).

 

WHAT ARE SOME SYMPTOMS OF HERNIATED DISK (PINCHED NERVE)?

The first symptom of a herniated disk is usually back pain in the area of the affected disk. Some researchers believe this pain is a signal that a disk’s tough outer shell has been injured or weakened, not necessarily that the inner core has herniated. If the inner core does herniate and press on a nearby nerve, the resulting symptoms vary depending on the location of the herniated disk:

• In the cervical region– There can be pain in the neck, shoulder, shoulder blade, arm or chest, together with numbness or weakness in the arm or fingers. If the pain is centered in the chest and arm, it can mimic the chest pain of heart disease. Occasionally, frequent urination and headaches can occur.
• In the thoracic region– Symptoms tend to be vague, misleading and long lasting. There may be pain in the upper back, lower back, chest, abdomen or legs, together with weakness and numbness in one or both legs. Some affected people also complain of poor control of their bladder and bowel.
• In the lumbar region– Many people suffer from years of intermittent and mild lower back pain before a single triggering event (such as heavy lifting, sudden bending, abrupt twisting) aggravates their symptoms to the point that they seek medical attention. It also may develop without an identifiable triggering event.

In most people with a lumbar disk herniation, severe leg pain is the chief complaint. This pain is called sciatica, because it comes from pressure on the sciatic nerve. It usually begins in the lower back, and then spreads into the buttocks and down the back of one thigh and leg. Sciatica typically becomes worse if the patient coughs, sneezes, bears down or moves the back abruptly. While often relieved by rest, sciatica may become worse with driving or lifting. In addition, there may be numbness, tingling or muscle weakness in the buttocks or leg on the side of the pain.

In rarer and more severe forms of lumbar disk herniation, the nerve is compressed more extensively. If this happens, additional symptoms can develop, including pain around the anus; loss of bowel and bladder control; and numbness around the genital area, buttocks or backs of the thighs.

 

ARE THERE TREATMENT OPTIONS? 

In most cases, a herniated disk (with or without sciatica) will respond to conservative treatment. This may include limited bed rest (generally no more than a day or two); warm baths; heating pads; and medications, such as aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs) or muscle relaxants. Spinal injections may also help some patients who are unresponsive to oral therapy.

If you have lost bowel or bladder control, if you have evidence of progressive nerve damage, or if you have unrelenting pain that persists despite weeks of conservative treatment, more aggressive treatment may be needed, including surgery. In most cases, this means removing the disk (diskectomy), which may require major spinal surgery.

If you suspect you have symptoms of a herniated disk, visit your doctor early so that you can prevent it from worsening.

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