Search This Blog

Saturday, March 21, 2009

What is a Herniated Disc ?



[Extracted from ABOUT.COM]

Many patients with back pain, leg pain, or weakness of the lower extremity muscles are diagnosed with a herniated disc. When a disc herniation occurs, the cushion that sits between the spinal vertebra is pushed outside its normal position. A herniated disc would not be a problem if it weren't for the spinal nerves that are very close to the edge of these spinal discs.

What is the spinal disc ?

The spinal disc is a soft cushion that sits between each vertabrae of the spine. This spinal disc becomes more rigid with age. In a young individual, the disc is soft and elastic, but like so many other structures in the body, the disc gradually looses its elasticity and is more vulnerable to injury. In fact, even in individuals as young as 30, MRIs show evidence of disc deterioration in about 30% of people.

What happens with a 'herniated disc' ?

As the spinal disc becomes less elastic, it can rupture. When the disc ruptures, a portion of the spinal disc pushes outside its normal boundary--this is called a herniated disc. When a herniated disc bulges out from between the vertebrae, the spinal nerves and spinal cord can become pinched. There is normally a little extra space around the spinal cord and spinal nerves, but if enough of the herniated disc is pushed out of place, then these structures may be compressed.



What causes symptoms of a herniated disc ?

When the herniated disc ruptures and pushes out, the nerves may become pinched. A herniated disc may occur suddenly in an event such as a fall or an accident, or may occur gradually with repetitive straining of the spine. Often people who experience a herniated disc already have spinal stenosis, a problem that causes narrowing of the space around the spinal cord and spinal nerves. When a herniated disc occurs, the space for the nerves is further diminished, and irritation of the nerve results.

What are the symptoms of a herniated disc ?

When the spinal cord or spinal nerves become compressed, they don't work properly. This means that abnormal signals may get passed from the compressed nerves, or signals may not get passed at all. Common symptoms of a herniated disc include :


a) Electric Shock Pain
Pressure on the nerve can cause abnormal sensations, commonly experienced as electric shock pains. When the compression occurs in the cervical (neck) region, the shocks go down your arms, when the compression is in the lumbar (low back) region, the shocks go down your legs.

b) Tingling & Numbness
Patients often have abnormal sensations such as tingling, numbness, or pins and needles. These symptoms may be experienced in the same region as painful electric shock sensations.

c) Muscle Weakness
Because of the nerve irritation, signals from the brain may be interrupted causing muscle weakness. Nerve irritation can also be tested by examining reflexes.

d) Bowel or Bladder Problems
These symptoms are important because it may be a sign of cauda equina syndrome, a possible condition resulting from a herniated disc. This is a medical emergency, and your should see your doctor immediately if you have problems urinating, having bowel movements, or if you have numbness around your genitals.

All of these symptoms are due to the irritation of the nerve from the herniated disc. By interfering with the pathway by which signals are sent from your brain out to your extremities and back to the brain, all of these symptoms can be caused by a herniated disc pressing against the nerves.

How is the diagnosis of a herniated disc made ?

Most often, your physician can make the diagnosis of a herniated disc by physical examination. By testing sensation, muscle strength, and reflexes, your physician can often establish the diagnosis of a herniated disc.

An MRI is commonly used to aid in making the diagnosis of a herniated disc. It is very important that patients understand that the MRI is only useful when used in conjunction with examination findings. It is normal for a MRI of the lumbar spine to have abnormalities, especially as people age. Patients in their 20s may begin to have signs of disc wear, and this type of wear would be expected on MRIs of patients in their 40s and 50s. This is the reason that your physician may not be concerned with some MRI findings noted by the radiologist.

Making the diagnosis of a herniated disc, and coming up with a treatment plan depends on the symptoms experienced by the patient, the physical examination findings, and the x-ray and MRI results. Only once this information is put together can a reasonable treatment plan be considered.

Treatment of a herniated disc depends on a number of factors including :

* Symptoms experienced by the patient
* Age of the patient
* Activity level of the patient
* Presence of worsening symptoms

Most often, treatments of a herniated disc begin conservatively, and become more aggressive if the symptoms persist. After diagnosing a herniated disc, treatment usually begins with :

1) Rest & Activity Modification
The first treatment is to rest and avoid activities that aggravate your symptoms. Many disc herniations will resolve is given time. In these cases, it is important to avoid activities that aggravate your symptoms.

2) Ice & Heat Applications
Ice and heat application can be extremely helpful in relieving the painful symptoms of a disc herniation. By helping to relax the muscles of the back, ice and heat applications can relieve muscle spasm and provide significant pain relief.

3) Physical Therapy
Physical therapy and lumbar stabilization exercises do not directly affect the herniated disc, but they can stabilize the lumbar spine muscles. This has an effect of decreasing the load experienced by the disc and vertebrae. Stronger, well balanced muscles help control the lumbar spine and minimize the risk or injury to the nerves and the disc.

4) Anti-Inflammatory Medications
Nonsteroidal anti-inflammatory medications (NSAIDs) are commonly prescribed, and often help relieve the pain associated with a disc herniation. By reducing inflammation, these medications can relieve some pressure on the compressed nerves. NSAIDs should be used under your doctor's supervision.

5) Oral Steroid Medications
Oral steroid medications can be very helpful in episodes of an acute (sudden) disc herniation. Medications used include Prednisone and Medrol. Like NSAIDs, these powerful anti-inflammatory medications reduce inflammation around the compressed nerves, thereby relieving symptoms.

6) Other Medications
Other medications often used include narcotic pain medications and muscle relaxers. Narcotic pain medications are useful for severe, short-term pain management. Unfortunately, these medication can make you drowsy and can be addictive. It is important to use these for only brief periods of time. Muscle relaxers are used to treat spasm of spinal muscles often seen with disc herniations. Often the muscle spasm is worse than the pain from the disc pressing on the nerves.

7) Epidural Steroid Injections
Injections of cortisone can be administered directly in the area of nerve compression. Like oral anti-inflammatory medications, the idea is to relieve the compression on the nerves. When the injection is used, the medication is delivered to the area of the disc herniation, rather than being taken orally and travelling throughout your body.

Is surgery necessary in the treatment of a disc herniation ?
As mentioned, treatment of a disc herniation usually begins with the steps listed above. However, surgical treatment of a herniated disc may be recommended soon after the injury if there is a significant neurological deficit to your problem. Symptoms on pain and sensory abnormalities usually do not require immediate intervention, but patients who have significant weakness, any evidence of cauda equina syndrome, or a rapidly progressing problem may require more prompt surgical treatment.

Most often surgery is recommended if more conservative measures do not relieve your symptoms. Surgery is performed to remove the herniated disc, and free up space around the compressed nerve. Depending on the size and location of the herniated disc, and associated problems (such as spinal stenosis, arthritis, etc.), the surgery can be done by several techniques. In very straightforward cases, endoscopic or microscopic excision of the herniated disc may be possible. However, this is not always recommended, and in some cases, a more significant surgery may need to be performed.

Lumbar Discectomy

A discectomy is a surgery done to remove a herniated disc from the spinal canal. When a disc herniation occurs, a fragment of the normal spinal disc is dislodged. This fragment may press against the spinal cord or the nerves that surround the spinal cord. This pressure causes the symptoms that are characteristic of herniated discs.

The surgical treatment of a herniated disc is to remove the fragment of spinal disc that is causing the pressure on the nerve. This procedure is called a discectomy. The traditional surgery is called an open discectomy. An open discectomy is a procedure where the surgeon uses a small incision and looks at the actual herniated disc in order to remove the disc and relieve the pressure on the nerve.

How is a discectomy performed ?

A discectomy is performed under general anesthesia. The procedure takes about an hour, depending on the extent of the disc herniation, the size of the patient, and other factors. A discectomy is done with the patient lying face down, and the back pointing upwards.

In order to remove the fragment of herniated disc, your surgeon will make an incision over the center of your back. The incision is usually about 3 centimeters in length. Your surgeon then carefully dissects the muscles away from the bone of your spine. Using special instruments, your surgeon removes a small amount of bone and ligament from the back of the spine. This part of the procedure is called a laminotomy.

Once this bone and ligament is removed, your surgeon can see, and protect, the spinal nerves. Once the disc herniation is found, the herniated disc fragment is removed. Depending on the appearance and the condition of the remaining disc, more disc fragments may be removed in hopes of avoiding another fragment of disc from herniating in the future. Once the disc has been cleaned out from the area around the nerves, the incision is closed and a bandage is applied.

What is the recovery from a discectomy ?

Patients often awaken from surgery with complete resolution of their leg pain; however, it is not unusual for these symptoms to take several weeks to slowly dissipate. Pain around the incision is common, but usually well controlled with oral pain medications. Patients often spend one night in the hospital, but are usually then discharged the following day. A lumbar corset brace may help with some symptoms of pain, but is not necessary in all cases.

Gentle activities are encouraged after surgery, such as sitting upright and walking. Patients must avoid lifting heavy objects, and should try not to bend or twist the back excessively. Patients should avoid strenuous activity or exercise until cleared by their doctor.

What are the potential complications of a discectomy ?

The most common problem of a discectomy is that there is a chance that another fragment of disc will herniate and cause similar symptoms down the road. This is a so-called recurrent disc herniation, and the risk of this occurring is about 10-15%.

Most patients find relief of much, if not all, of their symptoms from a discectomy. However, the success of the procedure is about 85-90%, meaning that 10% of patients who undergo a discectomy will still have persistent symptoms. Patients who have symptoms for long periods of time, or severe neurologic deficits (such as significant weakness) are at higher risk of incomplete recovery.

Other risks of surgery include spinal fluid leaks, bleeding, and infection. All of these can usually be treated, but may require a longer hospitalization or additional surgery.

What is endoscopic microdiscectomy ?

Newer techniques may allow your surgeon to perform a procedure called an endoscopic discectomy. In an endoscopic discectomy your surgeon uses special instruments and a camera to remove the herniated disc through very small incisions.

The endoscopic microdiscectomy is a procedure that accomplishes the same goal as a traditional open discectomy, removing the herniated disc, but uses a smaller incision. Instead of actually looking at the herniated disc fragment and removing it, your surgeon uses a small camera to find the fragment and special instruments to remove it. The procedure may not require general anesthesia, and is done through a smaller incision with less tissue dissection. Your surgeon uses x-ray and the camera to "see" where the disc herniation is, and special instruments to remove the fragment.

Endoscopic microdiscectomy is appropriate in some specific situations, but not in all. Many patients are better served with a traditional open discectomy. While the idea of a faster recovery is nice, it is more important that the surgery is properly performed. Therefore, if open discectomy is more appropriate in your situation, then the endoscopic procedure should not be done. Discuss with your doctor if endoscopic microdiscectomy may be appropriate for you.

No comments: