Slipped disc

What causes a slipped disc?

A slipped disc - more accurately known as a prolapsed disc - occurs when the outer annulus splits, resulting in the nucleus inside bulging out of the disc. The bulging disc can put pressure on the whole spinal cord or, more commonly, on a single nerve root, where a nerve leaves the spine. This means that a prolapsed disc can cause pain both in the area of the protruding disc and in the area of the body controlled by the nerve that the disc is pressing on. If the disc is in the lower back, this results in sciatica.

It is not always clear what causes a disc to prolapse, although age is one factor. As you get older, your discs start to lose their water content, making them less flexible and more likely to rupture. Smoking also plays a role as it causes the discs to lose their natural flexibility.

It's important to note that not all prolapsed discs cause symptoms such as pain, weakness or tingling. Many people will go their whole life and not know that they have a prolapsed disc, even though they have one.

There are a number of other factors that can put increased pressure and strain on your spine. These include:

• bending awkwardly
• jobs that involve heavy or awkward lifting
• jobs that involve lots of sitting
• being overweight
• weightbearing sports, such as weightlifting
• a traumatic injury to your back, such as a fall or car accident

Situations such as these can weaken the disc tissue and can sometimes lead to a prolapsed disc.

Symptoms of a disc prolapse

Most people with a disc prolapse have pain on one side of the body that starts slowly and gradually gets worse. The pain you experience when a disc presses on a nerve is often aggrieved by coughing, sneezing or sitting down.

Symptoms will vary depending on whether the prolapsed disc is in the neck or lower back:

Prolapsed disc in the neck

A prolapsed disc in the neck can cause:

• Localised neck pain during movement 
• Numbness or pins and needles in the neck, shoulder, arm or hand
• Weakness in certain muscles of arm

Prolapsed disc in the lower back

A prolapsed disc in the lower back can cause:

• Back pain during movement
• Numbness or pins and needles in the back, buttocks, genitals, legs or feet
• Weakness in certain muscles in the leg

Sciatica

The sciatic nerve is the longest nerve in the body. It is made up of several smaller nerves. It runs from the back of the pelvis, through the buttocks and down the legs to the feet. If a slipped disc is putting pressure on part of the sciatic nerve, it leads to pain in the leg, hip or buttocks. This is called sciatica.

Cauda equina syndrome

This is a serious condition where the nerves at the very bottom of the spine become compressed. Symptoms of cauda equina syndrome include:

• lower back pain
• numbness in your groin
• paralysis of one or both legs
• pain in there ectum
• loss of bowel control
• loss of bladder control 
• pain in the inside of your thighs

You should seek medical assistance immediately if you develop these symptoms. Visit the accident and emergency department of your nearest hospital. Do not waste time making an appointment with your GP, physiotherapist or osteopath. If cauda equina syndrome is not promptly treated, the nerves to your bladder and bowel can become permanently damaged.

Diagnosing a slipped disc

The Mansfield Clinic specialises in the diagnosis and the treatment of people with disc prolapses. Prolapsed discs are diagnosed from your symptoms and your medical history. Dr Allfree will carry out a physical examination to test your:

• posture
• reflexes
• muscle strength
• walking ability
• sensation in your limbs
• straight leg raising test

Further tests

If your symptoms do not ease after four to six weeks, an MRI scan may be required to rule out other conditions and investigate the size and position of the prolapsed disc. Some of the tests you may have are described below.

Magnetic resonance imaging (MRI) scan

An MRI scan uses a strong magnetic field to produce detailed images of the inside of your body. MRI scans allow us to take a very detailed cross-sectional pictures of the discs and the nerve roots inside your spine. They are very effective at showing the position and size of a prolapsed disc. They can also pinpoint the affected nerves. These can be arranged for you if necessary at the Mansfield Clinic. MRI scans can normally be arranged and completed within two weeks of referral.

X-rays

X-rays are not generally used as a test to look for slipped discs as they only see the bones and do not give a view of the nerves and spinal cord.

Treating a prolapsed disc

It can take several weeks to recover from a slipped disc. Treatment usually involves a combination of physical therapy, such as osteopathy, medication to relieve the pain, and either a caudal epidural or nerve root block injection. Dr Allfree is an Orthopaedic Physician who has extensive experience in performing caudal epidurals and nerve root block injections.

Surgery to release the compressed nerve and remove part of the disc may be considered in severe cases, or if the pain continues for too long. This procedure is called a spinal decompression, or discectomy. If surgical treatment is required, the Mansfield Clinic can arrange for this to be organised.

In many cases, a prolapsed disc will eventually shrink back away from the nerve and the pain will ease as the disc stops pressing on the affected nerve.

If you have a prolapsed disc, it is very important to keep active. Initially moving may be difficult, but after resting for a few days you should start to move around, but try not to do things that aggravate the leg pain. This will help keep your back mobile and stop the joints becoming stiff and the muscles that support the spine becoming weak. Keeping moving will help to speed up your recovery.

Any exercise you do should be gentle and not put too much strain on your back. Exercises that involve high impact, such as running, jumping or twisting, should be avoided at first as they may cause a flare-up of the pain. You may well need some specific exercises to aid your recovery, and Dr Allfree will advise you on an appropriate regime.

Preventing a prolapsed disc

Taking a few sensible precautions, such as leading a healthy lifestyle, can help prevent back pain and lower your risk of getting a slipped disc. For example, you should:

• take regular exercise
• use safe techniques when lifting heavy objects
• always maintain good posture when sitting and standing
• stop smoking if you smoke
• keep your weight under control