What is slipped disc?
The bones that form the spine or backbone are stacked over each other, separated by a cushion covering of round, flat, compressible discs. These spinal discs make the spine flexible, allowing it to bend and twist. However, these discs are vulnerable to getting ruptured or bulging abnormally into a space that surrounds a nerve root (spinal canal), pushing against it.
This damaged disc puts pressure on either the whole spinal cord or on a single nerve root, which means that a slipped disc pain can be experienced both in the area of the protruding disc as well as the body part that the affected (pressed) nerve transmits to.
Also known as herniated or prolapsed disc, slipped disc is a condition where a spinal disc ruptures and the gel inside leaks out, resulting in back pain and pain in in other areas of the body. The nerves and nerve root of the region is affected, most commonly seen with the sciatic nerve, which is the longest nerve in the body that runs from the back of pelvis, down both legs to the feet.
Herniated discs impair nerve function, and lead to weakness, numbness and pain in the leg or arm it supplies. It most commonly occurs in the discs of the lower back (lumbar region) and neck (cervical region). A small percentage of herniated discs lead to nerve impingement.
What are the causes of the disorder?
The exact cause why a spinal disc breaks down is unknown, but the possible causes are age (spinal discs lose water content, making them less flexible and prone to rupturing), wear and tear (disk degeneration) or disease. Traumatic events like a fall of blow to the back can cause herniated disc, as can putting excess pressure on back muscles instead of leg and thigh while lifting heavy weights.
Which specialist should be consulted in case of signs and symptoms?
Upon experiencing symptoms of slipped disc, a person must consult an orthopaedic surgeon, and may be further referred to neurosurgeon and a doctor specializing in physical medicine and rehabilitation.
What are the screening tests and investigations done to confirm or rule out the disorder?
Medical history and a physical exam are generally sufficient to diagnose slipped disc. Physical exam is carried out by asking the patient to lie down and move legs in various positions to determine the exact cause of pain and check reflexes, muscle strength, walking ability, and ability to sense touch, vibration or pinpricks.
Other tests may be conducted to check severity and nerve involvement:
- Imaging tests –
- X-rays rule out other causes of back pain like broken bone, spinal alignment issue, tumour or infection.
- Computerised tomography (CT) scan creates cross-sectional images of the spinal column and surrounding structures.
- Magnetic resonance imaging (MRI) creates images of internal structure of spine to locate the herniated disc and identify the nerve affected by it.
- Myelogram involves an x-ray by first injecting a dye into the spinal fluid to show the pressure being exerted on the spinal cord and nerves.
- Nerve tests – Electromyograms and nerve conduction studies measure how electric impulses are being transmitted along a nerve tissue, and are used to determine the location of nerve damage.
What treatment modalities are available for management of the disorder?
First line of treatment is avoiding painful postures and following an exercise regimen along with pain medication to relieve symptoms. It is seen that most people feel better in a month’s time and the displaced and protruded disc often shrinks with time. However, if it fails, other forms of therapy or even surgery may be considered.
- Medication – The following medication is used:
- Over-the-counter pain medication, for mild to moderate pain.
- Narcotics, if over-the-counter medicines do not work.
- Nerve pain medication, to relieve pain due to nerve damage.
- Muscle relaxants, for back or leg spasms.
- Cortisone injections, administered directly into the area surrounding spinal nerves to suppress inflammation.
- Physical therapy – Physical therapists guide the patient through exercises and positions that help reduce the pain from a herniated disc. As the symptoms begin to improve, the therapist will guide the patient towards more advanced rehabilitation programme to improve core muscle strength and stability that will improve back health and prevent future injuries. Along with physical therapy, heat/ice treatment, ultrasound and short-term bracing for neck or lower back may also be used.
- Surgery – Surgery is conducted on a small percentage of cases under the following situations:
- Conservative treatment methods fail to improve symptoms after six weeks.
- A portion of the protruded disc lodges in the spinal canal, presses on a nerve and causes weakness.
- Basic daily activities like standing or walking become too difficult for the patient.
During the surgery, the surgeon may remove only the protruding disc portion (common) or may remove the entire disc (rare) and fuse the vertebrae using metal hardware to maintain spinal stability. Alternatively, an artificial disc may be placed in lieu of the removed disc.
What are the known complications of the disorder?
The spinal cord separates into a group of long nerve roots known as cauda equine (or a horse’s tail) at the lower end of the spinal canal. In rare cases, disc herniation can lead to compression of the entire cauda equine, an emergency condition that requires surgery to prevent permanent paralysis or weakness.
Patients with herniated disc must watch out for any signs of worsening of symptoms like numbness or weakness affecting daily activities, bladder or bowel dysfunction or loss od sensation in inner thighs, back of legs and around rectum (saddle anaesthesia).
What precautions or steps are necessary to stay healthy and happy during the treatment?
Pain arising from a herniated disc can affect both physical and mental wellbeing. Patients need to learn ways of coping with chronic back pain and reducing factors like stress to keep pain under control.
Relaxation techniques like deep breathing are quite useful. Further, all physical activity and twisting of back and heavy lifting must be limited in the initial days of back pain, and gradually resumed in the next few weeks.
How can the disorder be prevented from happening or recurring?
Taking measures to stay safe at work and play, exercising to maintain weight and good posture and lifting weights using the correct technique, can prevent back injury and disc herniation. Those suffering from spinal ailments may be recommended a back brace to support the spine and prevent injuries from lifting heavy weights.