Herniated discs or a slipped disk is where the spongy spinal discs between the vertebra (bones stacked up in the column of the spine) bulge out from their position. The term “slipped disc” is a misnomer since these discs are fixed in position and cannot slip. Older people and weight lifters are susceptible to this condition. In most cases, disc herniation occurs in the lumbar region or the lower back. The cervical (neck) and the thoracic (upper back) regions are the second and third most affected regions.
In the lumbar region, discs usually “slip” between the 4th and 5th lumbar vertebrae or the 5th lumbar vertebra and the sacrum. Pain along the distribution of the nerve root is the most common symptom. Occasionally, the herniated discs can compress the cauda equina or nerve roots below the spinal cord, resulting in cauda equina syndrome. In these instances, the patient experiences bladder and bowel malfunction, numbness of both legs and eventual paralysis.
The symptoms of slipped discs occur on one side of the body depending on the location of the prolapse. Mild or no back pain is experienced if there is only protrusion of the disc material.
When the bulge presses against a nerve root, symptoms manifest in the body parts innervated by the affected nerve. The general symptoms are pain, numbness, tingling and muscular weakness in the corresponding body part.
Herniated discs in the lumbar region, the most commonly affected vertebrae, causes pain in the thighs, buttocks and legs while those in the cervical region affect the arms. The sciatic nerve root is located in the vicinity of the terminal lumbar vertebrae and slipped disc in these regions causes sciatica.
Intervertebral discs are donut-shaped cushions made of a soft gelatinous material (nucleus pulposus) in the core surrounded by a tough exterior. These act as shock absorbers for the vertebral column of the spinal cord. When there is a rupture in the peripheral part, the jelly-like material squeezes and bulges out. Depending on the extent of the prolapse, the protrusion may press against nerves in the corresponding region of the spinal cord. This causes the symptoms experienced by people suffering from herniated discs.
Wear and tear due to drying up of the nucleus pulposis is associated with ageing and is the most common cause of herniated discs. Excess body weight, occupations involving weight-lifting or incorrect posture for long periods of time, increase pressure on the vertebra and thereby, increase the risk of developing herniated discs. Less frequently, a sudden and severe impact may weaken the ligaments that keep the discs in place. This can rupture and lead to a bulging immediately but is more likely to contribute to a slowly developing herniation.
The condition usually heals on its own within one to six months. Adequate rest to the spinal cord along with regular physical therapy helps in faster recovery. The physical therapist may also include short-term bracing of the affected region and electrical stimulation, as a part of the treatment routine.
During this period the following medications may be given to provide symptomatic relief :
- Pain relievers (ibuprofen, acetaminophen and naproxen)
- Drugs for nerve pain (gabapentin, pregabalin, duloxetine, tramadol and amitriptyline)
- Muscle relaxants (diazepam, cyclobenzaprine)
- Anti-inflammatory agents such as cortisone
Surgery is usually performed in only 10% of the patients of herniated discs when the condition does not respond to the conservative treatment methods listed above.