Between each of these vertebrae are cushion like structures called discs which act as shock absorbers. Strong ligaments and muscles surrounding the spine keep the bones in position and therefore, the spine remains erect. When the disc present between 2 vertebrae gets injured due to lifting heavy weights, trauma or straining, it could bulge outside, compress the spinal cord /nerves and cause a disease called disc bulge or a disc prolapse. It could also be called slipped disc or disc herniation.
Disc prolapse can occur for anybody. It is more common in males and its incidence is high between 30 to 50 years of age.
Disc prolapse could be caused by an accident or trauma, lifting unaccustomed heavy weights, travelling in bumpy roads, straining your backs too much. In a good numbers of patients, the correct inciting event may not be picked up at all.
Disc prolapses are common in the lumbar (lower back) level because of the curvature of the spine (lordosis). Therefore it is common to see disc prolapses at L4-5 and L5-S1 levels. This prolapse can cause compression of the spinal nerves exiting the spine and cause symptoms like pain, tingling and numbness radiating down the legs. Next common place to have prolapse is the cervical (neck) spine which causes pain, tingling and numbness radiating down the hands
When the disc actually bulges out, it commonly goes towards the back or posteriorly where the spinal cord and spinal nerves are passing down the spinal cord. This compression causes a mechanical and inflammatory change around the nerves. This results in symptoms like pain, tingling and numbness radiating down the course of the nerve. In case of a lumbar disc prolapse, patients have radiating pain down the legs (Sciatica)
Mild compression causes symptoms like back pain radiating down the legs, tingling, numbness, ‘electric shock’like sensations, pins and needles, etc. These symptoms may be there in the lower backs, buttocks, back / side of the thighs, back of the knees, calf muscles, ankles and all the way down to the soles and toes. These symptoms can occur in any one side or on both legs. Depending on the level and degree of compression, the symptoms may vary. On visiting a physician, he may check sensations, motor power and reflexes along the different suspected nerves. Straight leg raising test can clinically suggest nerve root compression.
Severe disc prolapse and compression of the spinal nerves results in inability to move the ankle or foot, inability to control bowel habits and urination or total numbness of the entire limb. Severe compression could also lead to numbness around the saddle region (around the anus) called cauda equine syndrome. This could be because of a trauma or a major fall requires urgent surgical decompression. Other red flags of back pain include back pain with high fever suggestive of an infection, tumour, major trauma, vertebral fracture, etc. If you have any of these symptoms, see your physician immediately.
Luckily about 70 to 80% of disc prolapse resolve by themselves. So even though patients have sciatica pain due to disc prolapse, unless it is a severe disc prolapse, conservative management is sufficient for the first 6 weeks. So most disc prolapses can be treated conservatively with pain killers for the first 6 weeks.
Your physician may ask you to take x rays and MRI of the lumbar spine. X rays may show reduction in disc height and MRI may confirm presence of disc bulge / disc prolapse / disc herniation. Nerve conduction studies and EMG may supplement these findings. Keeping these records safely is essential for medical records and insurance purposes.
Conservative management is required in the first 6 weeks or if your physician feels the disc prolapse is mild in nature.
- Medicines: Simple analgesics like paracetamol or anti-inflammatory medications like diclofenac, ketorolac may be prescribed.
- Nerve related medications: Nerve pain responds to medicines like pregabalin, gabapentin, amitriptyline and duloxetine. Normal painkillers will not reduce nerve related pain.
- In some situations, narcotics, muscle relaxants and oral steroids are used.
- Avoid lifting heavy weights, avoid smoking.
- Physical therapy is essential to resume normal activities. Modalities like TENS, ultrasonic waves, interferential therapy, etc are beneficial and work well in mild disease. Spinal flossing and core strengthening exercises will hasten recovery. Yoga is beneficial.
- Bed rest for more than 3 days is not advisable. Patients should be encouraged to resume mild activity and physical therapy and rehabilitation exercises with medications as soon as possible.
- Wearing lumbar belt / supports continuously or for long periods of time can cause muscle atrophy and is not advisable unless specifically indicated. Spinal traction has conflicting evidence in terms of usage in disc prolapse patients.
If in spite of conservative management, back pain and radiating leg pain still persists, patients could consider nerve root / epidural injections in pain clinics. Pain physicians offer interventional procedures for pain like
- Nerve root injections: Nerve root injections are done with x ray guidance around the nerve which is suspected to be compressed. Medications like local anesthetics, steroids and hyaluronidase may be used in these procedures. The anti-inflammatory medication reduces nerve root inflammation and edema caused by compression and relieves pain.
- Epidural injections: Caudal and lumbar epidural injections are effective in relieving sciatic pain. Supplementary physical therapy exercises will prolong the effects of therapeutic injections. If required, these procedures can be repeated.
- Disc decompression procedures: Disc decompression procedures like decompressors, hydro dissections, nucleotomes are pain procedures meant to reduce the disc material and thereby relieve pain. Percutaneous discectomies are day care procedures done under local anesthesia and are safe because they are done by injections through the skin and can not cause any permanent damage.
Open surgery under general anesthesia is reserved for patients with neurological deficits like foot drop, complete numbness of the legs, inability to control bladder and bowel habits, severe pain not responding to conservative management or nerve root blocks. Cauda equine syndrome requires urgent surgical decompression.
Surgical options available include laminectomies, discectomies, micro discectomies, endoscopic discectomies, lumbar stabilizations, lumbar interbody fusion surgeries (TLIF), disc replacements, etc.
These procedures require a hospital stay of 3-5 days and recovery time of 2-3 weeks. Post-operative physical therapy / spine strengthening is always advised. Complications include infection, bleeding, paraplegia, recurrence of pain, etc.