A herniated disc, also known as slipped disc or prolapsed disc, can occur in any part of the spine, but most commonly occurs in the lower back.
The intervertebral discs are pads of cartilage located between each vertebra. Their function is shock absorption and allowing free movement of the back such as flexion, extension, side bending and rotation. Disc herniations can occur anywhere in the spine, but commonly occur in the lumbar region. Lumbar spine has 5 vertebrae which are separated by 5 intervertebral discs. The intervertebral disc comprises of three parts: The vertebral end plates, the annulus fibrosus and the nucleus pulposus. The nucleus pulposus is present in the centre and this is the part which herniates due to a weak and degenerated wall (annulus fibrosus).
If the disc herniation is severe, then it compresses the spinal column. The pressure on the spinal cord from the herniated disc causes pain and other symptoms in an individual.
Causes of Herniated Disc
- Degeneration of the discs due to ageing.
- Injury or trauma to the spine.
- Excessive strain on the back.
Symptoms of Herniated Disc
About 90% of lumbar spine herniations happen at either L4/L5 or L5/S1. The symptoms depend on the location of the herniation and the degree of spinal cord compression. Most common symptoms are lower back pain along with the following:
- If the disc herniation occurs in the L5/S1 region, then pain is usually felt down the back of the leg, sometimes till the foot (sciatica).
- If the disc herniation occurs in the L4/L5 region, then pain may be felt on the external part of the leg and downwards into the shin or on top of the foot.
- If the disc herniation occurs in the L3/L4 region, then pain is felt on the outer hip and radiates to the front of the thigh.
Neural Symptoms: These symptoms are produced due to nerve injury or nerve compression. Symptoms are numbness, tingling and weakness. Weakness is present especially in the foot along with difficulty in lifting the foot (foot drop). This often occurs in L4/L5 herniation.
Pain Patterns: Pain usually occurs after simple movements, such as bending over. The pain is worsened by sitting, bending, lifting and coughing or sneezing and is alleviated by lying down, particularly on the unaffected side. The pain is least felt in the morning.
Bladder/Bowel Symptoms: If a patient has loss of bladder or bowel control then immediate medical attention should be sought, as this is a serious condition. It may be cauda equina syndrome and can cause permanent loss of bladder or bowel control and paralysis in the lower body.
Diagnosis of Herniated Disc
- Neurologic examination
- Blood tests
- MRI scan
- CT scan
Treatment of Herniated Disc
- In many cases, conservative treatment is sufficient.
- Rest should be taken.
- Anti-inflammatory medications or NSAID's such as ibuprofen and naproxen help in reducing pain.
- Physical therapy also helps.
- For severe cases, corticosteroid injection may be given.
- Traction is also helpful, although in some patients the pain increases after initial pain relief.
Surgery For Herniated Disc
Surgery is required if the patient does not benefit from conservative treatment and if the symptoms do not improve.
Microdiscectomy For Herniated Disc
It comprises of surgically removing the portion of the disc which has herniated. This is successful in majority of the patients. In some patients there may be repeated episodes of disc herniation. Microdiscectomy is often performed on an out-patient basis and does not require an overnight stay. The patient can return to daily activities within 1-3 weeks.
In case of severe herniations or recurrent herniations, a full discectomy may be done where the entire disc is removed and the vertebrae located above and below the disc are fused.
Prognosis and Recovery of Herniated Disc
Prognosis and recovery following lumbar disc herniation depends on size of herniated disc.
Prognosis and Recovery of Small Symptomatic Lumbar Herniated Disc-
Small herniated disc often shrinks in 2 to 4 weeks. The symptoms like pain, tingling, numbness and weakness in muscles may last for 1 to 4 weeks. Symptoms may subside with rest and pain medications. If symptoms continue after 1 to 2 weeks, physical therapy is advised. Physical therapy for 2 to 4 weeks may eliminate the symptoms, if not, then patient is advised epidural injection. Series of epidural injection may help to reduce symptoms to tolerable level or symptoms may disappear. Recovery time could be 2 to 6 weeks and prognosis is very good.
Prognosis and Recovery of Moderate Symptomatic Lumbar Herniated Disc-
Moderate sized disc herniation occupies 1/3rd of the spinal canal or foramina. The pain and numbness become predominant symptoms. Pain is moderate to severe at rest and severe to very severe with activities. Pain never subsides with conservative treatment. Physical therapy for 4 to 6 week followed by series of epidural steroid injection may help to reduce or eliminate the pain arising from moderate symptomatic lumbar disc herniation. The recovery time for moderate symptomatic lumbar disc herniation could be 4 to 8 weeks. Prognosis; pain may subside after series of epidural injection and physical therapy. Pain may continue and patient may need surgery.
Prognosis and Recovery of Large Symptomatic Lumbar Herniated Disc -
The herniation of lumbar disc of large size causes significant symptoms, which often does not respond to physical therapy and epidural injection. Patient often refuses surgical treatment and surgical treatment is delayed by 4 to 6 weeks for trial of physical therapy and epidural steroid injection. Patient may need hospitalization for severe pain, which is not responding to oral opioids. Overall patient may not be considered for surgery for several weeks unless numbness and weakness become significant. Patient is often considered for emergency surgery. Recovery after surgery for large symptomatic lumbar disc herniation may take 4 to 6 weeks. Overall recovery period can last for 6 to 12 weeks depending on when patient decided to consider surgery. Prognosis after surgery for large symptomatic lumbar disc herniation depends on surgical procedure. Overall literature suggests 60 to 78% of patients gets tolerable pain relief after first surgery for large lumbar disc herniation and may not need follow up treatment except physical therapy. But 20 to 30% of the patient may need second surgery, which could be spinal fusion surgery. Recovery after spinal fusion surgery could be 4 to 6 months or longer depending on residual symptoms and surgical complications.