Herniated disc

The human spine is made up of two dozen small bones (vertebrae) that are stacked on top of each other to create the spinal column. Between each vertebra is a soft, gel-like substance enclosed by a tough outer ring of concentric sheets of collagen tissue (annulus), together they form a disc that binds and acts as a cushion between each adjacent vertebra. Each vertebra is also held to the others by groups of ligaments.

Degeneration of the annulus can weaken it to a point where bulging and/or tearing of the annulus with leakage of the gel-like substance ends in a herniated disc.

This can happen in any disc but most commonly in the lower back.  The symptoms include pain, numbness, or a weakened arm or leg. Symptoms tend to improve as time passes, and surgery is not always required to relieve the problem.

Symptoms

The symptoms depend entirely on where the herniated disc is located and whether it compresses the adjacent spinal nerves. Often, it mostly affects one side of the body.

• Pain in the arm or leg – If it occurs in the lower back, the patient will feel pain in the buttocks, thigh, calf, lower back, and foot.
  If it occurs in the neck, the sharp pain will be located in the shoulder and arm and might go through the arm or leg when the patient coughs, sneezes, or changes to different positions.
• Numbness – The patient with a herniated disc usually has numbness or tingling pain in the body part where the spinal nerves are compressed.
• Muscle weakness - Muscles innervated by the affected nerves will be weakened, affecting the ability to hold objects if arm muscles are involved.

Occasionally, a herniated disc may not have any symptoms; it is found incidentally on imaging of the spine for other purposes.

When to consult a doctor

Patient should seek medical attention if they experience neck or back pain that spreads to the arm or leg together with the sensation of numbness, tingling pain, and muscle weakness.

What causes a herniated disc

Disc degeneration often progresses gradually before ending in a herniated disc. As people grow older, their discs become less flexible and more easily tear or rupture. Using the back muscles to lift or hold heavy items can sometimes cause disc herniation. Traumatic incidents such as a fall or a blow to the back can cause disc herniation, but this rarely occurs. 

The risk factors of a herniated disc are as follows: 

• Overweight – Being overweight can result in extra stress to the discs in the lower back.  
• Jobs that require strenuous physical efforts – Those whose jobs require lifting, pulling, pushing, bending sideways tends to elevate the risk of a herniated disc.
• Genetic factors – Sometimes, the risk is passed on from generation to generation. 
• Smoking – Smoking reduces oxygen supply to discs, causing them to break quickly and easily. 
• Driving - Sitting for long periods combined with vibration from the car can cause pressure on the spine.
• Sedentary lifestyle – Regular exercise can help prevent herniated discs.

Complications of herniated disc

Rarely, emergency surgery might be necessary to avoid paralysis. Patient is strongly advised to seek immediate medical attention if the following occurs: 

• Symptoms worsen – Increased pain, weakness, or numbness affecting activities of daily living. 
• Bladder or bowel dysfunction – Cauda equina syndrome can cause difficulty in urination and emptying of the bowel. 
• Saddle anesthesia - This sensation loss affects areas including the thighs, back of the legs, and area around the anus that is progressively worse. 

How to prevent a herniated disc 

• Regular exercise can help strengthen the trunk muscles responsible for stabilizing and supporting the spine.
• Maintain good posture, which can help lessen pressure on the spine and discs. Keep the back straight when sitting for long periods. Lift heavy items using the leg muscles, not the back muscles. 
• Maintain a healthy BMI – Being overweight will add constant higher pressure on the spine and disc.  
• Do not smoke. 

Diagnosis

The doctor will take your medical history and examine the back for tenderness during the physical examination. Patient will need to lie flat and move legs in various positions which will help to pinpoint the cause of the pain. 

Additional neurological exams will be performed to check the reflexes, muscle strengths, stability when walking, and ability to sense touches, pinpricks, or vibrations.

If other conditions are suspected, the doctor may suggest additional tests as follow: 

Imaging tests

• X-rays – Plain X-rays cannot itself detect herniated discs but can rule out back pain caused by infection, tumor, spinal alignment issues, or a broken bone.  
• CT scan – CT scanner will take slice of images in different planes and combine them to generate cross-sectional images of the spinal column.
• MRI – Radio waves and magnetic field will create the body’s structures images which can help confirm the location of the herniated disc and see whether spinal nerves are affected. 
• The myelogram is when a dye is injected into the spinal fluid undergoing a CT scan. It helps to show compression of the spinal cord from multi-level herniated discs.  

Nerve tests

• Nerve conduction study – This will help with electrical nerve impulses measurement. It measures how fast the impulse moves through the nerve. 
• Electromyography (EMG) – The doctor will put a needle electrode through the skin and insert into different muscles. This will help measure the electrical activity of muscles when contracted and at rest.
• Both tests help find the presence, location, and extent of diseases that damage the nerves and muscles.

Treatment

Conservative treatment uses pain medication to help reduce symptoms and avoid movements that can trigger pain. 

Examples of medications

• Over-the-counter pain medication – The doctor might recommend pain medicine available at the pharmacy if the pain is mild or moderate.  
• Neuropathic drugs can decrease pain by affecting nerve impulses. 
• Muscle relaxers can help with muscle spasms. Common side effects are sedation and feeling dizzy.  
• Cortisone injections – The doctor may recommend a corticosteroid that can be injected around the spinal nerves if oral medications do not give symptom relief.

Physical Therapy

The doctor may suggest physical therapy. A physical therapist will show the positions and exercises that help reduce the pain. 

Surgical procedures

Few people with herniated discs will require surgical procedures. However, the doctor will suggest surgery if medicines do not improve numbness, weakness, difficult standing or walking, loss of bowel control, and disabling pain after six weeks.

Surgeons can remove just a portion of the disc in most cases. The entire disc must be removed in rare instances and with this, the adjacent vertebrae might need to be fused with a bone graft. The process of bone fusion requires the use of metal hardware in the spine to help with spinal stability. Sometimes, the surgeon will suggest artificial disc placement.

Lifestyle changes and self-care tips

• Applying cold or heat packs can help reduce pain and inflammation. After a few days, heat packs can be used to help relieve the pain. 
• Avoiding bed rest - Stiff joints and weak muscles can be caused by staying too much in bed. Rest in a comfortable position for 30 minutes, then take a short walk. Try to avoid any activities that can trigger the symptoms. 
• Takes time to resume regular activity – Move slowly, especially when bending forward and lifting objects.

Preparing for the doctor’s appointment

The doctor may refer the patient to a specialist doctor in orthopedic surgery, neurology, or neurosurgery.

Prepare to answer these questions from the doctor:

• When did these symptoms first begin?
• When you first experienced the symptoms, did you lift, push, or pull anything at that time? 
• Does the pain interfere with your daily life?
• Is there anything that improves the symptoms?
• Is there anything that triggers the symptoms?
• Do you take any medications or supplements? If so, what are they? 
• Does the pain spread into the arms or legs?
• Do you feel weakness or numbness in the arms or legs?
• Do you experience changes in bowel or bladder habits?
• When you cough or sneeze, does it worsen the symptoms?
• Does the symptom interfere with sleeping or working?
• Does the occupation require heavy lifting?
• Do you smoke cigarettes?
• Did you recently gain weight?