Lateral Disc Herniation

The intervertebral discs of the spine are located between the vertebral bodies, to provide cushioning of the spine from downward movements, as we assume and erect position and put weight on our backs. These discs have a gelatinous substance in their core, and layers of crisscrossing fibers in its cover. The gelatinous interior has the ability to absorb water and nutrients from the body to provide enough cushioning so that it may keep the vertebral bodies from contacting one another. The exterior of the disc is the solid part of the disc that enables it to hold its basic shape so that the disc does not leak or come apart. Due to a variety of factors that may hurt the discs or age them, holes or tears may develop in the outer part of the disc, allowing the material to be ejected out and into the spaces of the spine. This is known as a disc herniation or disc protrusion. A lateral disc herniation is a situation where the disc herniates laterally, affecting the structures located in the sides of the spine.

A bulging disc is a condition where the wall of the disc becomes thinned to the point where it bulges outwards, after no longer being able to hold its essential shape. A disc herniation is a condition where the outer wall tears entirely, and the material within its nucleus projects outwards. The direction that the bulge or herniation takes greatly effects whether or not the patient experiences back pain or leg radiculopathy. Patients will likely be affected by the disc hernation if the pushed out material pushes into the spinal nerves or the nerve roots. Because the nerve roots branch off the spinal cord and through the sides of the spine, they will likely be affected by a lateral disc herniation.

A lateral disc herniation is also known as a lateral disc protrusion. At each level of the spinal cord, a pair of nerves branch to the left and right sides to supply neurologic functioning to both sides of our bodies. When the disc herniates laterally, the disc material may press into one or both bilateral nerve roots. Pressure on the nerve root is also known as nerve root compression. As a result of this nerve root compression, patient may feel pain at that level of the spine and at any part of the body that nerve supplies.

A disc protrusion may occur for a number of reasons, though age related wear and tear is the most likely cause. The spine has intervertebral discs beginning between the 2nd and 3rd cervical vertebra, all the way to the last lumbar vertebra and the 1st sacral body. These discs are soft and spongy and allows for some downward motion of the spine as pressures are placed to it. Due to vertical forces, these discs lose some of their water as the discs are pushed downwards and outwards. The discs re-absorb water as we lie down at night. These discs remain healthy and flexible to pressure for our childhoods and young adulthood, but become vulnerable to wear and tear with age.

Due to age related effects, the discs may bulge outwards or tear entirely along its walls, to contact the exiting spinal nerves. These bulges and hernaitions may occur in the cervical, thoracic, and lumbar spine. Symptoms include:
  • Acute pain
  • Chronic pain
  • Sciatica
  • Tingling and numbness in the arms and legs
  • Muscle weakness
  • Pain that travels to other areas of the body. This symptom may be called radiating pain or referred pain.
Treatment of a lateral disc herniation will require an accurate diagnosis, which may include a physical examination, medical imaging, and nerve root block injections. A physical examination may indicate possible nerve root compression due to a patient's neurologic symptoms and reduced reflexes. MRI or CT Scans may show the disc material pressing into the affected nerves. One procedure, called Selective Nerve Root Block (SNRB) may also be used as a diagnostic tool. This procedure involves the injection of lidocaine and steroid into the sheath covering the nerve root. The patient is awake throughout this minimally invasive surgery to tell the doctor whether or not the anesthetic agent in the injection provided pain relief. A confirmation of pain relief related to the injection will provide confirmation that this nerve is the patient's main pain generator.