Lumbar Herniated Discs

What is a herniated disc?
The spine is comprised of a series of connected bones called "vertebrae." The disc is a combination of strong connective tissues which hold one vertebra to the next acting as a cushion between the vertebrae and allowing for segmental motion. Were it not for the intervertebral discs, our spines would be a stiff column of immobile bone. The disc is made of a tough outer layer called the "annulus fibrosus" and a gel-like center called the "nucleus pulposus." This disc is often described as a “hard version of a jelly donut.” As we age, the center of the disc may start to lose water content, making the disc less effective as a cushion. This degenerative process may be associated with weakening of the annulus of the disc and ultimately a displacement of the disc’s center (herniated or ruptured disc) through a crack in the outer layer. Alternatively, such displacement may occur as a result of an acute injury to the disc. Most disc herniations occur in the bottom two discs of the lumbar spine, at and just below the waist level.

A herniated lumbar disc can press on the nerves in the spine and, through combined mechanical and chemical or inflammatory processes, may cause pain, numbness, tingling or weakness of the leg, often referred to as "sciatica." The medical term describing such injury is “radiculopathy”. Sciatica affects about 1-2% of all people, usually between the ages of 30 and 50, but both younger and older people can be affected. A herniated lumbar disc may also cause back pain, although back pain alone, without leg pain, can have many causes other than a herniated disc.

How is it diagnosed?
The physiatrists of Long Island Spine Rehabilitation Medicine perform a detailed history and physical examination, which includes an assessment of the distribution of pain and sensory disturbance, a complete assessment of lower limb strength, as well as an assessment of lower limb reflexes. Often, through such an approach, the exact spinal nerve affected by a herniated disc can be identified. Other times, due to the variations in our “wiring” and overlap in the functions provided by neighboring lumbar spinal nerves, the identification of the affected spinal nerve may remain less clear.

The diagnosis of lumbar disc herniation and radiculopathy can be confirmed by advanced imaging of the lumbar spine in the form of either computed tomography (CT) scans or magnetic resonance imaging (MRI). X-ray images can show bone spurs, loss of disc space height, and narrowing of the neural foramen or “tunnels” through which the spinal nerves travel, but X-rays, or “plain films / radiographs” cannot show soft tissues such as disc herniations or the spinal nerves. The CT and MRI scans provide more detailed pictures of each of the structures of the lumbar spine and can identify most disc herniations. In select cases where diagnostic uncertainty should remain or if additional information regarding the extent of nerve injury is needed, electrical studies of the nerves, also referred to as nerve conduction studies or EMG (electromyography) studies may be performed. These studies can detect evidence of nerve damage that can result from a disc herniation.

The physiatrists of Long Island Spine Rehabilitation Medicine have completed extensive training in performing these studies and are either board certified in electrodiagnostic medicine or board eligible for subspecialty certification in neuromuscular medicine. In our practice, these tests are performed with the latest diagnostic equipment and in a fashion which maximizes patient comfort.