SCREENING AND DIAGNOSIS

The first step in determining whether you may have a herniated disc is for your doctor to acquire a thorough personal history. He or she will then perform a physical examination which will include the use of various orthopedic and neurological tests. Orthopedic tests will include evaluation for spinal nerve root tension, tests which are often positive if a disc herniation is compressing a spinal nerve and preventing it from gliding. The neurological portion of the examination will include testing of your reflexes, muscle strength, sensation, walking ability and coordination. Your doctor may include a test for sensation and function in the area around the rectum, because this area can be affected by a herniated disk.

If you doctor suspects a herniated disc or another condition which may mimic a disc herniation additional diagnostic testing may be recommended. Additional testing may include one or more of the following tests.

§       Nerve Conduction Studies and Needle Electromyography: Special nerve studies are performed to determine if there is spinal nerve damage. They also are used to localize the site of compromise and to rule other neurological conditions which might present like spinal nerve compromise. During part of the study small needle are placed into select muscles of the involved extremity and along the side of the corresponding area of the spine. This part of the study is performed to assess the integrity of the nerve supply to the muscles.

§       Magnetic Resonance Imaging (MRI) Scan. A magnetic field is used to acquire detailed images of the spine. This test can be used to confirm the precise location and characteristics of a herniated disc. It is also used to help determine whether there is any associated compression of adjacent structures including the spinal cord and spinal nerves.  

§       Computerized Tomography (CT) Scan. This is a specialized form of X-ray that provides detained images of the spine. A computer is used to process information and create cross-sectional images of the spine and the structures around it. This technology can be used to develop three dimensional images of the spine for surgical planning.

§       Magnetic Resonance Myelogram: This is a specialized form of MRI. It is used for the same purpose as convention myelography. It can be performed without using any form of contract dye. It is often performed as apart of a routine MRI of the spine. The test is used to help determine whether there is a space occupying lesion causing compression of the spinal cord and/or spinal nerves.

§       Conventional Myelogram. A dye is injected into the spinal fluid. X-rays are then acquired of the spine form various angles. The test is used to determine if there is pressure on the spinal cord and/or the spinal nerves. The test is often used to help determine if a patient is a good candidate for surgery.  

§       X-rays. Plain X-rays can not be used to detect a herniated disc. X-rays do show the disc space but do not reveal the integrity of the disc.  They do show changes characteristic of a degenerative disc such as disc space narrowing and the development of bone spurs on the vertebral body around the disc space. X-rays are used to out other causes of back pain such as infection, dislocation, fracture and spinal arthritis.

PROGNOSIS

The prognosis associated with a disc herniation is usually good. With the passing of time most disc herniations getter smaller in size. This occurs due to the loss of water degenerative changes that occur in the disc which led to a loss of disc volume. Even a slight reduction of disc volume and the degree of herniation may be enough to reduce pressure on surrounding pain sensitive tissues of the spine.

COMPLICATIONS

A herniated disc usually does not constitute a medical emergency. Rarely, a large disc herniation in the low back can cause a cauda equina syndrome secondary to compression of multiple spinal nerve roots. Emergency surgery may be required to remove pressure off of the compromised spinal nerves in order to facilitate recovery and to reduce the risk for permanent impairment. . If the pressure remains on the nerves to long it may result in permanent loss of function of the legs, bowel and/or bladder. The following signs and symptoms, which suggest cauda equina syndrome, warrant a trip to the emergency room:

§       Significant or increasing pain, numbness or weakness spreading to one or both legs

§       Bladder or bowel dysfunction, including incontinence or difficulty urinating with a full bladder

§       Progressive loss of sensation in areas that would touch a saddle (inner thighs, back of legs and area around the rectum)

§       Loss of movement