Spinal disc herniation

large lumbar L4-L5 herniations MRI T2 SAG

large lumbar L4-L5 herniations MRI T2 SAG

A spinal disc herniation (prolapsus disci intervertebralis), informally and misleadingly called a “slipped disc”, is a medical condition affecting the spine, in which a tear in the outer, fibrous ring (annulus fibrosus) of an intervertebral disc (discus intervertebralis) allows the soft, central portion (nucleus pulposus) to bulge out. Tears are almost always posterior-ipsilateral in nature owing to the presence of the posterior longitudinal ligament in the spinal canal. This tear in the disc ring may result in the release of inflammatory chemical mediators which may directly cause severe pain, even in the absence of nerve root compression (see “chemical radiculitis” below). This is the rationale for the use of anti-inflammatory treatments for pain associated with disc herniation, protrusion, bulge, or disc tear.

A spinal disc herniation demonstrated via MRI.

It is normally a further development of a previously existing disc protrusion, a condition in which the outermost layers of the annulus fibrosus are still intact, but can bulge when the disc is under pressure.

Cervical disc herniation

MRI scan of cervical disc herniation between fifth and sixth cervical vertebral bodies. Note that herniation between sixth and seventh cervical vertebral bodies is most common.

Cervical disc herniations occur in the neck, most often between the fith & sixth (C5/6) and the sixth and seventh (C6/7) cervical vertebral bodies. Symptoms can affect the back of the skull, the neck, shoulder girdle, scapula,[6] shoulder, arm, and hand. The nerves of the cervical plexus and brachial plexus can be affected.[7]

Thoracic disc herniation

Thoracic discs are very stable and herniations in this region are quite rare. Herniation of the uppermost thoracic discs can mimic cervical disc herniations, while herniation of the other discs can mimic lumbar herniations.[8]

Lumbar disc herniation

MRI scan of large herniation (on the right) of the disc between the L4-L5 vertebrae.

Lumbar disc herniations occur in the lower back, most often between the fourth and fifth lumbar vertebral bodies or between the fifth and the sacrum. Symptoms can affect the lower back, buttocks, thigh, and may radiate into the foot and/or toe. The sciatic nerve is the most commonly affected nerve, causing symptoms of sciatica. The femoral nerve can also be affected[9] and cause the patient to experience a numb, tingling feeling throughout one or both legs and even feet or even a burning feeling in the hips and legs.

Normal situation and spinal disc herniation in cervical vertebrae.

Imaging
X-ray: Although traditional plain X-rays are limited in their ability to image soft tissues such as discs, muscles, and nerves, they are still used to confirm or exclude other possibilities such as tumors, infections, fractures, etc.. In spite of these limitations, X-ray can still play a relatively inexpensive role in confirming the suspicion of the presence of a herniated disc. If a suspicion is thus strengthened, other methods may be used to provide final confirmation.
Computed tomography scan (CT or CAT scan): A diagnostic image created after a computer reads x-rays. It can show the shape and size of the spinal canal, its contents, and the structures around it, including soft tissues.

MRI Scan of lumbar disc herniation between fourth and fifth lumbar vertebral bodies.
Magnetic resonance imaging (MRI): A diagnostic test that produces three-dimensional images of body structures using powerful magnets and computer technology. It can show the spinal cord, nerve roots, and surrounding areas, as well as enlargement, degeneration, and tumors. It shows soft tissues even better than CAT scans.
Myelogram: An x-ray of the spinal canal following injection of a contrast material into the surrounding cerebrospinal fluid spaces. By revealing displacement of the contrast material, it can show the presence of structures that can cause pressure on the spinal cord or nerves, such as herniated discs, tumors, or bone spurs. Because it involves the injection of foreign substances, MRI scans are now preferred in most patients. Myelograms still provide excellent outlines of space-occupying lesions, especially when combined with CT scanning (CT myelography).
Electromyogram and Nerve conduction studies (EMG/NCS): These tests measure the electrical impulse along nerve roots, peripheral nerves, and muscle tissue. This will indicate whether there is ongoing nerve damage, if the nerves are in a state of healing from a past injury, or whether there is another site of nerve compression.

Stages of Spinal Disc Herniation

MRI scan of cervical disc herniation between fifth and sixth cervical vertebral bodies. Note that herniation between sixth and seventh cervical vertebral bodies is most common.

MRI scan of large herniation (on the right) of the disc between the L4-L5 vertebrae.

Narrowed space between L5 and S1 vertebrae, indicating probable prolapsed intervertebral disc – a classic picture.

MRI Scan of lumbar disc herniation between fourth and fifth lumbar vertebral bodies.

source.

Number of View: 9439

Leave a comment