Sciatica

Anatomy & Background

The vertebra of the lumbar spine are the largest vertebra in the body because they carry the most weight and are subject to the greatest amount of stress, and is also most associated with back and leg pain.

The two lowest levels (L4-L5) and (L5-S1) have the most flexion and extension motion stress, and the highest rate of injury. The intervertebral discs of these two levels also have the highest rate of disc degeneration and herniation. The L5 vertebra is the most common site of spondylosis and spondylolisthesis. The most common lumbar nerves that get pinched or entrapped are the L4, L5, S1 levels. Entrapment of these nerves may lead to a condition called Sciatica.

Spinal Nerves

The spinal nerves are the electrical wires of the body. They originate at the spinal cord and exit the spinal column through the intervetebral foramen. Nerves exiting the area of the lumbar spine provide sensation and motor control to the back, buttocks, legs and down to the foot. Damage or interference with the transfer of information of these nerves can cause neurological problems such as pain, weakness, abnormal sensations, numbness and changes in spinal reflexes. These symptoms may occur in the back, leg and down to the foot.

What is Sciatica?

Sciatica is a common nerve irritation. The sciatic nerve can produce pain, numbness, and weakness down the leg along the areas innervated by the sciatic nerve. It is located under the piriformis muscle.

Causes

Anything that encroaches on or puts pressure on the sciatic nerve can be considered a cause of sciatica. Commons causes of sciatica include:

• Herniated discs that place pressure on the nerve, in addition to inflammation that irritates the nerve.
• Degenerative joint disease resulting in the formation of bony spurs on the facet joints can narrow the intervertebral space placing pressure on the exiting nerve.
• Trauma or muscle spasms can put pressure on the peripheral nerve, producing symptoms along that nerve’s distribution.
• Degenerative disc disease that results in wear on the intervertebral disc, and a reduction in disc height may result in loss of space at the intervertebral foramen compressing on the exiting nerve.
• Tightness of the piriformis muscle resulting in compression on the sciatic nerve underlying the muscle.

Symptoms

The symptoms experienced as a result of sciatica will be located along the path the sciatic nerve travels.

• Pain in the back or radicular to the buttock, into the leg and extending down behind the knee, to the foot depending on the nerve involved and the severity of the encroachment.
• Pain and tenderness localized at the level of the involved nerve.
• Muscle spasm and changes in posture in response to the injury.
• Pain with excess activity and relief with rest.
• Pain and tenderness localized at the level of the involved nerve.
• Loss of motion like the inability to bend backward, move sideways to the effected side, or stand erect for extended periods of time.
• Sitting, standing and walking can be difficult if the irritation is severe.
• Impairment of normal reflexes in the lower extremity.
• Numbness tingling may be experienced from the low back to the foot depending on the distribution of the affected nerve.
• Muscle weakness may occur on any muscle that is innervated by the pinched nerve. Long-term pressure on the nerve can produce atrophy or wasting of that particular muscle.

Treating Sciatica

Treatment of sciatica will depend on the severity of the condition, and the underlying cause of the nerve damage. When treating acute back problems:

• Rest. Avoid the activities that produce the pain (bending, lifting, twisting, turning, bending backwards, etc).
• Anti-inflammatory drugs and other pain medications.
• Apply ice in acute cases to the lumbar spine to help reduce pain and associated muscle spasm. Apply ice right away and then at intervals for about 20 minutes at a time. Do not apply directly to the skin.
• An exercise regiment designed specifically to address the cause of the symptoms associated with sciatica and improve joint mobility, spinal alignment, posture, and range of motion.
• Steroidal medication to reduce inflammation in moderate to severe conditions.
• Lumbar nerve or epidural injections
• Physical therapy for back and disc problems must remain conservative at the beginning to avoid aggravating the condition. Your therapist should emphasize rest, reducing the inflammation and increasing the blood circulation for healing. Once the initial inflammation has been reduced, a program of stretching and strengthening should be initiated to restore flexibility to the joints and muscles involved, while improving strength and stability of the spine. Each program  will be based on the structure causing the problem and symptoms. A program not tailored to the specific problem may aggravate symptoms

Mild Cases

In mild cases patients found that rest, ice and medication were enough to reduce the pain. Physical therapy is recommended to develop a series of postural, stretching and strengthening exercises to prevent re-occurrence of the injury. Return to activity should be gradual to prevent a return of symptoms.

Moderate to Severe Cases

If the problem persists, consult with your health care provider. Your physician will perform a thorough evaluation to determine the possible cause of your symptoms, the structures involved, the severity of the condition, and the best course of treatment.

Medicine Intervenes

In addition to performing a thorough examination your physician may order the following tests to make a more concise diagnosis:

• X-ray to determine if there is any joint degeneration, fractures, bony malformations, arthritis, tumors or infection present.
• MRI to determine any soft tissue involvement, including visualization of the discs, spinal cord and nerve roots.
• CT scans, which can give a cross section view of the spinal structures.

Medications to consider

Your physician may recommend several medication options individually or in combination to reduce the pain, inflammation and muscle spasms that may be associated with sciatic nerve irritation.

• Over the counter medications for mild to moderate pain.
• If over the counter medications are not effective your physician may prescribe stronger pain medication.
• Anti-inflammatory drugs or prescription NSAIDS (non-steroidal anti-inflammatory drugs) to reduce inflammation following acute injury.
• Muscle relaxers to reduce acute muscle spasm.
• Injections like facet injections, nerve blocks or an epidural. These may involve the injection of corticosteroids to a specific structure to reduce local inflammation.

Severe or Non-responsive Conditions

In the case of conditions that do not respond to conservative care surgery may be indicated. If you continue to experience some of the following symptoms:

• Increase in radiating or radicular pain
• Pain or nerve irritation that gets worse
• Weakness with muscle atrophy
• Associated disc involvement

If symptoms continue to get worse, surgery may be indicated to release entrapment and remove the degenerative changes that are compromising the nerve.

Medical Procedures

Injections like facet injections, nerve blocks or an epidural. These may involve the injection of corticosteroids to a specific structure to reduce local inflammation caused that is irritating the nerve roots of the Sciatic Nerve.

• Caudal Epidural Injections
• Interlaminar Caudal Epidural Steroid Injections
• Transforaminal Epidural Injections
• Selective Nerve Root Blocks

Surgical Procedures to address the structures that contribute to the    compression on the nerve roots of the Sciatic Nerve

• Endoscopic Decompression
• Endoscopic Foraminotomy
• Percutaneous Decompression
• IDET Intradiscal Eletrothermal Therapy
• Selective Endoscopic Discectomy
• Spinal Cord Stimulator
• Epidural Lysis of Adhesions
• Laser Facet Arthrotomy