Sciatica

Definition

Sciatica is a set of symptoms including pain, numbness, muscular weakness and tingling sensations that may be caused by compression or irritation of the lumbar nerve L4 and L5 and the sacral nerves S1,S2 and S3. The symptoms can be felt in the lower back, buttock, and/or various parts of the leg and foot.

Clinically Relevant Anatomy

The hip exists of the iliacum that is connected on the ventral side witch the symphybis pubis. On the posterior side the iliacum is connected with the sacrum witch is called the art sacroiliacum. The nerves that cause sciatica are L4,L5,S1,S2,S3.

Mechanism of Injury / Pathological Process

Sciatica is generally caused by compression of the nerve roots L4,L5,S1,S2 and S3.

When sciatica is caused by the compression of a dorsal nerve root it is called a radiculopathy.

An other cause of sciatica is a misalignment of the corpus vertebrae also called spondylolisthesis. This can be caused b a trauma or fall of the patient.

An other cause can be spinal stenosis which is a condition where the spinal canal narrows and compresses the spinal cord. In 15% of the population the sciatic nerve runs through the M Periformis. When the M Periformis shortens or has spasms it can compress the sciatic nerve.

Irritation of the sacroiliac joint can also irritate nerve L5 which lies on the sacroiliac joint. This is called sacroiliac joint dysfunction. Women who are pregnant frequently develop sciatica because there is a rapid increase in body mass, a shift of the center of gravity and a change of hormone secretion.

In rare cases a spinal tumor can compress the sciatic nerve and cause sciatica. Also in rare cases a muscle strain in the lower back can cause some inflammation that can pressure the sciatic nerve.

Characteristics

Sciatica is characterized by constant pain, tingling, weakness and numbness in only one side of the leg and/or buttocks. The pain also gets worse when sitting and standing up to walk.

Clinical Presentation

Sciatica can be caused by the compression or irritation of nerve L4, L5, S1, S2 and S3. The sciatic symptoms depend on witch nerve is compressed or irritated.

L4:When the L4 nerve is compressed or irritated the patient feels pain, tingling and numbness In the tight. The patient also feels weak when straitening the leg and may have a diminished knee jerk reflex.

L5:When the L5 nerve is compressed or irritated the pain, tingling and numbness may extend to the foot and big toes.

S1:When the S1 nerve s compressed or irritated the patient feels pain, tingling and numbness at the outer part of the foot. The patient also experiences weakness when elevating the heel of the ground and standing on tiptoes. Also the ankle jerk reflex is reduced.

Diagnostic Procedures

Sciatica is diagnosed by physical examination, neurological testing and patient history. The most applied diagnostic test is the straight leg rising test or Lasègue's sign also KEMP test can be done. 

Outcome Measures

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Medical Management

When treating sciatica the use of ice or heat is often used. The heat or ice is placed on the affected area for 20 minutes every 2 hours.

Medications are commonly prescribed for the treatment of sciatica but evidence of clinical trails suggest that the use of analgestics to relieve pain isn’t proven.Research failed to prove significant difference between placebos, NSAIDs, analgesics, and muscle relaxants. There is also no proof in the use of opoids and compound drugs.In severe cases of sciatica a epidural steroid injection is often used. This treatment consists of an injection of steroid in the affected area to reduce the inflammation and pain. The effect are temporary and can last from a weak up to a year. An epidural injection doesn’t work with everyone.

In severe cases of sciatica elective surgery is proposed. This treatment focuses on the removal of the underlying cause by removing the hernia and eventually parts of the disc. When the sciatica is caused by a lumbar spinal stenosis a lumbar laminectomy is recommended. In this surgery, the small portion of the bone and/or disc material that is pinching the nerve root is removed. In cases of a disc herniation that caused the sciatica a microdescectomy is recommended. With this surgery a small opening is created. With the use of magnification the portion of the herniated disc that is pinching the nerve is removed. One study has proven that there is significant difference in the first year but no significant difference after 4 and 10 years.

Acupuncture has been proven to reduce pain in the back. The practice is centered on the philosophy of achieving or maintaining well being through the open flow of energy via specific pathways in the body. Hair-thin needles are inserted into the skin near the area of pain.

Also neuromuscular thechiques are often uses. The exist of apliing pressure witch the knukkles, fingers or elbow on a certain point between 10 and 30 seconds.

Massage therapy has proven to be useful witch the treatment of back pain. It increases the blood circulation, muscle relaxation and the release of endorphins.

Physical Therapy Management

The physical therapy exercises consist of strengthening, stretching and low impact aerobic conditioning. When patient follow a physical therapy program the patient will not only recover more quickly but are also less likely to develop future episodes of sciatica. There are differences between the exercises due tot the cause of sciatica. There are specific exercises for sciatica that is caused by herniated disc, spinal stenosis, degenarative disc decease, ithmic spondilolisthesis, pereformis syndrome, sacroiliac joint syndrome.
In general the strengthening exercises can help strengthen the spinal column and the supporting muscles, ligaments and tendons. These focus on the abdominal, lower back, gluteus and hip muscles. These core muscles support the spine keeping it in alignment and facilitating movements that extend or twist the spine with less chance of injury or damage.
The stretching exercises focus on the muscles who are who are tight and inflexible. These are frequently the hamstrings.
The low impact aerobic exercises such al walking and swimming encourage the exchange of fluids and nutrients to help create a better healing environment. During aerobic exercise there is also an increase in secretion of endorphins which are the body natural painkillers.

When suffering from sciatica due to a herniated disc they often prescribe extension exercises ore press ups for example Upper Back Extension and for the abdomen Curl-Ups.

When the cause of the sciatica is spinal stenosis flexion exercises of the lower back are suggested. Flexing the lower spine increases the size of these passageways and allows the irritation or impingement to resolve. The stretching exercises of the back are Back Flexion. For strengthening the abdominal muscles frequently used exercises are Hook-lying March and Curl-Ups.

When suffering from sciatica due to degenerative disc disease a dynamic lumbar stabilization program is recommended. This program tries to find the most comfortable position for the lumbar spine and pelvis and training the body to maintain this position during activities. In doing this correctly, one can improve the proprioception of the lumbar spine and reduce the excess motion at the spinal segments. This will in turn reduce the amount of irritation at these segments, relieving pain and protecting the area from further damage. Examples of these exercises are Hook-lying March, Hook-lying March Combination andBridging.

Sciatica can also be caused by spondylolistesis. In this case there are flexion based exercises and a stabilization program needed. The objective of this program is to teach the lumbar spine to remain stable in a flexed position. A few examples are Hooked-lying March, Curl-Ups and Pelvic Tilt.

In cases of sciatica caused by a piriformis syndrome stretching of the piriformis muscle, hamstrings muscle and hip extensor muscles may be used to decrease the pain of the patient and regain his range of motion.

When the sciatica is caused by a Sacroiliac Joint Dysfunction the treatment consists of range of motion exercises directed at the SI joint this can often restore normal movement and alleviate the irritation of the sciatic nerve. The 3 most important exercises are Single Knee to Chest Stretch, Press-Up and Lumbar Rotation(non-weight bearing).

The use of spinal manipulation or chiropractic tries to create a better healing environment. Research suggests that spinal manipulation is affective for acute cases of sciatica but hasn’t proven useful witch chronic cases of sciatica.Chiropractic treatment is based on the hupothesis that vertebral decompresion can be prevented by a flexion distraction procedure. Due to this procedure there is a greater intervertebral space ans les compression on the vertebral elements . For example the patient lies on its stomach witch a little flexion in the spine.Due to a dawnward flexion a destraction occurs. It has been proven that this treatment decreases the interdiscal pressure.

Differential Diagnosis

spondyloarthropathies, spinal claudication, nerve entrapment at the fibular head, thalamic cerebrovascular accident, multiple sclerosis, thoracic spinal fracture, Cauda equina syndrome.

Key Evidence

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Key Research

Genevay S, Finckh A, Zufferey P, Viatte S, Balagué F, Gabay C. Adalimumab in acute sciatica reduces the long-term need for surgery: a 3-year follow-up of a randomised double-blind placebo-controlled trial. 2011 Oct 13.(C)
Ashworth J, Konstantinou K, Dunn KM. Prognostic Factors in Non-Surgically Treated Sciatica: A Systematic Review. 2011 Sep 25.(A1)

Wassenaar M, van Rijn RM, van Tulder MW, Verhagen AP, van der Windt DA, Koes BW, de Boer MR, Ginai AZ, Ostelo RW. Magnetic resonance imaging for diagnosing lumbar spinal pathology in adult patients with low back pain or sciatica: a diagnostic systematic review. 2011 Sep 16.(A1)

van Rijn RM, Wassenaar M, Verhagen AP, Ostelo RW, Ginai AZ, de Boer MR, van Tulder MW, Koes BW. Computed tomography for the diagnosis of lumbar spinal pathology in adult patients with low back pain or sciatica: a diagnostic systematic review. 2011 Sep 14.(A1)
Righesso O, Falavigna A, Avanzi O. Correlation between persistent neurological impairment and clinical outcome following microdiscectomy for treatment of lumbar disc herniation. 2011 Aug 10.(C)

Erginousakis D, Filippiadis DK, Malagari A, Kostakos A, Brountzos E, Kelekis NL, Kelekis A. Comparative prospective randomized study comparing conservative treatment and percutaneous disk decompression for treatment of intervertebral disk herniation. 2011 Aug.(B)

Resources

Clinical
Loren Fishman, Carol Ardman. Sciatica Solutions: Diagnosis, Treatment, and Cure of Spinal and Piriformis Problems. W W Norton & Co Inc. 2007.

John Barrett, Douglas Noel Golding. The practical treatment of backache and sciatica.1984.

Larry P. Credit,Sharon G. Hartunian,Margaret J. Nowak .Relieving sciatica. Old Broadway.2000.p 30-34. (D)

Sites
http://en.wikipedia.org/wiki/Sciatica
http://www.spine-health.com/conditions/sciatica/what-you-need-know-about-sciatica
http://orthoinfo.aaos.org/topic.cfm?topic=a00351
http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Sciatica?open
http://bodyandhealth.canada.com/channel_condition_info_details.asp?disease_id=197&channel_id=42&relation_id=10900
http://www.sciaticacurepain.com/

Case Studies

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