Terminology Update
The terminology pertaining to lumbar spinal disk herniations has been confusing, inconsistent, and contradictory. Consequently, in 2014, the North American Spine Society, the American Society of Spine Radiology, and the American Society of Neuroradiology convened a combined task force to agree upon the nomenclature. The results were published in the Spine Journal, and titled (1):
Lumbar Disc Nomenclature:
Version 2.0
In summary, and based on CT or MRI imaging, a herniated lumbar spine intervertebral disk has four categories:
The Normal Disk
The Bulging Disk
If any part of the annulus extends beyond the normal disc space, it is considered to be a bulging disk.
The Protrusion Disk
In the protrusion disk, the base of the displaced material is greater than the distance the disk material had moved towards the intervertebral foramen and/or the central neural canal.
The Extrusion Disk
In the extrusion disk, the greatest measure of the displaced disk material is greater than the measure of the base of the displaced material.
The Sequestration Disk
In the sequestration disk, the disk material has lost all connection with the original disk material.
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A disk herniation that compresses, irritates or inflames a single nerve root is called discogenic radiculopathy. Nerve root compression/irritation/inflammation can cause radiating leg pain down the course of the sciatic nerve. Consequently, this radiating leg pain is often referred to as sciatica. If this sciatica is initiated by the intervertebral disk, it is referred to as discogenic sciatica.
Technically, the sciatic nerve is made up of nerve roots L4, L5, S1, and as such a problem with any of these nerve roots can cause sciatica.
If the intervertebral disk is the cause of the nerve root compression/irritation/inflammation, the single most important clinical test is the straight-leg-raising test. While supine, the subject is asked to raise their straight leg as far as possible. Normally this causes the lower lumbar nerve roots to slide out of the intervertebral foramen by approximately ½ inch (12 mm). If the nerve root is compressed/irritated/inflamed, pain may start at about 30 degrees from the horizontal (2, from Kapandji).
Important questions pertaining to herniated lumbar intervertebral disc with radiculopathy/sciatica include:
The answers to many of these questions are thoroughly explored in an important article published May 5, 2016 in The New England Journal of Medicine, titled (3):
Herniated Lumbar Intervertebral Disk
The authors are Richard A. Deyo, MD, MPH, and Sohail K Mirza, MD, MPH. Dr. Deyo is from the Oregon Institute of Occupational Health Sciences. A search of the United Stated National Library of Medicine (June 12, 2016) shows he is an author or contributing author to 378 indexed publications. Dr. Mirza if from the Department of Orthopedic Medicine, Dartmouth School of Medicine. A search of the United Stated National Library of Medicine (June 12, 2016) shows he is an author or contributing author to 87 indexed publications. These men are leading experts on the clinical guidelines pertaining to the lumbar spine and intervertebral disk syndromes.
In this article, Drs. Deyo and Mirza make the following points:
What are the typical presenting symptoms for
patients suffering from discogenic radiculopathy/sciatica?
Drs. Deyo and Mirza note that approximately 85% of patients with sciatica have a herniated intervertebral disk. Hence, sciatica is the single most important presenting symptom of discogenic radiculopathy/sciatica.
What are the most important clinical tests
for the patient with suspected discogenic radiculopathy/sciatica?
Drs. Deyo and Mirza note that the majority of patients “with back and leg pain and a positive straight-leg-raising test suggests a herniated disk.” Straight-leg-raising is positive for nerve root compression if sciatica occurs by elevating the leg to between 30 and 70 degrees.
Other helpful tests include deep tendon reflexes, superficial sensation, myotomal strength, and Valsalva tests.
Are spinal x-rays required or helpful in establishing
the diagnosis of discogenic radiculopathy/sciatica?
Spinal x-rays are not required or helpful in establishing the diagnosis of discogenic radiculopathy/sciatica. Spinal x-rays may show levels of disc degeneration of varying degrees, but are non-revealing as to the presence or type of disc herniation and compressive neuropathology. Spinal x-rays may show the presence of other complications to discogenic radiculopathy/sciatica, such as birth anomalies (tropism, lumbosacral transitional segments, scoliosis, leg length inequality, etc.) and/or acquired syndromes (degenerative osseous central canal stenosis, spondylolisthesis, fracture, etc.). Spinal x-ray may also show evidence of tumor and/or infection. As such, exposing spinal x-rays is dependent upon the clinical judgment of the provider.
When is computed tomography (CT) and/or magnetic resonance imaging (MRI) advisable for a patient with suspected discogenic radiculopathy/sciatica?
Drs. Deyo and Mirza do not recommend routine use of CT or MRI because “on imaging, disk bulging is common among asymptomatic persons (in approximately 60% of persons at 50 years of age).” They state:
“CT or MRI is necessary only in a patient whose condition has not improved over 4 to 6 weeks with conservative treatment.”
“The use of CT or MRI should be discouraged unless the symptoms do not decrease over 4 to 6 weeks” of conservative treatment.
For how long is it advised and/or safe for
the patient with discogenic radiculopathy/sciatica
to have their signs and symptoms managed conservatively?
Drs. Deyo and Mirza state:
Six weeks of conservative therapy is generally recommended in patients with herniated lumbar disks, in the absence of a major neurological deficit.
“Unless patients have major neurologic deficits, surgery is generally appropriate only in those who have nerve root compression that is confirmed on CT or MRI, a corresponding sciatica syndrome, and no response to 6 weeks of conservative therapy.”
In the absence of severe neurologic deficits, discogenic sciatica patients should have conservative treatment for 6 weeks before agreeing to more invasive approaches (glucocorticoids injections, surgery).
The mean time for resolution of discogenic sciatica symptoms with conservative care is 12 weeks.
Patients who first use conservative treatment for discogenic sciatica and later opt for surgery still do well, indicating an “absence of a therapeutic window for surgery that closed quickly.”
How effective is conservative treatment for the discogenic radiculopathy/sciatica patient, as compared to surgical treatment?
Drs. Deyo and Mirza state that most patients with radicular sciatica who do not undergo surgery will improve. They further note:
Conservative treatment does not change the natural history of disk herniation, but offers relief of symptoms. Most herniated disks will shrink with resolution of symptoms over 3-12 months.
Minor motor deficits will resolve in most patients who are treated conservatively.
“Elective surgery is an option for patients with congruent clinical and MRI findings and a condition that does not improve within 6 weeks.”
“Patients with severe or progressive neurologic deficits require a referral for surgery.”
There is “no significant advantage of surgery over conservative treatment for sciatica relief at 1 to 4 years of follow-up.”
“By 1 year, outcomes of early surgery generally do not differ from those of prolonged conservative therapy.”
Is chiropractic spinal adjusting (specific manipulation) safe and effective for patients suffering from discogenic radiculopathy/sciatica?
Drs. Deyo and Mirza clearly indicate that chiropractic spinal manipulation is both safe and usually effective in the management of patients suffering with discogenic radiculopathy/sciatica, stating:
A randomized trial of chiropractic manipulation for subacute or chronic back related leg pain “showed that manipulation was more effective than home exercise with respect to pain relief at 12 weeks.”
“A randomized trial involving patients who had acute sciatica with MRI-confirmed disk protrusion showed that at 6 months, significantly more patients who underwent chiropractic manipulation had an absence of pain than did those who underwent sham manipulations (55% vs. 20%).”
In addition, for many decades, published studies have supported the effectiveness and safety of spinal manipulation for the management of discogenic radiculopathy/sciatica (4, 5, 6, 7, 8, 9). A recent study adding to the evidence is presented here (10).
In 2006, physicians Valter Santilli, MD, Ettore Beghi, MD, Stefano Finucci, MD published a study in the Spine Journal, titled (10):
Chiropractic manipulation in the treatment of
acute back pain and sciatica with disc protrusion:
A randomized double-blind clinical trial of
active and simulated spinal manipulations