What is Sciatica (Sciatic Nerve Pain) and How Is It Diagnosed?

What is Sciatica (Sciatic Nerve Pain)?

Sciatica, also known as sciatic nerve pain, is a term that refers to the very uncomfortable pain, tingling, and often numbness that radiates from the low back, into the buttocks and down the back of the leg. It is one of the most debilitating types of pain syndromes, accounting for a large percentage of disability.

The cause of sciatica is irritation of the nerve roots in the lower back. The sciatic nerve is a large thick nerve comprised of the nerve roots from the fourth lumbar (L4) nerve root to the third sacral (S3) nerve root. Thus, irritation of any one or more of the nerve roots between L4 and S3 could cause some type of sciatic nerve pain. Most often irritation of a lumbar nerve root is caused by a herniated disc at the L5 nerve root. The second most common level of disc herniation is at the L4 nerve root.  A lumbar disc herniation can be relatively small, protruding perhaps 1 to 2 millimeters, but still cause some acute or chronic pain.  Alternatively, a disc protrusion can be large, perhaps 10 to 12 millimeters, causing significant pain.Sciatica - Sciatic Nerve Pain

The sciatic nerve is one of the largest nerves in the entire body. As such if two or more nerve roots are irritated, such as with a herniated disc at L4 and L5, you could have extremely debilitating pain. Even if one nerve root is irritated to a significant degree, such as with a large L5 disc herniation, extreme debilitating pain can occur.

Other conditions that can cause sciatica are:
•    spondylosis (arthritis in the lumbar spine)
•    spondylolisthesis (forward displacement of the lumbar vertebrae)
•    spinal stenosis (narrowing within the spinal canal from herniated disc or spondylosis)
•    failed back surgery syndrome
•    other pathology causing lumbar nerve root irritation

Sciatica Diagnosis

The “gold standard” for diagnosis of disc herniation and other causes of sciatica is magnetic resonance imaging (MRI) of the lumbar spine. Some indications of the cause of sciatica can be detected by lumbar spinal X-ray also. The primary diagnostic differences between lumbar MRI and lumbar X-ray is you can see the nerve on lumbar MRI, whereas in lumbar X-ray you can see the bones well, but not the soft tissue, such as the disc and nerve roots.

Diagnosis of the level and extent of a lumbar disc protrusion can also be accurately determined by an expertly trained and experienced Doctor of Chiropractic (DC) or orthopedic surgeon who specializes in conditions of the low back. This is accomplished by history and physical exam.

Because I’ve been a chiropractor for over 20 years, prior to an MRI, I often accurately determine the level and the extent of a lumbar disc protrusion with 1-2 millimeters of the disc herniation specified in a subsequent MRI finding.

If you live or work in San Carlos, CA, or nearby and you suspect you are experiencing sciatic nerve pain or you have been diagnosed with sciatica and you need treatment, give us a call or just walk in during our office hours for a free 10-minute initial consultation.