Sciatica (pronounced sigh-at-ih-kah) is a result of irritation at the sciatic nerve. It is a relatively common diagnosis which can result from several different problems. For those of you who are unfamiliar with sciatica, the most common symptom is pain running from the low back, down the buttocks, and into the back of the leg to the foot. This is the path of the sciatic nerve. Components of this nerve start at the L3 segment of the low back and combine with each lower segment to form the full sciatic nerve. It then runs down the back of the leg to your foot. Compression of the nerve at any point along this nerve path can create symptoms of sciatica.
In addition to pain along the sciatic nerve distribution, other common symptoms with sciatica include numbness, tingling, or burning along the path of the nerve. In more severe cases weakness in the leg can occur. The condition commonly occurs with individuals in their 50s, typically develops over time versus being caused by a specific trigger, and can be relatively mild or severely debilitating. It usually only occurs along one leg at a time, but can affect both legs. Pain typically increases during sitting activities and can make standing and walking difficult; however, symptom presentation can vary depending on the area of compression.
There are several possible causes for sciatic symptoms. The most common causes are listed as follows:
- Disc herniation
- Degenerative disc disease
- Lumbar spinal stenosis
- Piriformis syndrome
- Sacroiliac (SI) joint dysfunction
Posterior disc herniations along the L3 to L5 segments can cause compression along the sciatic nerve due to the backward position of the disc material pressing on the nerve. Disc degeneration, which is a natural part of aging, ends up decreasing the joint space irritating the nerve root. Spondylolisthesis is when a small stress fracture allows a vertebral body to shift forward on another, thus putting it out of alignment. The narrowed disc space, fracture, and slipping forward of the vertebrae can cause pinching of the sciatic nerve. Spinal stenosis, which could be caused by a bone spur, causes a narrowing of the space that the nerve roots pass through; thus causing increased compression on the nerves. The piriformis is a muscle that runs deep in the buttock region. This muscle can be anatomically split in different ways around the sciatic nerve including the nerve passing overtop, underneath, or through the muscle. Tightness, weakness or irritation in this muscle can increase compression on the sciatic nerve as it passes along the buttock region. SI joint dysfunction can cause irritation at the L5 (lowest lumbar segment) nerve. Other less common causes of sciatica include: pregnancy, scar tissue, muscle strains, spinal tumors, and infection.
So, then, what treatments are the most effective for this condition? Our next blog will explain the best treatment strategies for sciatica.