What is Sciatica?
Sciatica is a condition that occurs when nerve roots are compressed or irritated in the area of the spine located in the lower back. This condition is also called lumbar radiculopathy. Lumbar refers to the area of the spine in which it occurs, while radiculopathy is the word used to describe pain, weakness, tingling and numbness caused by irritation of the nerve roots.
What Causes Sciatica?
Nerve roots are the area of nerves where they branch off from the spinal cord to connect to different parts of the body. The nerves send signals to the brain to create sensations, like texture or pain. Irritation or compression of the nerve roots is usually caused by disc herniation or degenerative changes to the spine that put pressure on nerve roots.
Conditions that may causes compression in the lumber area of the spine vary, but can include herniated disc, degenerative disc disease, and spinal stenosis. When the roots of the nerves are compressed, it causes muscle weakness, pain and numbness in the area connected to the affected nerves.
Symptoms and Diagnosis
When the roots of the nerves are compressed anywhere along the spine, it causes muscle weakness, pain and numbness in the area connected to the affected nerves. The nerve roots in the lumbar area of the spine branch off the spinal cord and through the boney structure that protects them out to the feet, legs, hips, and buttocks. This means that compression of those nerve roots may cause pain or other sensations in the feet, legs, hips, and buttocks.
Symptoms vary depending on where the nerve roots are being compressed, but commonly include pain, weakness, tingling, or numbness. The area where these symptoms are felt may depend on where in the spine the nerve roots are compressed. Each vertebrae in the spine is assigned a numbered level. The 5 vertebrae in the lumbar section are L1 through L5, while the sacrum is S1. The locations of symptoms can vary depending on where the nerve roots are compressed, as the nerve roots in each level correspond to different places. Below is a list of symptoms you may experience depending on the level at which your sciatica is occurring:
- L2 - hip weakness and pain in your thigh
- L3 - weakness in your knee, as well as pain and weakness in your thigh.
- L4 - foot weakness and pain that travels from the lower back down to the knee or foot.
- L5 - pain down the outside of your leg to the top of your foot or big toe, as well as foot weakness
- S1 - weakness in your foot and pain down the back of your calf to the outside of your foot and little toe
To diagnose sciatica, a physician will review a patient's medical history, asking about the location and type of the symptoms to help determine if a nerve root is being affected. A physical exam will follow, focusing on range of motion and flexibility, as well as muscle strength, sensation, and reflexes to determine what nerve root is being compressed.
To verify the diagnosis, several tests may be needed. An X-ray will be performed first, which can help identify the presence of trauma or osteoarthritis, as well as early signs of infection or tumor growth. A CT scan or an MRI may follow. A CT scan can show the amount of space nerve roots are allotted by the foramen, or openings in the vertebrae of the spine. An MRI scan can best reveal the location and extent of nerve compression because it is designed to show the soft tissues around the spine, including discs, ligaments and nerves.
How is Sciatica Treated?
Symptoms of sciatica can often be relieved by conservative treatments like anti-inflammatory medication, physical therapy, and rest. Bracing may be prescribed. Most patients respond well to this treatment, with symptoms improving from six weeks to three months. However, if there is evidence of nerve damage or if symptoms fail to improve over time, surgery may be needed to remove pressure from the spinal roots. The procedure needed varies according to the source of the nerve root compression and its location in the spine.