From top to bottom down the entire length of the spine, at each spinal level, nerves exit through holes in the bone of the spine (foramen) on the right and left side of the spinal column. These nerves are called nerve roots, or radicular nerves. They branch out from each level of the spine and go to different parts of our body.
For example, nerves that exit the cervical spine travel down through the arms, hands and fingers. This is why neck problems that affect a cervical nerve root can cause pain and other symptoms through the arms and hands (radiculopathy), and low back problems that affect a lumbar nerve root can radiate through the leg and into the foot (radiculopathy or sciatica), thus prompting leg and/or foot pain.
The nerve roots are named for the level of the spine at which they exit. However, nerve roots are not labeled consistently throughout the entire spine.
In the cervical spine, the nerve root is named according to the LOWER spinal segment that the nerve root runs between. For example, the nerve at the C5-C6 level is called the C6 nerve root.
It is named this way because as it exits the spine, the nerve root passes OVER the C6 pedicle (a piece of bone that is part of the spinal segment).
In the lumbar spine, the nerve roots are named according to the UPPER segment that the nerve runs between. For example, the nerve root at the L4-L5 level is called the L4 nerve root.
The nerve root is named this way because as it exits the spine it passes UNDER the L4 pedicle (a piece of bone that is part of the spinal segment).
The area that the naming change occurs is at the C7-T1 level (Thoracic 1), meaning that there are eight cervical nerve roots and only seven cervical vertebrae. It should be mentioned that two nerves cross each disc level and only one exits the spine (through the foramen) at that level.
The first step toward treating radiculopathy/sciatica is to fully understand various conditions causing spinal root inflammation.
Radicular pain is a type of pain that radiates into the lower extremity directly along the course of the spinal nerve root. Radicular pain is caused by compression, inflammation and/or injury to a spinal nerve root arising from common conditions including herniated disc, foraminal stenosis and previous surgery. Leg pain can be accompanied by numbness and tingling, muscle weakness and loss of reflexes. The most common symptom of radicular pain is called sciatica or radiculopathy, which is pain that radiates along the sciatic nerve down the back of the thigh and sometimes into the calf and foot. Radicular pain can be effectively treated conservatively (non-surgically) with physical therapy, medications and epidural injections. If conservative treatments fail, decompression surgery such as laminectomy or discectomy may alleviate radicular pain.
Some of the most common symptoms of radicular pain include:
- Unexpected muscle weakness or fatigue
- Chronic neck or back pain, stiffness or soreness
- A numb or tingling feeling in the extremities
- Sciatic pain
- Loss of reflexes or diminished motor skills