Lumbar Radiculopathy: Low Back and Leg Pain
Approximately 80% of the population is plagued at one time or another by back pain. Associated leg pain occurs less frequently. Pain can be bothersome and debilitating, limiting daily activities. Leg and back pain can be caused by a variety of reasons, not all of which originate from your spine.
For the purpose of this article, we will focus on lumbar radiculopathy, which refers to pain in the lower extremities in a dermatomal pattern. A dermatome is a specific area in the lower extremity innervated by a specific lumbar nerve. This pain is caused by compression of the roots of the spinal nerves in the lumbar region of the spine. Diagnosing leg and back pain begins with a detailed patient history and examination.
Your medical history helps the physician understand the problem. It is important to be specific when answering medical questions related to pain onset but remembering every detail is often not critical. Keeping records of your medical history, including medical problems, medications you are taking and surgeries you have had in the past is helpful.
Regarding your leg and back pain, it may be helpful to keep a journal of your activities, documenting when the pain began, the activities that aggravate your pain and those that relieve your symptoms. It is also important to determine whether your back pain is more bothersome than your leg pain or visa versa. You may be asked if you are experiencing any numbness or weakness in your legs or any difficulty walking. Remember, understanding the cause of your problem is based on the information you provide.
Most people describe radicular pain as a sharp or burning pain that shoots down the leg. This is what some people call sciatica. This pain may or may not begin in the low back. Leg pain caused by compressed nerve roots generally has specific patterns. These patterns of pain depend on the level of the nerve being compressed. After reviewing your history, your physician will perform a physical examination. This will help the physician determine if your symptoms are due to a problem that is caused by spinal nerve root compression. To help you understand the exam performed by your physician lets pause for a quick anatomy lesson.
The spine is comprised of 33 vertebrae (bones stacked on top of each other in a "building-block" fashion) that have 4 distinct regions: Cervical, Thoracic, Lumbar, and Sacral. Discs, cushion-like tissues separate most vertebrae and act as the spine's shock absorbing system. The disc has a tough outer ring of fibers called the Annulus Fibrosus and a soft gel-like center called the Nucleus Pulposus.
There are seven flexible cervical (neck) vertebrae that support the head. There are twelve thoracic (chest) vertebrae, which attach to ribs. The five lumbar vertebrae are large and carry the majority of the body weight. The sacral region helps distribute the body weight to the pelvis and hips.
The spinal cord is housed within the protective spinal column. Spinal nerves come from the spinal cord and travel through a tunnel or foramen. The nerves provide sensory (allowing you to touch and feel) and motor information (allowing the muscles to function) to the entire body.
Lumbar Radiculopathy: Proper Diagnosis Key to Effective Treatment of Back and Leg Pain
You may be asked to stand, walk or lie down on the exam table during the physical examination. In a lying position, your physician will raise each of your legs to demonstrate flexibility and strength in your low back and legs. The following table is a summary for the examination performed and possible findings:
|Nerve Root Involved
||Possible Exam Findings with Nerve Root Compression
||Decreased hip flexor strength
||Decreased patellar reflex
Sensation loss of the anterior thigh
Weakness in quadriceps muscle
Pain in the area of the anterior thigh
||Sensory loss of the anterior lateral or medial foot
Possible decreased patellar tendon reflex
Weakness of the quadriceps
Pain in the area of the anterior leg
||Sensory loss in the dorsum of the foot and great toe
Weakness of the anterior tibialis, great toe (extensor hallicus longus), and hip abductors
Pain down the side of the leg
||Decreased Achilles reflex
Sensory loss of the lateral foot and the small toe
Weakness of the gastrocnemius, gluteus maximus, plantar flexor, and great toe
Pain down the back of the leg into the bottom or side of the foot
To further determine the source of your symptoms, and to confirm your diagnosis, your physician may request other tests such as an X-Ray or MRI (Magnetic Resonance Imaging).
An X-Ray is used to show the bony anatomy of the spine. In an X-Ray, the physician is looking for the alignment and integrity of the bony structures. Integrity in this sense means no degeneration in the bone structures.
An MRI produces images of the soft tissues of the spine. Using an MRI, the physician looks at the soft tissue structures such as the discs, ligaments, spinal cord, and spinal nerves. The physician looks at the integrity of the discs themselves for degeneration (dark in color because of loss of hydration), bulging or herniation (where the disc contents protrude into the spinal canal and compress the nerves or spinal cord). If there is a herniation present, the MRI helps the physician determine if the nerves are being pinched or smashed by the herniated disc.
Low back pain with lumbar radiculopathy is often treated conservatively. This may include a combination of rest, medication, and a home exercise or structured physical therapy program.
Surgery may be recommended if symptoms persist after conservative treatment. These symptoms may include severe pain, increasing numbness, or weakness of the legs. The decision for surgical intervention is often made when conservative treatment has failed and the symptoms are interfering with your daily function causing lifestyle changes such as an inability to work or participate in the activities you enjoy.
Understanding Lumbar Radiculopathy
A combination of medical history, physical examination, and diagnostic testing helps your physician understand your symptoms. It is important for you as the patient to understand your symptoms, as well. Understanding your symptoms allows you to seek treatment when appropriate. Your family physician is an excellent source for initial assessment and treatment, followed by referral to a spine specialist when necessary.