Lumbar radiculopathy : introduction, diagnosis & treatment

Approximately 80% of the population is plagued at one time or another by back pain, especially lower back pain. Associated leg pain (called lumbar radiculopathy or sciatica) 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 in 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 (see image below). A dermatome is a specific area in the lower extremity that has nerves going to it from 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 lower back pain begins with a detailed patient history and examination.

Dermatomes (above): Where you feel back and/or leg pain
may help your doctor diagnose nerve compression.

Medical History: Important when Diagnosing Lower Back Pain and Sciatica

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.

Journal Your Back and Leg Pain

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.

Spinal Anatomy: Helpful for Understanding Your Lower Back Pain

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 (neck), thoracic (upper/mid back), lumbar (low back), and sacrum (pelvis).

Discs are cushion-like tissues that separate most vertebrae and act as the spine's shock absorbing system. Eaach disc is comprised of a tough outer ring of fibers called the annulus fibrosus, and a soft gel-like center called the nucleus pulposus.

There are 7 flexible cervical (neck) vertebrae that help to support the head. Twelve thoracic vertebrae attach to ribs. Next, are 5 lumbar vertebrae; they 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 elements of spinal canal. Spinal nerves branch from the spinal cord and exit the spinal canal through passageways between the vertebral bodies. The passageways are called neuroforamen. Nerves provide sensory (allowing you to touch and feel) and motor information (allowing the muscles to function) to the entire body.

In the next article (click the Continue Reading link below), we discuss how your doctor determines what is causing your lower back pain and sciatica, which is essential to the proper treatment plan and symptom relief.

Commentary by a Spine Expert

Lumbar radiculopathy is a common problem that results when nerve roots are compressed or irritated. This excellent article discusses the basic anatomy and clinical manifestations of lumbar radiculopathy, which is often referred to generically as sciatica. These symptoms can be due to a variety of causes such as disc bulges, degenerative narrowing of the space for the nerves (spinal stenosis or foraminal stenosis), spinal instability, deformity of the vertebrae, or herniated disc fragments outside of the disc space.

In 70-80% of patients, sciatica is transient, and resolves with nonsurgical treatments such as anti-inflammatory medications, physical therapy, exercise, spinal manipulation, or other nonsurgical modalities. A proportion of patients with sciatica require surgical intervention in instances where nonsurgical therapies have failed to provide adequate pain relief, and there is pathology [cause] that is present compressing the nerves. A very small proportion of patients require urgent surgery. If a very large lumbar disc herniation causes severe nerve damage, with paralysis or acute bowel or bladder incontinence, then emergency surgery may be required.

Physical Examination to Diagnose Low Back Pain

During the physical and neurological examination, the physician observes your ability to move (range of motion) and movements that are difficult and/or that cause symptoms. Your reflexes are also tested and may reveal important findings about which nerve root(s) may be compressed.

In the table below, "L" means lumbar (low back) and "S" means sacral (back of the pelvis). The number that follows denotes the level in the particular region of the spine.

The table (below) shows what findings your physician may find during his/her examination.

Nerve Root Involved	Possible Exam Findings with Nerve Root Compression
L2	Decreased hip flexor strength (hip flexor muscles allow you to lift your knee toward your chest)
L3	Decreased patellar reflex (knee jerk response) Sensation loss of the anterior thigh (front of one or both thighs) Weakness in quadriceps muscle (a large muscle group at the front of each thigh) Pain in the area of the anterior thigh (front of a thigh)
L4	Sensory loss of the anterior, lateral or medial foot (front, side or inside of a foot) Possible decreased patellar tendon reflex (knee jerk response) Weakness of the quadriceps muscle Pain in the area of the anterior leg (front of a leg)
L5	Sensory loss in the dorsum (top) of the foot and great toe Weakness of the anterior tibialis (front of a shinbone) , great toe (extensor hallicus longus), and hip abductors (moves a leg outward from the hip) Pain down the side of the leg
S1	Decreased Achilles reflex (heel) Sensory loss of the lateral (side) foot and the small toe Weakness of the gastrocnemius (calf muscle), gluteus maximus (buttock muscle), plantar flexor (enables you to point your foot), and great toe Pain down the back of the leg into the bottom or side of the foot

Imaging Tests Help Confirm the Diagnosis

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.

Treatments

Low back pain with lumbar radiculopathy is often treated conservatively. These non-surgical treatments may include a combination of:

• Rest
• Medication
• Spinal injections are dual purpose; may manage pain andprovide diagnostic information
• Home exercise or structured physical therapy program

Spine surgery may be recommended if symptoms persist after a period of 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.

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Source :  http://www.spineuniverse.com/conditions/back-pain/low-back-pain/lumbar-radiculopathy-low-back-leg-pain