Lumbosacral Radiculopathy

Causes

• Herniated (Slipped) Disc:
  • This is the most common cause. The soft, jelly-like center of an intervertebral disc pushes through a tear in its tougher outer layer, directly compressing or irritating a nearby nerve root.
  • Often caused by bending, lifting, or twisting movements, or sometimes occurs spontaneously.
• Spinal Stenosis:
  • Narrowing of the spinal canal (central stenosis) or the openings where nerve roots exit the spine (foraminal stenosis).
  • Can be caused by age-related changes, bone spurs (osteophytes), thickened ligaments, or arthritis.
• Degenerative Disc Disease:
  • Age-related wear and tear on the spinal discs can lead to disc thinning, collapse, and instability, potentially irritating nerve roots.
• Spondylolisthesis:
  • A condition where one vertebra slips forward over the vertebra below it, which can narrow the spinal canal and compress nerves.
• Piriformis Syndrome:
  • The piriformis muscle, located deep in the buttock, can compress the sciatic nerve, causing sciatica-like symptoms. This is considered a non-spinal cause of radiculopathy.
• Spinal Tumors or Cysts: (Rare) Growths can press on nerve roots.
• Spinal Infections or Inflammation: Can cause swelling and nerve compression.
• Trauma: Injuries to the spine from accidents or falls.
• Diabetes: Can lead to nerve damage (diabetic neuropathy), which can mimic radiculopathy symptoms or make nerves more susceptible to compression.

Symptoms

• Pain:
  • Often described as sharp, shooting, burning, or electric-shock-like.
  • Starts in the lower back or buttock and radiates down one leg, often below the knee, and into the foot.
  • Can worsen with certain movements, coughing, sneezing, or prolonged sitting.
• Numbness or Decreased Sensation: Along the nerve pathway in the leg or foot.
• Tingling or "Pins and Needles" Sensation (Paresthesia): In the leg or foot.
• Muscle Weakness: In the muscles supplied by the affected nerve, leading to difficulty walking, lifting the foot (foot drop), or standing on toes.
• Reflex Changes: Diminished or absent reflexes (e.g., Achilles or patellar reflex).
• Bowel or Bladder Dysfunction: (Rare, but serious) If nerve roots supplying the bladder and bowel are severely compressed (Cauda Equina Syndrome), this is a medical emergency.

Diagnosis

• Medical History: The doctor will ask about the location, nature, onset, and duration of your pain, as well as any factors that make it better or worse. Information about previous back problems, injuries, and overall health is also gathered.
• Physical Examination:
  • Neurological Exam: Assessment of sensation, muscle strength, and reflexes in the legs and feet to identify which nerve root is affected.
  • Straight Leg Raise Test: A common test where the doctor raises the straightened leg; pain radiating down the leg can indicate nerve root compression.
  • Palpation: Feeling the spine and muscles for tenderness or spasm.
  • Range of Motion: Assessing flexibility and movements that aggravate pain.
• Imaging Tests:
  • X-rays: Can show bony changes like arthritis, bone spurs, or alignment issues, but do not show soft tissues like discs or nerves.
  • MRI (Magnetic Resonance Imaging): The most common and effective imaging test for radiculopathy. It provides detailed images of soft tissues, including discs, nerves, spinal cord, and ligaments, clearly showing herniated discs or spinal stenosis.
  • CT Scan (Computed Tomography): Can provide detailed images of bone structures and may be used if MRI is contraindicated.
• Electromyography (EMG) and Nerve Conduction Studies (NCS): May be performed to assess nerve function and confirm nerve damage, differentiate radiculopathy from other causes of nerve pain (e.g., peripheral neuropathy), and identify the specific nerve root involved.

Treatment

• Conservative Treatments (often first-line):
  • Rest and Activity Modification: Short periods of rest may be helpful, but prolonged bed rest is generally not recommended. Avoid activities that worsen pain.
  • Pain Medications:
    • NSAIDs (Nonsteroidal Anti-inflammatory Drugs): (e.g., ibuprofen, naproxen) To reduce pain and inflammation.
    • Muscle Relaxants: To relieve muscle spasms.
    • Oral Corticosteroids: For short-term pain relief and to reduce inflammation.
    • Neuropathic Pain Medications: (e.g., gabapentin, pregabalin, tricyclic antidepressants) Specifically target nerve pain.
  • Physical Therapy:
    • Exercises to strengthen core muscles, improve flexibility, and enhance posture.
    • Manual therapy (massage, mobilization) to reduce muscle tension and improve spinal mechanics.
    • Modalities like heat, ice, ultrasound, or electrical stimulation.
  • Epidural Steroid Injections: Corticosteroids are injected into the epidural space around the spinal nerves to reduce inflammation and pain. Provides temporary relief.
  • Chiropractic Care or Osteopathic Manipulation: Can help with spinal alignment and reduce nerve irritation.
• Surgical Treatments (for persistent or severe cases):
  • Microdiscectomy: The most common surgery for herniated discs. A small portion of the herniated disc that is pressing on the nerve is removed.
  • Laminectomy/Laminotomy: Removal of part of the lamina (bone that forms the back of the spinal canal) to decompress the spinal cord or nerve roots, often for spinal stenosis.
  • Spinal Fusion: May be considered in cases of spinal instability, where vertebrae are permanently joined together to prevent movement.
  • Artificial Disc Replacement: In some cases, a damaged disc can be replaced with an artificial one.

Getting Through a Radiculopathy Flare

Most nerve root pain from a disc improves substantially within six to twelve weeks whatever is done, which shapes every decision: imaging waits unless there is a warning sign, and surgery is reserved for the minority whose pain or weakness does not settle.

When imaging helps, and when it misleads

An MRI in the first weeks rarely changes treatment, and disc bulges appear in many adults with no pain, so a scan waits until symptoms persist past about six weeks, weakness progresses, or an injection or surgery is planned. It is ordered immediately for new bladder or bowel trouble, saddle numbness, or weakness in both legs, which can mean cauda equina syndrome and is an emergency. Our low back pain article explains how the first visit is structured.

Medication for the weeks it is needed

Naproxen or ibuprofen taken on a schedule for a week or two does more than occasional doses; meloxicam is a once-daily alternative. A short course of prednisone gives some people modest early relief. Gabapentin and pregabalin help some people with the burning, electric quality of the pain and do little for others, so they are trialed for a few weeks and stopped if not clearly helping. Duloxetine is an option when pain has lasted months. Opioids add risk without changing the course, and our managing pain without opioids guide sets out what works instead.

Move more than feels natural

Bed rest beyond a day or two slows recovery. Walking, changing position often, and a physical therapy program that progresses from nerve-gliding and gentle extension to core strength shortens the flare and reduces recurrence. Sitting, especially in a car or soft couch, is usually the worst position. Heat and ice are reasonable, and neither replaces movement.

Injections and surgery: what they can and cannot do

An epidural steroid injection reduces leg pain for weeks to months in many people and is most useful for getting through the worst stretch; it does not repair the disc. Surgery relieves leg pain faster than waiting, but outcomes converge by a year or two for most people, so it is chosen for persistent disabling pain, worsening weakness, or foot drop rather than on the scan alone. Spinal stenosis, the other common cause in older adults, follows a different course.

What else produces leg pain

Piriformis syndrome, hip arthritis, peripheral arterial disease, and diabetic neuropathy each mimic a nerve root and are treated differently; our sciatica versus piriformis article walks through the distinction. Our musculoskeletal team coordinates therapy, imaging, and referral. NINDS and MedlinePlus publish patient guidance on nerve root pain and its treatment.

If leg pain from your back has lasted more than six weeks, or you have noticed new weakness in a foot, schedule a visit.