Radiculopathy

Radiculopathy (from Latin radix 'root'; from Ancient Greek πάθος (pathos) 'suffering'), also known as pinched nerve, refers to conditions where one or more nerves are affected and do not function properly (a neuropathy). This can result in pain (radicular pain), weakness, altered sensation (paresthesia), or difficulty controlling specific muscles. Pinched nerves occur when surrounding bone or tissue, such as cartilage, muscles, or tendons, put pressure on the nerve, disrupting its function.

In radiculopathy, the issue arises at or near the nerve root, shortly after its exit from the spinal cord. However, symptoms often radiate to the body part served by that nerve. For instance, a nerve root impingement in the neck can produce pain and weakness in the forearm, and an impingement in the lower back can manifest symptoms in the foot.

Radicular pain is distinct from referred pain, which has different mechanisms and clinical features.

Polyradiculopathy refers to conditions where more than one spinal nerve root is affected.

Causes

Radiculopathy is often caused by mechanical compression of a nerve root at the exit foramen or lateral recess, secondary to intervertebral disc herniation, degenerative disc disease, osteoarthritis, facet joint degeneration/hypertrophy, ligamentous hypertrophy, or spondylolisthesis.

Other causes include neoplastic diseases, infections like shingles, HIV, or Lyme disease, spinal epidural abscess, spinal epidural haematoma, proximal diabetic neuropathy, Tarlov cysts, sarcoidosis, arachnoiditis, tethered spinal cord syndrome, or transverse myelitis.

Repeated and prolonged exposure to certain work-related activities such as physically demanding work, bending, twisting, lifting, and carrying can increase the risk of developing lumbosacral radiculopathy. Less common causes include injury from tumours compressing nerve roots and diabetes causing ischaemia or lack of blood flow to nerves.

Signs and Symptoms

Radiculopathy is diagnosed through symptoms of pain, numbness, paresthesia, and weakness in a pattern consistent with a particular nerve root, such as sciatica. Neck or back pain may also be present. Physical examination may reveal motor and sensory deficits in the distribution of a nerve root.

Spurling's test may reproduce symptoms radiating down the arm in cervical radiculopathy, while a straight leg raise or femoral nerve stretch test may demonstrate radiculopathic symptoms down the leg for lumbosacral radiculopathy. Deep tendon reflexes may be diminished or absent in areas innervated by the affected nerve root.

Diagnosis typically involves electromyography and lumbar puncture. Conditions like shingles and Lyme disease should be considered based on patient history and symptoms, confirmed with laboratory tests. Acute Lyme radiculopathy is worse at night and may be accompanied by sleep disturbance, lymphocytic meningitis, facial palsy, or Lyme carditis.

Diagnosis

Patients whose symptoms do not improve after 4-6 weeks of conservative treatment or those older than 50 years may require further diagnostic tests. Initial studies may include projectional radiography, while magnetic resonance imaging (MRI) and electrodiagnostic testing (nerve conduction study and electromyography) can provide more detailed insights. MRI can reveal degenerative changes, arthritic disease, or other lesions, while electrodiagnostic tests can detect nerve root injury.

Treatment

Treatment aims to resolve the underlying cause and restore nerve function. Conservative treatments include bed rest, physical therapy, and nonsteroidal anti-inflammatory drugs (NSAIDs) or analgesics for pain management. Evidence supports spinal manipulation for acute lumbar and cervical radiculopathies and epidural steroid injection for lumbosacral radiculopathy.

Rehabilitation

For recent injuries, formal physical therapy is typically delayed for 2-3 weeks. Initial conservative treatments, such as acetaminophen and NSAIDs, are recommended for acute lumbosacral radiculopathy. Therapeutic exercises, tailored to the patient's abilities, aim to stabilise the cervicothoracic region and prevent re-injury. While neck braces are generally not indicated, strengthening exercises are introduced gradually to reduce reliance on them.

Surgery

Surgical options are considered for patients who do not improve with conservative treatments. Procedures such as foraminotomy, laminotomy, or discectomy may be performed. For cervical radiculopathy, anterior cervical discectomy and fusion are common, though both anterior and posterior procedures have similar effectiveness and complication rates.

Epidemiology

Cervical radiculopathy has an annual incidence rate of 107.3 per 100,000 for men and 63.5 per 100,000 for women, while lumbar radiculopathy affects approximately 3-5% of the population. The most affected age group is 45-64 years, with females more frequently affected than males. Private insurance covers most cases, followed by Medicare.

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Self-assessment MCQs (single best answer)

What is the most common location for radiculopathy in the neck?

What is another term for radiculopathy?

Which of the following is NOT a common cause of radiculopathy?

What type of pain is radicular pain distinct from?

Which diagnostic test is typically used to detect nerve root injury?

What conservative treatment is NOT typically recommended for radiculopathy?

Which surgical procedure is commonly performed for cervical radiculopathy?

What is a common symptom of radiculopathy?

What test may reproduce symptoms radiating down the arm in cervical radiculopathy?

Which age group is most affected by cervical radiculopathy?