Lumbar Radiculopathy: Signs and Symptoms
Core Clinical Presentation
Lumbar radiculopathy presents as dysfunction of a nerve root with pain radiating down the leg below the knee (sciatica), accompanied by sensory impairment, weakness, or diminished deep tendon reflexes in a specific nerve root distribution. 1
Cardinal Symptoms
- Pain characteristics: The hallmark is sciatica—pain radiating below the knee following the sciatic nerve distribution, typically described as burning, aching, or shooting in quality 2, 1
- Pain pattern: Can be continuous or intermittent, often worsened by specific movements or positions 2
- Radicular distribution: Pain follows a dermatomal pattern corresponding to the affected nerve root (most commonly L3, L4, L5, or S1) 3
Neurological Deficits
- Motor weakness: Specific muscle groups affected depending on nerve root level—for example, ankle dorsiflexion weakness (foot drop) with L5 involvement, or gastrocnemius weakness with S1 involvement 4, 3
- Sensory changes: Numbness, tingling, or altered sensation in the corresponding dermatome 1, 3
- Reflex abnormalities: Diminished or absent deep tendon reflexes, such as absent Achilles reflex with S1 radiculopathy 4, 3
Physical Examination Findings
- Positive straight leg raise test: Reproduction of radicular pain when the leg is raised between 30-70 degrees, indicating nerve root tension 4, 1
- Functional impairment: Patients may ambulate with a limp or demonstrate difficulty with specific movements 4
- Postural changes: Observable alterations in gait or posture to minimize pain 3
Red Flag Symptoms Requiring Urgent Evaluation
- Cauda equina syndrome: Urinary retention or incontinence, bilateral lower extremity weakness, and saddle anesthesia—this constitutes a surgical emergency 5
- Progressive motor deficits: Worsening weakness over time, such as progressive foot drop 5
- Suspected malignancy, infection, or fracture: Constitutional symptoms, fever, unexplained weight loss, or history of trauma 5
Natural History and Prognosis
- Most cases improve within the first 4 weeks with conservative management 5
- The majority of disc herniations demonstrate reabsorption or regression by 8 weeks after symptom onset 5
- Approximately 50% of older adults experience chronic noncancer pain, with low back pain being the most common type 2
Common Pitfalls in Recognition
- Disc abnormalities are present in 29-43% of asymptomatic individuals, so imaging findings must correlate with clinical symptoms 5
- Radicular pain often responds poorly to simple analgesics and standard first-line neuropathic pain medications 5, 1
- The condition can be confused with other causes of leg pain, making careful neurological examination essential 3