What are the signs of lumbar nerve root compression?

From the Guidelines

Lumbar nerve root compression typically presents with signs of nerve root irritation, including low back pain, radiculopathy, and physical examination signs such as weakness, sensory changes, or numbness in the lower limbs.

Common Signs and Symptoms

• Low back pain
• Radiculopathy
• Weakness in the lower limbs
• Sensory changes or numbness in the lower limbs
• Absent lower limb reflexes
• Perianal or saddle numbness
• Impairment of bladder, bowel, or sexual function These signs and symptoms can be caused by various etiologies, including lumbar disc herniation, neoplasm, infection/inflammation, spinal stenosis, and hemorrhage 1.

Diagnostic Imaging

Imaging studies, such as MRI lumbar spine without IV contrast, can help diagnose lumbar nerve root compression by accurately depicting soft-tissue pathology, assessing vertebral marrow, and evaluating spinal canal patency 2, 1.

Clinical Evaluation

A thorough clinical evaluation, including physical examination and medical history, is essential to diagnose lumbar nerve root compression and to guide further diagnostic testing and treatment 3, 1.

From the Research

Signs of Lumbar Nerve Root Compression

The signs of lumbar nerve root compression can vary, but common symptoms include:

• Muscle weakness, which can present with or without pain 4
• Pain at rest, at night, and on coughing 5
• Positive straight-leg-raising tests, which are more common in disc herniation than in lateral stenosis 5, 6
• Motor disturbances, such as patellar reflex changes, which are most often seen in central spinal stenosis 5
• Sensory disturbances, which are most common in patients with complete disc herniation 5
• Decreased muscle strength and sensory loss, which are consistent signs of nerve root compression 6
• Reflex changes, which can be intermediate signs of nerve root compression 6

Specific Nerve Roots Affected

Different nerve roots can be affected, including:

• L3, L4, L5, and S1 nerve roots, which can be compressed by foraminal or extraforaminal stenosis on the concave side of the scoliosis curve 7
• L5 and S1 nerve roots, which can be affected by lateral recess stenosis on the convex side of the scoliosis curve 7

Clinical Examination

A thorough clinical examination is necessary to diagnose lumbar nerve root compression, including:

• History taking, which can help identify symptoms such as pain on coughing-straining-sneezing, a feeling of coldness in the legs, and urinary incontinence 6
• Physical examination, which can include tests such as straight leg raising, crossed straight leg raising, Bragard's sign, and Naffziger's sign 6