Is Sciatica Considered Radiculopathy?
Yes, sciatica is the most common symptom of lumbar radiculopathy, but the terms are not interchangeable—sciatica describes the symptom (leg pain in sciatic nerve distribution), while radiculopathy describes the underlying nerve root dysfunction. 1
Definitions and Relationship
Radiculopathy is defined as dysfunction of a nerve root associated with pain, sensory impairment, weakness, or diminished deep tendon reflexes in a nerve root distribution. 1
Sciatica is defined as pain radiating down the leg below the knee in the distribution of the sciatic nerve, suggesting nerve root compromise due to mechanical pressure or inflammation. 1 The American College of Physicians explicitly states that sciatica is the most common symptom of lumbar radiculopathy. 1
Key Clinical Distinctions
Sciatica is a symptom, not a diagnosis—it describes the pain pattern but does not specify the underlying pathology. 2
Radiculopathy is a pathophysiological diagnosis that includes objective findings such as motor weakness, sensory deficits, and reflex changes in addition to pain. 1
The term "sciatica" is often used synonymously with lumbar radiculopathy in clinical practice, though this usage is technically imprecise since sciatica refers only to the pain component. 3
Clinical Implications
A patient can have sciatica without meeting full criteria for radiculopathy if they have radiating leg pain but lack objective neurological findings (weakness, sensory loss, or reflex changes). 1
Conversely, radiculopathy always involves nerve root dysfunction with demonstrable neurological deficits, not just pain. 1
Diagnostic Approach
The diagnosis of radiculopathy requires a comprehensive neurological examination including:
- Knee strength and reflexes for L4 nerve root assessment 4
- Great toe and foot dorsiflexion strength for L5 nerve root 4
- Foot plantarflexion and ankle reflexes for S1 nerve root 4
- Dermatomal sensory distribution testing 4
The combination of radicular pain pattern, dermatomal sensory changes, and motor weakness in a nerve root distribution establishes the diagnosis of radiculopathy even without a positive straight leg raise test. 4
Common Pitfalls
Do not assume all leg pain is radiculopathy—referred pain from the lower back can radiate to the leg without nerve root involvement, and these conditions have different prognoses and treatments. 2
Sciatica-like symptoms can arise from non-radicular sources including sacroiliac joint dysfunction, which can clinically mimic radiculopathy and requires MRI of the spine to differentiate. 5
The straight leg raise test has high sensitivity (91%) but poor specificity (26%) for disc herniation, meaning many positive tests are false positives. 4