Lumbosacral radicular pain (sciatica)

Most disc-related sciatica improves, and large extrusions often regress on their own. Examine with the straight leg raise tests, localize the root, rule out cauda equina syndrome, and remember extraspinal mimics.

1. Know which straight leg raise rules in and out. In a Cochrane review, the ipsilateral straight leg raise was sensitive (0.92) but not specific (0.28), while the crossed straight leg raise was specific (0.90) but insensitive (0.28) for disc herniation ¹.
2. Localize foot drop by muscles outside the fibular nerve. Weak ankle inversion (tibialis posterior) and hip abduction (gluteus medius) point to L5 rather than the fibular head. Sensory nerve action potentials are preserved in radiculopathy because the lesion is proximal to the dorsal root ganglion ².
3. Herniations often regress. In pooled data, spontaneous regression occurred in 96% of sequestrations, 70% of extrusions, 41% of protrusions and 13% of bulges with conservative care ³.
4. Rest does not help sciatica. Moderate-quality evidence shows little or no difference in pain or function between advice to rest in bed and advice to stay active for sciatica ⁴.
5. Cauda equina syndrome is a surgical emergency. Saddle anesthesia, new urinary retention and reduced anal tone with bilateral leg symptoms need emergent MRI and urgent decompression; urinary retention marks a worse prognostic stage, so outpatient imaging and medication trials are inappropriate ⁵.
6. Consider deep gluteal mimics. Buttock pain worse with sitting, tenderness over the greater sciatic notch and pain with piriformis-loading maneuvers suggest piriformis (deep gluteal) syndrome when lumbar imaging is unrevealing ⁶.

Progressive motor deficit, saddle anesthesia or sphincter dysfunction overrides the usual conservative pathway and calls for emergent imaging and surgical evaluation ⁵.

• A positive crossed straight leg raise supports herniation; a negative one does not exclude it ¹.
• A negative ipsilateral straight leg raise makes herniation less likely because the test is sensitive ¹.
• Complete resolution occurred in 43% of sequestrations and 15% of extrusions ³.
• Extrusions and sequestrations regress more often than bulges and protrusions ³.
• In foot drop with a normal superficial fibular sensory response but sensory loss, suspect a root lesion ².
• Piriformis syndrome remains controversial; its literature is mainly case series and narrative reviews ⁶.
• Hip abduction weakness from gluteus medius involvement implicates the superior gluteal nerve territory, which a fibular neuropathy spares ².
• In acute low back pain without sciatica, advice to stay active gives small gains over bed rest ⁴.

• Using a negative crossed straight leg raise to rule out herniation ¹.
• Assuming a large extrusion will need surgery because of its size ³.
• Blaming fibular neuropathy for foot drop when inversion and hip abduction are weak ².
• Prescribing bed rest for sciatica in the belief that it speeds recovery ⁴.