Lumbar spinal stenosis and neurogenic claudication

Walking-induced buttock and leg symptoms relieved by flexion, sitting or lying down mean neurogenic claudication; confirm stenosis on MRI, expect a benign course in many, and match minimally invasive options to the anatomy.

1. The syndrome has provocative and palliative features. NASS describes gluteal or leg pain or fatigue, with or without back pain, provoked by upright exercise such as walking and relieved by forward flexion, sitting or recumbency ¹.
2. The natural history is often benign. For mild to moderate symptoms, NASS consensus is that about one-third to one-half do well, and rapid or catastrophic neurologic decline is rare; some medical treatments studied likely did not alter the course ¹.
3. MRI confirms the anatomy. NASS suggests MRI as the most appropriate noninvasive test for canal narrowing or root impingement (grade B); ASPN advises diagnosis from imaging combined with history ¹².
4. Epidural steroids sit in the algorithm. MIST recommends epidural steroid injections for symptomatic stenosis and allows repeats after significant temporary improvement ².
5. PILD targets thick ligamentum flavum. Percutaneous image-guided lumbar decompression should be considered for mild-to-moderate stenosis with neurogenic claudication, spondylolisthesis grade 2 or less, and at least 2.5 mm ligamentum flavum hypertrophy (grade A) ².
6. Spacers suit stable, mild-to-moderate disease. Interspinous spacers should be considered with spondylolisthesis grade 1 or less and no dynamic instability, such as facet fluid on imaging (grade A) ².

Rapidly progressive neurologic decline points to open decompression, with or without fusion; MIST reserves it for a favorable risk-benefit balance or this setting ².

• Standing flexion-extension radiographs are recommended to look for dynamic instability at the index level ².
• Upright, hyperlordotic MRI may detect more stenosis than supine imaging in selected patients ².
• In MiDAS ENCORE, 143 patients had PILD and 131 had epidural steroids ³.
• At 2 years after PILD, Oswestry Disability Index improved by 22.7 points and pain by 3.6 points ³.
• No serious device- or procedure-related adverse events occurred with PILD; 1.3% had a related adverse event ³.
• MIST also supports interspinous fusion for mild-to-moderate stenosis with degenerative disc disease and spondylolisthesis grade 2 or less, with or without instability ².
• In the randomized phase of MiDAS ENCORE, PILD outperformed epidural steroids at 1 year ³.
• Spinal cord stimulation and intrathecal drug delivery are options when more direct methods fail or are unsuitable ².

• Calling walking-induced leg pain relieved by forward flexion, sitting or lying down vascular claudication; that palliative pattern is the hallmark of neurogenic claudication ¹.
• Offering interspinous spacers when facet fluid suggests instability ².
• Expecting inevitable neurologic deterioration without surgery ¹.