Spinal Canal and Neuroforaminal Stenosis in Relation to Intervertebral Disc Syndrome
Spinal canal and neuroforaminal stenosis alone do not necessarily indicate intervertebral disc syndrome, as they can result from various pathologies including degenerative changes, ligamentum flavum hypertrophy, facet joint arthropathy, and congenital narrowing. 1
Pathophysiology and Relationship
- Spinal stenosis refers to compression of nerve roots due to narrowing of the spinal canal, lateral recesses, or intervertebral foramina, which can have acquired or congenital origins 2
- Most cases of spinal stenosis are acquired and caused by multiple factors including hypertrophy of the ligamentum flavum, enlarged osteophytes, degenerative arthritis, and disc herniations 2
- Intervertebral disc syndrome typically involves disc pathology that may contribute to but is not synonymous with spinal stenosis 3
- Stenosis can occur from various structures including osteophytosis of the vertebral body, uncovertebral joint hypertrophy, disc protrusion, ossification of the posterior longitudinal ligament, and ligamentum flavum hypertrophy 3
Diagnostic Considerations
- MRI without contrast is the preferred initial imaging modality for evaluating suspected neural compression, providing excellent soft-tissue contrast and accurately depicting spinal pathology 4, 5
- MRI can differentiate between various causes of stenosis, including whether disc pathology is the primary contributor 6
- CT can depict bony encroachment on the spinal canal in cases of disc-osteophyte complexes but MRI provides better visualization of the marrow and spinal cord 1
- Clinical correlation between radiographic findings and symptoms is crucial, as imaging findings alone may not always correlate with clinical presentation 5
Clinical Implications
- Spinal stenosis may lead to symptoms similar to those seen in intervertebral disc syndrome, including radicular pain, sensory disturbances, and motor weakness 7
- When lumbar disc degeneration allows rotatory and lateral instability, posterolateral bulging of the annulus fibrosus into the root canal can occur, contributing to stenosis symptoms 8
- The presence of vertebral bone marrow edema on MRI in patients with spinal stenosis may predict early progression of intervertebral disc degeneration after decompression surgery 9
Management Considerations
- Treatment approaches differ based on whether stenosis is primarily due to disc pathology or other causes 1
- For stenosis related to disc herniation, epidural injections may be recommended according to some guidelines 1
- For stenosis primarily related to bony or ligamentous causes, different interventions may be more appropriate 1, 2
- Novel interventions for symptomatic lumbar spinal stenosis, such as minimally invasive lumbar decompression and interspinous spacers, are emerging treatment options 2
Pitfalls to Avoid
- Assuming that all cases of spinal stenosis are due to intervertebral disc pathology can lead to inappropriate treatment selection 1
- Failing to correlate imaging findings with clinical symptoms may result in unnecessary interventions 5
- Overlooking other potential causes of stenosis beyond disc pathology, such as ligamentum flavum hypertrophy or facet joint arthropathy 2, 3
In conclusion, while intervertebral disc pathology can contribute to spinal canal and neuroforaminal stenosis, the presence of stenosis alone does not definitively indicate intervertebral disc syndrome, as multiple other pathologies can cause similar imaging findings.