From the Guidelines
The workup for spinal stenosis should begin with a thorough history and physical examination, followed by MRI of the lumbar spine as the initial imaging modality of choice, as it provides excellent soft-tissue contrast and accurately depicts lumbar pathology, including disc degeneration, as well as the thecal sac and neural structures 1. When evaluating patients with persistent back and leg pain who are potential candidates for invasive interventions, MRI is the preferred imaging modality, as it can visualize discs and accurately evaluate the degree of spinal stenosis, although clinicians should be aware that findings on MRI are often nonspecific 1. The following steps should be considered in the workup:
- Start with a thorough history and physical examination to assess for degenerative changes, spondylolisthesis, or other structural abnormalities.
- MRI of the lumbar spine is the gold standard imaging modality, as it provides detailed visualization of neural compression, ligamentum flavum hypertrophy, disc herniation, and other soft tissue pathologies.
- CT myelography may be considered when MRI is contraindicated or unavailable, as it can be useful in assessing the patency of the spinal canal/thecal sac and of the subarticular recesses and neural foramen 1.
- Electromyography (EMG) and nerve conduction studies can help differentiate spinal stenosis from peripheral neuropathy or other neuromuscular conditions when the diagnosis is unclear.
- Laboratory tests are not typically necessary but may include inflammatory markers (ESR, CRP) if inflammatory causes are suspected.
- Bone density testing may be appropriate in older patients to assess for concurrent osteoporosis.
- Functional assessment should include evaluation of walking distance before symptom onset, neurological examination focusing on motor strength, sensory changes, and reflexes, and assessment of bowel and bladder function to rule out cauda equina syndrome. This comprehensive workup allows for accurate diagnosis and appropriate treatment planning, whether conservative management or surgical intervention is indicated.
From the Research
Spinal Stenosis Workup
- The diagnosis of lumbar spinal stenosis can generally be made based on a clinical history of back and lower extremity pain that is provoked by lumbar extension, relieved by lumbar flexion, and confirmed with cross-sectional imaging, such as computed tomography or magnetic resonance imaging (MRI) 2.
- MRI evaluation of lumbar spinal stenosis can be performed using different methods, including measurement of dural sac cross-sectional area (DSCA) and morphological grading A-D, both of which have acceptable inter- and intraobserver agreements and strong intercorrelation 3.
- The severity of stenosis graded using surgeons' visual assessment of spinal stenosis as well as measurement of dural cross-sectional area on MRI does not consistently indicate the patient's disability level, as measured by the Oswestry Disability Index (ODI) and Short Form 36 (SF-36) 4.
- Preoperative MRI findings, such as morphological grade of stenosis, quantitative grade of stenosis, disc degeneration, facet joint tropism, and fatty infiltration of the multifidus muscle, have no clinically relevant association with patient reported disability and pain at baseline 5.
- Severe disc degeneration (Pfirrmann score 4-5) is significantly associated with less chance of achieving a 30% improvement on the ODI score after surgery for lumbar spinal stenosis, while other preoperative MRI findings are not associated with patient reported outcome 6.
Diagnostic Criteria
- Clinical history of back and lower extremity pain provoked by lumbar extension and relieved by lumbar flexion 2.
- Confirmation with cross-sectional imaging, such as computed tomography or MRI 2.
- Measurement of dural sac cross-sectional area (DSCA) and morphological grading A-D on MRI 3.