Differentiate the clinical presentation of a herniated nucleus pulposus from spinal stenosis.
Spinal stenosis, which is primarily seen in older patients, is caused by a combination of enlarging posterior facet joints, osteophytes from osteoarthritis, hypertrophy of the ligamentum flavum, and bulging of a disc annulus. All these structures may impinge on nerve roots or the cauda equina and produce typical radicular low back pain. Patients with spinal stenosis experience neurogenic claudi-cation, leg pain when walking. Sitting and resting relieve the pain. Neurogenic claudication differs from vascular claudi-cation in that the sitting position relieves the pain in the for-mer and cessation of walking relieves the pain in the latter.
The pain of spinal stenosis differs from that of disc dis-ease in that sitting with flexion of the lumbar spine relieves spinal stenosis pain. Disc disease pain is typically relieved by reclining and may be increased with flexion of the lumbar spine. Another difference between spinal stenosis and disc disease is that pain and neurologic deficits can extend over several dermatomes with spinal stenosis because of the diffuse nature of the disease. A herniated nucleus pulposus manifests as a localized disease of specific dermatomal distribution. Spinal stenosis is characterized by chronic mild discomfort that progresses over time. Conversely, the hallmark of disc disease is the acute and severe onset of radicular pain.
A CT scan or MRI examination ultimately makes the definitive diagnosis. It is important that the findings on these scans are correlated with the clinical symptoms.