Neurogenic intermittent claudication related to spinal stenosis.

BACKGROUND: The pathophysiology of neurogenic intermittent claudication (NIC) is not very well understood. We examined the theory of "two-level" spinal stenosis as the pathologic cause of NIC. METHODS: Forty-five consecutive patients with NIC were chosen for the study group and another 45 patients with chronic low back pain, but without NIC, were consecutively chosen for the control group. All the patients were examined using several methods that included a personal history survey, physical examination, X-ray studies, computed tomography (CT) and magnetic resonance imaging (MRI). RESULTS: Two-level central canal stenosis was found on MRI in 88.9% of the study group compared to only 37.8% of the control group (Fisher's exact two-tailed test, P = 0.0000). In the study group, 77.8% of the patients had severe or moderate facet joint degeneration on CT. The remaining 22.2% of patients had mild facet joint degeneration. In the control group, 40% of the patients had severe or moderate facet joint degeneration, while it was mild or normal in the remaining 60% (Fisher's exact two-tailed test, P = 0.0005). On X-ray, 42.2% of the study group compared with 17.7% of the control group had spondylolisthesis (Fisher's exact two-tailed test, P = 0.0129). In 35% of the study group compared with 11.1% of the control group, X-ray findings showed scoliosis (Fisher's exact two-tailed test, P = 0.0115). The lumbosacral angle in the study group was 35.8 degrees +/- 6.1 degrees compared to 33.1 degrees +/- 7.5 degrees in the control group (independent Student's two-tailed t-test, P > 0.05). CONCLUSIONS: Our study strongly supports pathophysiology for NIC that is closely related to two-level spinal canal stenosis. Degenerative joint disease, spondylolisthesis and scoliosis of the lumbar spine are predisposing factors of NIC.