Lumbar spinal stenosis is a well recognized clinical entity resulting in low back pain and leg pain.

However, our understanding of the neuropathophysiological changes is limited, and precise etiology of neurologic signs and symptoms associated with lumbar spinal stenosis is not clearly known yet. And the degree of narrowing of the spinal canal and its relationship to electrophysiologic changes is also not known.

So, to find out that certain types of the spinal configuration may be related to the development of spinal stenosis, we compared various radiologic parameters on plain radiographs and CT scanning between the control and the lumbar spinal stenosis groups, And to find out the relationship between the configuration of the spine and somatosensory evoked potentials, we measured various radiologic parameters on plain rediographs and CT scanning in radiologically proven 46 lumbar spinal stenosis patients, and compared these radiologic parameters between the two groups which elicited abnormal and normal somatosensory evoked potentials.

The results were as follows.

1) Convex, trefoil canal shape and type N lamina of L4 which had narrow interarticular and interlaminar distance and the more sagittal facet joints were more frequently found in lumbar spinal stenosis.

2) There was no relationship between the configuration of the spine and somatosensory evoked potentials in lumbar spinal stenosis. And radiologic findings which are morphlogic and anatomic should not necessarily be considered as responsible for the patients' physiologic complaints and small canal by itself may not have any predictive value in symptomatic patients. So, we think it is essential to include somatosensory evoked potential study which is a physiologic study in the diagnosis of spinal stenosis.