Before surgery, we performed MRI on 20 patients who had multiple level herniated nucleus pulposus, compared with 54 patients who had single level herniated nucleus pulposus. The single level group was deviled into two groups, one of multiple and the other of single protruded disc which was seen by MRI.
The multiple level group had multiple neurological signs, and the same incidences of protruded and degenerated lmber vertebral discs seen on MRI as the multiple protruded group. In particular, there were high incidences of protruded and degenerated discs seen on MRI on upper and lower level of the operated discs. For that reason, the multiple protruded discs seen on MRI maybe related with congenital factors. For diagnosis of multiple protruded discs seen on MRI, we carefully examined neurological signs, and the effect of nerve root infiltration.