Migration of lumbar disc herniation: an unusual case.

We illustrate a patient with a migrating lumbar disc fragment that caused a change in radicular symptoms from the L3 nerve root on one side to the L5 nerve root on the contralateral side, documented by magnetic resonance imaging (MRI). Our patient presented with 3 months of L3 pain on the right side with sensory and motor changes. Over a 24-hour time period, the right leg pain disappeared and he developed left leg pain attributable to left L5 nerve root compression. Investigation with MRI revealed an epidural mass, which was hypointense on Tl-weighted and T2-weighted images that had migrated, initially compressing the right L3 nerve root, to now compress the left L5 nerve root. The patient did not wish to pursue surgery. Disc fragment migration patterns are discussed. We conclude that extruded disc fragments may migrate distant from their initial origin.