Metachronous Bilateral Painless Foot Drop Secondary to Spinal Stenosis: Case Report.

Foot drop (FD) is an uncommon manifestation of nerve root compression secondary to lumbar degenerative disease (LDD). In most of these patients, FD is unilateral and is associated with low back pain and leg pain. A small number of cases have been described with bilateral FD, which is reported to occur simultaneously in a synchronous fashion. A 63-year-old male with a remote history of spinal surgery due to left painless FD presented with a new episode of right FD, this new FD initiated suddenly and it was not associated with low back pain or radicular pain. Magnetic resonance imaging (MRI) showed bilateral lumbar stenosis at L3-4 and subarticular stenosis at right L4-5 level causing compression of right L5 nerve root. Fenestrations, removal of flavum ligament and medial facetectomy were performed bilaterally at L3-4 and on the right side at L4-5 level. Postoperatively, the patient experienced progressive improvement on right foot dorsiflexion. The occurrence of bilateral painless FD presenting in a metachronous way as observed in the present case is a very unusual scenario. To the best of author's knowledge, cases with these characteristics have not been previously reported.