Sudden bilateral foot drop: an unusual presentation of lumbar disc prolapse.

Bilateral acute foot drop is reported in a 30-year-old healthy male. He presented with a 7-day history of sudden severe backache, radiating to both the lower limbs and 1-day history of sudden bilateral ankle weakness that progressed to bilateral foot drop within 6 hours. He also developed retention of urine. Investigations revealed a large central disc prolapse at L3-4 with significant canal stenosis at that level. Following surgery the patient had progressive improvement.