Foraminal L5-S1 disc herniation and conus medullaris syndrome: a vascular etiology?

A 56-year-old man presented with a conus medullaris syndrome lumbar magnetic resonance imaging showed only a right foraminal disc herniation at the L5-S1 level. Operative removal of the protrusion was followed by prompt neurological improvement. We postulate that the discrepancy between extent of compression shown by imaging and the neurological findings may reflect vascular compression of the artery of Desproges-Gotteron, an anatomical variant.