Case report: MR findings of Guillain-Barré syndrome.

Guillain-Barré syndrome (GBS) is characterized as an acute, symmetrically progressive, inflammatory demyelinating polyneuropathy. We report a case of GBS in which gadolinium-enhanced magnetic resonance (MR) imaging showed marked enhancement of nerve roots of the conus medullaris and cauda equina. On enhanced MR imaging, the spinal cord and nerve roots in the thecal sac generally do not take up much gadolinium because of the blood-nerve barrier or blood-brain barrier. Therefore, in our case, marked enhancement of nerve roots indicates a breakdown of the blood-nerve barrier. It is thought to correlate with the inflammatory infiltration of GBS.