Acute Urinary Retention and Guillain-Barré Syndrome: A Zebra or a Horse.

Acute immune-mediated polyneuropathies are grouped under the umbrella term Guillain-Barré syndrome (GBS). GBS can often present with variable clinical findings. Typical features of GBS include a progressive, symmetric muscle weakness and absent deep tendon reflexes. This case report describes a confusing presentation in a patient who had been having preceding back pain prior to the onset of a worsening back pain associated with autonomic symptoms of GBS with urinary retention. This caused initial diagnostic confusion with cauda equina syndrome being the leading diagnostic possibility until ruled out with magnetic resonance imaging. The case demonstrates the importance of not anchoring completely on the initial diagnostic probability but on continuing the workup of acute urinary retention associated with other neurologic symptoms as cauda equina was effectively ruled out. The case also highlights the sometimes problematic errors that can occur with observation medicine.