Paradoxical Hyperreflexia in a Patient With Classic Guillain-Barré Syndrome.

backgroundGuillain-Barré syndrome (GBS) is a rare entity with characteristic features, including progressive ascending paralysis. Patients typically present with progressive symmetrical weakness with areflexia in bilateral lower extremities, which can be confounded by psychiatric comorbidities. This case is unusual in that the patient had paradoxical hyperreflexia and normal CSF protein levels during her initial presentation, later confirmed to be GBS. CASE PRESENTATION: Here, we describe the case of a young female with bipolar disorder who presented to the hospital with complaints of week-long bilateral lower leg weakness that started abruptly about a month after an episode of multiple stools of bloody diarrhea. The initial neurological exam revealed 4/5 bilateral lower extremity strength and near global areflexia, excluding a 3+ right patellar reflex, and CSF studies returned normal CSF protein levels.  Based on the clinical presentation of worsening ascending paralysis, electromyography (EMG) findings, and nerve conduction studies (NCS) consistent with an axonal and demyelinating neuropathy, we diagnosed her with the classic form of Guillain-Barré syndrome with paradoxical hyperreflexia. Imaging results, laboratory findings, treatment decisions, and outcomes of this case are presented.