Posterior reversible encephalopathy and Guillain-Barré syndrome: which came first, the chicken or the egg? A review of literature.

Posterior reversible encephalopathy (PRES) is a rare occurrence in patients with Guillain-Barré syndrome (GBS) with only nine adult cases reported to date. We conducted a review of the literature and compared previous cases with a novel case admitted to our clinic. In light of the timing of the symptoms, it is assumable that arterial hypertension can develop acutely during a phase of GBS-related autonomic dysfunction and subsequently precipitates PRES. According to this, dysautonomia caused by GBS could precede motor weakness; thus, PRES in the absence of any strong alternative etiology may suggest an underlying GBS.