Rapidly developing weakness mimicking Guillain-Barré syndrome in beriberi neuropathy: two case reports.

Objective: We examined the diagnostic difficulty in thiamine deficiency.
Methods: We report on two patients with polyneuropathy associated with thiamine deficiency (i.e., beriberi neuropathy) that presented with acute motor symptoms mimicking Guillain-Barré syndrome.
Results: The cause of the thiamine deficiency was associated with gastrectomy to treat cancer in a 46-y-old man and with dietary imbalance in a 33-y-old man. The thiamine deficiency was not related to alcohol intake in either patient. In both patients, the upper and lower extremities showed a rapidly progressive weakness over the course of 1 mo. Muscle weakness in the first patient progressed even after admission to the hospital, and urinary retention, Wernicke's encephalopathy, lactic acidosis, paralytic ileus, and heart failure appeared subsequently. Clinical symptoms in both patients showed improvement after initiation of thiamine administration, although some residual deficit remained.
Conclusion: Thiamine deficiency must be actively considered as a possible cause of polyneuropathy, and variability in its clinical features should be taken into consideration.