Electrodiagnostic / Neuromuscular Medicine
Lucila Beuses, MD, MSc
Resident Physician
Icahn School of Medicine at Mount Sinai
New York, New York, United States
Adam Schulman, MD
Resident Physician
Icahn School of Medicine at Mount Sinai
New York, New York, United States
Tabinda Syed, DO
Attending Physician
Hackensack Meridian Healthcare at Riverview Medical Center
Red Bank, New Jersey, United States
Lucila I. Beuses, MD
Icahn School of Medicine at Mount Sinai
New York, New York, United States
A 37-year-old female with alcohol use disorder (AUD) and malnutrition presented to an outside hospital with ascending weakness and numbness that progressed over months. Concern for Guillain-Barré syndrome (GBS) led to IVIG and PLEX treatments; however, symptoms did not improve. Chronic inflammatory demyelinating polyneuropathy (CIDP) was then suspected, and steroids were given. Nevertheless, treatment failed, and she required transfer to a tertiary hospital. Reevaluation was notable for weakness, pinprick/temperature sensory loss in a stocking-glove distribution, distal vibration/proprioception sensory loss, and areflexia. Thiamine level was undetectable. Other serological and CSF studies were unremarkable. Nerve conduction studies (NCS) revealed diffuse mixed demyelinating/axonal sensorimotor polyneuropathy. High-dose IV thiamine was administered, resulting in improvement, which suggested a predominant thiamine deficiency etiology. She was admitted to acute rehab, where she continued to make functional progress.
Discussions: Dry beriberi is a length-dependent sensorimotor polyneuropathy caused by severe thiamine deficiency. AUD and malnutrition, as in this case, are common causes of deficiency. Given similar presentations, CIDP and GBS are difficult to distinguish from dry beriberi. NCS can be crucial to identify the etiology because dry beriberi typically demonstrates an axonal pattern with greater sensory than motor deficits, whereas CIDP and GBS typically demonstrate a demyelination pattern with greater motor than sensory deficits. However, end-stage dry beriberi can show demyelination on NCS, which can introduce ambiguity. The key distinguishing feature of dry beriberi is the rapid improvement seen in patients following thiamine administration that is not seen in CIDP or GBS. Early recognition in patients is critical to prevent irreversible neurological damage.
Conclusions: Physicians should consider dry beriberi in their differential diagnoses for polyneuropathies in at-risk populations, and a therapeutic trial of thiamine is warranted when suspicion is high. This case can guide management to improve outcomes and shorten hospital stays in patients with dry beriberi.
