Acute beriberi neuropathy mimicking Guillain-Barré syndrome after a strict vegetarian diet

Vitamin B1 (thiamin) is required in the metabolism of carbohydrates, lipids, proteins, and energetic metabolism within Krebs cycle. It has also an essential role in acetylcholine synthesis and neurotransmission.1 Thiamin deficiency can lead to various manifestations such as Gayet-Wernicke syndrome, wet beriberi with congestive heart failure, or dry beriberi with peripheral neuropathy. We report herein a case of Guillain-Barré-like neuropathy caused by acute vitamin B1 deficiency in a young girl consecutive to a strict vegetarian diet. A 14-year-old girl with unremarkable medical history has presented with numbness and weakness of lower limbs developing insidiously for a month. Two weeks before admission, weakness progressed to upper limbs and cramping pain in legs has appeared. The patient had difficulties at swallowing and she has become unable to walk 1 day before admission. In the preceding 3 months, the patient has undergone a strict diet made only of vegetables and yogurt to get thinner. Her weight has dropped from 66 to 42 kg. At examination, the girl was thin and pale and her voice was dysphonic. Her body mass index (BMI) was 15.24 kg/m2. She was not able to walk without double help. Her muscular testing revealed distal-dominant weakness in her four limbs. Deep tendon reflexes were absent. She had also hypoesthesia in her legs. Cranial nerves examination noted a facial diparesis. Psychological interrogatory did not reveal any behavioral or alimentary disorder. Nerve conduction studies showed a severe sensory and motor neuropathy with axonal and demyelinating mechanism predominantly in lower limbs. It has revealed decreased motor potentials amplitude with conduction blocks, abnormal temporal dispersion of the motor responses, and the sensory potentials were not recordable (Table 1). Cerebrospinal fluid analysis made on the day of admission revealed normal protein content (0.29 g/l) and no leukocytes. Thiamin plasma level was low: 13 ng/ml (normal range: 20-50 ng/ml). Concentration of vitamin B12 (cobalamin) and B9 (folic acid) were normal. Routine hematological and biochemical tests showed no abnormalities. Electrocardiogram was also normal. Intravenous Iranian Journal of Neurology