From stargazing chicks to seizing infants

Thiamine, or vitamin B1, was the first of the vitamins to be identified. Thiamine comprises pyrimidine and thiazole rings joined by a methylene bridge¹; thiamine phosphoesters are cofactors for several enzymes involved in carbohydrate metabolism, the respiratory chain, and the synthesis of neurotransmitters and nucleic acid precursors.² B1 cannot be synthesized by humans, and must be ingested in the human diet, mainly in the form of grains. Active transport processes and phosphorylation are required for its delivery and activation. Human tissue stores are limited, and deficiency appears within days to weeks of absolute deficiency.

Thiamine deficiency is common in malnourished populations, and, when recognized promptly, is a readily reversible cause of neurologic dysfunction. If it is not recognized and treated rapidly, selective neuronal death may ensue, with devastating consequences. In this issue of Neurology®, Fattal-Valevksi and colleagues³ describe the outcomes in a subset of infants who received a thiamine-deficient soy formula, and add a new variation to the presentations …