Wernicke's encephalopathy secondary to hyperemesis gravidarum in pregnancy

Wernicke's encephalopathy (WE) is a rare, acute neurological condition that develops due to thiamine deficiency in pregnant women with severe hyperemesis gravidarum (HG). This is a case report of a 28-year-old woman at 17 weeks of gestation with a prior spontaneous abortion and a history of laparotomy surgery to treat infertility. The patient had three out of four diagnostic requirements as put by the European Federation of Neurological Societies. Brain magnetic resonance imaging (MRI) showed symmetrical medial thalamic hyperintensities consistent with WE. Notably, thyroid function tests revealed gestational thyrotoxicosis, which contributed to HG severity but did not explain the cerebellar dysfunction or characteristic MRI changes, indicating superimposed thiamine deficiency and coexistence of HG-related thyrotoxicosis and WE. WE is significantly underdiagnosed in the nonalcoholic population, especially in pregnant women who generally have a high demand for thiamine. This case highlights the need to consider WE in pregnant women presenting with prolonged HG and to initiate parenteral thiamine promptly to prevent irreversible neurological injury.