Case Presentation: A 23 year-old woman presented with blurry vision and difficulty walking for two weeks. Her family also reported two weeks of progressive memory changes and a 52-pound weight loss over four months. One month prior to presentation, while pregnant at 18 weeks gestation, she was admitted with three months of vomiting and five days of epigastric pain. Laboratories revealed a lipase elevation to 10 times above the normal limit and magnetic resonance imaging revealed pancreatitis and sludge in the gallbladder. She was diagnosed with hyperemesis gravidarum and presumed gallstone pancreatitis. One day prior to planned cholecystectomy, an ultrasound revealed intrauterine fetal demise, prompting dilation and evacuation. On the current presentation, examination revealed a dysphoric woman, severe psychomotor retardation, reduced attention span, and monosyllabic responses, all initially ascribed to depression after a pregnancy loss. She exhibited bilateral horizontal and vertical end-gaze nystagmus, normal lower extremity strength but decreased proprioception and sensation to light touch, markedly diminished bilateral lower extremity deep tendon reflexes, and severe ataxia. Initial laboratories and imaging were unremarkable. The patient was diagnosed with Wernicke encephalopathy due to hyperemesis gravidarum. Administration of high-dose intravenous thiamine resulted in rapid improvement in mental status, speech, and blurry vision. One week after admission the patient was able to ambulate with a walker and was discharged to a rehabilitation facility. Thirteen days after admission a serum thiamine level returned at 16 nanomoles per liter (normal 78-165). At six months, the patient had fully recovered.
Discussion: Thiamine, also known as vitamin B1, is critical for glucose and amino acid metabolism, and nerve impulse propagation. Clinicians treating patients with alcohol use disorder are acutely aware of the risk of thiamine deficiency, but the risk is underappreciated in patients with poor oral intake or malabsorption, such as those with a history of bariatric surgery, anorexia nervosa, malignancy, AIDS, and hyperemesis of pregnancy. In one study, almost one quarter of patients with severe thiamine deficiency had a non-alcohol-related etiology. In our patient, thiamine stores were reduced by months of emesis and further depleted by the increased metabolic demands of pregnancy and likely by the administration of dextrose-containing intravenous fluids at her previous admission. Thiamine deficiency can cause Wernicke encephalopathy, classically consisting of a triad of nystagmus, ataxia, and encephalopathy, and it can result in coma and death. However, all three symptoms are present at diagnosis in only approximately 16% of cases; therefore a high index of suspicion is essential. The diagnosis is clinical, and since treatment is safe and inexpensive, testing of thiamine levels should never delay treatment with high-dose parenteral thiamine. It is critical that all patients at risk for thiamine deficiency, including those with hyperemesis gravidarum, receive high-dose thiamine supplementation to prevent Wernicke encephalopathy.
Conclusions: Pregnant women with hyperemesis are at increased risk of thiamine deficiency and Wernicke encephalopathy. This case demonstrates that clinicians should maintain a high index of suspicion to diagnose and a low threshold to treat any patient with hyperemesis gravidarum with high dose parenteral thiamine.