A 64-year-old man is hospitalized with abdominal pain, nausea, and vomiting. The patient has had several similar episodes in the past and was advised to avoid alcohol consumption. Evaluation reveals epigastric tenderness and elevated serum amylase and lipase levels. The patient is admitted, and treatment with bowel rest and intravenous fluids is begun. During hospitalization, he develops new-onset confusion. Physical examination shows horizontal nystagmus and gait ataxia. Brain imaging reveals abnormalities in the mammillary bodies and periaqueductal gray matter. Which of the following most likely precipitated this patient's current neurologic condition?

Question

A 64-year-old man is hospitalized with abdominal pain, nausea, and vomiting.  The patient has had several similar episodes in the past and was advised to avoid alcohol consumption.  Evaluation reveals epigastric tenderness and elevated serum amylase and lipase levels.  The patient is admitted, and treatment with bowel rest and intravenous fluids is begun.  During hospitalization, he develops new-onset confusion.  Physical examination shows horizontal nystagmus and gait ataxia.  Brain imaging reveals abnormalities in the mammillary bodies and periaqueductal gray matter.  Which of the following most likely precipitated this patient's current neurologic condition?

Quizplus · Accepted Answer

11ec160b_39e1_4a5f_9249_e9bf7613d8cb_MD0001_00 This patient with pancreatitis (nausea/vomiting, abdominal pain, elevated lipase) and a history of alcohol use disorder received intravenous fluids and developed the classic triad of Wernicke encephalopathy (WE): Oculomotor dysfunction: horizontal nystagmus, lateral rectus palsy, ophthalmoplegia Gait ataxia: slow, wide-based gait; postural ataxia Encephalopathy: confusion, apathy, inattentiveness, disorientation WE is a complication of thiamine (vitamin B₁) deficiency and most commonly occurs in patients with a history of long-standing alcohol use or other forms of chronic malnourishment (eg, anorexia, short-bowel syndrome). Thiamine is a vitamin cofactor for multiple enzymes involved in glucose metabolism, and deficiency results in the brain's inability to utilize glucose, leading to neuronal damage and necrosis. Iatrogenic WE can be precipitated by the administration of glucose-containing fluids (this patient likely received these as a maintenance fluid), which deplete the last remaining stores of thiamine. Areas of the brain with high metabolic demand are particularly susceptible; focal hemorrhage or atrophy of the mammillary bodies is characteristic. The periaqueductal gray, thalamus, and medulla may also be affected. Intravenous thiamine should be administered before infusion of glucose-containing fluids in at-risk patients and in all patients with suspected WE. Ocular irregularities are the first to respond to thiamine and typically normalize within hours. Gait ataxia and confusion typically respond over the course of days to weeks. (Choice A) Abrupt alcohol cessation can cause alcohol withdrawal. Tremor and diaphoresis are common and may progress to delirium, seizures, and death. Ataxia and ophthalmoplegia are unexpected. (Choice B) Chronic hyponatremia can occur in patients with heavy alcohol use. Overly rapid correction with normal saline causes osmotic demyelination syndrome, which manifests as dysarthria, confusion, and paralysis. Some patients become "locked in" (ie, alert but unable to move or verbally communicate); however, extraocular muscles are spared. (Choice D) Hypotonic fluid administration can result in acute hyponatremia, which can cause cerebral edema. Symptoms are typically progressive, with headache and nausea occurring before alterations in mental status. Ophthalmoplegia and ataxia are unexpected. (Choice E) Prophylactic low-dose anticoagulation is typically recommended to prevent deep venous thrombosis (DVT) in patients with prolonged hospitalization or inactivity. Pulmonary embolism, the most common sequela of DVT, typically causes pleuritic chest pain, tachycardia, and dyspnea. (Choice F) Thiamine supplementation is used for both prevention and treatment of WE; it does not precipitate the disease. Educational objective: Wernicke encephalopathy is a complication of thiamine deficiency characterized by encephalopathy, ataxia, and oculomotor dysfunction. It occurs most commonly in patients with chronic alcohol use and may be precipitated by infusion of glucose-containing fluids. Neuroimaging reveals focal hemorrhage or atrophy of the mammillary bodies.

A 64-Year-Old Man Is Hospitalized with Abdominal Pain, Nausea, and Vomiting