A 32-year-old primigravida at 18 weeks gestation is evaluated in the emergency department for increasing confusion and incoherence. Her husband says that she has become increasingly unsteady while standing and has fallen twice. The patient was previously seen in the emergency department for nausea and vomiting and was treated with intravenous fluids and antiemetics. Although she continues to take oral antiemetics, she has had persistent vomiting and has lost 7 kg (15.4 lb) of her prepregnancy weight. Blood pressure is 110/60 mm Hg and pulse is 98/min. Fetal heart tones are 155/min. Physical examination shows nystagmus but no scleral icterus. Pupils are equal and reactive to light and accommodation. Abdominal examination shows epigastric pain but no rebound or involuntary guarding. The patient has trace pedal edema over her bilateral lower extremities and bilaterally absent ankle reflexes. Laboratory results are as follows: Which of the following is the most likely diagnosis in this patient?

Question

A 32-year-old primigravida at 18 weeks gestation is evaluated in the emergency department for increasing confusion and incoherence.  Her husband says that she has become increasingly unsteady while standing and has fallen twice.  The patient was previously seen in the emergency department for nausea and vomiting and was treated with intravenous fluids and antiemetics.  Although she continues to take oral antiemetics, she has had persistent vomiting and has lost 7 kg (15.4 lb) of her prepregnancy weight.  Blood pressure is 110/60 mm Hg and pulse is 98/min.  Fetal heart tones are 155/min.  Physical examination shows nystagmus but no scleral icterus.  Pupils are equal and reactive to light and accommodation.  Abdominal examination shows epigastric pain but no rebound or involuntary guarding.  The patient has trace pedal edema over her bilateral lower extremities and bilaterally absent ankle reflexes.  Laboratory results are as follows:  Which of the following is the most likely diagnosis in this patient?

Quizplus · Accepted Answer

11ec25c8_da8a_f7cf_bc81_d9065531fc44_MD0003_00 This patient's presentation of altered mental status (eg, encephalopathy), oculomotor dysfunction (eg, nystagmus), and gait ataxia are suggestive of Wernicke encephalopathy (WE), a neurological disease due to a thiamine deficiency. Although most commonly associated with alcoholism, WE can also occur with hyperemesis gravidarum (HG), a severe, persistent nausea and vomiting of pregnancy that results in weight loss and dehydration. Patients with HG commonly have hypochloremic metabolic alkalosis, hypokalemia, hypoglycemia, and elevated serum aminotransferases, all of which occur as the result of protracted vomiting. Treatment for this patient should include antiemetics, fluids, and thiamine supplementation. Patients with HG often require glucose infusions due to prolonged hypoglycemia. However, glucose infusion prior to thiamine supplementation can exacerbate WE and should be delayed until the patient has received thiamine. WE in pregnancy is associated with an increased risk of spontaneous abortion; thiamine supplementation may decrease this risk. (Choice A) Acute fatty liver of pregnancy can present with nausea, vomiting, elevated serum aminotransferases, and hypoglycemia but typically occurs in the third trimester. At 18 weeks gestation, this diagnosis is unlikely. (Choice B) HELLP syndrome can present with nausea, vomiting, and elevated serum aminotransferases. However, HELLP syndrome also requires low platelets and evidence of hemolysis for diagnosis, which are not seen in this patient. Physical examination findings include hyperreflexia rather than absent reflexes. (Choice C) Late neurosyphilis manifests years after an initial syphilitic infection and is characterized by tabes dorsalis (eg, sensory ataxia, lancinating pain) and Argyll Robertson pupils (eg, normal pupillary constriction with accommodation but not light). This patient has a normal pupillary examination and an acute presentation. (Choice E) Vitamin B12 deficiency presents with dementia and a subacute combined degeneration due to demyelination of spinocerebellar tracts (eg, gait ataxia), lateral corticospinal tracts (eg, spastic paresis), and dorsal columns (eg, loss of position and vibration sense). However, the clinical course of vitamin B12 deficiency is indolent rather than acute. Patients also have a macrocytic anemia (mean corpuscular volume >100 fL). Educational objective: Wernicke encephalopathy is a complication of hyperemesis gravidarum that results from thiamine deficiency. Classic presenting symptoms include encephalopathy, oculomotor dysfunction, and gait ataxia.

A 32-Year-Old Primigravida at 18 Weeks Gestation Is Evaluated in the Emergency