A 20-year-old woman, gravida 1 para 0, at 36 weeks gestation is brought to the emergency department by her mother due to a seizure. The patient was sitting outside when she suddenly had a 2-minute seizure with loss of urinary continence. She is still confused when she arrives in the emergency department. Her mother reports that the patient has had increasing anxiety and has been acting out for the past several days. Her only surgery was a splenectomy after a motor vehicle collision last year. Temperature is 37.7 C (99.9 F), blood pressure is 158/98 mm Hg, and pulse is 120/min. The patient is agitated and diaphoretic. The pupils are dilated bilaterally. The cranial nerves are intact. The neck is supple and nontender. Cardiopulmonary examination is normal. The abdomen is gravid without rebound or guarding, and the uterus is nontender. There is 2+ pitting pedal edema bilaterally. Sensation and strength are normal in the bilateral upper and lower extremities. Laboratory results are as follows: CT scan of the head is normal. Which of the following is the most likely diagnosis in this patient?

Question

A 20-year-old woman, gravida 1 para 0, at 36 weeks gestation is brought to the emergency department by her mother due to a seizure.  The patient was sitting outside when she suddenly had a 2-minute seizure with loss of urinary continence.  She is still confused when she arrives in the emergency department.  Her mother reports that the patient has had increasing anxiety and has been acting out for the past several days.  Her only surgery was a splenectomy after a motor vehicle collision last year.  Temperature is 37.7 C (99.9 F), blood pressure is 158/98 mm Hg, and pulse is 120/min.  The patient is agitated and diaphoretic.  The pupils are dilated bilaterally.  The cranial nerves are intact.  The neck is supple and nontender.  Cardiopulmonary examination is normal.  The abdomen is gravid without rebound or guarding, and the uterus is nontender.  There is 2+ pitting pedal edema bilaterally.  Sensation and strength are normal in the bilateral upper and lower extremities.  Laboratory results are as follows:  CT scan of the head is normal.  Which of the following is the most likely diagnosis in this patient?

Quizplus · Accepted Answer

This patient at 36 weeks gestation likely had a generalized tonic-clonic seizure. New-onset seizures in pregnancy can be due to either pregnancy-specific (eg, eclampsia) or nonobstetric (eg, meningitis, intracranial bleeding) conditions. The most common cause of seizures in pregnant and postpartum women is eclampsia, which is classically associated with preeclampsia (ie, new-onset hypertension at ≥20 weeks gestation with proteinuria and/or signs of end-organ damage). Although this patient has hypertension, her additional findings of agitation, dilated pupils, hyponatremia, normal head CT scan (vs white matter edema seen in eclampsia), and absence of proteinuria suggest another etiology (Choice B). This patient's seizure is likely due to amphetamine intoxication. Amphetamines cause overstimulation of alpha-adrenergic receptors, causing tachycardia, hypertension, and occasionally hyperthermia. Patients may also have diaphoresis and minimally reactive, dilated pupils. Severe intoxication can cause electrolyte abnormalities, including significant hyponatremia (possibly serotonin-mediated) and resultant seizure activity. Amphetamine intoxication is confirmed with urine drug testing. Distinguishing between eclampsia and other causes of seizure is essential because it may determine whether or not there is a need for emergency delivery. (Choice C) Heat stroke can cause altered mental status and electrolyte abnormalities. However, patients have an elevated temperature (>40 C [104 F]) often associated with hemodynamic instability (eg, hypotension). (Choice D) Hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome is a hypertensive disorder of pregnancy that can cause seizures (ie, eclampsia). In contrast, this patient's hematocrit level is normal (ie, no hemolysis), and patients with HELLP syndrome typically have platelet counts <100,000/mm³. (Choice E) Pneumococcal meningitis can cause seizures and altered mental status in patients with prior splenectomy. However, patients typically have high fever and nuchal rigidity, making this diagnosis less likely. Educational objective: Amphetamine intoxication can present with hypertension, agitation, diaphoresis, dilated pupils, and a generalized tonic-clonic seizure (due to hyponatremia). References: Stimulant use in pregnancy: an under-recognized epidemic among pregnant women. (http://www.ncbi.nlm.nih.gov/pubmed/30601144)

A 20-Year-Old Woman, Gravida 1 Para 0, at 36 Weeks