A 23-year-old woman is brought to the emergency department after a seizure episode. The seizure occurred at work and was not preceded by any prodromal symptoms or aura. The patient's coworkers reported that she became unresponsive with generalized tonic-clonic movements lasting 1-2 minutes followed by several minutes of confusion. She experienced urinary incontinence but no tongue biting. The patient has no medical problems and takes no prescription medications. She has no prior head trauma and no family history of epilepsy. Vital signs and neurologic examination are normal. Serum electrolytes, glucose, calcium, magnesium, complete blood count, renal function tests, and liver function tests are unremarkable. A non-contrast head CT scan is normal. Which of the following is the most appropriate next step in management?

Question

A 23-year-old woman is brought to the emergency department after a seizure episode.  The seizure occurred at work and was not preceded by any prodromal symptoms or aura.  The patient's coworkers reported that she became unresponsive with generalized tonic-clonic movements lasting 1-2 minutes followed by several minutes of confusion.  She experienced urinary incontinence but no tongue biting.  The patient has no medical problems and takes no prescription medications.  She has no prior head trauma and no family history of epilepsy.  Vital signs and neurologic examination are normal.  Serum electrolytes, glucose, calcium, magnesium, complete blood count, renal function tests, and liver function tests are unremarkable.  A non-contrast head CT scan is normal.  Which of the following is the most appropriate next step in management?

Quizplus · Accepted Answer

The initial diagnostic evaluation of a first-time seizure in an adult is aimed at excluding metabolic (eg, hypoglycemia, electrolyte disturbances) and toxic (eg, amphetamine use, benzodiazepine/alcohol withdrawal) causes. Basic laboratory tests typically include serum electrolytes, glucose, calcium, magnesium, complete blood count, renal function tests, liver function tests, and a toxicology screen. In addition to laboratory screening, ECG should be obtained in patients with loss of consciousness to evaluate for possible underlying arrhythmia. (Choice B) Once metabolic and toxic etiologies are excluded as the cause of seizure, most patients require neuroimaging (eg, brain MRI or CT scan) to evaluate for structural brain abnormalities (eg, tumor, stroke, mesial temporal sclerosis) that may serve as a seizure focus. Lumbar puncture can be considered after neuroimaging has ruled out a space-occupying lesion, but it is typically reserved for patients with suspected meningitis (eg, fever, headache, nuchal rigidity). (Choice C) Reassuring and discharging the patient are not appropriate at this time as the etiology and recurrence risk of the seizure have not been determined. (Choice D) Routine EEG is useful for risk-stratifying patients after a first-time seizure once metabolic and toxic etiologies have been excluded. The presence of epileptiform activity on an EEG indicates a higher risk of seizure recurrence and therefore may justify the need to start anti-epileptic therapy. (Choice E) Valproic acid is generally avoided in young women of reproductive age as it may cause congenital anomalies (eg, neural tube defects) during pregnancy. It is also premature to start the patient on any anti-epileptic therapy at this time as she may have had a provoked seizure due to substance abuse. Educational objective: The initial diagnostic workup of a first-time seizure in an adult should include basic blood tests (eg, serum electrolytes, glucose, calcium, magnesium, complete blood count, renal and liver function tests) and a toxicology screen to evaluate for metabolic and toxic causes. Unprovoked seizures generally require further evaluation with neuroimaging and EEG. References: Evaluation of a first seizure. (http://www.ncbi.nlm.nih.gov/pubmed/17508528)

A 23-Year-Old Woman Is Brought to the Emergency Department After