A 17-year-old girl is brought to the emergency department by her mother after an episode of loss of consciousness 20 minutes ago. The patient was taking a shower when her mother heard her fall. By the time the mother opened the bathroom door, she was lying on the floor and unresponsive. The patient woke up within a few minutes and was taken to the emergency department by ambulance. During transport, she was drowsy and confused. The mother notes that the patient recently broke up with her boyfriend, has been under significant stress at school, and has been sleeping poorly. In the emergency department, blood pressure is 120/70 mm Hg, pulse is 90/min, and respirations are 13/min. The patient is now alert and answers questions appropriately. Examination of the head shows no obvious injury, step-off, or hematoma. The pupils are symmetric and reactive to light. Fingerstick glucose level is 100 mg/dL. Which of the following is most likely to be seen in this patient?
Seizure | Vasovagal syncope | |
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This patient experienced sudden loss of consciousness (LOC) associated with a loss of postural tone (eg, fall and unresponsiveness while in the shower) and delayed return to baseline mental status, findings concerning for a seizure (eg, generalized tonic-clonic seizure). Although the incidence of epilepsy is highest in early childhood and late adulthood, a first-time seizure can occur at any age and can be unprovoked. Emotional stress and lack of sleep (as seen in this patient) may lower the seizure threshold.
Tonic-clonic movements typically last <3 minutes and may be unwitnessed, as in this case. An aura (eg, olfactory hallucination) sometimes precedes the event, and biting injuries (eg, tongue lacerations) are common during the convulsion.
Generalized seizures almost always have a delayed return to baseline neurologic functioning due to a postictal state of transient confusion, lethargy, and/or focal neurologic deficits. In contrast, syncope is a transient LOC with loss of postural tone followed by immediate, spontaneous return to baseline neurologic functioning.
(Choice A) This patient's recent psychosocial stressors raise concern for intentional ingestion, but acetaminophen toxicity causes a predictable clinical sequence of nausea and vomiting, right upper quadrant pain, and potential liver failure and death. Seizures are not typical.
(Choice B) Orthostatic hypotension is characterized by a significant drop in blood pressure after shifting from a lying to a standing position, typically causing presyncope. Etiologies include intravascular volume depletion (eg, dehydration) and medication-related autonomic instability (eg, alpha blockers). Although LOC can occur, subsequent confusion would not be expected unless associated with a head injury, which is not seen in this patient.
(Choice C) Pulsus paradoxus is a fall in systemic blood pressure >10 mm Hg during inspiration. It is common in patients with cardiac tamponade, which can present with syncope but also causes tachycardia, hypotension, and elevated jugular venous pressure, none of which are seen here.
(Choice D) A systolic murmur that increases with standing is characteristic of hypertrophic obstructive cardiomyopathy (HOCM). Syncope associated with HOCM is usually induced by exertion, and the return to neurologic baseline is immediate.
Educational objective:
Seizures are characterized by sudden loss of consciousness, loss of postural tone, and a postictal state with delayed return to baseline neurologic functioning. Tongue lacerations can occur with tonic-clonic movements.