A 16-year-old girl is brought to the urgent care clinic after passing out. The patient was sitting at her desk in school when she gradually slid out of her desk to the floor and lost consciousness. The patient was unresponsive with her eyes closed for 20 minutes. She states, "I felt weak before I passed out, and I felt my head throbbing after it hit the floor". The school nurse documented her blood pressure during the episode as 128/76 mm Hg and pulse as 78/min. After the episode, the patient was alert and wanted to resume her school activities. She has no medical history. The patient is awake and alert. Her head is atraumatic. The pupils are equal and reactive to light. The lungs are clear to auscultation. Hearts sounds are without murmurs. Muscle strength is 5/5 in the upper and lower extremities. Gait is normal. ECG is normal. Which of the following is the most likely diagnosis in this patient?

Question

A 16-year-old girl is brought to the urgent care clinic after passing out.  The patient was sitting at her desk in school when she gradually slid out of her desk to the floor and lost consciousness.  The patient was unresponsive with her eyes closed for 20 minutes.  She states, "I felt weak before I passed out, and I felt my head throbbing after it hit the floor". The school nurse documented her blood pressure during the episode as 128/76 mm Hg and pulse as 78/min.  After the episode, the patient was alert and wanted to resume her school activities.  She has no medical history.  The patient is awake and alert.  Her head is atraumatic.  The pupils are equal and reactive to light.  The lungs are clear to auscultation.  Hearts sounds are without murmurs.  Muscle strength is 5/5 in the upper and lower extremities.  Gait is normal.  ECG is normal.  Which of the following is the most likely diagnosis in this patient?

Quizplus · Accepted Answer

Explanation: This patient had sudden-onset, apparent loss of consciousness (LOC) and postural tone concerning for syncope. However, several features suggest psychogenic pseudosyncope (PPS), a type of conversion disorder, rather than syncope. Syncope occurs due to global cerebral hypoperfusion. In contrast, PPS is an apparent, transient LOC without impaired cerebral perfusion. Although no single clinical finding conclusively defines PPS, it is commonly associated with the following features: Prolonged LOC (eg, 20 min): PPS episodes typically last many minutes to hours versus approximately 1-2 minutes in syncope. Absence of objective findings during the episode: As in this patient, typical objective findings accompanying syncope (eg, abnormal vital signs, pallor, sweating) are usually absent on examination. Patient's reports of symptoms/events that occurred during the episode (eg, "I felt my head throbbing after it hit the floor"): This awareness rules out true LOC. Symptoms are often reported in a detached or disassociated manner (la belle indifférence). PPS episodes typically occur before witnesses, and patients often experience a high frequency of them (eg, >1 episode/day, >50 episodes/year). A history of psychiatric disorder is often present. (Choice A) Cataplexy, an emotionally triggered, sudden loss of muscle control, can mimic syncope; however, it typically occurs in patients with narcolepsy, who usually have other symptoms such as excessive daytime sleepiness. Cataplexic episodes are typically brief (eg, <2 min) versus prolonged (eg, ~20 min). (Choice C) In children, congenital long QT syndrome can cause arrhythmia leading to syncope. However, syncopal episodes are typically brief (eg, <2 min); ECG is frequently abnormal (eg, prolonged QT interval). (Choice D) Seizures can cause a prolonged LOC (ie, postictal period); however, features more suggestive of seizure include a trigger (eg, emotional stress, flashing lights), tonic-clonic movements of the extremities, and tongue lacerations. In addition, open eyes with abnormal eye movements (vs eye closure) are more consistent with epileptic seizures. (Choice E) Vasovagal syncope causes LOC, often preceded by a prodrome (eg, nausea). Episodes are typically brief (eg, <2 min), and patients do not describe events that occurred during unconsciousness (eg, "I felt my head throbbing after it hit the floor"). Educational objective: Psychogenic pseudosyncope is a type of conversion disorder characterized by an apparent loss of consciousness without impaired cerebral perfusion. Prolonged duration of unconsciousness, absence of objective physical findings, and high frequency of episodes are common. References: Psychogenic pseudosyncope: clinical features, diagnosis and management. (http://www.ncbi.nlm.nih.gov/pubmed/33024500)

A 16-Year-Old Girl Is Brought to the Urgent Care Clinic