CPEN Neurological Emergencies 4 — Questions and Answers
Question 1: A 9-year-old with ALL presents with altered mental status and bilateral papilledema. Lumbar puncture is deferred. Which intervention is MOST immediately indicated?
- Administer ondansetron for nausea
- Start dexamethasone and obtain urgent head CT (Correct answer)
- Perform emergent LP regardless of papilledema
- Initiate hypertonic saline 3% bolus empirically
Correct answer: Start dexamethasone and obtain urgent head CT
Papilledema contraindicates LP before imaging; dexamethasone reduces cerebral edema while CT defines the cause in this immunocompromised patient.
Question 2: Hypertonic saline (3% NaCl) is ordered for a pediatric patient with severe TBI. The GOAL serum sodium target is:
- 125–135 mEq/L
- 135–145 mEq/L (normal)
- 150–160 mEq/L (Correct answer)
- 165–175 mEq/L
Correct answer: 150–160 mEq/L
For ICP management with hypertonic saline, the goal serum sodium is typically 150–160 mEq/L to create an osmotic gradient that reduces cerebral edema.
Question 3: An infant presents with opisthotonus, high-pitched cry, and a bulging fontanelle. Bacterial meningitis is confirmed. When should dexamethasone be given?
- 30 minutes after the first antibiotic dose
- 15–20 minutes before or with the first antibiotic dose (Correct answer)
- Only after 48 hours if the child is not improving
- It is contraindicated in infants under 6 weeks
Correct answer: 15–20 minutes before or with the first antibiotic dose
Dexamethasone is most effective when given 15–20 minutes before or concurrently with the first antibiotic dose to blunt the inflammatory response.
Question 4: Which EEG pattern is pathognomonic for absence seizures in children?
- Hypsarrhythmia
- 3 Hz spike-and-wave discharges (Correct answer)
- Focal temporal sharp waves
- Generalized polyspike bursts
Correct answer: 3 Hz spike-and-wave discharges
Absence seizures (petit mal) are characterized by 3 Hz generalized spike-and-wave discharges on EEG, often provoked by hyperventilation.
Question 5: A 15-year-old presents with thunderclap headache — worst of life, sudden onset. After a negative CT, the NEXT step is:
- Discharge with migraine analgesics
- Lumbar puncture to detect xanthochromia (Correct answer)
- MRI brain without contrast
- Prescribe triptans and neurology follow-up
Correct answer: Lumbar puncture to detect xanthochromia
CT misses ~2% of subarachnoid hemorrhages; LP detecting xanthochromia or blood in CSF is essential when CT is negative after thunderclap headache.
Question 6: Which finding differentiates pseudotumor cerebri (idiopathic intracranial hypertension) from other causes of elevated ICP in a 13-year-old obese girl?
- Abnormal brain MRI with mass lesion
- Normal brain MRI with elevated CSF opening pressure >25 cmH2O (Correct answer)
- Low CSF protein with decreased glucose
- Fever and meningismus
Correct answer: Normal brain MRI with elevated CSF opening pressure >25 cmH2O
IIH is diagnosed by elevated opening pressure (>25 cmH2O) with normal brain imaging, CSF composition, and no identifiable cause.
Question 7: A 4-year-old presents with acute onset right-sided facial droop and inability to close the right eye, but normal eye movements and no limb weakness. The MOST likely diagnosis is:
- Central facial nerve palsy from stroke
- Bell's palsy (peripheral CN VII palsy) (Correct answer)
- Brainstem tumor
- Ramsay Hunt syndrome
Correct answer: Bell's palsy (peripheral CN VII palsy)
Bell's palsy is a peripheral CN VII palsy causing complete unilateral facial weakness including forehead and eye closure, distinguishing it from central causes.
CPEN Neurological Emergencies 4
A 9-year-old with ALL presents with altered mental status and bilateral papilledema.
Lumbar puncture is deferred.
Which intervention is MOST immediately indicated?