Neonatal seizures and encephalopathy — branching viva

Station opening

Examiner: "Define a neonatal seizure and explain why the great majority are described as provoked rather than epilepsy." [5]

Strong candidate (must-hit)

• Defines a neonatal seizure as the clinical or electrographic expression of abnormal, excessive neuronal discharge in the immature brain, almost always provoked by a treatable brain insult (HIE commonest, then stroke, haemorrhage, infection, metabolic derangement, malformation); explains that provoked (acute symptomatic) seizures reflect an acute insult, whereas epilepsy is a chronic tendency to unprovoked seizures. [5]

Weak candidate

• "A seizure is when the baby shakes." [5]

Branch A — The encephalopathic term infant

Examiner: "A term infant born after placental abruption with cord pH 6.85 has focal clonic seizures and lethargy at 2 hours. What is your diagnosis, your first-line drug, and the neuroprotective decision?" [1]

Strong

• Diagnoses moderate hypoxic-ischaemic encephalopathy (Sarnat stage 2) with provoked seizures; checks blood glucose first, gives phenobarbital 20 mg/kg IV as first-line antiseizure medication, starts continuous EEG; activates therapeutic hypothermia to 33.5 to 34.5 °C for 72 hours within the 6-hour window, citing the TOBY (Azzopardi 2009) and NICHD (Shankaran 2005) trials and the Jacobs 2013 Cochrane meta-analysis for the mortality and disability benefit. [1] [5]

Weak

• "Give phenytoin and observe; consider cooling if it gets worse." [1]

Branch B — The tremulous well-looking infant (the jitteriness trap)

Examiner: "A well-looking term infant has fast, rhythmic trembling that started when the incubator was opened and stopped when the nurse held the limb. The baby is alert. A colleague wants to start phenobarbital. What do you say?" [5]

Strong

• States this is jitteriness (a tremor), not a seizure: fast, stimulus-sensitive, abolished by holding the limb flexed, preserved consciousness, no ocular or autonomic features. Jitteriness is the commonest mimic of neonatal seizures and must not be treated with antiseizure drugs; the response is reassurance and correction of any underlying cause (hypoglycaemia, drug withdrawal). [5]

Weak

• "Yes, give phenobarbital to be safe — any abnormal movement in a neonate could be a seizure." [5]

Branch C — The preterm infant with apnoea

Examiner: "A 28-week infant on the NICU has recurrent apnoea, bradycardia and desaturation with no visible motor activity. The team thinks it is apnoea of prematurity. What is your concern and your next step?" [8]

Strong

• Recognises that apnoea, bradycardia and desaturation can be the only sign of a seizure in a preterm infant (an autonomic/subtle seizure); triggers continuous EEG to confirm or exclude an electrographic seizure, because clinical observation alone misses most NICU seizures; treats to an electrographic endpoint if confirmed, and searches for the cause (IVH, metabolic, sepsis). [5] [8]

Weak

• "It is apnoea of prematurity — increase the caffeine dose." [8]

Branch D — The refractory seizure and the missed cause

Examiner: "Seizures persist despite phenobarbital 20 mg/kg and levetiracetam 50 mg/kg. The initial glucose and electrolytes were normal. What is your principle, and which two causes must you not miss?" [5]

Strong

• States the principle: a refractory neonatal seizure is often a missed cause, not a drug-ladder failure. Re-screens for a metabolic cause (ammonia, lactate, amino acids, organic acids) and performs a lumbar puncture and cranial MRI. Two must-not-miss causes: HSV encephalitis (start aciclovir 20 mg/kg IV every 8 hours empirically while awaiting CSF PCR) and a pyridoxine- or pyridoxal-phosphate-dependent seizure (trial the cofactor). [5]

Weak

• "Add a third antiseizure drug and continue." [5]

Close

Examiner: "Summarise your approach to a neonatal seizure in one sentence." [5]

Strong

• "A neonatal seizure is a provoked event — so I stabilise, check the glucose, confirm with continuous EEG, treat reversible causes, give phenobarbital 20 mg/kg IV first line and escalate to an EEG endpoint, and cool moderate-to-severe HIE within 6 hours at 33.5 to 34.5 °C for 72 hours; I stop the antiseizure drug before discharge if the infant is neurologically normal, because the cause drives the prognosis." [1] [5]