Febrile seizures: Case

This boy is in febrile status epilepticus. He meets the defining criteria for a febrile seizure (age 6 months to 5 years, fever, no central nervous system infection, no prior afebrile seizure), but the convulsion has lasted 35 minutes, which is over the 30 minute boundary for febrile status epilepticus and makes this a neurocritical emergency. The viral exanthem suggests the fever source, and the absence of meningeal signs is reassuring but does not yet exclude meningitis in a child this age. The immediate priority is to terminate the convulsion and to escalate to second-line therapy, because the two buccal midazolam doses in the community have not worked. [3]

Clinical findings and acute termination

The pattern is that of febrile status epilepticus in a child with a viral illness. The 35 minute duration, persisting despite two benzodiazepine doses, marks refractory convulsive status epilepticus that demands second-line therapy without delay. I would secure the airway, give oxygen, confirm the normal bedside glucose, obtain intravenous access, and call for senior paediatric and anaesthetic help. Because the seizure has already been refractory to benzodiazepines, I would give a second-line agent immediately, either intravenous levetiracetam at 40 mg per kg to a maximum of 2.5 g or intravenous fosphenytoin at 20 mg PE per kg, in a high-dependency or intensive care setting with preparation for airway support. [1]

If the convulsion persisted, I would proceed to a third-line agent (a midazolam infusion or other anaesthetic agent) under anaesthetic and intensive care guidance. Throughout, I would monitor the oxygen saturation, the airway, and the blood pressure, because repeated benzodiazepines and second-line agents can cause respiratory depression and hypotension. The McIntyre trial underpins the use of buccal midazolam in the community, but its failure here is exactly the scenario in which escalation to intravenous second-line therapy is required. [2]

Investigations and exclusion of meningitis

Once the convulsion is controlled, the diagnostic task is to confirm the fever source and to exclude meningitis and encephalitis. The prolonged convulsion itself is a reason to lower the threshold for a lumbar puncture, because a child in febrile status epilepticus is not a simple febrile seizure and the 2011 AAP lumbar-puncture thresholds for simple seizures do not apply in their conservative form. I would send blood cultures, a full blood count, electrolytes, calcium, magnesium, glucose, and a C-reactive protein, and I would perform a lumbar puncture once the airway is safe, sending cerebrospinal fluid for cell count, protein, glucose, gram stain, culture, and viral polymerase chain reaction. [1]

Given the prolonged convulsion, I would also consider neuroimaging once the child is stable, to exclude a structural lesion or complications, and an electroencephalogram to exclude non-convulsive status. The widespread viral exanthem with febrile status epilepticus raises the possibility of human herpesvirus 6 infection (roseola), which the FEBSTAT study found to be over-represented among children with febrile status epilepticus and linked to acute hippocampal injury. [4]

Prognosis, follow-up, and counselling

The prognosis for this child is more guarded than for a simple febrile seizure, because febrile status epilepticus carries a real risk of hippocampal injury and of later temporal lobe epilepsy. The FEBSTAT study showed that febrile status epilepticus can produce acute hippocampal swelling that in a proportion of children progresses to hippocampal sclerosis and temporal lobe epilepsy, so this child needs paediatric neurology follow-up and, in many centres, a magnetic resonance imaging scan at several months to look for evolving hippocampal sclerosis. [3]

On discharge I would address the family's anxiety, the recurrence risk, and the question of prevention. I would explain that this was a prolonged febrile seizure rather than a simple one, that the risk of another febrile seizure is higher after a complex attack, and that a rescue benzodiazepine plan (buccal midazolam at 0.5 mg per kg) is appropriate given the prolonged nature of his seizure. I would not prescribe continuous or intermittent prophylactic antiepileptics, because the harms outweigh the benefits, per the AAP 2008 guideline and the 2021 Cochrane review. I would correct the antipyretic misconception: paracetamol and ibuprofen are for comfort, not prevention. The family leaves with a written rescue plan, a safety-net, advice on when to call an ambulance, and a clear follow-up arrangement. [5] [2]