Febrile convulsions

Febrile convulsions are seizures that are provoked by febrile illness in children aged 6 months - 6 years, that are:

• Not caused by a CNS infection.
• Without previous neonatal seizures or previous unprovoked seizure.
• Not meeting criteria for acute symptomatic seizures.

The term febrile convulsions replaced the term “febrile seizures” in 2006.

It is the most common form of childhood seizures. It affects 3% of children, with 1/3rd of children having recurrent febrile seizures after the initial one.

Pathophysiology

It is not entirely understood how febrile convulsions occur. It is believed that there is an interplay of genetics environmental factors.

1. Genetic factors - evidence suggests that genetic factors may play a role in susceptibility to febrile convulsions. Certain genetic mutations or variations have been associated with an increased risk of febrile seizures.
2. Immature brain - the developing brain of young children may be more susceptible to the effects of fever. Immaturity of certain brain structures and pathways, particularly those involved in temperature regulation and seizure threshold, may contribute to the occurrence of febrile convulsions in this age group.
3. Fever-induced excitability - fever can lead to increased neuronal excitability in the brain, making the brain more susceptible to seizures. Elevated body temperature can alter the balance of neurotransmitters and ion channels in the brain, leading to hyperexcitability and abnormal electrical activity.

80% of cases of febrile convulsions are triggered by viral infection and most commonly with Roseola infantum (HHV-6) as well as influenza.

Age is an important factor as the recurrence of seizures declines as one grows older.

⚠️ Risk factor

Approximately 50% of children have no identifiable risk factors:

• Family history
• High peak temperature - this is more important of a risk factor than how fast the temperature rise occurs.
• Zinc and iron deficiency

These 3 risk factors also increase the risk of having epilepsy.

🔢 Classification

We can classify febrile convulsions as either simple, complex or febrile status epilepticus.

😷 Presentation

• Fever and other symptoms indicative of infection.
• Tonic-clinic seizure - a generalised seizure.
• Focal seizure - movement limited to one side of the body or one limb.
• Post-ictal drowsiness

🔍 Investigations

⭐️ It is a clinical diagnosis based on the clinical history and exclusion of other diagnoses, such as:

• CNS infection
• Epilepsy
• Intracranial lesions - such as tumours or haemorrhage.
• Syncope
• Non-accidental injury
• Delirium
• Metabolic/electrolyte abnormalities

If there has been a complex seizure → a CT head should be done e

🧰 Management

We’ll look at management of the initial management of an acutee febrile seizure, the post-seizure management and the long-term management.

🚨 Complications

• Febrile status epilepticus
• Epilepsy
• Cognitive impairment