Febrile Seizures

Definition

Epidemiology

• Affects 2-5% of children (up to 8% in Japanese children)
• The most common seizure disorder in the pediatric age group
• Age range: 6 months to 6 years; rare before 3 months or after 6 years
• Strong familial tendency - polygenic inheritance in most cases; autosomal dominant in some families

Classification

Simple Febrile Seizures

• Generalized tonic-clonic semiology
• Duration <15 minutes
• Only one seizure in a 24-hour period
• No focal features
• Child aged 6 months to 6 years
• Full recovery to neurological baseline

Complex Febrile Seizures

• Duration >15 minutes
• Focal features (focal ictus or lateralized postictal weakness such as Todd's paralysis)
• More than one seizure in 24 hours or within the same febrile illness
• Age <6 months or >6 years

A subset - febrile status epilepticus - is defined as a febrile seizure lasting >30 minutes.

Genetics

• Polygenic in isolated cases; single-gene mutations more often found in familial recurrent cases
• GEFS+ (Generalized Epilepsy with Febrile Seizures Plus): Autosomal dominant, heterogeneous expression. Some family members have typical self-limiting febrile seizures; others have febrile seizures persisting beyond age 6 or overlapping with other seizure types.
• Dravet syndrome (Severe Myoclonic Epilepsy of Infancy): Starts with prolonged, often asymmetrical febrile seizures, but progresses to afebrile seizures and cognitive decline. Caused by truncating mutations in SCN1A (sodium channel subunit) or GABRG2 (GABA-A receptor subunit). This is NOT a benign condition.
• Digenic inheritance has been described (two mutations required for expression).

Pathophysiology

• Rising or peak body temperature lowers the seizure threshold in the immature brain
• Herpesvirus 6 (HHV-6) is a common precipitant - it causes high fever and may have direct neurotropic effects
• Any viral or bacterial illness, or rarely immunization, can trigger fever and thus a febrile seizure
• Febrile status epilepticus can injure the hippocampus: ~11.5% of affected children show unilateral increased hippocampal T2 signal on MRI acutely, which may evolve into hippocampal sclerosis

Workup

Simple Febrile Seizure

Complex Febrile Seizure

• Routine LP, labs, and imaging are still not automatically indicated in the absence of other signs of serious infection
• Exception: children with seizure >30 minutes who appear ill warrant evaluation for serious bacterial infection (including CSF)
• Do not delay antibiotics in a sick-appearing child pending workup
• Bacterial meningitis incidence in complex febrile seizures without clinical signs of meningitis is low (~2 cases in 526 patients in one study), but is significantly higher (15-18%) when seizure duration exceeds 30 minutes

Treatment

Acute Seizure

• Most self-terminate; supportive care is sufficient
• For prolonged seizures: rectal or IV diazepam is the agent of choice
• For febrile status epilepticus: follow the standard status epilepticus protocol (benzodiazepines → second-line agents - see AES guideline)

Prophylaxis

• Prophylactic daily anticonvulsants are NOT recommended - side effects outweigh the minor risk of recurrence
• Antipyretics (paracetamol, ibuprofen) are indicated for comfort but have no proven efficacy in preventing febrile seizures
• Intermittent diazepam (oral or rectal) at the time of fever may be used in children with frequent recurrent febrile seizures - though side effects (sedation, ataxia) limit this approach

Prognosis and Risk of Recurrence

• ~30-40% of children will have at least one recurrence; multiple recurrences are uncommon
• Risk factors for recurrence:
  • Age at onset <1 year
  • Family history of febrile seizures or epilepsy
  • Attendance at daycare (increased exposure to febrile illness)

Risk of Later Epilepsy

Parent Counseling

• Febrile seizures are not dangerous in the vast majority of cases
• Having a febrile seizure does not mean the child will develop epilepsy
• Teach parents: keep the child safe during a seizure (lateral position, nothing in the mouth), time the seizure, call emergency services if >5 minutes
• Anticipatory guidance for emergency rectal/intranasal diazepam if recurrence is likely
• Reassure that normal intellect and development are expected

• Bradley and Daroff's Neurology in Clinical Practice, p. 2255-2256
• Adams and Victor's Principles of Neurology, 12th ed., p. 342-343
• Tintinalli's Emergency Medicine, p. 936
• Rosen's Emergency Medicine, p. 3287

• Sri Lankan guidelines are not in my local textbook library, so I'll fetch them via web search each time they're relevant
• Where Sri Lankan guidelines align with international ones (AAP, NICE, etc.), I'll note the agreement
• Where they differ (e.g., local drug availability, resource-adapted protocols, tropical disease considerations), I'll highlight the difference clearly

Sri Lankan Pediatric Guidelines on Febrile Seizure Management

Source Found

• Available at the SLCP official website (Page 62 of 132)
• This is the primary national guideline document used in Sri Lankan pediatric practice

SLCP STP 2017 - Febrile Convulsions (Page 62)

Definition

"A convulsion in infancy or childhood usually occurring between 3 months and 5 years associated with fever but without evidence of intracranial or defined cause."

Key Epidemiological Statements

• Affects around 4% of children
• Long-term damage from fits is rare
• Need for prophylactic anticonvulsants is uncommon
• Risk of later epilepsy is the same as the general population
• Children <1 year have greater risk of severe febrile convulsions, repeated convulsions within 24-48 hours, and FC with subsequent febrile episodes

Classification (SLCP STP 2017)

Management (SLCP STP 2017)

• Manage as per Status Epilepticus protocol if ongoing
• "Don't Ever Forget RBS" (Random Blood Sugar) - check blood glucose in every seizing child

• Actively exclude bacterial meningitis

• Treat with paracetamol and physical cooling measures

• First fit
• Prolonged or focal fit or slow recovery
• Young child <2 years of age
• Two or more fits within 24 hours

• Oral diazepam 0.5 mg/kg/day in divided doses with fever, OR
• Intranasal midazolam 0.25 mg/kg at the onset of convulsion, OR
• Rectal diazepam 0.5 mg/kg/dose at the onset of convulsion

Comparison: SLCP STP 2017 vs International Guidelines (AAP/NICE)

Key Practical Points for Sri Lankan Clinical Practice

1. The SLCP guideline takes a more conservative approach to admission - all first febrile seizures and all children under 2 years are admitted, regardless of whether it is simple or complex. This differs from AAP guidance which allows discharge if the child has returned to baseline.
2. Intranasal midazolam is included as an option (alongside rectal diazepam) for home/prehospital use - this reflects increasing evidence for its practicality in resource-appropriate settings.
3. The "Don't Ever Forget RBS" reminder is a distinctly Sri Lankan mnemonic highlighting the importance of checking blood glucose in every seizing child, acknowledging that hypoglycaemia can mimic or co-exist with febrile seizures.
4. Dengue fever is a relevant local consideration - the SLCP Dengue guidelines specifically note that dengue can cause febrile convulsions, and electrolyte disturbances (especially hyponatraemia from inappropriate IV fluids) can cause seizures in dengue patients. This is not part of international febrile seizure guidelines.
5. The SLCP APLS (Advanced Paediatric Life Support) manual (also published by SLCP) governs management of prolonged febrile seizures / febrile status epilepticus using the standard APLS algorithm.