Febrile Seizures: What you need to know…

Article By: Dr. Sayoni Roy Chowdhury, Consultant, Pediatric Neurology, Madhukar Rainbow Children’s Hospital

A febrile seizure is a seizure occurring in a healthy young child that is accompanied by a fever (100.4°F or more). Fever can be due to an underlying infection, commonly upper respiratory tract or gastrointestinal infection.
Febrile seizures are the most common cause of seizures in childhood, affecting 2 to 5% of the pediatric population. Most febrile seizures are self-limited and do not bear an impact on children’s neurodevelopmental trajectory.

What are the symptoms of febrile seizures?
Febrile seizures typically affect children between 1-2 years of age, ranging from 6 months to 5 years. They commonly occur on the 1st day of a febrile illness. The most frequent symptoms are:
• Generalized jerking/stiffening of all four limbs or one-half of the body
• Loss of consciousness
• Uprolling of eyeballs, frothing from the angle of mouth, bladder or bowel incontinence may be associated with jerks
A child might feel drowsy or fall asleep after the event, but after a short while, returns back to normal.
Febrile seizures can be classified as simple or complex. Simple febrile seizures last for a few seconds up to 15 minutes and occur once in 24 hours. Complex febrile seizures, on the contrary, are longer (> 15 minutes), may affect one-half of the body and can even recur within a day.

What are the causes of febrile seizures?
The exact cause of febrile seizures is hitherto unknown. Certain viral infections and genetic susceptibility are common risk factors that may affect a vulnerable, growing brain under the stress of a fever.
Nearly, one-third of children with febrile seizures may experience a recurrence. The risk factors frequently implicated in recurring febrile seizures include age younger than 1.5 years, shorter fever duration (< 1 hour) prior to the seizure, temperature less than 104°F and first-degree relative (parents or siblings) with a history of febrile seizures.

What are the complications of febrile seizures?
Febrile seizures don’t pose any long-term negative impact on the cognitive abilities. However, a very small proportion of children may be exposed to the risk of subsequent epilepsy (future unprovoked seizures) in those with complex febrile seizures, atypical age of onset of febrile seizures (age > 3 years), family history of epilepsy, neurodevelopmental abnormality and shorter fever duration (<1 hour) before seizure onset.

How to diagnose febrile seizures?
Febrile seizure is a clinical diagnosis. Evaluation should begin with a focused history and comprehensive examination, looking for focal neurologic signs and determining the cause of the fever. A well-appearing child with a simple febrile seizure doesn’t need any diagnostic testing. However, lumbar puncture (cerebrospinal fluid study) may be considered in infants with incomplete/unknown immunization status or if the child was pretreated with antibiotics as signs of meningitis (central nervous system infection) may be less reliable in these situations. In children with complex febrile seizures, neurologic examination aids us in the decision for need of further investigations like neuroimaging, lumbar puncture.
Once a child is diagnosed with febrile seizure, the prime focus should be on anticipatory guidance for parents. The emphasis should be on reassuring parents about the benign nature of febrile seizures, favorable prognosis and home management of seizures.