A child having fever and throwing a fit is a common occurrence. 'Fever going to brain'- that's often the colloquial description of the condition known as ‘Febrile convulsion’. But is it really so? The typical scene always begins dramatically and ends rather tamely. A child who was perfectly all right a few moments ago suddenly rolls up his eyes or stares blankly, begins jerking violently or becomes limp and is found to have high-grade fever. By the time the terrified parents rush to the nearest medical facility, the baby almost always stops convulsing and either goes off to sleep or regains normalcy without any treatment.
Febrile convulsion, also known as a febrile seizure or a febrile fit is a peculiar entity which has mystified parents and paediatricians alike from the days of Hippocrates. The medical thinking about this entity has undergone a sea-change over the recent years and still even some of the medical practitioners are not clear about the new concepts. Let's try and demystify this needlessly dreaded thing. What's a febrile convulsion? It's a convulsion associated with sudden rise of temperature typically observed in infancy and pre-school years. By definition, it is not associated with any intra-cranial infection like meningitis or encephalitis and is to be distinguished from epilepsy. Is it a common occurrence?
Yes, it is pretty common -occurring in almost 2-4 per cent of the children in the typical age group of six months to seven years (three months to five years according to some authorities). Around half of those cases occur between 1 to 2 years of age. Why does it occur?The exact mechanism of this phenomenon is still a mystery. Relative immaturity of the brain with low seizure threshold and an increased likelihood of common febrile infections in that particular age group are often cited as the reasons. The sudden rise of body temperature somehow seems to trigger simultaneous, excessive electrical discharges from the brain- cells leading to the seizure. What are the common causes for this?Simple, focal infections like a cold, a throat infection or a middle ear infection (Otitis media) are the most likely causes. Viral illnesses like Roseola infantum (Exanthem subitum) or Measles and Bacillary Dysentery (Shigella gastroenteritis) are some other important causes. What are the types of febrile seizures?
Febrile seizures can be either simple or complex. A simple febrile seizure occurs within few hours of the onset of fever, lasts less than 15 minutes, is generalised and doesn't recur within 24 hours. When multiple, prolonged or focal in nature, they are called complex. Are they hereditary?Though the exact genetic mode of inheritance isn't defined, they tend to occur in families. The risk of occurrence in the siblings is around 10-20 per cent and even higher if the parents also suffered from them in their childhood. Do they recur?Yes, often they do recur. One-third of the patients are likely to get another febrile seizure after the first one and almost 10 percent get three or more in the specified age-group. Younger the age of onset and stronger the family history of febrile seizures, more is the likelihood of recurrence. Do they frequently progress to epilepsy?
This is the biggest worry for the parents and luckily the outlook is positive. Epilepsy by definition is an illness characterised by recurrent, non-febrile seizures. Most of the children outgrow febrile seizures and less than five per cent actually progress to epilepsy in later life. Frequent recurrences of febrile fits don't indicate any increased risk for epilepsy. Abnormal neurological development from before, complex febrile seizures and a strong family history of epilepsy are the risk factors for the development of epilepsy in future. Do they cause any brain damage or growth problems?
The answer is a big 'No'! Even with frequently recurring febrile convulsions, there is no increased risk for neurological, intellectual or growth handicaps. Should vaccinations be avoided in such patients?
No, not at all. They should receive all the vaccines as in the normal children. The concept of avoiding DPT or Pertussis vaccine in such patients is not correct. What investigations are needed in such cases?
According to latest thinking, routine blood tests, lumbar punctures (for CSF), X-rays and scans are unnecessary if clinical judgment is heavily in favour of simple febrile seizures. Complex febrile seizures, very young patients and suspicion of other possible serious causes warrant investigations. Does an abnormal EEG mean something serious in these cases?
Actually EEG (Electroencephalogram) has no value in predicting a recurrence of the febrile fit or future development of epilepsy. So an EEG abnormality has no serious significance. In fact the recent trends are for avoiding EEG altogether in most such cases. How do I manage such a convulsion at home?
Don't panic. Just turn the patient on the side. Loosen or remove the tight clothes. Take care that he doesn't hurt himself. Don't try to forcibly keep the mouth open. Sponge the body with tepid water. If the convulsion doesn't stop within 10 minutes, take the child to the nearest medical facility. Aren't some medicines necessary to prevent these fits?
Long term preventive medicines like Phenobarbitone or Sodium Valproate are found to have much more risk of serious side effects than advantage and are no longer in vogue. Some centres advocate short-term use of oral or per rectal Diazepam or Lorazepam at the beginning of a febrile episode for prevention but usually reserve this measure for frequent recurrences. One important point of note: No medicine has any role in preventing progression to epilepsy. Then what are the precautions for the likely recurrence?
Just the routine measures to bring down fever like Paracetamol administration and a tepid sponging are more than sufficient. Too much vigorous fever control has not been shown to have any additional benefit. So let me make it short and sweet for you. Ø Febrile seizure is a benign, age-specific, self-limiting phenomenon. Ø Though it has high chances for recurrence, it doesn't usually progress to epilepsy. Ø It doesn't cause any brain damage or growth problems. Ø In most cases investigations are unnecessary. Ø It usually doesn't require anything other than simple fever-controlling measures.
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