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group of children give a much more positive view. Such studies show that most children with
febrile convulsions are normal individuals who have simple febrile convulsions, the majority
of which do not recur. In such children there is little evidence of long-term effects on
behaviour or intelligence and the increased risk of later epilepsy is slight. The minority of
children have complex febrile convulsions and for most of them the outlook is good. However
within this group there are a few children who are at particular risk of having later epilepsy,
the risk being greatest for those who have febrile convulsions with focal features, which tend
to be prolonged and to occur in the younger children.
A study in the United States of children with febrile status epilepticus (lasting 30 minutes or
more) found evidence of acute hippocampal T2 hyperintensity on MRI scans in a proportion
of those children, followed by the radiological appearance of hippocampal sclerosis after one
year. Longer follow-up is needed to determine the relationship of these findings to temporal
lobe epilepsy50.
Clinical characteristics
Febrile convulsions are all either tonic-clonic or possibly hypotonic in type and are never
myoclonic seizures, spasms or non-convulsive attacks. Most are brief and bilateral, but long-
lasting and/or partial (unilateral) febrile convulsions do occur: 7075% of these are the initial
febrile convulsion experienced by the child17.
Simple febrile convulsions are the commonest type of febrile convulsion. They are brief (<15
minutes) generalised seizures that do not occur more than once during a single febrile
episode. Some just consist of staring, perhaps accompanied by stiffening of the limbs and
they may not cause the parents great concern. Often they are much more dramatic. In the
CHES birth cohort14 about 40% were not considered sufficiently severe to necessitate
admission. About two-thirds of the children suffered only one febrile convulsion ever.
Complex febrile convulsions may be more severe than simple febrile convulsions in the
CHES cohort 95 children (25% of the children with febrile convulsions) had complex
convulsions and 78% of them were admitted to hospital a higher proportion than was found
in those with simple convulsions14. In these 95 children the complex features were as follows:
55 (58%) multiple, 32 (34%) prolonged and 17 (18%) focal (some had more than one
complex feature). It is important to emphasise that the most severe attacks made up a very
small proportion of all febrile convulsions.
Management
Introduction
Management of children with febrile convulsions remains controversial17-19,57-9. Groups of
experts have published guidelines. These include the Consensus Development Panel which
met at the National Institutes of Health in America in 198060, the 1991 Joint Working Group
of the Research Unit of the Royal College of Physicians (RCP) and the British Paediatric
Association (BPA)61 and the American Academy of Pediatrics62-3.
Initial assessment
First the convulsion should be stopped if it is continuing. Then the temperature should be
measured to confirm that the child is febrile (the rectal temperature is more reliable than oral
or axillary). It is important to determine whether or not the fever preceded the convulsion.
The parents/carers may report a febrile illness and they may have measured the child’s
temperature before the seizure started. The history and the general physical examination may
provide clues: there may be an exanthematous rash or evidence of an upper respiratory tract
