Fighting fits
Childhood malaria and seizures
Fits are dramatic events. They frighten onlookers, particularly parents.
Recurrent fits, epilepsy, have profound and broad implications for the
sufferer and their family: they not only interfere with everyday activities,
but also social functioning and job prospects. Furthermore, in some parts
of Africa, epilepsy and convulsions are often thought to be caused by
supernatural forces. Seizures are common in malaria endemic areas, particularly
in sub-Saharan Africa.
In some areas, over 20% of children admitted to hospital have a history
of convulsions and the incidence of epilepsy in Africa is higher than
many other parts of the world. But is there any link between these common
conditions? Would control of malaria prevent seizures in Africa?
Febrile seizures (characterised by fever) are the most common type
of seizure in children and occur in children six months to five years
old,
most often in association with mild infections. Most are simple and
stop spontaneously. Complex febrile seizures (i.e. prolonged or repetitive)
occur in 20-30% of cases and are associated with the subsequent development
of epilepsy.
In malaria endemic areas, Plasmodium falciparum malaria is the most
common cause of fever in children less than five years. Falciparum malaria
is
the most common cause of admission to hospital, with malaria thought
to be the diagnosis in over 65% of children admitted with convulsions.
Whilst P. falciparum may not be the cause of all cases of convulsions
in children, there is evidence that it may cause epilepsy: convulsions
are more common in falciparum than in vivax malaria despite a similar
febrile response; 54% of convulsions occur when the child is without
a fever and 86% have complex symptoms; a much higher proportion than
in febrile seizures and with a different outcome.
Epilepsy is common in malaria endemic areas. Establishing a link between
malaria and epilepsy is difficult, since there are many causes of epilepsy.
In Kilifi, on the Kenyan coast, research has demonstrated an association
between exposure to severe malaria and the development of epilepsy
in children. Children exposed to cerebral malaria or malaria and complex
seizures had a greater chance of developing epilepsy than unexposed
children
in the community.
So what could be the link? Suggested areas for new and continued research
include:
- P. falciparum could cause focal brain damage, resulting in epilepsy
but there is little evidence to support this mechanism in most
children.
- A genetic component could be responsible. Children who are diagnosed
with malaria and have seizures are more likely to have family members
who have contracted malaria, although the evidence for a hereditary
component is not strong.
- Recent research suggests that malaria antibodies may play a role
in affecting brain cell function, but whether these antibodies lead
to epilepsy
is not yet established.
Charles Newton
Kenya Medical Research Institute
PO Box 230
Kilifi
Kenya
cnewton@kilifi.mimcom.net
See also:
‘Seizure disorders among relatives of Kenyan children with severe
falciparum malaria’, Tropical Medicine and International Health
8(1): 12-16, by A.C. Versteeg et al, 2003, www.id21.org/health/h4av1g1.html
‘Epileptic seizures and malaria in Kenya children’, Transactions
of the Royal Society of Tropical Medicine and Hygiene 90(2): 152-155,
by C.M. Waruiru et al, 1996
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