Childhood epilepsies
Srimathy Vijayan takes an in-depth look at this important, but often neglected topic
In the January 2008 edition of The Lancet Neurology, reviewed Childhood epilepsies. (1) Such reviews are of great importance as they stress the requirement of ensuring that epilepsy occurring in childhood is considered as a different clinical entity to that occurring in adulthood. The word “epilepsy” is derived from the Greek word “epilambanein” which means “to seize or attack”. The seizures associated with epilepsy are the result of sudden, excessive electrical discharges in groups of brain cells.
Why is childhood epilepsy an important cause for concern?
Childhood epilepsies present with a complex array of symptoms which produce various syndromes. Scientists are still yet to understand the aetiology and biochemical mechanisms behind this condition. The diagnosis can be challenging and a misdiagnosis rate of up to 30% has been implicated. (2) Additionally, in combination with the diagnostic difficulties, the potentially serious consequences of anti-epileptic drugs has meant that the requirement to diagnose the condition accurately in children is imperative to avoid unnecessarily treating them. (3) However, perhaps the ultimate (did you mean ultimate?) reason for discussing childhood epilepsies in depth is the grave impact that they have on children in childhood and throughout their later careers.
Epidemiology
It is important to recognize the difference between epilepsy and seizures. Although 5% of the world’s population may have a seizure at any time during their life, (4) only a third of these people will develop epilepsy. Thus epilepsy is only diagnosed when an individual has the tendency to experience recurrent seizures; at least two, unprovoked, more than 24 hours apart as stated by The World Health Organization (WHO). Globally about 50 million people have epilepsy. (4) The annual incidence of epilepsy is 23-190 per 100 000. The incidence in children is more variable still and indeed higher at 25 - 840 per 100 000 per year. (5) In part, this higher rate is thought to reflect the population structure of developing countries, where by and large, the population consists of young individuals with reduced life expectancy. The overall prevalence of epilepsy ranges from 2.7 to 41 per 1000 population, though the rate of active epilepsy (i.e. at least one seizure in the preceding five years) is in the range 4-8 per 1000. (6) (7) Specific prevalence figures for childhood epilepsy are hard to come across.
Mortality
International vital statistics give annual mortality rates for epilepsy as 1-2 per 100 000 (8). Based on a meta-analysis of studies investigating mortality in the past 100 years, the standardized mortality ratio (SMR) for epilepsy, which is the ratio between the deaths observed among patients with epilepsy and the deaths expected in a reference population with a similar age distribution, ranges from 1.6 to 5.3 in children. (9) Interestingly the SMR is inversely correlated with age, therefore the highest deaths caused by epilepsy occur during the childhood years. These findings, in conjunction with the generally higher incidence of epilepsy in children have prompted international public health bodies to target this particular age group.
Treatment and Availability
The treatment of childhood epilepsies involves a cocktail of anti-epileptic drugs. It is noteworthy to appreciate the inherent ethical /legal issues present with conducting randomized controlled trials involving children. As a result very few therapeutic trials evaluating anti-epileptic drugs in children are available. This current hurdle is being addressed by many relevant bodies. (10) However, all countries have developed their own set of guidelines recommending treatment schedules for childhood epilepsy. For example the UK’s National Institute of Clinical Excellence (NICE) published in October 2004. (11) Other treatments are related to non-medicinal interventions. These include surgery for those patients where a focal lesion can be identified. More recently, vagal nerve stimulation, whereby an electrical device is implanted in the brain, has offered renewed hope, though this treatment is likely to be confined to use only in developed countries at present. Lastly, another alternative option is the use of a ketogenic diet. (12)
Despite the treatment options available, significant proportions of children with epilepsy receive either no treatment or sub-optimal treatment. Many factors influence this such as economic status, the quality of the healthcare system and peripheral services, rural or urban residence, and the cultural frameworks of societies. Anti-epileptic drugs are limited, with only first-generation therapy made available to most developing countries. (13) Furthermore, in such countries they are often only available for short periods of time, with the drugs sold in pharmacies only located within city centres. (14) As a result many individuals are unable to access them. The cost of supplying these treatments, even the common first-generation drugs for a relative period of time often equates to a month’s worth of wages for some individuals. (13) For example the cost of phenobarbital in South-East Asia is 2·7 times higher than in Europe. (15) Furthermore, hospital services for epileptic children are another neglected area in many developing countries.
Impact of childhood epilepsy
Children diagnosed with epilepsy can be considered as one of the most vulnerable groups within society and are often thought to have a “hidden disability”. The epilepsy itself can make the child’s life disabling and as a result, personal development can be hindered. Often academic work is compromised due to long absences. Additionally, the stigma associated with epilepsy can also form a disabling component in many childrens’ lives. Consequently, they face profound psychological and social consequences. (16) In fact, the influence of epilepsy on a child’s life has been shown to have poorer social outcomes than that of a child with any other chronic childhood illness. (17) This impact does not cease in childhood and often continues well into adult life where children with epilepsy have been shown to have lower rates of employment, poor marital outcomes and behavioural difficulties. A diagnosis of epilepsy in a child is often translated to many other aspects of the child’s (and indeed family member’s) life who are often under considerable emotional strain which quite often leads to depression. (18)
Impact of anti-epileptic drugs
As mentioned earlier, the impact of anti-epileptic drugs is equally significant. Such medications are known to cause a wide array of side-effects including appetite disturbances, weight gain, liver toxicity, insomnia and many more. Recently the implications of anti-epileptic drugs on childhood growth have been investigated, with conclusions stating that anti-epileptic drugs disturb endocrine function (particularly the reproductive system) of children possibly leading to infertility. (19) Additionally, anti-epileptic drugs have also been associated with reduced bone density leading to fractures (20). More ironically though, the impact of such medications on the immature child’s brain is another area of ambiguity. (21) It is apparent that although the main goal is to control seizures, an understanding of the consequences of the long term use of anti-epileptic drugs in the management of childhood epilepsy is essential.
Prognosis of childhood epilepsy
Given there are many types of epileptic syndromes with various outcomes, no one common prognosis can be stated. Nonetheless it is generally accepted that children who develop epilepsy in their adolescent years have the condition lifelong. Thus the requirement to monitor and manage children with the condition is long-lasting, and often involves the management of the many other aspects of growing up to reach adulthood.
WHO’s work
The WHO has long been engaged in work regarding epilepsy. In 1997, a joint project involving the World Health Organization (WHO), International League Against Epilepsy (ILAE) and International Bureau for Epilepsy (IBE) was launched called the “Global Campaign against Epilepsy: Out of the shadows”. The mission statement put forward was, “to improve acceptability, treatment, services and prevention of epilepsy worldwide”. The publication of the “Atlas: Epilepsy care in 2005″ (15) was a key component of this project and highlighted various public health concerns regarding epilepsy. Stigma is a core element of the project and the commitment to develop approaches to reduce the stigma encountered in epilepsy is demonstrated by the CREST study: Collaborative Research on Epilepsy Stigma Project. Other areas of intervention from WHO’s perspective include providing pharmaceutical treatment options to children in developing countries at subsided, if not free, rates and to help governments plan, implement and succeed in setting up hospital care for children with severe epileptic illness.
Conclusion
Childhood epilepsies are a major public health concern. The implications of the disease stem well beyond the health related outcomes of individuals, affecting the psychological, social and emotional wellbeing of children. Furthermore, children are a particularly susceptible group of patients who require specialist care to meet their growing needs. It is important for health care professionals to consider the multiple dimensions to this medical condition, and work with their partners to improve the care that is provided, as well as to educate the public to “accept” this medical condition like all the others we come across in our day to day lives.
Srimathy Vijayan
5th Year medical student
University of East Anglia
Norwich
UK
s.vijayan@uea.ac.uk
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