Fact Sheet N° 167
Revised February 2001
EPILEPSY: SCIENTIFIC AND MEDICAL ADVANCES
Research into epilepsy falls into
two main categories: basic and clinical. However, the vast majority of the
technology required to carry out this research and the benefits which accrue
from the research are only available in developed countries.
This focuses on the fundamental
mechanisms which underlie the development of epilepsy, the cause of spontaneous
seizures, their different manifestations, their timing and duration, and the
consequences of repeated seizures on brain function. Understanding the cellular
(neuronal) and brain processes responsible for individual seizure types and
epileptic disorders will lead to new approaches to prevention, treatment and
care. The following are key points in this research:
- Recent work has traced specific types of seizures to distinct disturbances
in neuronal connections in the brain, and the chemical transmission of
information between neurones.
- Neuropharmacologists have subsequently identified or designed compounds
which selectively interfere with these abnormal brain functions, leading to
the development of new anti-epileptic drugs which are able to treat specific
types of epilepsy with less impairment of normal brain function. This is
because they are less sedative and have fewer cognitive side-effects.
- In the past few years, there have also been advances in research on the
genetic basis of some epileptic syndromes, mainly in childhood and
adolescence, with the identification of specific chromosomal linkages which
increase the probability that an epileptic disorder will appear, usually in
association with other acquired or environmental factors.
- Identification of some of the genes responsible for a predisposition to
epilepsy may reveal the basic neurochemical or physiological defects which
need to be prevented or corrected. This, in turn, may help scientists to
develop new anti-epileptic treatments.
- It is quite possible that research over the next decade on molecular
genetics of human epilepsy will result in an entirely new classification of
epileptic disorders and a better understanding of the fundamental causes of
the many forms of epilepsy.
This research is primarily concerned with the application of
new diagnostic technologies and therapeutic interventions. It also includes
understanding regional differences in the various types of epilepsy and their
cause, studying the provision of health services for people with epilepsy and
the cost-effectiveness of treatments. Further research, in the fields of
psychology and sociology, and which is not detailed here, has improved the
understanding of the impact of the disease on people with epilepsy and enabled
the formulation of rehabilitation programmes.
It is only in the last decade that clinical neuroscientists
have been able to look directly at the structure and function of the living
human brain. This has been through the use of:
- Magnetic resonance imaging (MRI) has enabled the majority of structural
brain abnormalities responsible for epileptic seizures to be visualized.
- Positron emission tomography (PET) and single photon emission computed
tomography (SPECT) can help pinpoint an epileptic region by looking at
localized dysfunction in brain blood flow, metabolism and chemical processes
during and between seizures.
- Computerized electroencephalography (EEG) and magnetoencephalography (MEG)
can readily locate the sites of origin of epileptic discharges.
- Magnetic resonance spectroscopy (MRS) is also being used to non-invasively
identify areas of brain damage as well as disturbances in brain metabolism
and neurotransmitter function.
- Although MEG and MRS remain experimental diagnostic tools, most of these
techniques are being used in epilepsy centres in developed countries not
only for research but also for evaluation of people who may benefit from
brain surgery as treatment for intractable, drug resistant forms of the
- It has recently been shown that early effective treatment with
anti-epileptic drugs will control seizures in up to 70% of newly-diagnosed
adults and children.
- Attention is now being directed at the most appropriate choice of drug for
specific epilepsy syndromes.
- The reasons why some people develop chronic drug-resistant epilepsy is
also being investigated.
- For approximately two decades, no new major anti-epileptic medications
were introduced. In the last few years, however, five new anti-epileptic
drugs have reached the market and several more drugs are currently in the
clinical testing stages. In part, this is due to pharmacological application
of the better understanding of the basic mechanisms of epilepsy.
The 20 last years, major advance has been the recognition
that certain specific epileptic syndromes, which respond poorly to drug
treatment, have an excellent chance of successful treatment with surgical
- Recent advances in diagnostic technology and surgical techniques have led
to an increasing use of surgical treatment of epilepsy.
- Pharmacological and surgical therapies are today based on correcting or
eliminating specific epileptic disturbances. This not only provides the
greatest opportunity for people to be relieved of disabling seizures and the
disturbing side-effects of treatment, but it also avoids the long-term
psychosocial consequences of living with an uncontrolled epileptic disorder.
Recent research has found that particular seizures result from particular
neuronal activity and new anti-epileptic drugs which can better target these
seizures have been developed.
- Molecular genetics may soon shed new light on the fundamental causes of
- New diagnostic tools have been developed to aid clinicians in their
identification of types of seizures.
- Anti epileptic drugs which include "old" and new are controlling
seizures in almost 75% patients.
- Successful surgery is now an option for many people with epilepsy who
previously did not respond to anti-epileptic drug treatment.
- Many of these benefits are unfortunately only felt in more developed
For further information, please contact the Office of the
Spokesperson, WHO, Geneva. Tel: (+41 22) 791 2599. Fax: (+41 22) 791 4858.
All WHO Press Releases, Fact Sheets and Features as well as other information on
this subject can be obtained on Internet on the WHO home page http://www.who.int/