Thursday, January 8, 2015

Epilepsy Research Highlights of 2014

was an important year for epilepsy research. A review in the January 2015 issue of Nature Neuroscience cites four milestones, each emphasizing a positive trend toward increasing reliance on research collaborations and data sharing. The piece starts with the International League Against Epilepsy’s (ILAE's) long-awaited update of the definition of the word “epilepsy” itself. In 2013, a person with epilepsy was stuck with a lifelong diagnosis, whether they continued to have seizures or not. Under the new definition, people may officially shed the diagnosis once they have been both seizure free for ten years and off seizure meds for the last five of those. People who have outgrown childhood epilepsy syndromes also now may consider their epilepsy “resolved.” Of course, this doesn't change the fact that both of those groups are more likely to have recurring seizures than the population at large, but it does reflect a growing international consensus that an epilepsy diagnosis may outgrow its helpfulness after years of medicine-free seizure freedom. Epilepsy has also been upgraded (or downgraded, I suppose, depending how you look at it)  from a “disorder” to a “disease,” a taxonomic shift better reflecting the gravity of the diagnosis.

The Nature piece also cites a study that resolves an old debate about the dangers of extended fever-related seizures (febrile status epilepticus). Such seizures can, and often do--the study shows--cause significant damage to hippocampi. And that that damage can evolve into hippocampal sclerosis, which can cause temporal lobe seizures later on. In other words, extended febrile seizures are serious business.

The third study Nature cites is a genetic meta-analysis drawing on more than 8,000 epilepsy patients and about 26,000 controls. The study included 12 large genotype-phenotype genetic databases from three continents to locate genetic markers for common epilepsies. It found two key risk locations for all epilepsies. The work suggests that even though epilepsy is a wildly diverse disorder--I mean disease--a wide range of common seizure types seem to have some common genetic roots.

Fourth, the Nature piece refers to research showing that while heritable genetic mutations have received the bulk of study from researchers, somatic genetic mutation--those that occur after an individual is formed, and are not heritable--may be a fairly common cause of brain malformations associated with epilepsy. These mutations are found in only a small percentage of the body’s cells and so don’t usually show up in the standard genetic analyses. The upshot, somatic mutations will be a promising area of genetic study in coming years.

Finally, the review cites a large multi-center study of the effects of anti-epileptic drugs (AEDs) on the children of breastfeeding mothers who take them. The conclusion: go ahead and breastfeed your baby and continue to take your meds. “Breastfed children displayed higher IQ and enhanced verbal abilities compared with non-breastfed children,” the study concludes, whether the mother is taking AEDs or not.


What Nature didn’t describe in its review was the blossoming of research on 1) implantable devices, 2) the effective control of epilepsy through dietary treatments, and 3) the study of cannabidiol (CBD), an extract of the marijuana plant. All three are areas of quick research growth and of high excitement at the annual American Epilepsy Society meeting in Seattle a month ago. 

At that meeting, awards were also given for new and vastly improved algorithms developed for seizure recognition and prediction. In time, these algorithms, and others like them, will enable to implantable devices to shut down mounting seizure activity before it achieves critical mass. Like the milestones outlined in the Nature piece, this one was largely the product of data sharing and international collaboration. It is an excellent trend! 

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