Can epileptic seizures be predicted and prevented?

Q & A with Professor Berj L. Bardakjian

In honour of Epilepsy Awareness Month, Erin Vollick sat down with a leading neurological researcher at the University of Toronto, Berj L. Bardakjian.

A biomedical engineering Professor at the Institute of Biomaterials & Biomedical Engineering (IBBME) and the Edward S. Rogers Sr. Department of Electrical & Computer Engineering (ECE), Bardakjian works with a team of neurological specialists to classify different brain states using recordings of its electrical rhythms, and from there, to pinpoint seizure zones in the epileptic brain – research that could reduce the amount of tissue cut during corrective surgical procedures, as well as lead to better surgical outcomes.

What is epilepsy?

Contrary to what most people imagine, epilepsy is not considered a disease, but a disorder characterized by changes in the brain that lead to seizures. But epilepsy actually covers a wide range of disorders. There is not just one type of epilepsy, but many.

Our present theory is that seizures are caused when the brain is in a state of hyper-excitability. I think of the brain as a symphony. The electrical activity in the brain is polyrhythmic, as there are many interacting rhythms, and none of them are “regular”. But with an epileptic seizure, suddenly, all the cells in the brain start synchronizing together and they enter a singular, regular rhythm, which means that all the other normal functions of the brain are not occurring.

What are some of the historical associations surrounding epilepsy?

Epilepsy used to imply “possession.” Historically, people who suffered epileptic seizures were thought to be possessed by the devil, or were entering mythical or mystical states. Personally, I wonder about many of our geniuses – Napoleon Bonaparte, Beethoven, and Van Gogh, for instance, all had epilepsy. Was their genius related to their epilepsy? Is hyper-excitability what gave us Beethoven’s 9th symphony?

What causes hyper-excitability?

Hyper-excitability occurs due to possible chemical environment changes in the brain, at times even visual changes. A few years ago, for instance, people in Japan who were watching TV were getting seizures from the flickering lights in their television programs.

How is epilepsy managed?

There are three main courses of treatment. Children who have epilepsy can be put on a “ketogenic diet” – it’s a horrible diet, very high in fat, but it can help control the seizures.

Drugs are the next step, and these drugs are designed to reduce the excitation of the brain that leads to this synchronous brain activity and seizures.

Drugs don’t work for some people, so surgery is an option. Surgeons will try to cut out that part of the brain that is the focal point of the seizures. But there are some areas of the brain that can’t be cut, such as those vital cognition areas. Also, you can only perform surgery if the epilepsy is “focal” to one region, and not “generalized” in multiple sites of the brain.

What kind of research is your team conducting?

The big buzz word right now is ‘Deep Brain Stimulation’.  We’re trying to create implantable devices that can predict seizures and stimulate the brain in such a way as to prevent seizures. Via electrodes, we want to input into the brain high complexity electrical signals – like a symphony – that would mimic the rhythmic signals that normal, functioning brains produce. The simulator we’re working on is a model of the electrical rhythmic activities of the functioning brain.

This kind of therapy wouldn’t have the drawbacks that drugs have. For one thing, this is a more localized treatment, and this kind of therapy would sidestep any drug sensitivity and side-effect issues.

But currently we’re trying to pinpoint those regions in the brain where seizures are occurring with a greater degree of accuracy.

How can you pinpoint or predict seizures?

We record the electrical activity of the brain and then classify the various state transitions between these activities. We then look for differences in pre-seizure states. Sometimes we simply detect the seizures.

What has changed in epilepsy research in the last 20 years?

What’s new about our research, and the best part of the research we’re conducting right now, is that we work as part of a team: neurologists at Toronto Western Hospital, neurosurgeons, pharmacologists, neurophysiologists, physicians, and neural (biomedical) engineers.

What breakthroughs do you think are imminent or potentially imminent?

First, and we’re nearly there: we’re trying to help surgeons cut out the focal region in the brain that needs to be removed to stop seizures. Currently, surgeons just cut as much as they can rather than what needs to be cut, and even that doesn’t guarantee they cut out the right region.

From an ongoing research perspective, we’re trying to understand more about the hyper-excitability that leads to epileptic seizures. This is still an outstanding mystery – and we’re using various models, such as computer models, to answer those questions.

This story originally appeared in a University of Toronto publication, and is reproduced here with permission.

Tagged: Health, Blog

Share: Print

Leave Comments

Blog Posts

Northern flying squirrel.

When habitats collide

Sharon Oosthoek | August 4, 2015

1995 was a very good year to be a southern flying squirrel in Ontario. It marked the start of a series of unusually warm winters that saw the rodents creep north 240 kilometres into the range of their larger cousin, the northern flying squirrel. The incursion wasn’t widely noticed by humans. The two species are closely-related and look much alike with their large dark eyes and furry membrane between their front and rear legs that they use to glide. But some humans were watching — including wildlife geneticist Paul Wilson and population ecologist Jeff Bowman, both from Trent University ­— and they wondered if the two species were crossbreeding and having hybrid babies. When the researchers trapped flying squirrels and analyzed the DNA in their fur, they discovered that was exactly what was happening. The pair now believes this is the first example of hybridization following the expansion of a species’ range due to modern climate change. Testing by the Ministry of Natural Resources and Forestry suggests roughly four per cent of Ontario's flying squirrels are now genetic hybrids. Hybrid wildlife is not new. However, human-induced changes such as the deliberate introductions of animals, habitat fragmentation and climate change may be bringing species together more frequently and in greater numbers than ever before. The list of cross-breeding Canadian wildlife is already long:  the golden-winged warbler in Manitoba, Ontario and Quebec; the eastern wolf in Ontario and Quebec; and a handful of polar bear/grizzly crosses known as grizzlars in the Northwest Territories. Scientists also point to bob cat/lynx hybrids in New Brunswick, known as bob-o-linx, rainbow and cutthroat trout in Alberta, and spotted/barred owls in British Columbia. Now what? As humans wittingly and unwittingly move species around, is the resulting cross-breeding a good or bad thing? How will hybrids affect other animals and plants in the ecosystem? And what of endangered animals —  could hybrids genetically weaken their parent populations? These are all tricky, and as of yet, answered questions.  As Wilson and Bowman point out, some biologists worry that accepting hybrids could give people an excuse not to protect the habitat of endangered species.  These scientists also argue wildlife hybridization threatens unique lineages, with interbreeding potentially leading to the extinction of rare species. Others suspect hybrids may be Mother Nature's answer to the rapid changes humans have wrought. They say hybrids allow for a greater mix of genes within a single population of animals and act as an insurance policy of sorts. In other words, the greater an animal's genetic diversity, the more chance there is for it to adapt to a rapidly changing environment. This genetic adaptability is why Wilson now studies the hybrid squirrel genome for adaptive advantages, such as the northerner's ability to withstand cold and the southerner's ability to fight off diseases from warmer climates. “One could look at these hybrids as a creative reshuffling of the genetic material for a changing landscape,” says Wilson. “I mean climate change isn’t going to go away … maybe these hybrids are emerging as the most adapted animal for the changing landscape and climate.”
Timothy Muttoo (University of Waterloo) with clay filter

Low tech water filter

Christine Bezruki | July 27, 2015

It may use the most simple of technology, but a new water filtration system is transforming thousands of lives in the Dominican Republic. Designed by University of Waterloo Masters of Public Health student, Timothy Muttoo, in partnership with the non-profit organization FilterPure, the new filters use locally-sourced clay, sawdust and particles of silver to remove 99.99 per cent of all water contaminants. read more »

Breaking for water

Sharon Oosthoek | July 22, 2015

A strenuous workout should be accompanied by frequent water breaks, right? Not so fast, says Brock University physiologist Stephen Cheung. While that certainly is the received wisdom, Cheung points out that top-performing athletes almost always speed past water stops in an effort to shave seconds off their time. read more »
River rapids

Tribal waters

Noreen Fagan | July 20, 2015

Dan Walters is interested in water — especially in its emotional, spiritual and social connections to First Nation communities. A professor of geography at Nipissing University, Walter's current project assesses risk levels in drinking water and wastewater in the Dokis First Nation, located on the French River near Georgian Bay. read more »
Bay of Fundy

Changing tides

Sharon Oosthoek | July 13, 2015

Tidal speeds in Nova Scotia's Bay of Fundy can reach a staggering five metres per second.  By comparison a very fast river flows at about two to three metres per second, "and you wouldn't want to fall into a current like that," says Queen's University professor in coastal engineering Ryan Mulligan. read more »
More Blogs »