EPILEPSY
in the 21st CENTURY:
A Vision of New Treatment in the New Millennium
At the dawn of a brand new century, change is in the air. New technologies, medical advances and genetic breakthroughs are no longer the stuff of science fiction-we read about them almost daily in our morning newspaper. But what does the future hold for the person with epilepsy?
Epilepsy has been documented by historians for at least 3,000 years.
Called "the Sacred Disease" or "the Falling Evil" by the ancients, past "treatments" for
people with epilepsy have included exorcism, bleedings, castration, as well as drinking the blood of fallen gladiators.
Even though modern epilepsy treatments have advanced considerably from these practices, they can still feel quite primitive to the patient of today. Daily doses of anticonvulsant medications can control most seizures, but these drugs can have cognitive and other side effects that are difficult to live with. Epilepsy brain surgery, our other contemporary treatment, is still a seriously invasive procedure open to very few candidates. Is there hope for better treatment for people with epilepsy in the years ahead?
Epilepsy Toronto decided to ask that question of a number of neurologists who specialize in epilepsy at its conference Epilepsy in the 21st Century: A Vision of Treatment in the New Millennium. Here is a report from that fascinating conference.
Forecasting Seizures
Currently, people with epilepsy must take their anti-convulsant medication round-the-clock, every day, because we simply don't know when the next seizure is coming. But if we could predict when a seizure will occur, and get treatment directly to the brain at the right moment to prevent the seizure, epilepsy treatment could be revolutionized. Is it possible to know in advance when a seizure is going to occur?
Neurologist Dr. Richard Wennberg reported on the status of this exciting area of scientific inquiry.
Researchers now talk about "forecasting" a seizure, much like meteorologists forecast the weather. They look at the neurological system of the brain as a whole and do a "systems level analysis" using an EEG.
We know that the neurological system of the brain is composed of billions of tiny nerve cells, or neurons, which are responsible for transmitting, receiving and coordinating messages via electrical impulses. This is how the brain controls everything we do. Like a weather system, networks of neurons form a dynamic system of interactions and activities-a system that is not linear or predictable, but complex and chaotic.
When a person has epilepsy, these neuronal networks have a tendency
to change &om their normally complex, chaotic activity to a synchronized state in which all the neurons are doing
the same thing at the same time. This abnormal, synchronized firing of neurons is what creates a seizure.
According to Dr. Wennberg, the neuronal system sometimes starts to move towards a seizure, but then moves away and the seizure doesn't happen. A seizure is what systems analysts call a "sudden phase transition"- a change from one state to another, like the moment when water changes into steam, or into ice. As a sudden phase transition, a mathematical model of a seizure can be made using "non-linear dynamic theory" (such as chaos theory).
A researcher in Germany named Christian Elgers uses complex calculations to measure the synchrony of patients' EEGs and successfully forecast- two minutes, five minutes, some say even 30 minutes in advance-their seizures. J.L. Perez Velazquez of Canada has used the EEG to identify the very sensitive state that characterizes the transition into or out of a seizure (called "Type III Intermittency") during which the dynamic system is most susceptible to alteration or treatment.
Obviously, before patients with uncontrolled seizures will be able to
forecast their seizures using systems like these, we'll need to improve and further miniaturize our computer technology.
But how will the seizures, once forecast, be prevented?
Dr. Wennberg summed up one vision of the future this way: "The person with epilepsy with uncontrolled seizures may one day be able to have a device implanted within their brain in the region that the seizures start from, hooked up to a sensor that detects when the seizure will occur and then will induce either an electrical stimuli, or the local application of a liquid drug to abort the seizure before it happens."
This sensor could be similar to a cardiac pacemaker, only it would detect that brain waves were going to synchronize and give a stimulus that would promote chaos and return the brain to its unsynchronized, non-seizure state.
"Forecasting seizures sounds like science fiction, but it's already in the planning stages and will be in the testing phases within a year or two, although not in routine use for a decade", commented Dr. Wennberg.
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