EPILEPSY - AN EXPLANATION

Courtesy of the CEA, 2019

A special thank you to the Canadian Epilepsy Alliance for sharing their up to date and correct epilepsy information

AN EXPLANATION

A seizure is a sudden burst of electrical activity in the brain, which causes a temporary disturbance in the way brain cells communicate with each other. The kind of seizure a person has depends on which part and how much of the brain is affected by the electrical disturbance that produces the seizure. A seizure may take many different forms, including a blank stare, uncontrolled movements, altered awareness, odd sensations, or convulsions. Seizures are typically brief and can last anywhere from a few seconds to a few minutes.

WHAT IS A SEIZURE?

A seizure is an electrical disturbance in the brain caused by brain cells firing in a highly rhythmic fashion. The kind of seizure a person has depends on which part and how much of the brain is affected by the electrical disturbance. A seizure occurs when the normal electrical balance in the brain is lost. The brain’s nerve cells misfire: they either fire when they shouldn’t or don’t fire when they should. The result is a sudden, brief, uncontrolled burst of abnormal electrical activity in the brain. Seizures are the physical effects of such unusual bursts of electrical energy in the brain. During a seizure, out-of-sync signals from the brain travel along the nervous system pathway to sensors, like the nerves that sense light in the eyes or the nerves that flex muscles. These misfiring signals may keep the brain from understanding what the eyes see, so the person stares during a seizure. Or they may affect leg muscle tone and cause a person to fall down. The type of seizure depends on how many cells fire and which area of the brain is involved. A seizure may be an alteration in behaviour, consciousness, movement, perception and/or sensation.

Different parts of the brain are specialized to do different things. There are parts of the brain that help us speak, understand those around us, and coordinate our movements. Our brains are involved in everything we experience, think, say, feel or do. Any one of these functions can be altered or disrupted during a seizure. A seizure may take many different forms, including a blank stare, uncontrolled movements, altered awareness, odd sensations, or convulsions.

Seizures are usually brief and can last anywhere from a few seconds to a few minutes. The brain is very good at stopping seizure activity. Immediately afterwards, a person may have no lingering effects or they could experience temporary effects, such as muscle weakness or confusion.

WHAT IS A SEIZURE THRESHOLD?

A seizure threshold is the level of stimulation at which your brain will have a seizure. A very high fever, for instance, can sufficiently excite anyone’s brain to produce a seizure. People with epilepsy have a lower-than-normal seizure threshold, meaning that only slightly increased excitement will cause them to have a seizure. A seizure threshold is generally genetically inherited, but other factors can affect this level; young age and high fever are two factors that may lower one’s threshold, making a child more likely to have a seizure.

WHAT CAUSES EPILEPSY?

Epilepsy has many different causes. In any given individual, the cause is a combination of their genetically-determined seizure threshold, an underlying abnormality in the brain which predisposes them to epilepsy, and factors which bring on epilepsy at that time. Determining the specific cause for any one person’s epilepsy is usually difficult. In about 60% of all cases, no specific cause is found, much to the frustration of the epilepsy patients involved. Epilepsy of an unknown origin is called idiopathic epilepsy. In many cases it is presumed to be genetic.

IS EPILEPSY GENETICALLY INHERITED?

Some forms of epilepsy have now been linked to specific genes. In addition, scientists believe that everyone inherits a seizure threshold which determines how susceptible you are to seizures, but whether or not you ever develop epilepsy is another story. In fact, in most cases epilepsy develops without any family history of the condition.

If a parent has seizures, the likelihood of passing epilepsy on to their child is estimated to be about 6%, compared to a 1% or 2% risk of epilepsy in the general population. Basically, unless both parents have a strong family history of epilepsy, the chances that any of their children will inherit the tendency to have seizures are quite low.

WHO HAS EPILEPSY?

Epilepsy most often starts in childhood or else late in life, but anyone can develop epilepsy at any time. Epilepsy affects people of all ages, all nations, and all races. It can even occur in animals. Next to migraine headaches, it is the most common neurological disorder there is. One in every 100 Canadians has active epilepsy. The chance of acquiring it at some time during life (i.e. its cumulative incidence) is about 1- 2 %.

WHAT IS THE HISTORY OF EPILEPSY?

As far back as the historical record goes, people have always had epilepsy. Typically misunderstood and regarded with superstition, epilepsy has historically been mistreated in strange and horrific ways. Exorcism, ointments, amulets and enemas were used as treatments in ancient Babylon, for example. Ancient peoples often believed that seizures were curses of gods and that people with epilepsy held prophetic powers. Attitudes of past societies toward epilepsy have left a legacy of stigma and damaging misconceptions that still persists today.

Some of the most exceptionally creative and talented people in history have had epilepsy, including: St. Paul, Alexander the Great, Julius Caesar, Dante, Joan of Arc, Isaac Newton, Molière, Napoleon Bonaparte, Handel, Beethoven, Flaubert, Paganini, Tennyson, Byron, Charles Dickens, Fydor Dostoyevsky, Vincent Van Gogh, Lewis Carroll, Alfred Nobel, Agatha Christie, Richard Burton.