What is Epilepsy?

Aug 21, 2016 | Trends

A girl is laughing. She is sitting in the kitchen munching on peanuts, enjoying the cracking of the shells and joking with her sister. Her parents are relaxing nearby; all is well. Looking at the clock, the girl’s mother cautions that it’s late and the girls had better go to bed. A short time later, the girls fall asleep giggling together.

A few minutes later, the tone of the house is about to drastically change. The girl wakes up and feels very strange. Her jaw is tight and keep jerking downwards to one side. She feels dizzy. She tries to get up to go down to her parents in the kitchen. She is struggling to walk down the stairs as keeping her balance is getting harder and harder. By the time she reaches the bottom step, she can no longer see and she is crying out to her parents. She hears them rushing to her from the kitchen and feels their hands grasp her. She is in a chair and her parents are rushing around. She feels very hot and starts to have images flash in front of her.

The next thing she remembers is being in the ward of a children’s hospital. 

***

When I was 8 years old, I made the huge mistake of riding my new, “grown up-girl” bicycle without a helmet (please don’t do this!). Out of nowhere, a group of people appeared on the path and I braked very suddenly. I flew over the handlebars of my pink birthday gift and hit a lamppost, head first. I then tore up my face on the pavement. After a brief trip to the hospital, a lot of medical tests, and a few weeks of recovery, I seemed totally fine and returned to school without even a scar. Not long afterwards, I had my first seizure.

These seizures were exhausting! From later accounts by my parents, they were pretty scary to watch. Luckily, after a few months, they became less and less severe until they eventually stopped and never came back. However not everyone is so lucky, if I can use the word. My seizures were most likely caused by my head injury and they disappeared before school vacation was over. I didn’t even need medication. For some people, the frequency of their seizures doesn’t fade on their own as time goes by. When these seizures become chronic, this is called epilepsy.

What is epilepsy? What are seizures?

Epilepsy is a neurological disorder characterized by repeated seizures. 1 in 26 people in the US will be diagnosed with epilepsy in their lifetime. An epileptic seizure is defined as a “transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain“. Put simply, all or some of your brain cells start firing really quickly and at the same time, overwhelming the brain, and inducing the symptoms of a seizure. This sudden firing is sometimes called an “electrical storm”. To be classified as epilepsy, these seizures must be recurrent and unprovoked. The symptoms of such seizures, or “fits”, can be anywhere from mild to severe depending on which parts of the brain are firing. They include muscle spasms, strange behaviour, loss of consciousness, headaches, dizziness and a wide range of others.

Anyone can have a seizure. A fever, low blood sugar, low blood pressure, lack of oxygen, illness, some medications and, as in my case, head trauma, can all cause seizures. However, to be diagnosed as epilepsy, the seizures must be occur more than once without a specific cause.

There is no hard and fast path for seizures to follow. Each person with epilepsy will have their own unique seizure patterns and symptoms although these tend to be stereotypic (similar each time) for a person. There are general trends with seizures however:

Stage Definition Description
Prodromal Phase

The early symptoms that signal the onset of a seizure.

Some people experience symptoms that a seizure is coming. The symptoms are very unique to each individual and some people don’t get any. These symptoms can occur anywhere from days to hours before a seizure and include migraines, irritability, and increased agitation

Aura

A “warning” sensation just at the beginning of an epileptic seizure.

This is the start of what is known as a partial seizure (see below) Symptoms here can range from fearfulness, hallucinations, imagined smells or tastes and dreamlike feelings. In my case, I experienced a kind of out-of-body feeling with lightheadedness but the specifics vary from person to person.

Ictus

The seizure itself.

The specifics of this depend on how much of the brain is firing. We’ll go into more detail below.

Post-Ictal Phase

After the seizure.

It’s common for people to fall asleep after a seizure. Some people have speech or motor difficulties and others may experience vomiting. Emotions and behaviour may change. This stage can be absent, last seconds, minutes, hours or even days.

What are the different types of epilepsy?

There is an ever-growing list of the types of epilepsy but they can be broadly categorized into two groups. These types are defined by a particular combination of symptoms. They can be generalized or partial (also called focal or localized). In the former, the “electrical storm” begins all over the brain whereas in the latter the storm begins in only one location of the brain. If the aura (see above) is the only part an individual’s seizure, they’ve had a simple partial seizure. If the seizure spreads to other areas of the brain and affects consciousness, it is known as complex partial seizure.

Generalized seizures can be divided into more types:

  • Absence (previously petit mal) seizures – the person stare without moving and may appear to be daydreaming.
  • Myoclonic seizures – the person’s muscles repeatedly jerk and spasm but the movements are more sporadic and isolated.
  • Clonic seizures –  the person’s muscles repeatedly jerk and spasm.
  • Tonic seizures – the person’s stiffens and falls unconscious. They may struggle to breathe as the chest tightens leading to a blue appearance of the face and lips.
  • Tonic-clonic (previously grand mal) seizures – usually the two types of seizure go together and are rarely seen on their own. Here the person is unconscious and is convulsing repeatedly.
  • Atonic seizures – the person’s muscles go limp.

Why do some people get seizures?

Many people have idiopathic epilepsy, meaning the cause is unknown but there are also many known causes of epilepsy. Some types of epilepsy are thought to have a genetic component, as there is a slightly greater chance of having epilepsy if a sibling also has it. Sometimes infections can lead to epilepsy due to scarring left in the brain post-infection. Stroke, Alzheimer’s Disease and head trauma can also induce epilepsy. Those with autism spectrum disorders, ADHD, Down’s syndrome and Rett syndrome are more likely to develop epilepsy.

Points to Take Away

  • Epilepsy is a neurological disorder.
  • There are many types of epilepsy.
  • Anyone can have a seizure and there are a variety of causes.
  • Having one or a few seizures does not mean you have epilepsy. Epilepsy is a chronic condition.
  • There are many possible causes of epilepsy but these are not always known in each case.
  • The seizure symptoms each person experiences are unique.

In future articles, we’ll look at current treatments and research and delve into possible future treatments based on ongoing clinical studies.

Helpful Resources

2016 Review: A clinical overview of epilepsy by Kaarkuzhali B. Krishnamurthy, MD
Epilesy.com on the basics of epilepsy
John Hopkins on the basics of epilepsy
WedMD summarized the types of seizures here and also here


Article by Olwen Reina. Contact Olwen at olwen@tempobioscience.com.

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