Epileptic seizure

A seizure is a transient disturbance of brain function due to abnormal excessive electrical discharges in brain cells.

Conceptual definition of seizure and epilepsy – 2005 report

An epileptic seizure is a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain. Epilepsy is a disorder of the brain characterized by an enduring predisposition to generate epileptic seizures, and by the neurobiologic, cognitive, psychological, and social consequences of this condition. The definition of epilepsy requires the occurrence of at least one epileptic seizure.

Nonepileptic seizures

Not all seizures are a form of epilepsy. Some seizures may resemble an epileptic seizure, with abnormal movements (including convulsions), impaired awareness or other symptoms similar to an epileptic seizure. The difference is that they are not caused by abnormal electrical activity in the brain. While most patients have either epileptic seizures or nonepileptic seizures, a patient can sometimes have both.

Nonepileptic seizures can be physiologic or functional (also called psychogenic).

  • Physiologic seizures include syncope (drop in pressure, which can lead to convulsive movements without epilepsy), cataplexy (loss of tone associated with a sleep disorder) and others.
  • Functional seizures are caused by psychological factors, for example extreme stress, which may present as an epileptic seizure.

Both types of seizure are involuntary and do not respond to antiepileptic treatment. A diagnosis can help in choosing the appropriate treatment. Unfortunately, since the symptoms are very similar, it can sometimes take a while before the correct diagnosis is made.

Reference: International League Against Epilepsy

Classification of seizures

Generalized seizures See PDF for more details

Rapidly engage bilateral networks

Myoclonic atonic
Myoclonic tonic
Absence with specific symptoms:
-Myoclonic absence
-Eyelid myoclonia

Focal seizures See PDF for more details

Engage networks limited to one hemisphere

Characterized by one or more symptoms:
Consciousness / Response to stimuli

Unknown See PDF for more details

Insufficient information to classify seizures as focal or generalized

Epileptic spasms

Reference: International League Against Epilepsy

Seizure emergency

You do not have to go to the emergency room every time you have a seizure. However, you must go to the emergency room if:

  • It is your first seizure
  • You have not been diagnosed with epilepsy and you have a seizure
  • You have a head injury or physical injury that needs to be treated
  • The seizure lasts longer than 5 minutes (where applicable, call an ambulance)
  • The seizure causes injuries that need to be treated
  • The seizure happens in water (bath, swimming pool, lake, etc.)
  • You are pregnant
  • You have another seizure soon after the first one and do not regain consciousness between seizures

Witnessing a seizure / What to do if you see a person having a seizure

Epileptic seizures can occur when a person is alone but also when other people are around.

If a seizure occurs, bystanders should:

  • Stay calm
  • Not put anything in the person’s mouth
  • Remove the person’s glasses, if they are wearing glasses
  • Clear the area of anything that could cause injury
  • Note the exact time the seizure started and how long it lasts
  • Stay with the person after the seizure until they return to their basal state

What is normal during a seizure:

  • The person’s breathing may be irregular during the seizure and slow and deep afterwards.
  • The area around the lips may be a bluish colour (cyanosis).
  • Irregular movements of all parts of the person’s body.

Do not do cardiopulmonary resuscitation during a seizure!

Seizure triggers

Certain factors can trigger seizures:

  • Fatigue
  • Sleep deprivation
  • Stress
  • Noncompliance with antiepileptic medication
  • Too much alcohol
  • Drug use

In some cases, a fever, a virus, a hormone imbalance or menstrual period can make a person more likely to have a seizure.

A person who has epilepsy should respect their limits in order to avoid situations that might lead to a seizure. While epilepsy does not mean that a person cannot lead a normal life, they have to be smart about it!

Seizure diary / seizure record

It is important to keep a record of your seizures because these observations are very helpful when it comes to choosing treatments and planning future investigations. A good seizure diary includes the number of seizures and a description of the seizures.

Many tools designed for this purpose are already available. The Epilepsy Clinic / Neuro Rive-Sud has created a simple tool for patients who would like to keep better track of their epileptic episodes. Here is the link: Seizure diary

SUDEP - Sudden Unexpected Death in Epilepsy

SUDEP is the acronym for “Sudden Unexpected Death in Epilepsy”. In SUDEP cases, no other cause of death is found when an autopsy is done. The prevalence of this phenomenon is 1 in 1,000. However, the risk increases to over 1 in 150 in people with refractory epilepsy. These sudden deaths are less common in children but are a leading cause of death in young adults with uncontrolled seizures.

In cases of SUDEP, the person with epilepsy is often found dead in a resting position (sometimes face turned into the pillow) and does not appear to have had a convulsive seizure. No cause has been identified to date. Some researchers think that a seizure causes an irregular heart rhythm. More recent studies have suggested that the person may suffocate from impaired breathing.

There is no treatment to prevent SUDEP. However, the best way to prevent SUDEP is by optimizing seizure control. For most people who have epilepsy, the illness is often well controlled, which lowers their risk for this rare phenomenon.

Reference: Epilepsy Foundation