Epilepsy is the 4th most common neurological condition and epilepsy affects more than 65 million people worldwide.
Epilepsy is a group of neurological diseases characterized by epileptic seizures. Epileptic seizures are episodes that can vary from brief and nearly undetectable to long periods of vigorous shaking. These episodes can result in physical injuries including occasionally broken bones.
Seizures and epilepsy are not the same. 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 disease characterized by an enduring predisposition to generate epileptic seizures and by the neurobiological, cognitive, psychological, and social consequences of this condition. In other words, a seizure is an event and epilepsy is the disease involving recurrent unprovoked seizures.
A person is considered to have epilepsy if they meet any of the following conditions:
At least two unprovoked (or reflex) seizures occurring greater than 24 hours apart.
One unprovoked (or reflex) seizure and a probability of further seizures similar to the general recurrence risk (at least 60%) after two unprovoked seizures, occurring over the next 10 years.
Diagnosis of an epilepsy syndrome
Epilepsy is considered to be resolved for individuals who had an age-dependent epilepsy syndrome but are now past the applicable age or those who have remained seizure-free for the last 10 years, with no seizure medicines for the last 5 years.
What Is A Seizure?
A seizure is a sudden surge of electrical activity in the brain.
A seizure usually affects how a person appears or acts for a short time.
Many different things can occur during a seizure. Whatever the brain and body can do normally can also occur during a seizure.
If I have just one or two seizures does that mean I will get epilepsy?
About half of the people who have one seizure without a clear cause will have another one, usually within 6 months.
If there is a known cause for your seizure (for example, brain injury or other type of known brain condition), then you are twice as likely to have another seizure.
If you have two seizures, there's about an 80% chance that you'll have more.
If your first seizure occurred at the time of an injury or infection in the brain, then you are more likely to develop epilepsy. Often, more seizures don’t occur until weeks or months after the initial injury or infection.
More seizures are also likely if your doctor finds abnormalities on a neurological examination (tests that are done in a doctor’s office to see how the nervous system is working).
An EEG test or electroencephalogram (e-LEK-tro_en_SEF-uh_LOG-ram) can look at the electrical activity of the brain and may help predict whether more seizures will occur. Certain patterns on the EEG are typical of epilepsy. If your brain waves show patterns of that type, you are about twice as likely to develop epilepsy.
What happens during a seizure?
Seizures can take on many different forms, and seizures affect different people in different ways. Anything that the brain does normally can also occur during a seizure when the brain is activated by seizure discharges. Some people call this activity “electrical storms” in the brain.
Seizures have a beginning, middle, and end. Not all parts of a seizure may be visible or easy to separate from each other. Every person with seizures will not have every stage or symptom described below. The symptoms during a seizure usually are stereotypic (occur the same way or similar each time), episodic (come and go) and may be unpredictable.
Some people are aware of the beginning of a seizure, possibly as much as hours or days before it happens. On the other hand, some people may not be aware of the beginning and therefore have no warning.
Some people may experience feelings, sensations or changes in behaviour hours or days before a seizure. These feelings are generally not part of the seizure, but may warn a person that a seizure may come. Not everyone has these signs, but if they do, the signs can help a person change their activity, make sure to take their medication, use a rescue treatment and take steps to prevent injury.
An aura or warning is the first symptom of a seizure and is considered part of the seizure. Often the aura is an indescribable feeling. Other times it’s easy to recognize and may be a change in feeling, sensation, thought, or behaviour that is similar each time a seizure occurs.
The aura can also occur alone and may be called a simple partial seizure or partial seizure without change in awareness.
An aura can occur before a change in awareness or consciousness.
Yet, many people have no aura or warning; the seizure starts with a loss of consciousness or awareness.
Common symptoms before a seizure:
Awareness, Sensory, Emotional or Thought Changes:
Déjà vu (a feeling of being there before but never have)
Jamais vu (a feeling that something is very familiar but it isn’t)
Visual loss or blurring
Fear/panic (often negative or scary feelings)
Dizzy or lightheaded
Nausea or other stomach feelings (often a rising feeling from the stomach to the throat)
Numbness or tingling in part of the body
The middle of a seizure is often called the ictal phase. It’s the period of time from the first symptoms (including an aura) to the end of the seizure activity - this correlates with the electrical seizure activity in the brain. Sometimes the visible symptoms last longer than the seizure activity on an EEG. This is because some of the visible symptoms may be after-effects of a seizure or not related to seizure activity at all.
Common symptoms during a seizure.
Awareness, Sensory, Emotional or Thought Changes:
Loss of awareness (often called “black out”)
Confused, feeling spacey
Periods of forgetfulness or memory lapses
Loss of consciousness, unconscious, or “pass out”
Unable to hear
Sounds may be strange or different
Unusual smells (often bad smells like burning rubber)
Loss of vision or unable to see
Formed visual hallucinations (objects or things are seen that aren’t really there)
Numbness, tingling, or electric shock like feeling in body, arm or leg
Out of body sensations
Déjà vu (feeling of being there before but never have)
Jamais vu (feeling that something is very familiar but it isn’t)
Body parts feels or looks different
Feeling of panic, fear, impending doom (intense feeling that something bad is going to happen)
Difficulty talking (may stop talking, make nonsense or garbled sounds, keep talking or speech may not make sense)
Unable to swallow, drooling
Repeated blinking of eyes, eyes may move to one side or look upward, or staring
Lack of movement or muscle tone (unable to move, loss of tone in neck and head may drop forward, loss of muscle tone in body and person may slump or fall forward)
Tremors, twitching or jerking movements (may occur on one or both sides of face, arms, legs or whole body; may start in one area then spread to other areas or stay in one place)
Rigid or tense muscles (part of the body or whole body may feel very tight or tense and if standing, may fall “like a tree trunk”)
Repeated non-purposeful movements, called automatisms, involve the face, arms or legs, such as
Lip-smacking or chewing movements
repeated movements of hands, like wringing, playing with buttons or objects in hands, waving
dressing or undressing
walking or running
Repeated purposeful movements (person may continue activity that was going on before the seizure)
Convulsion (person loses consciousness, body becomes rigid or tense, then fast jerking movements occur)
Losing control of urine or stool unexpectedly
Change in skin colour (looks pale or flushed)
Pupils may dilate or appear larger than normal
Biting of tongue (from teeth clenching when muscles tighten)
As the seizure ends, the post-ictal phase occurs - this is the recovery period after the seizure. Some people recover immediately while others may take minutes to hours to feel like their usual self. The type of seizure, as well as what part of the brain the seizure impacts, affects the recovery period – how long it may last and what may occur during it.
Common symptoms after a seizure.
Awareness, Sensory, Emotional or Thought Changes:
Slow to respond or not able to respond right away
Difficulty talking or writing
Feeling fuzzy, lightheaded or dizzy
Feeling depressed, sad, upset
Frustrated, embarrassed, ashamed
May have injuries, such as bruising, cuts, broken bones or head injury if fell during seizure
May feel tired, exhausted or sleep for minutes or hours
Headache or other pain
Nausea or upset stomach
General weakness or weak in one part or side of the body
Urge to go to the bathroom or lose control of bowel or bladder
What Causes Epilepsy?
Causes of epilepsy vary by age of the person. Some people with no clear cause of epilepsy may have a genetic cause. But what's true for every age is that the cause is unknown for about half of everyone with epilepsy.
Some people with no known cause of epilepsy may have a genetic form of epilepsy. One or more genes may cause the epilepsy or epilepsy may be caused by the way some genes work in the brain. The relationship between genes and seizures can be very complex and genetic testing is not available yet for many forms of epilepsy.
About 3 out of 10 people have a change in the structure of their brains that causes the electrical storms of seizures.
Some young children may be born with a structural change in an area of the brain that gives rise to seizures.
About 3 out of 10 children with autism spectrum disorder may also have seizures. The exact cause and relationship is still not clear.
Infections of the brain are also common causes of epilepsy. The initial infections are treated with medication, but the infection can leave scarring on the brain that causes seizures at a later time.
People of all ages can have head injuries, though severe head injuries happen most often in young adults.
In middle age, strokes, tumours and injuries are more frequent.
In people over 65, stroke is the most common cause of new onset seizures. Other conditions such as Alzheimer’s disease or other conditions that affect brain function can also cause seizures.
Common Causes of Seizures by Age:
Lack of oxygen during birth
Low levels of blood sugar, blood calcium, blood magnesium or other electrolyte problems
Inborn errors of metabolism
Maternal drug use
In Infants and Children:
Fever (febrile seizures)
Brain tumour (rarely)
In Children and Adults:
Congenital conditions (Down's syndrome; Angelman's syndrome; tuberous sclerosis and neurofibromatosis)
Progressive brain disease (rare)
What Are The Risk Factors of Epilepsy?
A risk factor is something that makes a person more likely to develop seizures and epilepsy. Sometimes a risk factor can cause scarring of the brain or lead to areas of the brain not developing or working right. Risk factors include:
Babies who are born small for their age
Babies who have seizures in the first month of life
Babies who are born with abnormal areas in the brain
Bleeding into the brain
Abnormal blood vessels in the brain
Serious brain injury or lack of oxygen to the brain
Infections of the brain: abscess, meningitis, or encephalitis
Stroke resulting from blockage of arteries
Conditions with intellectual and developmental disabilities
Seizures occurring within days after head injury ("early posttraumatic seizures")
Family history of epilepsy or fever-related seizures
Alzheimer's disease (late in the illness)
Autism spectrum disorder
Fever-related (febrile) seizures that are unusually long
Long episodes of seizures or repeated seizures called status epilepticus
Use of illegal drugs such as cocaine
Mild head injuries, such as a concussion with just a very brief loss of consciousness, do not cause epilepsy. Yet the effects of repeated mild head injuries and epilepsy are unknown.
What if I don’t have any of those risk factors?
Although the disorders and injuries on these lists help to explain many cases of epilepsy, more people with epilepsy don't have any of these. Often we just don't know how or why epilepsy gets started.
What Are Seizure Triggers?
Even though you may not know the cause of your epilepsy, you can look at whether there are factors (often called ‘triggers’) that precipitate or provoke seizures. These triggers may make a person with epilepsy more likely to have a seizure in certain situations. The triggers could change the number or severity of seizures. Learning if you have any triggers can help you learn what to do next. Sometimes people can learn how to modify their lifestyle or environment to lessen the risk of triggers.
Lack of sleep or disrupted sleep
Illness (both with and without fever)
Heavy alcohol use or seizures after alcohol withdrawal
Use of cocaine and other recreational drugs such as Ecstasy
Over-the-counter drugs, prescription medications or supplements that decrease the effectiveness of seizure medicines
Nutritional deficiencies: vitamins and minerals
Poor eating habits, such as long times without eating, dehydration or not enough fluids