By Medifit Education.
WHAT IS EPILEPSY?
Epilepsy is a common brain disorder characterized by recurrent seizures. Approximately 1 in 100 Canadians have epilepsy. The highest number of new cases are in seniors and young children, but epilepsy can begin at any age.
A health care professional may consider epilepsy as a possible diagnosis when a person has had two or more seizures. A medical diagnosis of epilepsy is based on multiple pieces of information: the description of the episodes; the person’s medical and family history; and the results of diagnostic tests. Fortunately, epilepsy is a treatable condition. Many people with epilepsy (two out of three) will achieve good seizure control with medication. When medication is not effective in preventing seizures there are other treatment options available.
Epilepsy is a chronic disorder, the hallmark of which is recurrent, unprovoked seizures. Many people with epilepsy have more than one type of seizure and may have other symptoms of neurological problems as well.
Sometimes EEG testing, clinical history, family history and outlook are similar among a group of people with epilepsy. In these situations, their condition can be defined as a specific epilepsy syndrome.
The human brain is the source of human epilepsy. Although the symptoms of a seizure may affect any part of the body, the electrical events that produce the symptoms occur in the brain. The location of that event, how it spreads and how much of the brain is affected, and how long it lasts all have profound effects. These factors determine the character of a seizure and its impact on the individual.
Having seizures and epilepsy also can also affect one’s safety, relationships, work, driving and so much more. How epilepsy is perceived or how people are treated (stigma) often is a bigger problem than the seizures.
CAUSES OF EPILEPSY
Epilepsy is a term used to describe many different neurological disorders that all have a common feature, an increased risk of having seizures.
Just as there are many different types of epilepsy there are many different causes too, which include:
- a brain injury or damage to the brain
- Anything that can injure the brain is a potential cause of epilepsy including: head trauma; stroke; brain injury during birth; neurodegenerative diseases; brain tumours; and many others. Epilepsy may begin weeks, months or years after an injury to the brain.
- structural abnormalities that arise during brain development
- Sometimes these structural changes in the brain are visible on a brain scan (such as a MRI), other times there could be subtle changes in brain structure that are not easy to detect with current imaging techniques. Epilepsy due to a structural abnormality may begin early in life, during adolescence or in adulthood.
- genetic factors
- Some genetic causes of epilepsy are inherited and there may be other family members with epilepsy, while other genetic factors that cause epilepsy occur at random.
- a combination of two or more of the above factors
For many people with epilepsy, the cause of their seizures is unknown. It is hoped that research and new developments in diagnostic testing will provide more answers for people with epilepsy and their families.
Epilepsy is more common than you might think. According to the Epilepsy Foundation, millions of Americans are living with the condition. Although it can strike either sex at any age, epilepsy is most often diagnosed in children and in older adults. “The older you get, the higher your risk becomes,” says Georgia Montouris, MD, assistant professor of neurology at the Boston University School of Medicine and director of epilepsy services at Boston Medical Center.
Because the causes of epilepsy are so varied, establishing a medical history is one of the first steps a physician will take when diagnosing the condition. Although many physicians will treat epilepsy solely on the basis of a patient’s medical history, there are other tools at your doctor’s disposal as well. Depending on what type of epilepsy is suspected — there are dozens of different forms — doctors may order an electroencephalograph, which records brain waves and can alert physicians to patterns that might indicate seizures. Magnetic resonance imaging, computerized tomography, and in some cases, positive emission tomography, also may be used as diagnostic tools.
IS THERE ANY TREATMENT?
Once epilepsy is diagnosed, it is important to begin treatment as soon as possible. For about 70 percent of those diagnosed with epilepsy, seizures can be controlled with modern medicines and surgical techniques. Some drugs are more effective for specific types of seizures. An individual with seizures, particularly those that are not easily controlled, may want to see a neurologist specifically trained to treat epilepsy. In some children, special diets may help to control seizures when medications are either not effective or cause serious side effects.
SYMPTOMS OF EPILEPSY
The main symptoms of epilepsy are repeated seizures (fits). There are many different types of seizure, depending on the area of the brain affected.
People with epilepsy can experience any type of seizure, although most people have a consistent pattern of symptoms.
Seizures can occur when you are awake or asleep.
Doctors classify seizures by how much of the brain is affected. There are:
- partial (or focal) seizures – where only a small part of the brain is affected
- generalized seizures – where most or all of the brain is affected
Some seizures do not fit into these categories and are known as unclassified seizures.
There are two main types of partial seizure.
SIMPLE PARTIAL SEIZURES
Simple partial seizures are where you remain fully conscious throughout.
Symptoms of a simple partial seizure can include:
- a general strange feeling that is hard to describe
- a “rising” feeling in your tummy – sometimes likened to the sensation in your stomach when on a fairground ride
- an intense feeling that events have happened before (déjà vu)
- experiencing an unusual smell or taste
- a tingling sensation, or “pins and needles”, in your arms and legs
- a sudden intense feeling of fear or joy
- stiffness or twitching in part of the body, such as an arm or hand
These seizures are sometimes known as “warnings” or “auras”, because they can be a sign that another type of seizure is on its way. This can give you time to warn people around you and make sure you are in a safe place.
COMPLEX PARTIAL SEIZURES
Complex partial seizures are when you lose your sense of awareness and can’t remember what happened after the seizure has passed.
The symptoms of a complex partial seizure normally involve apparently strange and random bodily behavior, such as:
- smacking your lips
- rubbing your hands
- making random noises
- moving your arms around
- picking at clothes
- fiddling with objects
- adopting an unusual posture
- chewing or swallowing
During a complex partial seizure, you will not be able to respond to anyone else, and you will have no memory of the event.
There are six main types of generalized seizure.
Absence seizures, which used to be called petit mal, mainly affect children, but they also occur in adults. They cause the person to lose awareness of their surroundings, usually for up to 15 seconds. The person will seem to stare vacantly into space, although some people will flutter their eyes or smack their lips. The person will have no memory of the seizure.
Absences can occur several times a day. They may affect a child’s performance at school, and can be dangerous if they occur at a critical time, such as crossing a busy road.
These types of seizures cause your arms, legs or upper body to jerk or twitch, as if you have received an electric shock. They often only last for a fraction of a second, and you will normally remain conscious during this time.
Myoclonic jerks often happen in the first few hours after waking up and can occur in combination with other types of generalized seizures.
These cause the same sort of twitching as myoclonic jerks, except the symptoms will last longer, normally up to two minutes. Loss of consciousness may also occur.
Atonic seizures cause all your muscles to suddenly relax, so there is a chance you may fall to the ground and there is a risk you could injure yourself.
Tonic seizures cause all your muscles to suddenly become stiff, which can mean you lose balance and fall over. Like atonic seizures, there is a risk of injury.
Tonic-clonic seizures or convulsions, which used to be known as grand mal, have two stages. Your body will initially become stiff and then your arms and legs will begin twitching. You will lose consciousness and some people will wet themselves. The seizure normally lasts a few minutes, but can last longer.
This type of seizure is what most people think of as an epileptic fit.
TYPES OF EPILEPSY
Epilepsy is the occurrence of sporadic electrical storms in the brain. These storms cause behavioural manifestations (such as staring) and/or involuntary movements (such as grand mal seizures).
There are several types of epilepsy, each with different causes, symptoms, and treatments.
When making a diagnosis of epilepsy, your doctor may use one of the following terms: idiopathic, cryptogenic, symptomatic, generalised, focal or partial.
- Idiopathic: no apparent cause can be found.
- Cryptogenic: no damage to the brain has been identified but other factors suggest the brain has been damaged.
- Symptomatic: symptoms are due to identified brain damage or disruption of brain function.
- Generalised: the seizures involve the whole brain at once.
Focal or partial: the electrical storm starts from one area of the brain. One type of partial seizure is called Jacksonian epilepsy.
Type 1: Idiopathic generalised epilepsy
In idiopathic generalised epilepsy there is often, but not always, a family history of epilepsy. Idiopathic generalised epilepsy tends to appear during childhood or adolescence, although it may not be diagnosed until adulthood. In this type of epilepsy, no nervous system (brain or spinal cord) abnormalities other than the seizures have so far been identified. The brain is structurally normal on magnetic resonance imaging (MRI) of the brain.
People with idiopathic generalised epilepsy have normal intelligence and the results of the neurological examination and MRI are usually normal. The results of the electroencephalogram (EEG – a test that measures electrical impulses in the brain) may show epileptic discharges affecting the entire brain (so called generalised discharges).
The types of seizures affecting patients with idiopathic generalised epilepsy may include:
- Myoclonic seizures (sudden and very short duration jerking of the extremities)
- Absence seizures (staring spells – also known as petit mal)
- Generalised tonic-clonic seizures (grand mal seizures)
Idiopathic generalised epilepsy is usually treated with various medications. Some forms of this condition may be outgrown, as is the case with childhood absence epilepsy and a large number of patients with juvenile myoclonic epilepsy.
Type 2: Idiopathic partial epilepsies
Idiopathic partial epilepsy begins in childhood (between ages five and eight) and there may be a family history. Also known as benign focal epilepsy of childhood (BFEC), this is considered one of the mildest types of epilepsy. It is almost always outgrown by puberty and is never diagnosed in adults.
Seizures tend to occur during sleep and are most often simple partial motor seizures that involve the face, and secondarily generalised (grand mal) seizures. The results of the EEG are typically diagnostic, as patients with BFEC exhibit very specific EEG brain wave patterns.
TYPE 3: SYMPTOMATIC GENERALISED EPILEPSY
Symptomatic generalised epilepsy is caused by widespread brain damage. Injury during birth is the most common cause of symptomatic generalised epilepsy. In addition to seizures, these patients often have other neurological problems, such as developmental problems or cerebral palsy. Specific inherited brain diseases, such as adrenoleukodystrophy (ADL, which was featured in the film Lorenzo’s Oil) or brain infections (such as meningitis and encephalitis) can also cause symptomatic generalised epilepsy. When the cause of symptomatic general epilepsy cannot be identified, the disorder may be referred to as cryptogenic epilepsy. These forms of epilepsy include different subtypes – the most commonly known type is the Lennox Gastaut syndrome.
Multiple types of seizures (generalised tonic-clonic, tonic, myoclonic, atonic and absence seizures) are common in these patients and can be difficult to control.
Type 4: Symptomatic partial epilepsy
Symptomatic partial (or focal) epilepsy is the most common type of epilepsy that begins in adulthood, but it does occur frequently in children. This type of epilepsy is caused by a localised abnormality of the brain, which can result from strokes, tumours, trauma, a congenital brain abnormality (one present at birth), scarring (or “sclerosis” of brain tissue), cysts or infections.
Sometimes these brain abnormalities can be seen on MRI scans, but often they cannot be identified, despite repeated attempts, because they are microscopic.
This type of epilepsy may be successfully treated with surgery that removes the abnormal brain area without compromising the function of the rest of the brain. Epilepsy surgery is very successful in a large number of epilepsy patients who have failed to respond to multiple anticonvulsant medications (at least two or three medications) and who have identifiable lesions. These patients undergo a pre-surgical comprehensive epilepsy evaluation in dedicated and specialised epilepsy centres.
By Medifit Education.