Types of Epileptic Seizures
Epilepsy, An Electrical Storm in the Brain
Epilepsy in Europe,The Facts and Figures
Babylonian Tablet on Epilepsy
The word 'epilepsy' comes from the Greek verb meaning “to seize, possess, or afflict.” The ancient Greeks had contradictory ideas about epilepsy, although they viewed the disorder as evil, they also associated it with sacred and genius.
Epilepsy is a disease of the brain that causes seizures.
A seizure is a disruption of the electrical communication between neurons (nerve cells).
A person is considered to have epilepsy if they meet any of the following conditions.
1. At lease two unprovoked (or reflex) seizures occurring greater than 24 hours apart.
2. 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 ten years.
Epileptic seizures occur as a result of abnormal changes in the electrical activity of the brain. These disturbances are likened to an 'electrical storm.' Neurons fire electrical impulses to neighboring cells stimulating them to fire. In people with epilepsy, too many neurons fire at once, resulting in seizures that can have neurobiological, cognitive, psychological and social consequences.
Epilepsy is an ancient disorder that can be traced as far back as the existence of the first medical records. The condition is equally distributed in Europe and the US, with no racial, social or gender boundaries. However, nearly 80% of people with the disease are found in developing countries.
The dramatic nature of epileptic seizures has often been the cause of much fear and misunderstanding throughout the ages, leading to the social stigma that can add to the burden of the disease for those affected.
In ancient times, epileptic seizures were believed to be the result of divine visitation, possession of the body by evil spirits or other supernatural forces, requiring exorcism and incantations.
We now know that epileptic seizures occur as a result of abnormal electrical activity in the brain of people who are predisposed to the disorder. The earliest detailed account of epilepsy is in the British Museum on a Babylonian tablet written around 2000 to 3000 years ago.
The chapter from the textbook on medicine consists of a collection of 40 cuneiform or tablets that describe various diseases and is known as Sakkiku, translated as “All Diseases.
Archeologists discovered two copies of an edited version of the Sakkiku, dated from the seventh century BCE, the twenty-fifth tablet of the Babylonian text, refers to the manifestations of miqtu, Babylonian for “ the falling disease.” However; since the Babylonians apparently had no real understanding or concept of pathology, each seizure type was associated with invasion of the body by a particular named evil spirit, therefore; treatment of the condition tended to be spiritual rather than medical. The idea that epilepsy was caused by supernatural means, continued well into modern times, and still retain a somewhat negative social influence in some parts of the world today.
When a seizure occurs in someone with epilepsy, there is a temporary loss of control that is often, but not always, accompanied by convulsions, unconsciousness or both. The sudden abnormal electrical discharges in the brain cause an alteration in sensation, behavior or consciousness.
The term 'seizure' is often used interchangeably with convulsions; this is when the body shakes rapidly and uncontrollably. During an episode of seizure, the muscles contract and relax rapidly. There are different types of seizures; some may have mild symptoms with no shaking of the body. The primary symptoms of epilepsy are repeated seizures. There are over 40 different types of seizures, depending on the area of the brain affected and the person's age.
Although the majority of people with epilepsy can experience a variety of seizures, most follow a consistent pattern of symptoms known as an epileptic syndrome. Seizures are medically classified by how much of the brain is affected.
What are the Causes and Triggers of Epileptic Seizures
Seizures can be triggered by a number of factors.
Some Common Triggers are:
Infection of the central nervous system
Bright, flickering or flashing light such as camera flash
The European Parliament's Written declaration on epilepsy states that 6 million people in Europe have epilepsy with 300,000 new cases diagnosed each year.
In the UK, approximately 20% of the population have seizures at some point in their life, diagnosis is usually made during childhood and the age of 65, with the highest incidence occurring between the ages of 20 – 60.
National statistics shows that 1 in 130 of the UK's population develops epilepsy, including 1 in every 280 children under the age of 16.
The average incidence of epilepsy per year in the U.S is estimated at 150,000. 30% of those diagnosed are children. Almost 500 new cases of epilepsy are diagnosed daily. Around 50,000 Americans die each year from seizures and related causes. One in 10 people will suffer a seizure in their lifetime, yet many people are unaware of this disease.
What causes Epilepsy
The cause of epilepsy is unknown. There is genetic involvement in some cases, and certain events are known to contribute to the development of the disorder.
Around 5% to 10% of all people will have an unprovoked seizure by the age of 80. Some people develop epilepsy as a result of head injury or medical conditions such as stroke, brain cancer and drug and alcohol misuse. The chances of experiencing a second seizure are said to be between 40% to 50%, in 60% of cases the cause of epileptic seizures are unknown.
Evidence of contributing factors for the development of epilepsy include:
Living in areas of high social deprivation
Prenatal development abnormality
Damage to the brain following an accident resulting in scarring of the brain
People born with a neurological condition that may later develop into epilepsy. 30% of people with learning disabilities suffer from epilepsy, 50% to 80% of people with cerebral Palsy suffer from epilepsy. Autism, 30% incidence and 50% with severe learning disability.
Risk Factors include:
Tumours, the risk is greatest for tumours in the temporal lobe and those that grows slowly
Head Injury results in between 6% to 20% of epilepsy cases, people who have experience a high-powered gunshot wound to the head, the risk is about 50%
Herpes Simplex Encephalitis, the risk of seizures occurring, is about 50%, with a high risk of 25% following the condition
Meningitis, following meningitis, the likelihood of epilepsy is less than 10%, but are more common during the infection
Prolonged drug and alcohol abuse
Stroke account for 15% of cases in the UK
- Subarachnoid haemorrhage
- Abnormality in brain development during childhood
The condition can often be confirmed by the use of neuroimaging evaluation (e.g., MRI, CT scanning) and electroencephalogram (EEG). However; before epilepsy can be diagnosed, other possible causes of the symptoms such as 'syncope' ( a temporary loss of consciousness caused by low blood pressure) must first be ruled out. Epilepsy cannot be cured. However, seizures can be controlled in about 70% of cases. In those people whose condition do not respond to medication, surgery or neurostimulation, a change in diet may be beneficial. Research shows that Ketogenic diet, a high fat, low carbohydrate diet can help to control epileptic seizures,
For some people, epilepsy is a lifelong condition, but for a substantial number, the symptoms will improve to a point where medication is no longer necessary.
Ketogenic Diet Shown to be Beneficial In Controlling Epileptic Seizures
Diet to Help Control Epileptic Seizures
Some quick Facts About Epilepsy
- Epilepsy is a neurological condition, meaning, it affects the brain, but it is also a physical condition because of the impact on the body as a result of seizures
- Epilepsy is defined as the tendency to have repeated seizures that originate in the brain. It is only diagnosed after a person has had more than one seizures.
- The first person who believed that epilepsy starts in the brain was the Greek philosopher Hippocrates (460-377 BC)
- The 19th-century Russian author, Dostoyevsky, is thought to have had a rare form of temporal lobe epilepsy ( Ecstatic Epilepsy) and gave a vivid account of the condition in his novel 'the idiot.'
- Given the right circumstances, anyone can have a seizure, but most people do not have seizures normally
- Seizures occur when there is a sudden interruption in the way the brain works
- There are over 40 different types of seizures, the symptoms vary depends on the particular area of the brain affected
- Symptoms of epileptic seizures can be as subtle as someone going 'blank' for a couple of seconds, they may wander about displaying confusion, or it can be as dramatic as someone falling to the ground and shake with convulsion. Not all seizures involve convulsion
- It is not possible to swallow the tongue during a seizure
- Never attempt to force anything into the mouth of someone having a seizure
- Never restrain someone having a seizure
- Epilepsy affects 50,000,000 people throughout the world
- One in 100 people will develop epilepsy
- One in 10 people will experience a seizure in their lifetime
- Epilepsy can develop as a result of genetics, stroke, head injury, infections and many other factors
- The cause of epilepsy is unknown in two-thirds of patients diagnosed with the disorder
- Uncontrolled seizures can lead to brain damage and death
- Seizures cannot be controlled with treatment in about 30% of patients
- Epilepsy affects more than 3 million Americans of all ages, more than Multiple Sclerosis, Cerebral Palsy, Muscular Dystrophy and Parkinson's Disease added together
- More people die from epilepsy than from breast cancer
- Epilepsy will be a long-term problem for many soldiers who have sustained traumatic brain injury on the battlefield
- Historically, epilepsy research has been under-funded. Funding for epilepsy lags behind average financing for all diseases by almost 50%
Types of Seizures
What is a Partial seizure
Partial seizures are not easy to recognise by the general public and are easily confused with other conditions. In a partial seizure, the burst of electrical activity is localised to a single part of the brain. The symptoms are focal; they originate from the specific area that is affected. There are many types of seizures, but they are broadly divided into two main types, namely, generalised seizures and partial seizures.
Most people tend to associate epilepsy with generalised seizures, or convulsions, but some people also develop partial seizures that can be simple or complex.
Simple partial seizures
Simple partial seizures are often divided into groups or categories according to the symptoms experienced, such as:
- Motor seizures
- Sensory seizures
- Autonomic Seizures
- Psychic seizures
While anyone can experience simple partial seizures, the condition is more likely to develop in people who have had a brain injury, stroke, brain tumour or brain infection but often, the cause is unknown.
These types of seizures are brief; they may last for less than 2 minutes. The person experiencing a simple partial seizure are fully awake, they remain alert and are capable of interacting throughout the seizure. However; simple partial seizures can affect emotion, movement, sensation and feelings in unusual and often frightening ways:
- Emotions. A sudden feeling of fear or a sense of doom, (something bad is about to happen) may be the result of a seizure affecting the area of the brain that deals with emotions.
- Movement. Convulsions can be experienced in most parts of the body. There can be twitching of the face, unusual movement of the tongue, eyes may move from side to side.
- Sensations. Since the different areas of the brain controls all five senses, simple partial seizures in those areas can cause sensations such as, the feeling of the breeze on the skin, unusual buzzing, hissing or ringing voices that are not there in reality, unpleasant taste, odd unpleasant smells and general distortions in how things appears.
When the area of the brain that is responsible for memory is affected, this can result in disturbing visions from the past. During this type of seizure, sudden nausea, a strange rising feeling in the stomach, sudden sweating, flushing and goosebumps are sometimes experienced.
There are reports of out of body experiences and distortion of time during a simple partial seizure. Well known places may suddenly look unfamiliar and conversely, new places and events may seem familiar, as though they have been experienced before (deja vu). Simple partial seizures can also evoke sudden and uncontrolled episodes of laughter or crying.
Complex Partial Seizures or (Temporal Lobe Epilepsy)
In complex partial seizures, a larger part of the brain is involved, and consciousness is affected. Those affected are not in control of their movements, action or speech, they are unable to interact appropriately, unaware of what is occurring and cannot remember after the event.
Although an affected person may appear to be conscious, and able to move about, it is an altered state of consciousness, almost trance-like. Seizures often develop in one of the brain's temporal lobes and are referred to as temporal lobe epilepsy, also known as psychomotor epilepsy. There are two types of temporal lobe epilepsy:
- Medial temporal lobe epilepsy involves the medial or internal structures of the temporal lobe and most common of the two, accounting for 80% of all temporal lobe seizures that begins in the part of the brain known as the hippocampus or its surrounding areas.
- Neocortical temporal lobe epilepsy occurs in the outer portion of the temporal lobe, and differs from the other types of epilepsy; this is because there is often no clearly defined area from which the seizure originates. The cause can include, lesions like tumours and vascular malformation, traumatic brain injuries or infections.
What are Generalised seizures
A person experiencing generalised seizures will be completely unconscious in most cases. There are six main types of generalised seizures:
- Absences, once known a petit mal and most often seen in children. The affected person becomes unaware of their surroundings for a few seconds; they appear to be staring vacantly into space or daydreaming. Some children may flutter their eyes or smack their lips, but have no memory of the seizure. This type of seizure can happen several times a day, and while not considered dangerous, it can impact on the child's performance at school.
- Myoclonic jerks, Appears similar to someone receiving an electrical shock, it causes the arms, legs or upper body to jerk and twitch, lasting only for a fraction of a second and consciousness is maintained. Myoclonic jerks often occur in conjunction with other types of generalised seizures.
- Clonic Seizures, loss of consciousness may occur, symptoms last longer, often up to 2 minutes.
- Atonic Seizures causes all the muscles in the body to relax suddenly. Chances are, the affected person may collapse to the ground, facial injuries are often sustained during this type of seizures.
- Tonic Seizures, here, the reverse to atonic seizure happens, tonic seizure causes all the muscles to become suddenly stiff. Injury to the back of the head is often sustained due to falls from a lack of balance.
- Tonic-clonic Seizures, also known as grand mal, this is the most common type of seizure occurring in 60% of all seizures due to epilepsy and is what most people think of as an epileptic seizure or fit. Tonic-clonic seizures occur in two stages. The body becomes stiff, the arms and legs start to twitch. Consciousness is loss and in some cases, there is incontinence of the bladder or bowel. Seizures often last around one to three minutes or longer.
What are Auras, Auras are basically the same as simple partial seizures, Auras describe the symptoms that may develop before a seizure, "a warning" that may include:
- Visual changes such as bright lights, zigzag lines, slowly spreading spots, distortion in the size or shape of objects, blind spot or dark spots in the field of vision.
- Auditory hallucinations (hearing voices or sounds)
- Olfactory hallucinations ( strange smells)
- Feelings of numbness on one side of the face or body
- Feeling separated from the body
Status Epilepticus (SE) is defined as a life-threatening condition in which the brain is in a state of persistent seizure. SE is defined as one continuous, unremitting seizure lasting longer than five minutes. The previous definition states a 30 minutes time limit, but treatment usually begins after the seizure has lasted around 5 minutes. There is evidence that after five minutes, seizures are unlikely to self-terminate. Five minutes is said to be sufficient time in which the neurons or brain cells can be damaged. SE is always considered to be a medical emergency.