الثلاثاء، 21 أغسطس، 2012

Epilepsy




 causes epilepsy

Epilepsy is caused by abnormal electric impulses in groups of nerve cells (neurons) found in the brain. For diagnostic purposes, epilepsy is divided into three main groups

Idiopathic epilepsy

Getty - epilepsy
Electroencephalography (EEG) can show where in the brain the convulsions start.
Idiopathic comes from the Greek words idios – which means self, own and personal
In cases of this type, the cause is unknown. However, it is believed that attacks are caused by the lack of a particular group of chemical substances (the neurotransmitters) used to regulate the electric impulses in the brain.
  • There may be an hereditary (genetic) background, since epilepsy of the same type is often seen among relatives. Moreover, EEG irregularities similar to those of the patient are often seen among family members, even if they do not suffer from epilepsy – a kind of genetic mark. New research has shown that certain cases of idiopathic epilepsy are clearly hereditary, caused by chromosomal abnormality.
  • The patient has no other signs of neurological illness or mental defects. CT and MRI scans are normal.

Symptomatic epilepsy

Epilepsy of this type is caused by a known illness in the brain.

Cryptogenic epilepsy

This is usually related to patients who have no obvious cause, as above, for their epilepsy and is associated with learning difficulties or developmental problems, such as the autistic spectrum disorder. There are often EEG abnormalities

Epilepsy triggers

Numerous illnesses or types of brain damage can cause epilepsy. The following are the most common.

Developmental anomalies

Damage occurring to the brain as it develops during the first three months of pregnancy.
This can be revealed by modern MRI scans and causes many of the difficult-to-control cases in children.
On the other hand, damage inflicted during delivery (cerebral palsy) is fairly uncommon.

Trauma to the skull

Unlike ordinary concussion, trauma or accidental injury can be so serious that the patient is admitted to a neuro-surgical ward.
The possibility of epilepsy following trauma varies from 5 to 50 per cent, with the highest risk following a depressed skull fracture where the brain tissue has been partly damaged or a gunshot wound to the head.

Blood clots (infarcts) and haemorrhages in the brain

About 10 per cent of all brain infarcts cause epilepsy.

Problems at birth

Epilepsy can result die to the baby suffering from lack of oxygen to the brain during delivery, such as the umbilical cord getting pressed on or being twisted.

Brain tumours

Especially slow-growing superficial tumours. Since these can be surgically removed, it is important to check for these if a patient develops epilepsy, especially if the attacks start in a limited part of the brain (focal attacks – consult the article on the types of attacks).
The most important techniques are CT scans and MRI scans.

Encephalitis

Prolonged seizures and fever convulsions could induce brain damage.

Alcohol abuse

May cause epilepsy as a result of the cramps associated with delirium tremens.







These are epilepsies with a clearly defined focal area within the brain. As a result, they have highly characteristic symptoms, such as visual hallucinations, or motor difficulties on one side of the body.
  • Benign occipital epilepsy (Benign focal epilepsy with occipital paroxysms)
  • Benign rolandic epilepsy (Benign focal epilepsy with centrotemporal spikes)
  • Frontal lobe epilepsy
  • Occipital lobe epilepsy
  • Mesial temporal lobe epilepsy
  • Parietal lobe epilepsy
Generalised epilepsies are those which have no defined focal area within the brain; as a result they have generalised symptoms as the whole brain becomes affected. Idiopathic is a medical term meaning that there is no clear environmental cause for the epilepsy and it is presumed that genetic factors predominate. There are usually no other handicaps and the EEG is often normal between fits. The response to drug treatment is usually good.
  • Benign myoclonic epilepsy in infants
  • Juvenile myoclonic epilepsy
  • Childhood absence epilepsy
  • Juvenile absence epilepsy
  • Epilepsy with generalised tonic clonic seizures in childhood
Generalised epilepsies are those which have no defined focal area within the brain; as a result they have generalised symptoms as the whole brain becomes affected. Symptomatic is a medical term meaning that there is some structural abnormality in the brain, either present at birth or occurring later in life. Other disabilities may be caused by this same abnormality (physical, intellectual or psychiatric). EEG investigations may reveal the abnormality and the response to drug treatment is variable in different individuals. (Some individuals have cryptogenic epilepsy, which is epilepsy in which no cause can be found, even though a cause is suspected.)
  • Infantile spasms (West syndrome)
  • Lennox-Gastaut syndrome
  • Progressive myoclonus epilepsies
This, of course, is the grouping for epilepsies which do not fit the classification schema.
  • Febrile fits
  • Epilepsy with continuous spike and waves in slow wave sleep (ESES)
  • Landau Kleffner syndrome
  • Rasmussen's syndrome
  • Epilepsy and inborn errors in metabolism
symptoms of epilepsy

Epilepsy is characterized by recurrent, disorganized, abnormal electrical firing in brain cells, which can disrupt normal functioning of the brain. This disruption can cause recurrent seizures, which is the main symptom of epilepsy. While these seizures are usually caused by abnormal electrical activity in the brain, they can manifest very differently from person to person. For instance, one type of seizure may cause a brief loss of consciousness, whereas another seizure type may cause uncontrollable jerking of the entire body.
Knowing the characteristic of your seizures is important because this will help your healthcare provider select the most appropriate treatment to manage your seizures. Most people suffering from epilepsy do not remember their seizures, or what was happening to them before their seizure occurred. In this case, it is important to involve family and friends to give an account of how your seizures presented and any other information related to it.
These are the most common symptoms experienced either before, or during, a seizure. Your symptoms will depend upon the type of seizures you are having, so you might not experience all of these symptoms:

Weakness

Weakness can occur in any seizure type and in any area of the body. For instance, weakness can either occur in an arm, a leg or both.

Anxiety

Anxiety is usually experienced in most seizure types and can signal a seizure is about to occur. In some types of seizures, anxiety, or an impending sense of doom, can be an aura, or a consistent symptom in a person right before they have a seizure.

Staring

Staring out into space is a symptom experienced by individuals who have absence seizures. Usually, these individuals appear to be briefly daydreaming when, in fact, they are actually experiencing a seizure. This usually only lasts for a few seconds and may be accompanied by blinking or repetitive movements, such as movement of the mouth or fingers.

Purposeless or Repetitive Movements

This can include actions such as picking lint off of a shirt, repetitive shifting, repetitive tapping of the fingers, repetitive chewing or repeating words. These movements can occur before a seizure occurs or during some seizures.

Loss of Consciousness

Some seizures may cause a loss of consciousness, which may last for a few seconds to hours.

Contraction, or Jerking, of Body Muscles

Usually when you think of seizures, the characteristic thought is that of every muscle contracting in the body. This is referred to as a grand mal seizure. However, involuntary muscle contractions can also occur in isolated areas of the body. For instance, muscle contractions in an arm may cause an object to crash to the ground. Muscle contractions in the legs may cause someone to drop to the ground, causing further injuries.

Epilepsy - Treatment Overview

Treatment can reduce or prevent seizures in most people who have epilepsy. This can improve quality of life. Controlling your epilepsy also lowers the risk of falling and other complications that can happen when you have a seizure.
First your doctor will figure out what type of epilepsy and what kinds of seizures you have. Treatment that controls one kind of seizure may have no effect on other kinds. Your doctor will also think about your age, health, and lifestyle when he or she plans your treatment.
It may take time for you and your doctor to find the right combination, schedule, and dosage of medicines to manage your epilepsy. The goal is to prevent seizures while causing as few side effects as possible. With the help of your doctor, you can weigh the benefits of a particular treatment against its drawbacks, including side effects, health risks, and cost.
After you and your doctor figure out the treatment that works best for you, make sure to follow your treatment exactly as prescribed.

Initial treatment

Initial treatment for epilepsy depends on the severity, frequency, and type of seizures and whether a cause for your condition has been identified. Medicine is the first and most common approach. Antiepileptic medicines do not cure epilepsy. But they help prevent seizures in well over half of the people who take them. For information about medicines for epilepsy, see Medications.
See information on:
Epilepsy: Taking Your Medicines Properly.
It is not always clear whether to begin treatment after a first seizure. It is hard to predict whether you will have more seizures. Antiepileptic medicines are not usually prescribed unless you have risk factors for having another seizure, such as brain injury, abnormal test results, or a family history of epilepsy.

Ongoing treatment

If epileptic seizures continue even though you are being treated, additional or other antiepileptic medicines may be tried.
In addition to medicines, other treatments may be added to help reduce the frequency and severity of epileptic seizures, including:
  • Ketogenic diet, which is a high-fat diet that has been used with some success to treat people, especially children, who have severe, uncontrolled seizures. Some doctors may not support its use.
  • Vagus nerve stimulation. The stimulator device is used with medicine or surgery.
  • Brain surgery. Some people with epileptic seizures do not respond to medicine but have great success with surgery.
Surgery is not used just as a last resort to treat epilepsy. Although brain surgery may sound frightening, it can successfully reduce seizures that are harmful, severe, frequent, or do not respond to medicines. Surgery can greatly improve the lives of some carefully screened people who have epilepsy. If you would like to know if surgery is a good choice for you, talk with your doctor.



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