Why seizures

They can be caused by any type of focal injury that leaves scar tangles. Medical history or MRI will identify a cause such as trauma , stroke or meningitis in about half of the people who have focal seizures. Developmental scars — ones that occur as part of fetal and early growth of the brain — are common causes of focal seizures in children. Focal seizures can start in one part of the brain and spread to other areas, causing symptoms that are mild or severe, depending on how much of the brain becomes involved.

At first, the person may notice minor symptoms, which is referred to as an aura. The person may have altered feelings or sense that something is about to happen premonition. Some people experiencing an aura describe a rising sensation in the stomach similar to riding on a roller coaster. As the seizure spreads across the brain, more symptoms appear. If the abnormal electrical activity involves a large area of the brain, the person may feel confused or dazed, or experience minor shaking, muscle stiffening, or fumbling or chewing motions.

Focal seizures that cause altered awareness are called focal unaware seizures or complex partial seizures. The electrical activity of the seizure can remain in one sensory or motor area of the brain, resulting in a focal aware seizure also called simple partial seizure.

The person is aware of what is happening, and may notice unusual sensations and movements. Focal seizures can evolve into major events that spread to the entire brain and cause tonic-clonic seizures. These seizures are important to treat and prevent since they can cause respiratory problems and injuries. Generalized-onset seizures are surges of abnormal nerve discharges throughout the cortex of the brain more or less at the same time.

Generalized seizures may have a genetic component, but only a small number of people with generalized seizures have family members with the same condition. There is a slight increase in risk for generalized seizures in the children or other family members of an affected person with generalized seizures, but the severity of the seizures can vary from person to person.

Genetic testing may reveal a cause for generalized seizures. Sleep deprivation or drinking large amounts of alcohol can increase the excitatory response and increase the risk of generalized-onset seizures, especially in people with a genetic tendency to have them.

There is no danger they will swallow their tongue. When the seizure stops, put them on their side in the recovery position. If they have vomited or have food or fluid in their mouth put them in the recovery position immediately. If possible, someone should go home with them. Seizures can cause changes in movement, sensation, awareness, thought or behaviour, depending on which part of the brain the seizure affects.

Some seizures involve only part of the brain — others involve the whole brain. An aura may involve odd smells, feelings of deja-vu where you feel you have been here before , tingling, vision disturbances, or fear or joy.

This aura is actually the first part of a seizure. During the seizure, the symptoms experienced depend on the type of seizure. A person may be alert during the seizure, and able to remember it afterwards, or may not remember it at all.

Most seizures last for less than 2 or 3 minutes and will stop on their own, without any treatment. Febrile seizures in children may last for a few minutes or even go on for an hour, with the child usually losing consciousness. They may appear red or blue in the face and their muscles may jerk or stiffen. These seizures are not harmful to the child. After a seizure has ended, there is a recovery phase known as the post-ictal phase before a person returns to their normal state.

During this phase a person may be confused , tired or exhausted, sore or thirsty. They may feel weak, sick or anxious, be injured, have lost control of their bladder or bowel, or have a headache. Seizures are classified depending on which part of the brain the seizure starts in, whether a person is aware during the seizure or not, and whether there is movement.

Focal onset seizures start in one small region of the brain the focus and may spread to other brain areas. They used to be known as partial seizures. Generalised onset seizures affect both sides of the brain from the start. This may cause a person to lose consciousness. The seizures may be:. This may be because a person was asleep or alone when the seizure started.

Febrile seizures also known as febrile convulsions are seizures brought on by fever in young children. They do not cause any long-lasting effects. For some people who have seizures, there will be some things that are likely to trigger a seizure.

Common seizure triggers include:. See a doctor if you or your child has a seizure for the first time, if there are several seizures, or if the seizures happen more often than usual. People diagnosed with epilepsy will normally need medication to control their seizures.

These medications are called antiepileptic drugs, and for up to 70 per cent of people their seizures will be controlled with this medication.

Do not stop taking the medication suddenly, as this may itself cause seizures. For children whose seizures do not respond to medication, a special diet called the ketogenic diet may help with some types of seizures. Your doctor or specialist will be able to advise whether this is suitable for your child.

Surgery to remove the brain tissue that is the focus of seizures may be considered for seizures that are resistant to other treatments, and that always happen in the same location of the brain. Vagus nerve stimulation involves implanting a device like a pacemaker into the chest. The device sends out weak electrical signals to the brain via the vagus nerve.

You may need blood tests often to check the level of medicine in your body. Based on this level, your healthcare provider may change the dose of your medicine. You may also have blood tests to check the effects of the medicine on your other organs.

Urine tests. Your urine may be tested to see how your body is reacting to the medicine. Electroencephalogram EEG. An EEG is a procedure that records the brain's electrical activity. This is done by attaching electrodes to your scalp. This test is done to see how medicine is helping the electrical problems in your brain.

This treatment sends small pulses of energy to the brain from one of the vagus nerves. This is a pair of large nerves in the neck. If you have partial seizures that are not controlled well with medicine, VNS may be an option. VNS is done by surgically placing a small battery into the chest wall. Small wires are then attached to the battery and placed under the skin and around one of the vagus nerves.

The battery is then programmed to send energy impulses every few minutes to the brain. When you feel a seizure coming on, you may activate the impulses by holding a small magnet over the battery. In many cases, this will help to stop the seizure.

VNS can have side effects such as hoarse voice, pain in the throat, or change in voice. Surgery may be done to remove the part of the brain where the seizures are occurring. Or the surgery helps to stop the spread of the bad electrical currents through the brain.

Surgery for epilepsy seizures is very complex. It is done by a specialized surgical team. You may be awake during the surgery. The brain itself does not feel pain. If you are awake and able to follow commands, the surgeons are better able to check areas of your brain during the procedure. Surgery is not an option for everyone with seizures. A seizure occurs when one or more parts of the brain has a burst of abnormal electrical signals that interrupt normal signals. There are many types of seizures.

Each can cause different kinds of symptoms. These range from slight body movements to loss of consciousness and convulsions. Health Home Conditions and Diseases Epilepsy. Focal partial seizures Focal seizures take place when abnormal electrical brain function occurs in one or more areas of one side of the brain. The 2 types of focal seizures include: Simple focal seizure The symptoms depend on which area of the brain is affected.

Complex focal seizure This type of seizure often occurs in the area of the brain that controls emotion and memory function temporal lobe. Generalized seizure A generalized seizure occurs in both sides of the brain. Types of generalized seizures include: Absence seizure This is also called petit mal seizure. Atonic seizure This is also called a drop attack. Generalized tonic-clonic seizure GTC This is also called grand mal seizure.

Myoclonic seizure This type of seizure causes quick movements or sudden jerking of a group of muscles. What causes a seizure? A seizure can be caused by many things. These can include: An imbalance of nerve-signaling brain chemicals neurotransmitters Brain tumor Stroke Brain damage from illness or injury Epilepsy may be caused by a combination of these. What are the symptoms of a seizure?

General symptoms or warning signs of a seizure can include: Staring Jerking movements of the arms and legs Stiffening of the body Loss of consciousness Breathing problems or stopping breathing Loss of bowel or bladder control Falling suddenly for no apparent reason, especially when associated with loss of consciousness Not responding to noise or words for brief periods Appearing confused or in a haze Nodding your head rhythmically, when associated with loss of awareness or loss of consciousness Periods of rapid eye blinking and staring During the seizure, your lips may become tinted blue and your breathing may not be normal.