Epilepsy is a disorder of the brain. People who have epilepsy have electrical activity in the brain that is not normal, causing seizures. There are different types of seizures. In some cases, a seizure may cause jerking, uncontrolled movements, and loss of consciousness.
In other cases, seizures cause only a period of confusion, a staring spell or muscle spasms. Epilepsy is also called a “seizure disorder”.
Epilepsy is not a mental illness, and it is not a sign of low intelligence. It is also not contagious. Seizures do not normally cause brain damage.
Between seizures, a person with epilepsy is no different from anyone else.
Because epilepsy is caused by abnormal activity in the brain, seizures can affect any process your brain coordinates.
Symptoms vary depending on the type of seizure. In most cases, a person with epilepsy will tend to have the same type of seizure each time, so the symptoms will be similar from episode to episode.
Doctors generally classify seizures as either focal or generalized, based on how the abnormal brain activity begins.
When seizures appear to result from abnormal activity in just one area of your brain, they’re called focal (partial) seizures. These seizures fall into two categories:
• Focal seizures without loss of consciousness. Once called simple partial seizures, these seizures don’t cause a loss of consciousness. They may alter emotions or change the way things look, smell, feel, taste or sound. They may also result in involuntary jerking of a body part, such as an arm or leg, and spontaneous sensory symptoms such as tingling, dizziness and flashing lights.
• Focal seizures with impaired awareness. Once called complex partial seizures, these seizures involve a change or loss of consciousness or awareness. During a complex partial seizure, you may stare into space and not respond normally to your environment or perform repetitive movements, such as hand rubbing, chewing, swallowing or walking in circles.
Symptoms of focal seizures may be confused with other neurological disorders, such as migraine, narcolepsy or mental illness. A thorough examination and testing are needed to distinguish epilepsy from other disorders.
Seizures that appear to involve all areas of the brain are called generalized seizures.
• Absence seizures. Absence seizures, previously known as petit mal seizures, often occur in children and are characterized by staring into space or subtle body movements such as eye blinking or lip smacking. These seizures may occur in clusters and cause a brief loss of awareness.
• Tonic seizures. Tonic seizures cause stiffening of your muscles. These seizures usually affect muscles in your back, arms and legs and may cause you to fall to the ground.
• Atonic seizures. Atonic seizures, also known as drop seizures, cause a loss of muscle control, which may cause you to suddenly collapse or fall down.
• Tonic-clonic seizures. Tonic-clonic seizures, previously known as grand mal seizures, are the most dramatic type of epileptic seizure and can cause an abrupt loss of consciousness, body stiffening and shaking, and sometimes loss of bladder control or biting your tongue.
Call your doctor if:
• You have a seizure that lasts longer than 5 minutes.
• You injured yourself during the seizure.
• The way you usually feel during and after having a seizure changes.
• It takes you longer than normal to recover after having a seizure.
• Your seizures become more severe or happen more frequently.
• A second seizure immediately occurs after the first.
• You are pregnant.
If you experience a seizure for the first time, seek medical advice.
Epilepsy has no identifiable cause in about half the people with the condition. In the other half, the condition may be traced to various factors, including:
•Genetics: People with a parent or sibling who has epilepsy are at an increased risk for developing epilepsy.
Researchers have linked some types of epilepsy to specific genes, but for most people, genes are only part of the cause of epilepsy. Certain genes may make a person more sensitive to environmental conditions that trigger seizures.
• Head trauma. Serious head injuries can cause epilepsy, sometimes years after the injury
• Brain conditions. Brain conditions that cause damage to the brain, such as brain tumors or strokes, can cause epilepsy. Stroke is a leading cause of epilepsy in adults older than age 35.
• Infectious diseases. Infectious diseases, such as meningitis, AIDS and viral encephalitis, can cause epilepsy.
• Prenatal injury. Before birth, babies are sensitive to brain damage that could be caused by several factors, such as an infection in the mother, poor nutrition or oxygen deficiencies. This brain damage can result in epilepsy or cerebral palsy.
• Developmental disorders. Epilepsy can sometimes be associated with developmental disorders, such as autism and neurofibromatosis.
How is epilepsy diagnosed?
To diagnose epilepsy, your doctor will review your medical history and perform a neurological exam. Your doctor may also recommend blood tests, and tests such as an electroencephalogram (EEG), computed tomography (CT) or magnetic resonance imaging (MRI). These tests allow your doctor to monitor your brain activity and examine your brain for problems such as bleeding or tumors.