Approximately one out of 100 people in the U.S. will experience an unprovoked seizure in their lifetime. But having only one seizure does not mean you have epilepsy. You need to experience at least two unprovoked seizures to be diagnosed as having epilepsy. While epilepsy can develop in any person at any age, people with certain conditions may be at higher risk.
Epilepsy results from abnormal electrical activity in the brain. Brain cells communicate by sending electrical signals in an orderly pattern. In epilepsy, however, these electrical signals become abnormal, giving rise to an "electrical storm" that produces seizures. These storms may be within a specific part of the brain or be generalized, depending on the type of epilepsy.
About 2.7 million Americans have been treated for epilepsy in the past five years. That's 8 or 9 out of every 1,000 people. In other words, out of 60,000 people filling a big stadium, about 500 have epilepsy.
New cases of epilepsy are most common among children, especially during the first year of life. The rate of new cases then gradually decreases until about age 10 when it levels off. After age 55 or 60, the rate starts to rise then, as people develop strokes, brain tumors, or Alzheimer's disease (all of which can cause epilepsy).
There are two classifications of seizures: partial and generalized. The classification is based on how the abnormal brain activity begins. In some cases, seizures can begin as partial and then become generalized.
- Partial seizures—These seizures appear to result from abnormal activity in just one part of the brain. These types of seizures fall into two categories:
- Simple partial seizures—These seizures do not result in 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 part of the body, and sensory symptoms such as tingling, vertigo and flashing lights.
- Complex partial seizures—These seizures alter consciousness, causing a person to lose awareness for a period of time. They often result in staring and non-purposeful movements, such as hand rubbing, twitching, chewing, swallowing or walking in circles.
- Generalized seizures—Seizures that seem to involve the entire brain are called generalized. There are four types of generalized seizures:
- Absence seizures (also called petit mal)—These are seizures characterized by staring and subtle body movement. They can also cause a brief loss of consciousness.
- Myoclonic seizures—These seizures usually appear as sudden jerks or twitches of the arms and legs.
- Atonic seizures (also known as drop attacks)—These seizures cause a person to lose normal muscle tone and suddenly collapse or fall down.
- Tonic-clonic seizures (also called grand mal)—The most intense of all types of seizures, these are characterized by a loss of consciousness, body stiffening and shaking, and loss of bladder control.
Seizure symptoms do vary. Seizures can take on many different forms and affect people in different ways. Not every person who has a seizure will experience every symptom described below. Because epilepsy is caused by abnormal activity in brain cells, seizures can affect any process your brain coordinates. 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.
Keep in mind that seizures have a beginning, middle, and end. When an individual is aware of the beginning, it may be thought of as a warning. But not all individuals are aware of the beginning and therefore have no warning. Sometimes, the warning is not followed by any other symptoms and may be considered a simple partial seizure.
The middle of a seizure may take different forms. For people who have warnings, the aura may continue or it may turn into a complex partial seizure or a convulsion. And for those who don’t have a warning, the seizure may continue as a complex partial seizure or may evolve into a convulsion.
The end to a seizure signifies a transition from the seizure back to the individual’s normal state. This signifies the recovery period for the brain. It may last from seconds to minutes to hours, depending on several factors including which part(s) of the brain were affected by the seizure and whether the individual was on anti-seizure medication.
Some common warning symptoms of an impending seizure include:
Early seizure symptoms (warnings):
Visual loss or blurring, tingling feeling, fear or panic, dizziness, headache, nausea, and/or numbness
Common symptoms during a seizure:
Confusion, deafness, electric shock feelng, loss of consciousness, visual loss or bluring, convulsions, difficulty talking, drooling, eyelid fluttering, eyes rolling up, falling down, inability to move, incontinence, teeth clenching/grinding, tongue biting, tremors, twitching movements, and/or breathing difficulty
Common symptoms which may occur after a seizure:
Memory loss, confusion, frustration, bruising, communication difficulty, injuries, exhaustion, headache, nausea, and/or thirst
In about half of the people with epilepsy, there is no identifiable cause. In the other half, the condition may be drawn to numerous factors, including:
• Genetic influence—Some types of epilepsy run in families. Researchers have linked some kinds of epilepsy to specific genes, though it is estimated that up to 500 genes could be tied to the condition.
• Head trauma—That which is sustained during a car accident or other traumatic injury.
• Medical disorders—Such as strokes or heart attacks that result in damage to the brain. Stroke is responsible for up to one half of epilepsy cases in those over age 65.
• Dementia—This is a leading cause of epilepsy among older adults.
• Diseases—Such as meningitis, AIDS and viral encephalitis can cause epilepsy.
• Prenatal injury—Fetuses are susceptible to brain damage caused by an infection in the mother, poor nutrition or oxygen deficiencies. This can lead to cerebral palsy in a child.
• Developmental disorders—Epilepsy can be associated with other developmental disorders, such as Autism and Down syndrome.
While the disorders and injuries on the above list help to explain many cases of epilepsy, often times the cause is just unknown. For those individuals who do not know the cause of their condition, they can look for triggers, that seem to make their seizures more frequent or more severe. Once identified, they should try to avoid them altogether or at least lessen their effects.
Some seizure-provoking triggers include:
• Missed medication
• Lack of sleep
• Severe psychological stress
• Heavy alcohol use
• Use of cocaine and other recreational drugs
• Over-the-counter or prescription medications or supplements that decrease the effectiveness of seizure medications
• Nutritional deficiencies
• Menstrual cycle