Epileptic seizures can affect any process in the brain due to abnormal activity in brain cells. A seizure can produce temporary confusion, complete loss of consciousness, a staring spell, or uncontrollable jerking movements of the arms and legs.
Symptoms vary depending on the type of seizure. In most cases, an individual with epilepsy will tend to have the same type of seizure each time, so the symptoms will be very similar from episode to episode, but some individuals have many different types of seizures, with different symptoms each time.
Doctors will classify seizures as either partial or generalized, based on how the abnormal brain activity begins. When seizures appear to result from abnormal activity in just one part of the brain, they are called partial or focal seizures. Seizures that seem to involve all of the brain are called generalized seizures. In some cases, seizures can begin in one part of the brain and then spread throughout the rest of the brain. Seizures may progress from partial to generalized.
Simple partial seizures: Do not result in loss of consciousness. These seizures may alter emotions or change the way things look, smell, feel, taste, or sound.
Complex partial seizures: Alter consciousness, causing the individual to lose awareness for a period of time. Complex partial seizures often result in staring and non-purposeful movements, such as hand rubbing, lip smacking, arm positioning, vocalization, or swallowing.
Generalized seizures involve epileptic activity in all or most of the brain.
Absence seizures (petit mal): Are characterized by staring, subtle body movements, and brief lapses of awareness.
Myoclonic seizures: Usually appear as sudden jerks of the arms and legs.
Atonic seizures: Are also known as drop attacks and may cause the individual to suddenly collapse or fall down.
Tonic-clonic seizures (grand mal): Are the most common form of generalized seizures. They are also the most widely recognized epileptic seizure. In a tonic-clonic seizure, the person loses consciousness, the body stiffens, and falls to the ground. This is followed by jerking movements. After a minute or two, the jerking movements usually stop and consciousness slowly returns.
Conditions resembling seizure disorders
Seizure disorders must be differentiated from a variety of problems whose symptoms approximate or closely resemble those of epilepsy. These include cerebrovascular (stroke-related) disorders, migraine, narcolepsy (a neurological condition with uncontrollable sleep attacks and persistent daytime sleepiness), syncope (fainting), and anxiety.
A pseudoseizure, or a psychogenic non-epileptic seizure, may also occur. These spells are not triggered by nerve cell discharges that cause true epilepsy, although the individual may experience muscle twitching and even apparent loss of consciousness. These spells have a psychiatric component and often coexist in people who have epilepsy with true seizures. EEG monitoring can help distinguish disorders that mimic epilepsy from true seizures.
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