Neurological Conditions

Epilepsy: Understanding Seizures and Brain Electrical Activity

Epilepsy is a chronic brain disorder characterized by recurring seizures. Seizures occur when groups of neurons produce abnormal bursts of electrical activity. This can temporarily affect movement, awareness, sensation, emotion, or behavior. A single seizure does not necessarily mean that a person has epilepsy.

Anatomical brain with a subtle neural electrical network and localized signal activity — Seizures involve temporary changes in electrical signaling within brain networks.

Brain signaling

What happens during a seizure?

Neurons normally communicate using electrical and chemical signals.

During some seizures, groups of neurons begin signaling excessively or abnormally.

Depending on where the activity occurs, a seizure may cause unusual sensations, staring or loss of awareness, involuntary movements, muscle stiffening or jerking, emotional or behavioral changes, or temporary confusion after the event.

Comparison of coordinated neuron signaling and synchronized excessive neural activity — Seizure activity can involve unusually synchronized or excessive signaling across groups of neurons.

Patterns of activity

Different seizure types

Seizures do not all look the same. Two broad categories include:

Focal seizures

Begin in one area of the brain. Symptoms depend on the affected brain region and may involve movement, sensation, awareness, memory, or emotion.

Generalized seizures

Involve networks on both sides of the brain. Some can cause loss of consciousness, stiffening, rhythmic jerking, or brief lapses of awareness.

Brain diagrams comparing focal onset in one region with generalized activity across both hemispheres — Seizure classification considers where activity begins and which networks become involved.

Many possible origins

Causes and risk factors

Epilepsy has many possible causes. They may include genetic factors, brain injury, abnormal brain development, stroke, infections, brain tumors, or other neurological conditions.

In many people, the cause remains unknown.

Clinical assessment

How epilepsy is diagnosed

Evaluation can involve:

description of the event
medical and family history
neurological examination
EEG to measure electrical brain activity
brain imaging such as MRI
blood or other testing when appropriate

Because many events can resemble seizures, professional evaluation is important.

Individualized care

Treatment and management

Treatment commonly includes antiseizure medicines.

When medications do not adequately control seizures, selected patients may be evaluated for surgery, implanted neurostimulation devices, specialized dietary therapies, or other individualized treatments.

Medication should never be stopped or changed without medical guidance.

Everyday management

Living with epilepsy

Everyday management can include taking medicines as prescribed, maintaining regular sleep, learning personal seizure triggers when identifiable, avoiding missed medication doses, creating a seizure safety plan, and educating family, school, or coworkers when appropriate.

Activities and safety recommendations vary depending on seizure type and level of control.

References