Seizure
| Epileptic seizure | |
|---|---|
| Other names | Epileptic fit, seizure, fit, convulsions |
| Generalized 3 Hz spike and wave discharges in an electroencephalogram (EEG) of a patient with epilepsy | |
| Specialty | Neurology, emergency medicine |
| Symptoms | Variable |
| Complications | Falling, drowning, car accidents, pregnancy complications, emotional health issues |
| Duration | Typically less than 2 minutes |
| Types | Focal, generalized; provoked, unprovoked |
| Causes | Provoked: Low blood sugar, alcohol withdrawal, low blood sodium, fever, brain infection, traumatic brain injury Unprovoked: Flashing lights or colours, unknown causes, previous stroke, brain injury, brain tumor |
| Diagnostic method | Based on symptoms, blood tests, medical imaging, electroencephalography |
| Differential diagnosis | Syncope, psychogenic seizure, migraine aura, transient ischemic attack |
| Treatment | Less than 5 min: Place person on their side, remove nearby dangerous objects More than 5 min: Treat as status epilepticus |
| Frequency | ≈10% of people (lifetime risk) |
A seizure is a sudden, brief disruption of brain activity caused by abnormal, excessive, or synchronous neuronal firing. Depending on the regions of the brain involved, seizures can lead to changes in movement, sensation, behavior, awareness, or consciousness. Symptoms vary widely. Some seizures involve subtle changes, such as brief lapses in attention or awareness (as seen in absence seizures), while others cause generalized convulsions with loss of consciousness (tonic–clonic seizures). Most seizures last less than two minutes and are followed by a postictal period of confusion, fatigue, or other symptoms. A seizure lasting longer than five minutes is a medical emergency known as status epilepticus.
Seizures are classified as provoked, when triggered by a known cause such as fever, head trauma, or metabolic imbalance, or unprovoked, when no immediate trigger is identified. Recurrent unprovoked seizures define the neurological condition epilepsy.