epilepsies

Epilepsies are a group of neurological disorders defined by a tendency to experience recurrent unprovoked seizures, caused by abnormal electrical activity in the brain. Seizures vary in type and intensity. Having a single seizure does not necessarily mean epilepsy, but two or more unprovoked seizures, or a high risk of recurrence, usually does.

Epilepsies are categorized by seizure type and by syndromes. Main categories are focal (partial) epilepsies, generalized epilepsies, combined focal and generalized epilepsies, and unknown onset. Focal epilepsies originate in a specific brain region; generalized epilepsies involve widespread networks from onset.

Causes are diverse. Genetic factors can predispose to certain epilepsies, and structural brain abnormalities, metabolic disorders, or developmental conditions can contribute. Acquired factors such as traumatic brain injury, stroke, infections of the brain, and brain tumors are also important. In many cases the cause remains unknown.

Diagnosis involves a detailed medical history and neurologic examination, supported by electroencephalography (EEG) and brain imaging such as magnetic resonance imaging (MRI). Classification follows international consensus models that separate epilepsies by seizure onset (focal, generalized, both, or unknown) and by etiological category (genetic, structural, metabolic, immune, infectious, or unknown).

Treatment typically starts with antiepileptic drugs (AEDs). Many people achieve long-term seizure control with medication, although a substantial minority have drug-resistant epilepsy. For focal drug-resistant epilepsy, options include surgical removal or disconnection of the seizure focus, laser ablation, neuromodulation (vagus nerve stimulation, deep brain stimulation, or responsive neurostimulation), and dietary therapies such as the ketogenic diet.

Impact and prognosis vary. With appropriate treatment, many people can lead active lives; some require ongoing adjustments in therapy and safety planning. Epilepsy carries a real risk of serious complications such as sudden unexpected death in epilepsy (SUDEP), underscoring the importance of regular medical follow-up and individualized care.