17.2 : 癫痫发作：分类

Epilepsy is a chronic neurological disorder characterized by unpredictable seizures.

Seizures can be provoked by identifiable factors or occur spontaneously. They are classified into focal and generalized seizures.

Focal seizures originate from specific brain regions and are sub-classified into focal aware seizures, where the person remains conscious throughout, and focal impaired awareness seizures, where consciousness is impaired during the seizure.

Generalized seizures involve both brain hemispheres from the onset and have several types.

Generalized absence seizures or 'petit mal' are characterized by a brief loss of consciousness, tonic-clonic seizures involve loss of consciousness and violent muscle contractions, and myoclonic seizures cause quick and involuntary muscle jerks.

Clonic seizures manifest as repetitive jerking movements, tonic seizures cause stiffening of the muscles, and atonic seizures lead to loss of muscle tone.

Additionally, epilepsy syndromes in children include infantile spasms, Lennox-Gastaut syndrome, juvenile myoclonic epilepsy, and Dravet syndrome.