What must be present for a seizure to be classified as a general seizure?

For a seizure to be classified as a general seizure, the defining characteristic is the loss of consciousness. General seizures, which encompass types such as tonic-clonic (grand mal) and absence seizures, involve abnormal electrical activity in both hemispheres of the brain. This widespread involvement leads to a change in consciousness, which can manifest as either a total loss of awareness or altered responsiveness.

While some general seizures can manifest with convulsions, and a post-ictal phase may occur following the seizure, these elements are not required for classification as a general seizure. Additionally, the duration of a seizure—especially exceeding 10 minutes—does not determine its classification; rather, it may indicate a different clinical concern such as status epilepticus. Thus, the hallmark feature for identifying a seizure as generalized is indeed the presence of loss of consciousness.