Which of the following best describes a tonic-clonic seizure?

A tonic-clonic seizure is characterized by a specific sequence of muscle activity that includes an initial phase of sustained muscle contraction (tonic phase) followed by rhythmic muscle contractions (clonic phase). During the tonic phase, the person may lose consciousness and their body becomes stiff as all muscle groups contract. This is followed by the clonic phase, in which the individual experiences involuntary muscle contractions and convulsions, resulting in shaking movements throughout the body.

This description aligns with the characteristics of a tonic-clonic seizure, making this response the most accurate representation of the seizure type. The other options do not capture the full clinical picture; for example, a brief lapse in consciousness refers to absence seizures, while uncontrolled shaking of one limb pertains to focal seizures, and confusion after a seizure describes the postictal state rather than the seizure itself.