What type of seizure is characterized by sudden brief contraction of muscle groups?

The myoclonic seizure is characterized by sudden, brief contractions of muscle groups. These seizures often appear as quick jerking movements or twitches, generally affecting groups of muscles. They can occur in isolation or in clusters and are typically short-lived, lasting only a second or two. Myoclonic seizures can happen at any age but often appear in adolescents and young adults.

In distinguishing this type of seizure from the others listed, tonic-clonic seizures involve both tonic (stiffening) and clonic (rhythmic jerking) phases, making them longer and more intense than the brief muscle contractions of myoclonic seizures. Absence seizures are characterized by a brief loss of awareness rather than muscle contractions, often resulting in a blank stare or unresponsiveness. Focal seizures start in a specific area of the brain and can present with various symptoms, which may or may not include muscle contractions, depending on the area affected. Therefore, myoclonic seizures uniquely capture the essence of sudden, brief muscle contractions as the defining characteristic.