__________ seizures involve brief jerks of a muscle or groups of muscles.

The blank in the statement "________ seizures involve brief jerks of a muscle or groups of muscles" is best filled with "myoclonic." A myoclonic seizure is characterized by sudden, brief, involuntary jerks or twitches of muscle groups or a single muscle. These jerks are typically very quick and can affect various parts of the body, most commonly the arms and shoulders, sometimes accompanied with a head nod. Myoclonic seizures are usually brief and do not cause loss of consciousness, and can occur alone or in clusters. These muscle jerks represent a sudden contraction of muscles, often described as shock-like movements. Myoclonic seizures can occur in people with epilepsy but may also be experienced occasionally by healthy individuals (for example, as hypnic jerks while falling asleep).