What type of seizure is characterized by a sudden loss of consciousness without motor manifestations?

An absence seizure is characterized by a brief and sudden loss of consciousness, which happens without any significant motor activity. During an absence seizure, the individual may appear to be staring blankly into space and can be unresponsive for a short duration, typically lasting only a few seconds. This lack of awareness is a defining feature of the absence seizure, and it is often followed by a quick return to normal activity, with no postictal confusion.

In contrast, tonic-clonic seizures involve both muscle stiffness (tonic phase) and rhythmic jerking movements (clonic phase), and they result in a more pronounced loss of consciousness along with visible motor activity. Myoclonic seizures consist of sudden jerks of the muscles without loss of consciousness, which distinguishes them from absence seizures. Complex partial seizures feature impaired consciousness as well, but they can also include automatic behaviors and specific movements, which are absent in simple absence seizures. Thus, the defining characteristic of an absence seizure is that it solely involves a loss of consciousness without any motor manifestation.