Which seizure type is characterized by a brief loss of consciousness without motor manifestations?

The seizure type characterized by a brief loss of consciousness without motor manifestations is absence seizures, specifically simple absence seizures. During these episodes, the individual may appear to "zone out" or have a momentary lapse in awareness, often lasting just a few seconds. These seizures do not involve any significant motor activity or convulsions; rather, they may be accompanied by subtle signs such as blinking or lip smacking, but these are not prominent motor manifestations.

Simple absence seizures are distinct from other seizure types because they are primarily defined by this lack of awareness without movement. This feature differentiates them from generalized tonic-clonic seizures, which involve a loss of consciousness along with generalized muscle stiffening and jerking movements. Complex partial seizures also involve a loss of consciousness but are usually associated with more complex behaviors or automatisms, and myoclonic seizures are characterized by sudden, brief muscle jerks. These differences highlight the unique characteristics of simple absence seizures, making them the correct answer.