Adults can have generalized seizures, which involve all areas of the brain, or partial seizures, which affect a specific brain area, explains WebMD. There are several different forms of both seizure categories, with generalized tonic-clonic seizures being the most common type of generalized seizure.
During a generalized tonic-clonic seizure, a patient becomes unconscious and subsequently begins violently jerking his body, notes WebMD.
There are two sub-categories of partial seizures: simple and complex, states WebMD. A patient experiencing a simple partial seizure remains conscious, while a complex partial seizure involves a loss of consciousness. One type of simple partial seizure is a simple motor seizure, during which the patient experiences motor symptoms, such as body stiffening and head jerking.