What characterizes complex partial seizures in contrast to simple partial seizures?

Complex partial seizures are characterized by altered consciousness. This means that during a complex partial seizure, the individual experiences a change in awareness or responsiveness, often leading to a lack of interaction with their environment. They may appear confused or unable to respond to questions and may not remember the event afterward. This altered state is a key distinguishing feature from simple partial seizures, where consciousness remains intact.

Motor symptoms can occur in both types of seizures but do not differentiate complex partial from simple partial seizures, as both can involve involuntary movements or automatisms. The presence or absence of postictal confusion also does not serve as a distinguishing factor. Both types can result in postictal confusion, although it may be more prominent following a complex partial seizure due to the level of altered consciousness experienced. Reduced muscle tone is not a characteristic feature specific to either type of seizure and is typically seen in different seizure classifications, such as absence seizures or atonic seizures.

Thus, the defining feature of complex partial seizures is the alteration in consciousness, highlighting the difference compared to simple partial seizures.