What type of seizure typically disrupts consciousness due to involvement of both cerebral hemispheres?

A generalized tonic-clonic seizure, also known as a grand mal seizure, typically involves both cerebral hemispheres, leading to a loss of consciousness. This type of seizure is characterized by two phases: the tonic phase, where there is stiffness and contraction of muscles, and the clonic phase, which involves rhythmic jerking of the body. The widespread involvement of both hemispheres is why consciousness is often completely disrupted during these seizures.

In contrast, simplified partial seizures are localized events that do not typically affect consciousness, while complex partial seizures can involve impaired consciousness but usually start in one hemisphere before potentially spreading. Myoclonic seizures, characterized by brief, shock-like muscle contractions, may not necessarily disrupt consciousness as they can occur without significant alterations in awareness. Therefore, the nature of a generalized tonic-clonic seizure, with its bilateral involvement and resultant loss of consciousness, makes it the correct choice for this question.