What is the primary feature of a tonic-clonic seizure?

The primary feature of a tonic-clonic seizure is characterized by two main phases: the tonic phase and the clonic phase. During the tonic phase, the individual experiences muscle stiffness, leading to a rigid body posture. This stiffness can cause the person to fall or become unresponsive. Following this, the clonic phase involves rhythmic jerking and clonic movements, which are the back-and-forth motions of the extremities and other parts of the body. The combination of these phases is what typifies a tonic-clonic seizure, making the option that describes these reactions the most accurate representation of this seizure type.

The other choices do not capture the key elements of a tonic-clonic seizure. Slurred speech and confusion generally relate to different types of seizures or postictal states rather than being primary features. Similarly, inability to communicate might occur as a result of confusion, but it is not a defining feature of tonic-clonic seizures. Loss of fine motor skills is more closely associated with other neurological conditions rather than the specific characteristics of tonic-clonic seizures.