Tonic-clonic seizures are the most common seizure disorder in adults and children. Because these seizures can develop suddenly, the client risks potential injury such as head trauma, fractures, burns, or motor vehicle accidents. Tonic-clonic seizures follow a typical patter: aura, tonic phase, clonic phase, and postictal phase.
The client experiences an aura such as a bright light, an odd taste in the mouth, or an unusual sound. A loud cry may be heard when air is forced out of the lungs. The client falls to the ground, loses consciousness, and has tonic contractions followed by clonic contractions. In tonic contractions, muscles are rigid with the arms and legs extended and jaws clenched. Pupils become fixed and dilated. Breathing stops briefly and cyanosis develops. During clonic contractions, movements are jerky as the muscels arternately contract and relax. The eyes roll back; tongue and cheek biting, as well as frothing from the mouth, may occur. Urinary and bowel incontinence are common. The entire seizure generally lasts about 1 to 2 minutes.
In the postictal phase, the client is unconscious for up to 30 minutes. The client regains consciousness slowly and may be confused and disoriented on waking. Individuals often experience headache, muscle aches, and fatigue after the seizure. Many people sleep for several hours afterward. Amnesia of the events before the seizure is normal.