Generalized tonic–clonic seizure

Generalized Tonic–Clonic Seizure

EEG showing spike-and-wave pattern typical of generalized seizures.

A generalized tonic–clonic seizure, also known as a grand mal seizure, is a type of seizure that affects the entire brain. It is characterized by a loss of consciousness and violent muscle contractions. This type of seizure is what most people think of when they hear the word "seizure."

Phases of a Generalized Tonic–Clonic Seizure

Generalized tonic–clonic seizures typically progress through several phases:

Prodromal Phase

The prodromal phase occurs hours or days before the actual seizure. During this phase, individuals may experience changes in mood or behavior, such as irritability or anxiety. Some people may have an aura, which is a specific sensation or feeling that precedes the seizure.

Tonic Phase

The tonic phase is the first stage of the seizure itself. During this phase, the person loses consciousness and the muscles suddenly contract, causing the person to fall if they are standing. The body becomes rigid, and breathing may be impaired, leading to a cyanotic appearance.

Clonic Phase

Following the tonic phase, the clonic phase involves rhythmic muscle contractions. The arms and legs jerk rapidly and rhythmically, bending and relaxing at the elbows, hips, and knees. This phase usually lasts for a few minutes.

Postictal Phase

After the clonic phase, the person enters the postictal phase. During this time, the person may be confused, fatigued, and may not remember the seizure. Recovery can take minutes to hours.

Causes

Generalized tonic–clonic seizures can be caused by various factors, including:

• Epilepsy
• Brain injury
• Infection
• Stroke
• Genetic disorders

Diagnosis

Diagnosis of generalized tonic–clonic seizures typically involves a combination of medical history, physical examination, and diagnostic tests such as EEG and MRI.

Treatment

Treatment for generalized tonic–clonic seizures often includes anticonvulsant medications. In some cases, surgery or vagus nerve stimulation may be considered.

Related Pages

• Epilepsy
• Seizure
• Electroencephalogram
• Anticonvulsant