Tonic-clonic

Tonic-clonic Seizure

A tonic-clonic seizure, formerly known as a grand mal seizure, is a type of generalized seizure that affects the entire brain. It is characterized by a combination of muscle stiffness (tonic phase) and rhythmic muscle contractions (clonic phase). Tonic-clonic seizures are among the most common types of seizures and are often associated with epilepsy, although they can occur in individuals without epilepsy as well.

Clinical Presentation

Tonic-clonic seizures typically progress through several stages:

Prodromal Phase

Some individuals may experience warning signs, known as auras, before the onset of a tonic-clonic seizure. These auras can include sensory changes, emotional disturbances, or other unusual sensations.

Tonic Phase

The tonic phase is characterized by sudden muscle stiffening. The person may lose consciousness and fall to the ground. The muscles of the body become rigid, and the person may cry out due to the forceful contraction of the respiratory muscles.

Clonic Phase

Following the tonic phase, the clonic phase involves rhythmic jerking of the limbs and face. This phase can last for several minutes and is often accompanied by autonomic symptoms such as increased heart rate and salivation.

Postictal State

After the clonic phase, the person enters a postictal state, which is a period of confusion, drowsiness, and fatigue. The duration of the postictal state can vary, but it often lasts for several minutes to hours.

Causes

Tonic-clonic seizures can be caused by a variety of factors, including:

• Epilepsy: A neurological disorder characterized by recurrent seizures.
• Head trauma: Injury to the brain can lead to seizures.
• Infections: Conditions such as meningitis or encephalitis can trigger seizures.
• Metabolic disturbances: Electrolyte imbalances, hypoglycemia, or hypoxia can cause seizures.
• Genetic factors: Some individuals have a genetic predisposition to seizures.

Diagnosis

The diagnosis of tonic-clonic seizures involves a combination of clinical evaluation and diagnostic tests:

• Electroencephalogram (EEG): An EEG can detect abnormal electrical activity in the brain associated with seizures.
• Neuroimaging: MRI or CT scans may be used to identify structural abnormalities in the brain.
• Blood tests: These can help identify metabolic or infectious causes of seizures.

Treatment

Treatment for tonic-clonic seizures typically involves:

• Antiepileptic drugs (AEDs): Medications such as phenytoin, valproate, and levetiracetam are commonly used to control seizures.
• Lifestyle modifications: Adequate sleep, stress management, and avoiding seizure triggers can help reduce the frequency of seizures.
• Surgery: In some cases, surgical intervention may be necessary to remove a seizure focus in the brain.

Prognosis

The prognosis for individuals with tonic-clonic seizures varies depending on the underlying cause. With appropriate treatment, many individuals can achieve good seizure control and lead normal lives. However, some may continue to experience seizures despite treatment.

Also see

• Epilepsy
• Seizure
• Electroencephalogram
• Antiepileptic drugs
• Neuroimaging