Epilepsy Types and Classifications Explained

Focal (Partial) Seizures

Focal seizures originate in a specific area of the cerebral cortex. These seizures are further divided into two subtypes: simple focal seizures and complex focal seizures. In simple focal seizures, the person remains fully conscious during the episode, and the seizure activity is localized. In contrast, complex focal seizures involve altered consciousness and may progress into a generalized seizure.

Generalized Seizures

Generalized seizures affect both hemispheres of the brain from the onset. These seizures often result in impaired consciousness and may be the first sign of epilepsy in some individuals. Common types of generalized seizures include:

Types of Generalized Seizures

• Tonic-Clonic Seizures – Also known as grand mal seizures, these are characterized by a sudden loss of consciousness, stiffening of the body, and rhythmic shaking.
• Myoclonic Seizures – These involve brief, sudden jerks or twitches of the muscles, often affecting the arms or legs.
• Absence Seizures – Previously called petit mal seizures, these typically cause a brief loss of awareness and staring spells, especially in children.
• Atonic Seizures – These result in a sudden loss of muscle tone, causing the person to collapse or drop their head.
• Clonic Seizures – These involve rhythmic, jerking movements, typically affecting both sides of the body.

Unclassified Seizures

In some cases, seizures cannot be clearly categorized due to limited diagnostic information or atypical features. These are labeled as unclassified seizures until further evaluation provides more clarity.