Types of Epileptic Seizures
Epileptic seizures are divided in to generalized and partial seizures depending on the portion of the brain they affect.
Generalized Seizures affect the entire brain and are also known as local seizures.
Clonic. Characterized by repetitive, rhythmic jerking of limbs. These movements are seen on both sides of the body simultaneously.
Myoclonic. Non-rhythmic jerks resulting from involuntary muscle twitching. These seizures usually target the neck, shoulders and upper arms. After the seizure, the patient may describe the sensation they experienced as brief electrical shocks.
Tonic. The patient’s muscles stiffen and the full body becomes rigid including arms, legs and torso. This type of seizure is usually limited to 20 seconds or less.
Atonic.The patient temporarily loses muscle tone. This is particularly problematic because a loss of leg strength often results in a fall and loss in neck control can result in damage to the head.
Generalized Tonic-Clonic (also called Grand Mal).The patient loses consciousness likely resulting in a fall. The patient then enters the tonic phase in which the patient’s muscles stiffen for 30 seconds to one minute. This is followed by the clonic phase of muscle jerking convulsions that affect the entire body for an additional 30 seconds to one minute. After this phase the patient may remain unconscious or be tired and confused. Common problems associated with tonic-clonic seizures are tongue biting, and loss of bladder and/or bowel control.
Absence (also called Petit Mal). Typically characterized by brief episodes of abruptly stopping activity and blankly staring for up to 20 seconds. During this time the patient is unconscious of his or her environment or actions. It is likely that after a seizure the patient will be unaware that anything has happened except for the possible realization of losing time. Additionally there is also an atypical absence seizure lasting up to 30 seconds in which the patients blink their eyes, jerk their lips, and lose some responsiveness. Absence seizures are mainly seen in children and adolescents.
Partial seizures affect a particular location in the brain, and are more common than general seizures in the epileptic population. This site of activity in the brain is referred to as the focus of the seizure.
Simple (consciousness/awareness retained during seizure)
- Motor. The patient’s muscles become rigid and he or she makes sudden jerks which may include turning of the head.
- Sensory. The patient perceives strange sensations affecting one or more of the five senses (taste, touch, sight, hearing or smell). When a seizure only involves these symptoms, it is referred to as an aura.
- Psychological. These seizures include a variety of psychological experiences that include re-experiencing memory, falling into a dreamy state, and feeling intense emotions not brought on by environmental factors.
Complex (loss of awareness)
Patients become unconscious as to their activity and perform common, coordinated actions such as lip smacking, chewing, fumbling of the hands, grunting and even walking.
Partial Seizure with Secondary Generalization
The patient is conscious when the seizure begins, but as it continues they lose consciousness and begin convulsing and experiencing the symptoms of a generalized tonic-clonic seizure.
Children’s Hospital of Orange County Epilepsy Center (2003). Managing Children with Epilepsy: School Nurse Guide.
Prepared in partnership with Kevin McHugh,BS (class of 2009), Case Western Reserve University School of Engineering.
More articles about epilepsy:
- Epilepsy Diagnosis and Treatment
- New Treatments for Epilepsy
- First Aid for Epileptic Seizures
- Epilepsy: A Guide for Teachers and School Nurses
- Back to the Epilepsy Overview
For more information:
Go to the Epilepsy health topic.