What Are Partial Seizures?

The names for types of seizures can be confusing, especially when they change the names. Complex partial seizures and simple partial seizures are a good example. These are old names for two common types of seizure. The main difference is that one causes change or loss of consciousness, and the other doesn’t.

partial seizure brain waves

Some seizures can cause a loss of consciousness, while others do not.

© KATERYNA KON/SCIENCE PHOTO LIBRARY | Getty Images

According to the Centers for Disease Control and Prevention, a seizure is an abnormal area of activity in the brain. Depending on where the activity is located, there are two main types. If there is abnormal activity on both sides of the brain, it is called a general seizure. If the abnormal activity is in one area on one side of the brain it is a focal seizure.

Complex partial seizures and simple partial seizures are two types of focal seizures. In some cases, a focal seizure can turn into a general seizure, called a secondary general seizure. Types of general seizures include absence and tonic-clonic seizures. Absence seizures are also called petit mal seizures. These seizures cause a brief lapse in consciousness. A person may just stare into space or blink their eyes rapidly. Absence seizures are most common in children. Tonic clonic seizures are also called grand mal seizures. During this type, a person falls to the ground and has muscle jerks and spasms.

Focal Seizures: Simple Partial Seizures

These focal seizures are now called focal onset aware seizures. These seizures do not cause loss of consciousness. Signs and symptoms of a simple partial seizure depend on where the focal area is in the brain, so there are a wide variety of possible symptoms. Symptoms can include a change in taste, vision, hearing, or smell. Some people see flashing lights, have tingling or numbness, or unexplained strong emotions. Signs may include jerking movement on one side of the body in an arm or leg. The symptoms tend to be the same with each seizure and the person is always awake and aware of the seizure.

Focal Seizures: Complex Partial Seizures

These seizures are now called focal impaired awareness seizures. Some simple partial seizures become complex partial seizures, and this type of seizure is the most common seizure for people with epilepsy. During this seizure a person will have a change in consciousness causing confusion or a dazed condition. A person may be in a dream-like state and not be able to respond to questions or commands.

Like other focal seizures, signs and symptoms depend on where the abnormal activity focus is in the brain. The most common area is in the temporal lobe which may cause stereotype automation. These are repeated movements like head nodding, hand movements, swallowing, or even walking in circles. Symptoms of other brain locations can include unusual body positions or vocalization, hallucinations, and uncontrolled jerking movements. After a complex partial seizure, a person may remain dazed and confused for several minutes.

Diagnosis of Partial Seizures

Epilepsy is the general term used for any type of seizure that keep coming back. The cause of these seizures can be a genetic defect, a brain abnormality you are born with, head trauma, brain infection, or a tumor. In many cases, the cause remains unknown. Seizures can come at any time, but they are often triggered by fatigue, lack of sleep, stress, fever, illness, alcohol, or drugs.

Epilepsy is diagnosed by the signs and symptoms of seizures. The most common way to confirm a diagnosis is with an electrical map of the brain called an electroencephalogram (EEG). Brain imaging studies like an MRI or PET scan can be used to find the source or cause of epilepsy in the brain.

Partial Seizures Treatment

In most cases, partial seizures can be controlled with medications. Treatment starts with a single medication. The dose of the medication may be increased until seizures are controlled. If one drug does not work, a second, or even a third drug may need to be added. In some cases, it is only possible to reduce seizures and not completely control them.

For partial simple seizures, the most common medications are carbamazepine (Tegretol) and lamotrigine (Lamictal), other seizure drugs may be added for control. For complex partial seizures, the most common medications are Tegretol, phenytoin (Dilantin), valproic acid (Depakote), and oxcarbazepine (Trileptal).


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Chris Iliades, MD

Dr. Chris Iliades is board-certified in Ear, Nose and Throat and Head and Neck Surgery from the American Board of Otolaryngology and Head and Neck Surgery. He holds a medical … Read More

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