Lesionectomy

Epilepsy: Lesionectomy

• What is a lesionectomy?
• Who is a candidate for lesionectomy?
• What happens before surgery?
• What happens during surgery?
• What happens after surgery?
• How effective is a lesionectomy?
• What are the side effects of surgery?
• What risks are associated with a lesionectomy?

What Is a Lesionectomy?
A lesionectomy is an operation to remove a lesion -- a damaged or abnormally functioning area -- in the brain. Brain lesions include tumors (masses of cells), scars from a head injury or infection, abnormal blood vessels and hematomas (swellings filled with blood).

A lesion causes seizures (is the seizure focus) in about 20% to 30% of people with epilepsy that do not improve after taking medication (intractable or refractory epilepsy). It is not known for certain if the lesion itself triggers the seizures, or if the seizures result from irritation to the brain tissue surrounding the lesion. For this reason, surgery may also include the removal of a small rim of brain tissue around the lesion, called lesionectomy plus corticectomy.

Who Is a Candidate for Lesionectomy?
Surgery may be an option for people whose epilepsy is linked to a defined lesion and whose seizures are not controlled by medication. In addition, it must be possible to remove the lesion and surrounding brain tissue without causing damage to areas of the brain responsible for vital functions, such as movement, sensation, language and memory. There also must be a reasonable chance that the person will benefit from surgery.

What Happens Before Surgery?
Candidates for lesionectomy undergo an extensive pre-surgery evaluation-including seizure monitoring, electroencephalography (EEG) and magnetic resonance imaging (MRI). These tests help to pinpoint the location of the lesion and confirm that the lesion is the source of the seizures. Another test to assess electrical activity in the brain is EEG-video monitoring, in which video cameras are used to record seizures while the EEG monitors the brain's activity. In some cases, invasive monitoring-in which electrodes are placed inside the skull over a specific area of the brain-also is used to further identify the tissue responsible for seizures.