Epilepsy surgery can include a wide range of surgical resection or disconnection options. Our team of epileptic specialists works closely with the neurologists at Penn State Neuroscience Institute to develop the most effective surgical option for each patient.
During surgical resection, the abnormal tissue is removed. There are multiple types of epileptic surgical resection, including:
- Lesionectomy – a lesion is a brain abnormality that shows up on imaging. Some types of lesions such as cavernous malformations (blood vessel abnormality) and tumors are prone to cause seizures. Pre-operative testing can confirm that lesions are causing epilepsy and can be removed surgically through a lesionectomy.
- Lobectomy – Each brain hemisphere (left and right) is divided into four main lobes – the frontal, temporal, parietal and occipital. Seizures can occur in any lobe, and a lobectomy removes the affected lobe of the brain. A temporal lobectomy – removal of the temporal lobes – is the most common type of epilepsy surgery. Other types of lobectomies can impact speech, memory, vision or motor function.
- Multilobar resection – involves removal of parts or all of two or more brain lobes. This surgery is reserved for more widespread abnormalities causing seizures, providing that no vital functions are in those regions.
- Hemispherectomy – the brain has both left and right hemispheres. In rare cases, children can have devastating and uncontrollable seizures. These seizures are associated with weakness on one side of the body, causing significant damage to one of the hemispheres. Surgery to remove or disconnect a hemisphere can be curative. The two main types of hemispherectomy include:
- Anatomic hemispherectomy – removes the entire half of the brain that is injured and generating the seizures. This includes all four lobes of the hemisphere: frontal, temporal, parietal and occipital.
- Functional hemispherectomy – separates the abnormal hemisphere from the normal hemisphere by disconnecting their communication fibers. Portions of the abnormal brain are often surgically removed in order to perform the disconnection.
Surgical disconnection surgeries involve cutting and dividing the fiber bundles that connect portions of the brain. The goal of surgical disconnection is to separate the area of the brain causing the seizures from the normal brain.
There are multiple types of surgical disconnection, including:
- Corpus callosotomy – the corpus callosum is one of the main fiber bundles that connect the brain’s two hemispheres. Debilitating generalized seizures or falling-type seizures can start on one side of the brain and quickly spread to the other, making the patient a candidate for this surgery. The procedure is palliative and a large part of the fiber bundle may be cut. Seizures may improve but often do not disappear.
- Functional hemispherectomy – this surgery involves separating the abnormal hemisphere from the normal one by disconnecting the communication fibers between them. Parts of the abnormal brain after often surgically removed to perform this dissection.
The Penn State Neuroscience Institute offers two additional types of epileptic surgery:
- Stereotactic radiosurgery – this surgery delivers a focused beam of radiation to a specific target area. Gamma Knife radiosurgery can be used to remove small, deep-seated lesions that are visible on an MRI.
- Vagus nerve stimulation – the vagus nerve stimulation (VNS) is an FDA-approve device for the treatment of epilepsy that isn’t controlled by medication. The VNS is an outpatient surgery that requires two separate incisions: the surgical placement of electrodes around the vagus nerve in the neck and a generator placed below the collar bone. A programmer can be used by the epileptologist from outside the skin to adjust the intensity, duration and frequency of stimulation to optimize seizure control. Vagus nerve stimulation rarely cures seizures but can decrease seizure severity and frequency. VNS is an option for candidates who aren’t eligible for other types of surgery.