Epilepsy Surgery

There are two general categories of epilepsy surgery. Epilepsy surgery is ablative when it used to change the patient’s brain physiology through destructive alteration of tissue. Epilepsy surgery is augmentative when brain physiology is influenced through a non-destructive procedure. A thorough pre-operative evaluation is essential in order to determine which type of surgical intervention may be appropriate.

Epilepsy Surgery


Pre-Operative Testing

In epilepsy surgery, understanding what to do is just as important as knowing how to do it. The goal of epilepsy surgery is to remove, disconnect, or non-destructively influence any abnormal brain area without causing injury to the patient’s normal brain tissue and neurologic function. To accomplish this, we must first identify the areas of the patient’s brain that have a normal physiology and those areas that are abnormal. This process is known as a pre-operative workup.

A range of tests are used to define the epileptic and normal brain areas before surgery, and to determine if a patient is a good surgical candidate. Different tests are appropriate for specific cases. Each study provides the surgical team with different and important information about the patient’s epilepsy. Pre-operative tests we use include:

  • vEEG (video EEG monitoring)
  • MRI (magnetic resonance imaging)
  • fMRI (functional MRI)
  • MEG (magentoencephalograpy)
  • SPECT (single-photon emission computed tomography)
  • PET (positron emission tomography)
  • Wada
  • Neuropsych (neuropsychological test)


Invasive Monitoring

Sometimes invasive monitoring is used to distinguish the abnormal epileptic network from normal brain functional areas more precisely, in order to improve the accuracy and safety of the surgery. Invasive monitoring uses implanted electrodes to record activity directly from the brain, thereby providing the most accurate information possible.

Invasive Monitoring


Cranial Epilepsy Surgery

Cranial epilepsy surgery is an ablative surgical procedure. It can involve a single operation to remove seizure-causing brain tissue, or two “staged” surgical operations, in which electrodes for invasive monitoring are implanted first, followed by surgery a week later to remove brain tissue that the monitoring has identified as abnormal. Epilepsy surgery patients are hospitalized for 4 to 10 days, depending on which approach is used.

Epilepsy surgery has evolved over the last 20 years at NYU Langone to the point where, today, procedures are much less invasive, little hair is removed, and the surgery is performed with better accuracy and precision due to advancements in neurosurgical technology. Complete seizure control is anticipated in 90% of the best surgery candidates, and at least 50% of the time for the more difficult patients. Following epilepsy surgery at NYU Langone, 65% of all our patients are seizure-free.

Stages of Epilepsy Surgery


Patients with MRI abnormalities such as a hippocampal scar, a low grade tumor, a developmental abnormality, or certain types of vascular lesions such as cavernomas are among the best candidates for epilepsy surgery; most patients who undergo epilepsy surgery have normal MRI exams.


For temporal lobe surgery, which is the most common type of epilepsy procedure performed, the patient typically returns to work or school four weeks after surgery.


Vagus Nerve Stimulation (VNS)

Another method to prevent seizures is with indirect electrical stimulation. Vagus nerve stimulation (VNS) influences the brain by keeping it more de-synchronized, which is exactly the opposite of what occurs during a seizure. Vagus nerve stimulation does this by using a device implanted in the neck area to send a specially-tuned electrical signal into the brain along the vagus nerve.

VNS surgery is same day surgery, meaning that the patient goes home the day of surgery, with no overnight stay in the hospital. VNS is well tolerated, and patients typically can return to work or school within two to three days. Once healed, there are no restrictions to sports or physical activities. VNS decreases the number of seizures by 50% or more in over half of the patients who have the device implanted. Routine battery life for the device is about five years, although this will depend upon the specific amount of stimulation needed, which varies for each patient.



Surgical Treatments of the Future

Responsive Neuro-Stimulation. There are several other surgical treatments currently under evaluation that will soon be available for routine clinical use. One very promising new technology is called responsive neuro-stimulation (RNS). RNS utilizes an implanted device that records signals directly from the brain, monitoring it for seizure activity. When an impending seizure is detected, it is then immediately stopped by sending an electrical signal to the area of the brain where the seizure is beginning.



Other Approaches. There is also experimental work being done to directly deliver anticonvulsant drugs to the epileptic area. Other methods such as local brain cooling and deep brain stimulation (DBS), which is already being used for Parkinson’s disease, may also be beneficial. Trigeminal nerve stimulation, a type of extracranial stimulation similar to VNS, may also be useful. While not yet approved for routine use, these treatments and other similar methods will surely become available for many epilepsy patients in the coming years.

For additional information about epilepsy surgery or for an appointment with Dr. Werner Doyle, our epilepsy surgeon, or to speak with an epilepsy specialist practitioner, call 646-558-0804 or 646-558-0800.

No medical insurance will be denied (all insurance is accepted), and if insurance authorization has not been obtained, a consultation with Dr. Doyle will be possible without any fee. Arrangements will be made so that any patient will be seen for an initial surgical consultation with or without the ability to pay.

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