Patient Services

Patient Guide to Surgical Procedures:

Surgery is an alternative treatment for many patients that do not respond to medical therapy. With our current understanding of functional cerebral anatomy and increasingly advanced techniques to safeguard its function, the risks of surgery can be predicted and substantial neurological deficit can be avoided.

Appropriate selection of candidates for these surgical interventions requires an experienced team that has access to advanced technology because this assures more accurate diagnosis, reduces risk, and enhances success.

Evaluation Process

The evaluation process may include four phases, beginning with the least invasive. This includes procedures described in Patient Guide to Procedures.

Phase one: The first evaluation phase is a comprehensive investigation that requires approximately a week of continuous audio-visual-electroencephalogram (EEG) monitoring in Yale's six-bed adult epilepsy unit or two-bed pediatric unit. During this time, the patterns of altered behavior and movement, along with the EEG recording during seizures, can help the epileptologists localize the source. Advanced imaging techniques such as magnetic resonance imaging (MRI), PET and SPECT scans along with neuropsychological testing are performed to determine function and pathology.

Phase two: The second phase entails performing an angiogram to study the vascular structures and WADA (intracarotid sodium amytal testing), which determines language dominance and memory assessment useful to surgical planning.

Phase three: If it is necessary to study the brain directly to pinpoint the source of the seizures, the patient may have EEG electrodes surgically implanted either on the surface or within the brain.

Phase four: Using all the information collected during the prior phases, the interdisciplinary team of specialists is now able to outline for the patient and family whether surgery is possible and what the results might be. If surgery is chosen, neurosurgeons proceed to remove any lesions or damaged brain revealed by the testing process to be the focus of the seizures.

WADA Testing (Phase II)

20 York Street, New Haven, CT,
Go to the first floor of the East Pavilion and sign in at the Admitting Desk.

Description: WADA testing is a procedure performed during angiography that assesses which side of your brain has your language and memory functions. During the test, one side of the brain is put to sleep (anesthetized) by injecting a medication into the carotid artery. There are 4 to 8 minutes during which the activities of one side of the brain are suspended, so the abilities of the other side of the brain can be tested in isolation. Typical uses of the test include the lateralization of language abilities (the surgeon wants to know if the side of the brain being operated on is the speech side or not), and a determination that the patient will not lose memory after surgery.

Patient Instructions:

• You will be admitted to the hospital for one night following the procedure.
• You will have pre-study blood drawn.
• You must inform the doctor of any allergies to medications.
• Drink only clear liquids after midnight (e.g., tea, clear broth, apple juice, water).
• Take your daily medications as usual (unless your physician gives you other instructions). If you are diabetic and require daily insulin injections, ask your primary care physician when you should take your insulin and inform us.
• You will be given local anesthetic into the groin prior to the passage of a catheter (a small, flexible tube) through the skin into the artery.
• You will notice a warm feeling lasting approximately ten to twenty seconds after the catheter is positioned within the carotid artery, and x-rays are taken while x-ray dye is injected through the catheter.
• You will hear noise as the x-ray machine takes pictures.
• You must remain motionless while the dye is injected and the x-rays are taken.
• You will be lying on the x-ray table for one to two hours.
• You will be asked to read words, identify objects, pictures, shapes and numbers, and answer questions about what you are shown.
• The catheter will be removed at the end of the test.
• Pressure will be applied to the site of the catheter insertion for ten to fifteen minutes until clotting forms and bleeding stops. A small dressing will be applied to the site. Stitches are not required.
• You will be able to eat and drink after the procedure is completed.
• You will need to lie flat for several hours to prevent bleeding at the injection site.

Intracranial Monitoring (Phase III)

In addition to the previously described MRI, SPECT and PET scans, neuropsychological assessment and EEG monitoring, some patients will require a more invasive evaluation. Approximately 40-60% of the patients considered for surgical treatment will need intracranial monitoring with implanted electrodes to localize the epileptogenic area responsible for seizure onset.

Intracranial monitoring consists of depth electrodes (thin wires placed deep in the brain to detect seizure activity that cannot be detected by electrodes placed on the surface of the head) or subdural or epidural strips or grids (small plastic strips or sheets containing electrodes placed on the surface of the brain underneath the skull).

During intracranial monitoring a team of research neuropsychologists may also perform brain mapping through electrical stimulation of the implanted intracranial electrodes. They are able to pinpoint the functional areas of the brain which are then safeguarded during surgery.

You will have a pre-operative visit prior to the scheduled surgery date. At this time you will meet with an anesthesiologist who will be with you during surgery. Instructions regarding surgery will also be provided at this appointment. You will have a visit with the neurosurgeon for any additional questions you may have prior to surgery, history and physical exam, and to provide permission to perform the surgery.

What to expect:

• The morning of the procedure you will arrive from home.
• You will be taken to the operating room where you will have anesthesia, then the neurosurgeon will place the electrodes.
• Once the surgery is completed (approximately 6-8 hours) you will go to the Neurological Intensive Care Unit. Pediatric patients will be taken to the Pediatric Intensive Care Unit. You will spend the first night in the intensive care unit.
• The day after surgery, you will have an MRI, a CT scan, and a Spect Cerebral Blood Flow study.
• After the above scans have been completed you will be taken to a specialized room that has audio-visual monitoring. Your electrodes will be connected to a specialized machine that will record your brain wave activity, and your behavior will be recorded with a camera in the room. This phase is similar to Phase I.
• You will have a large, bulky tight dressing on your head. Your face and eyes may be slightly swollen.
• After sufficient seizure activity is recorded, the electrodes will be removed. You will return to the operating room for the removal of the electrodes.
• You will be discharged to home a few days after the second operation.

Resection (Phase IV)

Resection is the surgical intervention of choice for control of seizures. Removal of the epileptogenic region, involves removing part of the lobe, the entire lobe, or at times, the hemisphere responsible for seizure onset.

What to expect:

• The morning of the procedure you will arrive from home.
• You will be taken to the operating room where you will have anesthesia, then the neurosurgeon will remove an area or lesion of the brain.
• Once the surgery is completed (approximately 6-8 hours) you will go to the Neurological Intensive Care Unit. Pediatric patients will be taken to the Pediatric Intensive Care Unit. You will spend the first night in the intensive care unit.
• The next morning you will be taken to the neurological medical unit.
• You will have a dressing on your head. Your face and eyes may be slightly swollen.
• You will be discharged to home a few days after the operation.

Corpus Callosotomy

Corpus Callosotomy is a surgical procedure to disrupt pathways between the two halves of the brain which are involved in certain generalized seizure disorders. It may be considered a therapeutic option in patients excluded from resective procedures because their seizures are either unlocalized, multifocal and bilateral, or localized but not resectable.

Corpus Callosotomy is an operation which aims only to limit the spread and clinical symptom of seizures by disconnecting the two cerebral hemispheres from one another.

What to expect:

• The morning of the procedure you will arrive from home.
• You will be taken to the operating room where you will have anesthesia, then the neurosurgeon will separate the two sides of the brain.
• Once the surgery is completed (approximately 6-8 hours) you will go to the Neurological Intensive Care Unit. Pediatric patients will be taken to the Pediatric Intensive Care Unit. You will spend the first night in the intensive care unit.
• The next morning you will be taken to the neurological medical unit.
• You will have a dressing on your head.
• You will be discharged to home a few days after the operation.

Multiple Subpial Transections (MST's)

Multiple Subpial Transections is a surgical approach for patients with well-localized epileptogenic areas which are unresectable due to their functional importance. This procedure aims to sever horizontal intracortical fibers that are presumed responsible for spreading seizure activity while preserving the other fibers that control neurologic function.

What to expect:

• The morning of the procedure you will arrive from home.
• You will be taken to the operating room where you will have anesthesia, then the neurosurgeon will perform the procedure.
• Once the surgery is completed (approximately 4-6 hours) you will go to the Neurological Intensive Care Unit. Pediatric patients will be taken to the Pediatric Intensive Care Unit. You will spend the first night in the intensive care unit.
• The next morning you will be taken to the neurological medical unit.
• You will have a dressing on your head.
• You will be discharged to home a few days after the operation.

Vagal Nerve Stimulators (VNS)

VNS involves mild electrical stimulation of the left vagus nerve in the neck. The vagus nerve stimulator sends electrical signals to electrodes (wires) that are attached to the vagus nerve. From the vagus nerve the signals travel up into the areas of the brain thought to be involved in causing seizures. Sending regular electrical signals to these parts of the brain may reduce the number or length of seizures, for some people.

It is usually only considered if a number of anti-epileptic drugs have failed to fully control seizures and for people who are not suitable for, or who do not want to have, brain surgery.

The stimulator is a bit like a heart pacemaker. It is implanted under the skin in the person's upper chest. This means there is a small scar and lump on the chest where it lies. Electrodes are connected to the stimulator at one end and are coiled around the vagus nerve (in the neck) at the other end. This means there is a scar in the fold of the neck where the electrodes are implanted.

The doctor uses a computer to program the stimulator. The level of stimulation is slowly increased to a suitable level for each individual. Usually the stimulator gives 30 seconds of stimulation every five minutes during the day and night.

The stimulator has a battery inside it, which may last up to ten years. When the battery is low the stimulator needs to be replaced. This means having an operation similar to when the stimulator was put in.

What to expect:

• The morning of the procedure you will arrive from home.
• You will be taken to the operating room where you will have anesthesia, then the neurosurgeon will insert the VNS.
• After surgery you will be taken to the Post-Anesthesia Care Unit until stable.
• You will be transferred to the medical floor for an overnight stay.
• You will be discharged the following day.
• You will have to come back to clinic in 2-4 weeks to have the VNS activated.

Research Protocols

• Epilepsy Clinical Research

Support for Patients and Families

• Epilepsy Foundation of Connecticut
• American Epilepsy Society
• Epilepsy Foundation of America
• eCommunities
• EpilepsyUSA
• Answerplace