Surgery Trends for Epilepsy and
Wade Mueller, MD
Medical College of Wisconsin Neurosurgeon
Named to Milwaukee Magazine’s “Top Docs” list.
“Awake” Surgery is proving to be very effective — some patients experience complete freedom from seizures, other seizures are greatly diminished, so much so that they can reduce their medications.”
Epilepsy and Parkinson’s disease are two serious neurological conditions that have debilitating effects. But some new and established surgical techniques, such as “awake” surgery are helping patients by alleviating some of the most formidable symptoms. Wade Mueller, MD, who has performed numerous “awake” surgeries — the most in the state — gives us an overview of what is available today and what patients can expect tomorrow.
Q: Let’s start with epilepsy. What is involved with treating epilepsy surgically?
We can treat epilepsy with surgical techniques in cases where medications are simply not helping the patient. Their seizures must be coming from a single area in the brain and that area must not be one that performs vital functions.
Our first step, once surgery has been decided upon, is monitoring the patient’s seizures to determine where they are coming from. This can take a few days because we need to gradually take the patient off their medication. A patient will spend a few days in the hospital with an EEG machine and video camera recording their seizures.
If for some reason this 24-hour EEG monitoring doesn’t give us the information we need, we can also do invasive monitoring where we actually put electrodes directly on the brain to give us a clearer picture of seizure activity. MRI and PET scans are additional methods for discovering the location of seizures. Once we have our information, we can plan a patient’s surgery.
Q: What surgical techniques are available to these epilepsy patients?
There are two types of epilepsy surgery we use. The first is “awake” surgery. We began doing “awake” surgery here at Froedtert & Medical College in 1991, the first hospital in our region to do so, and since then we’ve accumulated a lot of experience in it.
With “awake” surgery, the patient is under local sedation, so they can respond during the procedure. We open the skull to expose the part of the brain that we’ve identified as the location of the seizures. Then we place electrodes on the brain. We stimulate the brain during surgery and the stimuli is recorded on an EEG monitor. This EEG reading guides us to the areas of function, such as speech and movement, so that we can avoid them and remove only the area causing seizures. “Awake” surgery is proving to be very effective — some patients experience complete freedom from seizures, others’ seizures are greatly diminished, so much so that they can reduce their medications.
Another surgical technique for epilepsy and one that Froedtert & Medical College was instrumental in the development of is the Vagus Nerve Stimulator. This is actually a pacemaker-like device that is surgically implanted and connected to the vagus nerve in the neck. And, for reasons that aren’t really clear yet, this device is able to “block” many seizures before they occur. This technique is used for patients who have really exhausted their medication options, but the resective–type surgery that I previously described is not an option.
Q: What is looking promising for the future for epilepsy surgery?
A lot of the more exciting work being done in epilepsy, from a surgical point of view, has to do with imaging. Our neuropsychology group is deeply involved in research to better localize the areas of seizure onset and better identify those patients who will experience a significant reduction in seizures, yet not lose important brain functions.
Q: What about Parkinson’s disease? What surgical techniques are used here?
Surgery for Parkinson’s at Froedtert & Medical College is performed by neurologists who deal only with movement disorders. Like epilepsy, the mainstay of treatment is with medications, but if medications aren’t working, surgical options can be useful.
There are two major types of surgical techniques. Both are non-invasive and while they don’t cure the disease, they have been seen to relieve both tremors and rigidity. Both techniques begin with a CT or MRI scan to provide an accurate map of the brain. Then, in the radiofrequency waves technique, we insert an electronic probe into a small hole made in the skull. The probe electronically stimulates the targeted brain area, generating heat that eliminates the area causing Parkinson’s.
The other technique is called deep-brain stimulation. Here a neurosurgeon implants an electrode in the thalamus — the area of the brain associated with Parkinson’s tremors. A stimulator or battery is also implanted into the patient’s upper chest. This procedure is very effective and neurosurgeons also have the ability to reposition the electrode if they ever need to.
Q: What new developments can Parkinson’s patients expect in the future?
Again, as with epilepsy, imaging trials are looking very promising. Our fMRI team is attempting to better define the disease and develop treatments that can be tailored to individual patients.