Should I consider epilepsy surgery?
Clinical neurologist Professor David Reutens, Director of the Comprehensive Epilepsy Program at the Royal Brisbane and Women’s Hospital (RBWH), says that despite epilepsy surgery delivering life-changing outcomes for many people with intractable focal epilepsy, it remains ‘significantly underutilised’.
“Unfortunately, many patients who should be considered for surgery aren’t being referred to us, or are being referred to us very late,” says Prof Reutens.
“I’ve seen patients in their late 60s whose lives have been terribly affected by uncontrolled seizures but have never been referred for consideration for epilepsy surgery. They could have had surgery 30 years ago but, instead, their lives have been completely built around their epilepsy. And that, to me, is very sad.
“Uncontrolled seizures pose an ongoing risk of injury and death and can affect many aspects of life from mobility and independence to education, employment, and social, recreational, and reproductive options. Earlier intervention to stop seizures can remove the limitations imposed on a person’s life by epilepsy.”
Want to learn more about surgical interventions for epilepsy – specifically focal resection? Prof Reutens shares valuable insights for anyone impacted by this complex condition:
“There are many different types of surgery used in the treatment of epilepsy. At the top of the list is resection, where the surgeon removes the part of the brain causing the epilepsy. When this kind of operation is not an option, sometimes we can insert a vagal nerve stimulator, which is a form of neuromodulation that is effective in reducing seizure frequency.
“The stimulator is about the same size as a heart pacemaker and is implanted under the collarbone with an electrode connecting it to the vagus nerve, which runs down the neck. It delivers regular pulses of current to the nerve and this has been shown to modulate the brain’s excitability and reduce seizure frequency. Less commonly, a stimulator is used to deliver pulses directly to the brain, through electrodes implanted into the brain.
“Another kind of surgery is interstitial thermal therapy, which uses heat from a laser to destroy brain tissue generating seizures.”
Is resective surgery suitable for anyone with epilepsy?
“For us to consider resective surgery, the first thing is that the epilepsy should be refractory – that is, unresponsive to at least two appropriate medications that have been tried at reasonable doses – and significantly affecting the person’s life.
“Second, the epilepsy must be of focal origin, which means beginning in a particular part of the brain. Third, the part of the brain must be able to be removed without causing unacceptable impairment, so it shouldn’t be critical for cognitive, sensory and motor functions.
“If somebody has epilepsy that hasn’t responded to two medications, they really ought to be referred to a specialist centre. Quite often the patient will be prescribed an antiseizure medication that may work for a while and then seizures return. Their doctor will then prescribe a second antiseizure medication, and that medication also eventually fails to control seizures.
“Instead of just repeating the process, their doctor should then be referring the patient to a specialist epilepsy centre and one of the questions they should be asking is ‘could this person be a potential surgical candidate?’ We now know that patients with drug resistant epilepsy who get early surgical intervention have a better chance of becoming seizure free.”
Will surgery ‘cure’ my epilepsy?
“One of the common misconceptions is that antiseizure medications can be stopped very soon after epilepsy surgery. Generally, this is not the case. We know that the generation of seizures generally involves a network of brain regions that can be so extensive that removing the entire network would cause significant impairment.
“The main purpose of surgery is to remove the key parts of the network so that the rest of the network, and therefore the epilepsy, becomes medication responsive. For this reason, usually, our patients remain on antiseizure medications for several years after successful surgery. Some patients are able to wean off all medications after a period of seizure freedom.”
What makes someone a good candidate for epilepsy surgery?
“When we talk about epilepsy being ‘disabling’, as a criterion for surgery, it really depends on the individual’s circumstances. It is not only about seizure frequency, although we take that into account, but also about impact of epilepsy on the person’s life. For example, the inability to hold a driver’s licence is an important disability for many people. We spend time discussing the patient’s expectations and whether successful surgery will improve quality of life or independence. Ideally there would be strong psychosocial support from family and friends.
“Surgical workup is a fairly rigorous process. The investigations themselves can be challenging, but beyond that, the person with epilepsy has to prepare for success as well as the possibility of failure, because both of these can change their life.”
What is the assessment process for epilepsy surgery?
“To work out whether surgery should be recommended there is a period of intensive clinical evaluation and testing to pinpoint where the seizures are starting from and to figure out whether that part of the brain can be removed without causing new problems.
“The person will generally have a dedicated epilepsy series 3 Tesla MRI scan to show us the detailed structure of the brain. This aims to pick up any pathology that may be causing the epilepsy. An FDG-PET scan is performed; this scan measures the metabolism of glucose in the brain, which is often reduced in the region causing the epilepsy.
“To identify where the seizures are coming from, we need to be able to capture information when the person is having a seizure. This is done with video-EEG monitoring, where the person comes into hospital for up to two weeks, during which they are videoed while the EEG is recorded continuously. This test is performed in a specialised Epilepsy Monitoring Unit (EMU) at RBWH.
“During admission, antiseizure medications are often reduced until seizures occur. The test allows us to correlate the clinical features of the seizure with the pattern of electrical activity in the brain. During the EMU admission, we might do an ictal SPECT scan, where a special dye is injected intravenously during a seizure to give us a snapshot of activated brain regions – this can help to identify where the seizures are starting from.
“Sometimes, we still don’t have a clear picture of which part of the brain seizures are coming after these investigations and, occasionally, the information can only be obtained from electrodes implanted in the brain – a test called stereo-EEG.
“Intensive neuropsychological testing is also performed, which provides information on potential effects, if any, that surgery could have on cognitive function. If we are particularly worried that the surgery will be close to a region of the brain that is functionally important, we are sometimes able to use functional MRI scans to more accurately map the parts of the brain that are activated during the performance of a specific task.
“Everyone who goes through our surgery program also has an in-depth review with our neuropsychiatrist to support their mental health throughout the process, from the presurgical to the post-operative phases. Our Epilepsy Nurses also support the person with epilepsy and their family through what we know can be quite a journey.
“With some diseases you just do one test, and the result is either positive or negative, but in making decisions about epilepsy surgery we have to put together a whole bunch of information, drawing on a wide range of expertise. To do that effectively, I chair a surgical meeting once a week, in which a multi-disciplinary team of about 20 experts from different disciplines discuss all the information that we have gathered to come to a consensus on whether surgery should to offered as a treatment option. This process is critical in complex decision-making and planning to ensure the best possible outcomes for each individual patient.”
What are the risks and benefits of epilepsy surgery?
“The epilepsy surgical techniques commonly employed by our surgeons are very well established and have been used for many decades, so epilepsy surgery shouldn’t be considered experimental surgery. Over the years there have been improvements in imaging and surgical guidance that have increased surgical precision.
“It’s not really sensible to give an overall figure for risks and benefits for all types of epilepsy surgery because it depends on where the seizures are coming from, the underlying pathology and other individual factors.
“A common scenario would be anterior temporal lobe resection in an individual with mesial temporal epilepsy due to a pathological lesion called hippocampal sclerosis. Here, the likelihood of seizure freedom or a very good seizure outcome is around 70%, compared to about 10% from medical management. The overall complication rate of this operation is about 2%, ranging from the perioperative complications that can happen with any surgery to a very small risk of stroke.
“Any discussion of risks and benefits has to be individualised.”
What is the recovery like after epilepsy surgery?
“For an uncomplicated resective epilepsy surgery, such as a temporal lobe resection, we’d expect the patient to be in hospital for just under a week. We would expect recovery back to normal activity over a three-month period. We have an extensive post-operative follow up program and for several years after surgery.”
To find out more or access support, contact Epilepsy Queensland’s Living Well team on 1300 852 853.
