Epilepsy Surgery
In epilepsy surgery, the area of the brain responsible for seizures is removed.
Surgery for epilepsy is most effective when seizures occur exclusively in a single area of the brain. Surgery is not the first-line treatment for epilepsy. However, it may be considered if at least two anti-seizure medications have failed to control the seizure. It may be an option when medications are ineffective in controlling seizures. This condition is known as medically resistant or drug-resistant epilepsy. Epilepsy surgery is performed to stop or reduce the severity of seizures. In addition, surgery is performed to reduce the number of deaths associated with seizures, decrease the use of anti-seizure medications, and lessen the potential side effects of the medications.
There are a variety of surgical procedures available for the treatment of drug-resistant seizures. Before deciding on surgery, the doctors will discuss the options available to you and guide you through the necessary evaluation and testing.
Focal Resection
A focal resection is a surgical procedure that removes the area of the brain responsible for causing seizures. The area of the brain being removed is known as the “seizure focus,” or the origin of seizures.
Temporal Lobe Resection
Temporal lobe resection is the removal of a portion of the brain’s temporal lobe. An anterior temporal lobectomy is the most prevalent form of epilepsy surgery with the highest success rate. More than 85 percent of patients who are good candidates for a temporal lobectomy will experience an improvement in seizure control. The majority of patients must continue taking anti-seizure medications. With the guidance of their epilepsy team, patients are frequently able to reduce their medication dosage over time. About 25% of seizure-free individuals are eventually able to discontinue all seizure medications.
Frontal Lobe Resection
Frontal lobe resection is the removal of a portion of the frontal lobe where seizures originate. It is the second most frequent site for epilepsy surgery. Despite the fact that the success rate for frontal lobe surgery is lower than that of temporal lobe surgery, 70% of patients experience a significant improvement in their ability to control seizures. The majority of individuals will continue to require anti-seizure medication. Frequently, with the help of their epilepsy team, they are able to gradually reduce the dosage they need to take.
Parietal and Occipital Lobe Resection
The parietal and occipital lobes are situated in the back (posterior) portion of the brain. A parietal or occipital lobe resection is surgical removal of a portion or both of these lobes. In the majority of cases, this type of surgery is performed when it is discovered that an area of these lobes contains an abnormal structure or a lesion. This type of epilepsy surgery is more likely to be successful when a structural abnormality is present, such as a tumor or scar tissue.
Lesionectomy
This procedure entails the removal of the lesion and the surrounding brain tissue that is causing the seizures.
Multiple Subpial Transections (MST)
Multiple subpial resections are an alternative surgical procedure used if seizures originate in an area of the brain that cannot be safely removed. This would include regions that regulate speech and movement. When a portion of the seizure focus is located in a critical region (speech or movement) of the brain and a complete resection is not possible, MST may be performed in conjunction with a surgical resection.
Laser Interstitial Thermal Therapy (LITT)
It is a less invasive alternative to resection. It targets and destroys a small portion of brain tissue using a laser. The laser is guided by magnetic resonance imaging (MRI). Initial data on laser ablation surgery indicate that more than half of patients treated with LITT are seizure-free. This type of surgery is still being thoroughly investigated. An ongoing multicenter clinical trial is evaluating the safety and efficacy of this procedure in patients with mesial temporal sclerosis.
Anatomical or Functional Hemispherectomy and Hemispherotomy
Almost exclusively, these types of epilepsy surgery are performed on children whose seizures originate from a large region on one side of the brain (hemisphere). The procedures involve isolating the epileptogenic zone from the remainder of the brain. This is typically reserved for children with extremely extensive seizure onset areas. The outcomes of these surgical procedures are extremely favorable. Over 80% of people have significantly improved seizure control, and many are able to be seizure-free. A person with a progressive disorder, such as Rasmussen’s syndrome, may have a lower chance of controlling their seizures.
Corpus Callosotomy
Typically, corpus callosotomy is reserved for individuals with severe generalized epilepsy (meaning seizures affect both sides of the brain) who are prone to drop attacks (atonic seizures) and falls. The procedure involves severing the primary connection between the two hemispheres of the brain (sides of the brain).
Stereotactic Radiosurgery
Using numerous precisely focused radiation beams, stereotactic radiosurgery treats the region of the brain where seizures originate (seizure focus). There are numerous varieties of stereotactic radiosurgery. One of them is Gamma Knife. They are minimally invasive because the surgeon does not have to open the patient’s skull. Stereotactic radiosurgery employs three-dimensional imaging to deliver high doses of radiation to the epileptogenic focus while sparing the surrounding healthy tissue.
Deep brain stimulation
It involves the permanent placement of a device within the brain. The device emits electrical signals at regular intervals that disrupt seizure-inducing activity. This procedure is guided by magnetic resonance imaging (MRI). The implanted electrical pulse generator is located in the chest. The FDA has approved three neurostimulation devices for the treatment of drug-resistant epilepsy. These include vagus nerve stimulation, responsive neuro stimulation, and deep brain stimulation (DBS).
Preparation for Epilepsy Surgery
Each patient will prepare for surgery in a unique manner. Full pre-surgical testing, such as a Baseline electroencephalogram (EEG), Magnetic resonance imaging (MRI), Positron emission tomography (PET), Single-photon emission computerized tomography (SPECT), Functional MRI, Wada test, Brain mapping, Magnetoencephalography (MEG), psychological and neurology consultations, etc., are some general steps that everyone should take prior to undergoing surgery.
Epilepsy Surgery Procedure
During surgery, the heart rate, blood pressure, and oxygen levels are monitored. During surgery, brain waves may be recorded by an EEG monitor to pinpoint the region of the brain where seizures originate.
Surgery for epilepsy is typically performed under general anesthesia. The individual is unconscious throughout the procedure. In exceptional cases, the surgeon may awaken the patient during a portion of the operation in order to determine which regions of the brain control language and movement. In such instances, pain is treated with medication.
Depending on the type of surgery, a relatively small window is created in the skull by the surgeon. After surgery, the bone is replaced and secured to the remainder of the skull so that it can heal. In general, epilepsy surgery recovery can take weeks to months. Even if the hospital stay is only a few days, the brain takes longer to heal, particularly if an open surgery or craniotomy was performed.
Recovery from minimally invasive surgery and device implantation surgery may differ. In the first week following surgery, patients may experience headaches, stomach upset, and fatigue. On the side of surgery, there may be temporary swelling of the forehead and eye area, as well as jaw pain. After surgery, people are typically given medication to alleviate these symptoms. Most individuals return to school or work in four to six weeks. After surgery, a person’s attention span, thinking, and memory may not return to normal for several months. As people adjust to changes in their seizures, social changes may also occur over the course of months.
Benefits of Epilepsy Surgery
The benefit or “success rate” of epilepsy surgery varies according to the type of surgery performed. The greatest advantage of epilepsy surgery is a reduction in the frequency of seizures. For some individuals, this benefit means complete freedom from seizures. Others may experience fewer seizures as a result.
In general, research studies examining the benefits have revealed the following:
Approximately 70% of individuals who undergo temporal lobe resection experience a favorable outcome. Positive results include the absence of seizures or the occurrence of only infrequently disabling seizures.
Studies also indicate that approximately fifty percent of patients who undergo surgery to remove a seizure focus located in a different region (not the temporal lobe) experience a similar positive outcome. This can vary based on the location of the lesion in the brain and its underlying type.
Additional advantages of a successful operation may include:
- The capacity to reduce or reduce the number of anticonvulsant medications a patient must take. The adverse effects of anti-seizure medications can have a negative impact on the quality of life of many individuals who are considering surgery.
- A greater probability of returning to work and driving.
- People are less likely to experience anxiety and depression symptoms following a successful surgical procedure.
- Reduced risk of emergency seizures, status epilepticus, epilepsy-related injuries, and death.
- Less expensive living with epilepsy. After successful epilepsy surgery, direct and indirect epilepsy-related health care costs are significantly reduced, according to research.
The doctors will discuss the likelihood that you will benefit from epilepsy surgery. It is essential to remember that the benefits of surgery depend on the type of surgery performed and the location of the seizure focus.
