1. Which epilepsy patients are suitable for surgical treatment?
1) Drug-refractory epilepsy: 2 or more first-line antiepileptic drugs are used in sufficient quantity, and after more than 2 years of regular treatment, the seizures are still not controlled, affecting the patient’s daily work and life.
2) Epilepsy with clear “responsible lesion”: After detailed medical history, video EEG, high field intensity MRI (3.0 TMRI), PET-CT/PET-MRI and other modern neuroimaging techniques, the “responsible lesion” (epileptogenic focus) causing the seizure can be clearly identified. The “responsible lesion” (epileptogenic focus) for the seizure can be identified. These “responsible lesions” can be congenital (e.g., cortical dysplasia, etc.) or acquired (e.g., low-grade glioma, etc.).
3) Certain types of epilepsy, such as temporal lobe epilepsy and hippocampal sclerosis, have better surgical outcomes and may be actively considered for surgery.
4) For infants and children with epilepsy, especially those with intractable epilepsy affecting brain development or potentially disabling, surgery should be performed as early as possible if surgical pointers are available.
2. What are the main tests for preoperative evaluation of epileptic patients?
1) Long-range video electroencephalogram (VEEG): including interictal and interictal EEG, which is an important tool for the diagnosis of epilepsy.
2) MRI of the head: to understand the anatomical abnormalities of the brain and to detect the “responsible lesion”.
3) PET-CT: provides strong evidence for the localization of “epileptogenic foci” by analyzing the metabolism of brain tissue.
4) SPECT: The imaging results reflect the cerebral blood perfusion status, and can be used in different states of the patient (during and between seizures) to guide the localization of the “epileptogenic focus”.
5) Magnetoencephalography (MEG): The root cause of seizures is excessive discharge, and the electric field can generate magnetic field.
6) Symptoms and signs: The patient’s symptoms and signs are an important basis for localization that cannot be ignored. Detailed history and physical examination as well as comprehensive neuropsychological assessment are important in the diagnosis and treatment.
7) Stereotactic electroencephalography (SEEG): When noninvasive tests cannot precisely locate the epileptogenic focus, invasive tests such as stereotactic EEG can be considered.
8) Other tests that may be needed are: functional magnetic resonance imaging (fMRI) – to discover the relationship between functional brain areas and epileptogenic foci; magnetic resonance bop (MRS) – a more sensitive test to evaluate temporal lobe epilepsy and hippocampal sclerosis.
The localization of the “epileptogenic focus” is very important in the diagnosis and treatment of epilepsy. There is no single test that can provide the only reliable localization information, so we can choose a combination of the above tests to make a comprehensive judgment according to the specific situation of each patient. The more consistent the tests are, the more accurate the localization of the “epileptogenic focus” will be, and the more accurate the post-operative outcome of epilepsy.
3. What are the surgical procedures for epilepsy?
(1) Excisional surgery: to remove the cause of epilepsy, such as temporal lobectomy, neocorticotomy, hemispherectomy, etc.
(2) Palliative surgery: blocking the spread of epileptic discharges and reducing the degree of generalization, such as corpus callosotomy, multiple submural transverse fiber dissection, etc.
(3) Neuromodulation surgery: e.g. vagus nerve stimulation, deep brain stimulation, etc.
(4) Destructive surgery: such as laser thermal cautery, radiofrequency thermocoagulation, etc.
The doctor will choose the right type of surgery according to the patient’s specific situation, and the patient should fully communicate with the doctor to understand the pros and cons of surgery before making a comprehensive decision.
4. Can surgery cure epilepsy?
Before surgery, epilepsy patients want to know what the success rate or cure rate of surgery is, and they hope to control epilepsy without medication after surgery. The reason for this is that epilepsy is complex, and the results of surgery vary greatly between different types of epilepsy, and even for the same type of epilepsy, the prognosis varies greatly depending on the cause. It is difficult to quantify the results with concepts such as “cure rate” and “cure”. However, if the “epileptogenic focus” is accurately located, about 70% of patients can have their epilepsy significantly controlled or their seizures can be completely stopped after surgery.