Epilepsy Surgery
Epilepsy surgery is a specialized neurosurgical intervention performed for patients with drug-resistant (refractory) epilepsy. The primary objective is to eliminate or significantly reduce seizure frequency by resecting, disconnecting, or modulating the hyperactive area of the brain where seizures originate (the epileptogenic zone).
Main Categories of Epilepsy Surgery
Resective Surgery: The localized removal of the specific brain region responsible for generating seizures.
Anterior Temporal Lobectomy / Amygdalohippocampectomy: The most common and successful procedure for temporal lobe epilepsy.
Lesionectomy: Precise removal of a specific anatomical lesion causing seizures (e.g., cavernous malformation, cortical dysplasia, or low-grade tumor).
Extra-Temporal Resection: Removal of epileptogenic tissue in the frontal, parietal, or occipital lobes.
Disconnection Procedures: Interrupts neural nerve pathways to prevent seizure activity from spreading to other regions or across hemispheres.
Corpus Callosotomy: Surgical sectioning of the corpus callosum to stop generalized “drop attacks.”
Hemispherotomy / Hemispherectomy: Disconnecting or removing a severely damaged or diseased cerebral hemisphere (commonly performed in pediatric patients with conditions like Sturge-Weber syndrome or Rasmussen encephalitis).
Neuromodulation: Implantable electronic systems for patients whose seizure focus cannot be safely resected due to proximity to essential speech or motor regions.
Responsive Neurostimulation (RNS): Continuously monitors EEG patterns and delivers closed-loop electrical stimulation to disrupt detected seizure activity.
Vagus Nerve Stimulation (VNS): Delivers regular electrical pulses to the left vagus nerve to reduce brain network excitability.
Deep Brain Stimulation (DBS): Delivers electrical stimulation to subcortical targets like the anterior nucleus of the thalamus.
Minimally Invasive Ablation:
Laser Interstitial Thermal Therapy (LITT): An MRI-guided fiber-optic laser catheter destroys the seizure focus using heat through a tiny 3 mm skull opening, offering a shorter recovery time than open surgery.
Types of Epilepsy Surgery
| Surgical Category | Common Procedures | Target Indication | Primary Goal |
| Resective | Temporal Lobectomy, Lesionectomy | Focal drug-resistant epilepsy, Mesial Temporal Sclerosis | Complete seizure freedom |
| Disconnective | Corpus Callosotomy, Hemispherotomy | Atonic seizures (drop attacks), Extensive single-hemisphere disease | Prevent seizure propagation and severity |
| Neuromodulation | RNS, VNS, Thalamic DBS | Multifocal epilepsy, Seizures in eloquent cortical areas | Reduce seizure frequency and intensity |
| Ablative (MIS) | Laser Interstitial Thermal Therapy (LITT) | Deep-seated seizure foci, Hypothalamic hamartomas | Minimal invasive tissue destruction |
Pre-Surgical Diagnostic Evaluation
Phase 1: Non-Invasive Mapping
Video-EEG monitoring, high-resolution 3T Epilepsy-protocol MRI, PET/SPECT scans, and neuropsychological testing
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Phase 2: Stereo-EEG (sEEG) or Grid Placement
(If Phase 1 is inconclusive) Depth electrode placement (sEEG) or subdural grids implanted directly to pinpoint exact seizure boundaries
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Cortical Functional Mapping
Electrical stimulation mapping or fMRI conducted to identify and preserve critical motor, language, and memory areas
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Definitive Surgical Intervention
Targeted resection, laser ablation, disconnection, or neuromodulation device implantation based on mapped data