Drug-Resistant Epilepsy in Children: Surgical Management

What is pediatric epilepsy & how common is it?

Epilepsy is a symptom, not a single disease entity.

Epilepsy refers to a predisposition of the brain to generate recurrent, unprovoked electrical discharges that manifest clinically as seizures. In childhood, the overall prevalence is estimated at several children per 1,000, with higher incidence during the first year of life.

Many children have benign, self-limited syndromes (e.g., benign rolandic epilepsy), while others present with complex generalized or focal epilepsies that can be difficult to control. In approximately 10–20% of cases, epilepsy evolves into drug-resistant epilepsy.

What does drug-resistant epilepsy mean?

The use of two or more medications alone does not automatically imply “resistance” — specific criteria apply.

Drug-resistant (medically intractable) epilepsy is defined when, despite appropriate selection and adequate trials of at least two antiseizure medications (as monotherapy or in combination), seizures remain inadequately controlled.

In practice, children who fail two well-tolerated and properly titrated regimens have a low probability of achieving complete seizure freedom with additional medications. In such cases, epilepsy surgery or other advanced therapies should be considered early.

How does epilepsy in children differ from adults?

The developing brain is more vulnerable to seizures but also exhibits greater plasticity. Children’s brains are capable of functional reorganization following surgery.

Children more commonly exhibit:

• distinct pediatric epilepsy syndromes,
• extratemporal foci and multilobar abnormalities,
• cortical developmental malformations and other congenital anomalies.

Recurrent seizures in the developing brain can result in delays in language, learning difficulties, behavioral challenges, and cognitive decline. For this reason, early seizure control is critical.

Conversely, the pediatric brain demonstrates greater neuroplasticity, allowing functions (such as language) to be reorganized to other regions or even to the contralateral hemisphere. This often permits more extensive surgical approaches while preserving acceptable functional outcomes.

When should surgical treatment be considered?

Not as a “last resort,” but as an active therapeutic option when seizures are not controlled with medication.

A child with epilepsy should be referred to a specialized epilepsy center when:

• there has been failure of at least two appropriate antiseizure medications,
• seizures remain frequent or severe and impair development,
• there is a structural brain lesion (tumor, malformation, vascular abnormality, etc.),
• the child has a syndrome known to frequently progress to drug-resistant epilepsy (e.g., Rasmussen encephalitis, extensive cortical dysplasia, hemimegalencephaly).

Decisions are made carefully, but should not be unnecessarily delayed. Each period of uncontrolled seizures carries a cost to cognitive and psychosocial development.

How is the preoperative evaluation performed?

A multi-level assessment by a specialized team. Epilepsy surgery involves coordinated evaluation and care across multiple medical disciplines.

Surgical candidacy is determined by a multidisciplinary team (pediatric neurologist/epileptologist, neurosurgeon, neuropsychologist, neuroradiologist). This typically includes:

• High-resolution brain MRI — to identify structural abnormalities (tumors, malformations, gliosis, vascular lesions, etc.).
• Video-EEG monitoring — simultaneous seizure recording with video and EEG to localize the epileptogenic zone and characterize seizure type.
• Neuropsychological assessment — evaluation of memory, language, attention, and behavior to establish a baseline prior to surgery.
• When indicated: PET, SPECT, MEG, functional MRI (fMRI), TMS, and hemispheric dominance testing for detailed mapping of the epileptogenic focus and eloquent cortex (language, motor, visual pathways).

If noninvasive studies are insufficient, intracranial monitoring may be required with implantation of electrodes (subdural grids, depth electrodes, or stereo-EEG) for precise mapping. This invasive monitoring phase is referred to as Phase II.

What are the main types of surgical procedures?

Procedures fall into three categories: resection of the epileptogenic focus, disconnection, and neuromodulation.

The principal categories include:

• Resections — removal of the epileptogenic zone (e.g., tumor, cortical dysplasia, mesial temporal sclerosis).
• Multilobar resections, functional hemispherectomy — for extensive, unilateral hemispheric disease.
• Disconnection procedures — corpus callosotomy, multiple subpial transections (MST) to limit seizure propagation.
• Neuromodulation — primarily vagus nerve stimulation (VNS) in children as a palliative, nondestructive option.

For each child, the treatment plan is fully individualized, based on seizure type, anatomical localization, age, and pre-existing neurological status.

What are resections, multilobar procedures & hemispherectomy?

When a discrete focus is identified, targeted resection can offer true cure.

Focal resections & removal of the epileptogenic zone

These involve excision of a limited region of brain responsible for seizure generation — such as a tumor, cavernous malformation, cortical dysplasia, or post-traumatic/infectious gliosis. Procedures are often guided by intraoperative electrocorticography and functional mapping of language and motor areas.

Temporal lobe resections

Pediatric temporal lobe epilepsy may arise from hippocampal sclerosis as well as neocortical lesions (tumors, dysplasias). Surgery may involve anterior temporal lobectomy with or without selective amygdalohippocampectomy, depending on lesion type and language localization.

Multilobar procedures & functional hemispherectomy

In extensive hemispheric pathologies (e.g., Rasmussen encephalitis, large perinatal strokes, hemimegalencephaly, Sturge–Weber syndrome), functional hemispherectomy may be required, combining resection and disconnection of the affected hemisphere.

These children typically already have established hemiparesis and significant functional impairment from ongoing seizures. Postoperatively, they may develop a circumducting gait and loss of fine motor function in the contralateral hand, but in a large proportion they remain seizure-free without additional cognitive decline.

What are disconnection procedures?

When definitive cure is not feasible, the goal becomes substantial reduction in seizure severity.

Corpus callosotomy

Sectioning the corpus callosum prevents seizure spread from one hemisphere to the other. It is typically a palliative procedure for children with generalized or multifocal epilepsy and severe “drop attacks” (tonic/atonic seizures) associated with frequent injury.

The section may be partial (anterior ½–⅔) or complete. Possible transient effects include leg weakness, speech disturbances, or in complete sections, disconnection syndromes (more common in older children/adults). In younger children, functional consequences are generally mild.

Multiple subpial transections (MST)

Multiple subpial transections involve making superficial vertical cuts through the cortex, interrupting horizontal fibers to limit seizure propagation while preserving vertical fibers in eloquent cortex (e.g., motor, language areas). They are primarily used in functional regions where complete resection is not feasible. Although less effective than complete lesionectomy, in selected cases MST can significantly reduce seizure frequency and severity.

What is neuromodulation and when is it used?

When there is no clearly resectable focus, neuromodulation may be employed as a palliative adjunct to medication.

In children, the most established modality is vagus nerve stimulation (VNS). A small pulse generator is implanted in the chest wall and connected to an electrode wrapped around the left vagus nerve in the neck.

VNS is a palliative therapy: approximately 50–60% of children experience a greater than 50% reduction in seizure frequency, and a smaller proportion may achieve near-complete remission. It does not replace potentially curative resection when a clear focus exists, but is valuable in:

• multifocal or generalized epilepsy without a surgical target,
• children who are not candidates for major surgery,
• cases requiring adjunctive therapy alongside medications.

Other neuromodulation techniques (deep brain stimulation/DBS, responsive neurostimulation/RNS) are primarily studied in adults and applied selectively in pediatric patients.

What are the outcomes & prognosis after surgery?

The objective is “as few seizures as possible, with the best possible functional outcome.”

Outcomes depend on procedure type, underlying etiology, and patient age. In general:

• After functional hemispherectomy, seizure freedom rates approach 80–90%.
• In well-localized focal resections (tumors, dysplasias), a substantial proportion of children become completely or nearly seizure-free.
• In palliative procedures (corpus callosotomy, VNS), the goal is reduction in severity and frequency, particularly of falls and prolonged seizures.

Improvements are expected not only in seizure burden, but also in attention, behavior, sleep, and daily independence. The earlier seizures are controlled, the greater the likelihood of favorable long-term development.

Practical considerations, rehabilitation & family support

Epilepsy surgery is only the first chapter; ongoing care, rehabilitation, and psychosocial support are equally important.

After surgery, follow-up is coordinated with:

• a pediatric neurologist for medication adjustment,
• a neuropsychologist for cognitive evaluation and support,
• physical and occupational therapists where neurological deficits exist,
• the school system and special education services for individualized educational planning.

At Neuroknife, we encourage active parental participation in decision-making, provide access to support networks, and when possible connect families with others who have undergone similar experiences.