Focal seizures may begin with subtle symptoms that some people might not notice, such as a sudden feeling of fear, a tingling sensation in one part of the body, brief staring episodes, or repetitive involuntary movements. Although these symptoms may seem vague or unrelated to epilepsy, they can indicate abnormal electrical activity that begins in a specific area of the brain.Focal epilepsy is one of the most common types of epilepsy. Its symptoms and severity vary from person to person, depending on where the seizure begins in the brain and how far the electrical activity spreads. Seizures may occur while the person remains fully aware of their surroundings, or they may be accompanied by impaired awareness. In some cases, seizures can progress to involve the entire body.With advances in diagnostic and treatment methods, several options are now available to help control seizures and improve patients’ quality of life. These range from anti-seizure medications to surgery and neurostimulation techniques for suitable cases. Therefore, early recognition of symptoms and an understanding of the causes and potential risks are essential steps toward an accurate diagnosis and the most appropriate treatment.In this article from Dalili Medical, we will explore the symptoms, causes, and potential complications of focal epilepsy, how it is diagnosed, and the latest available treatment options. We will also explain which situations require urgent medical attention and answer frequently asked questions about this type of epilepsy.

1. What Is Focal Epilepsy?

Focal epilepsy is a type of epilepsy in which seizures begin due to abnormal electrical activity within a specific neural network in one hemisphere of the brain. Symptoms vary depending on the affected area and may include disturbances in movement, sensation, awareness, or emotions.

2. What Is the Difference Between a Focal Seizure and Focal Epilepsy?

A focal seizure is an individual event that originates in a specific area of the brain, whereas focal epilepsy is a neurological condition characterized by a predisposition to recurrent focal seizures. Experiencing a single seizure does not necessarily mean that a person has epilepsy, as the diagnosis depends on specific medical criteria.

3. Can Focal Epilepsy Occur Without Convulsions?

Yes. Focal seizures can occur without obvious convulsions. They may present as sensory changes, such as tingling, sudden emotional changes, repetitive automatic movements, or temporary disturbances in awareness. The symptoms depend on the area of the brain where the seizure begins.

4. Is Focal Epilepsy a Serious Condition?

The severity of focal epilepsy varies from person to person, depending on the type and frequency of seizures and the response to treatment. Some seizures may be brief and well controlled with medication, while others may cause falls or injuries. Abnormal electrical activity may also spread to both hemispheres of the brain, resulting in a bilateral tonic-clonic seizure involving the entire body. Therefore, obtaining an accurate diagnosis and following the prescribed treatment plan are essential.

5. Does Focal Epilepsy Affect Memory and Concentration?

Focal epilepsy may affect memory and attention in some patients, particularly when seizures are frequent or originate in brain regions responsible for memory. Sleep disturbances, mood changes, and certain medication side effects may also contribute to difficulties with concentration. A physician can identify potential causes and determine whether additional tests are needed.

6. Can People With Focal Epilepsy Lead Normal Lives?

Yes. Many people with focal epilepsy can study, work, and carry out their daily activities, particularly when seizures are controlled with appropriate treatment. However, safety precautions should be tailored to the nature of the seizures. Activities that could pose a risk if a sudden seizure occurs should be avoided or modified, and regular follow-up with a neurologist is important.

7. Can People With Focal Epilepsy Drive?

Driving eligibility depends on seizure control, the nature of the seizures, and the driving regulations in the patient's country of residence. Restrictions may apply for a specified period after a seizure. Patients should consult their physician and comply with all applicable medical and legal requirements before driving.

8. Can Focal Epilepsy Be Mistaken for Functional (Non-Epileptic) Seizures?

Yes. Some symptoms of focal seizures may resemble those of functional seizures, also known as psychogenic nonepileptic seizures (PNES). These are genuine episodes that are not caused by the abnormal electrical discharges typically associated with epileptic seizures. A person may also experience both conditions. Distinguishing between them requires a specialized medical assessment, and video-electroencephalography (video EEG) may be used when necessary to help determine the nature of the episodes.

Types of Focal Epilepsy

Focal seizures are classified according to the symptoms experienced by the person, the degree to which awareness is affected during the seizure, and the area of the brain where the abnormal electrical activity begins. A seizure may involve only mild sensory or emotional changes, cause involuntary movements, or temporarily impair awareness. In some cases, the electrical activity may spread to both hemispheres of the brain.

1. Focal Seizures With Preserved Awareness

In this type of seizure, the person remains conscious and aware of their surroundings throughout the episode. They may be able to speak, respond to others, and remember what happened after the seizure ends.

Common symptoms include:

• Numbness or tingling in a limb or another part of the body.

• Involuntary twitching of the hand or face.

• Sudden feelings of fear or an unusual sense of familiarity with a new situation.

• Perceiving smells or tastes that are not actually present.

• Nausea or a rising sensation moving from the stomach toward the chest.

• Temporary changes in vision, hearing, or other sensations.

This type was previously known as a simple partial seizure and is now referred to as a focal seizure with preserved awareness.

2. Focal Seizures With Impaired Awareness

In this type of seizure, the person's awareness or responsiveness to their surroundings is affected. They may appear distracted or confused, or they may be unable to respond normally during the episode. They may also have little or no memory of what occurred afterward.

Common symptoms include:

• Sudden staring and stopping the activity they were performing.

• Repetitive automatic movements, such as lip-smacking or chewing.

• Repeatedly rubbing the hands or fidgeting with clothing.

• Difficulty responding to questions or following instructions.

• Confusion, drowsiness, or fatigue after the seizure ends.

• Partial or complete inability to remember the events of the seizure.

This type was previously known as a complex partial seizure and is now referred to as a focal seizure with impaired awareness.

3. Focal Seizures With Motor Symptoms

These seizures are characterized by involuntary muscle movements caused by the involvement of brain regions responsible for motor control. The movements may be limited to a small part of the body or affect larger areas, depending on where the seizure begins and how the abnormal electrical activity spreads.

Common motor seizure patterns include:

• Clonic seizures: Characterized by repeated, relatively rhythmic muscle jerking.

• Tonic seizures: Involve sudden muscle stiffening.

• Myoclonic seizures: Present as brief, sudden muscle jerks.

• Automatisms: Involve repetitive automatic movements, such as chewing or moving the hands.

• Hyperkinetic seizures: May involve excessive, large, or unusual movements.

These symptoms may occur with preserved awareness or impaired awareness, depending on the nature of the seizure.

4. Focal Seizures With Non-Motor Symptoms

Not all focal seizures cause convulsions or obvious movements. Some may present as temporary changes in sensation, emotions, thinking, or autonomic bodily functions.

Common symptoms include:

• Sensory symptoms: Such as numbness or tingling, seeing unusual flashes of light, hearing strange sounds, or experiencing unfamiliar smells or tastes.

• Emotional symptoms: Such as sudden feelings of fear, anxiety, or changes in emotions without an apparent reason.

• Cognitive symptoms: Such as an unusual sense of familiarity (déjà vu), feeling that a situation has happened before, or temporary changes in thinking and memory.

• Autonomic symptoms: Such as nausea, sweating, changes in heart rate, or a tightening sensation in the stomach.

• Behavioral arrest: Such as suddenly stopping speaking or interrupting an activity for a brief period.

These symptoms vary depending on the brain region where the seizure begins. The presence of any single symptom alone is not sufficient to confirm a diagnosis of focal epilepsy.

5. Focal Seizures That Spread to Both Hemispheres of the Brain

Abnormal electrical activity may begin in a specific area of one hemisphere of the brain and then spread to both hemispheres, resulting in a focal-to-bilateral tonic-clonic seizure.

The seizure may initially present with focal symptoms, such as an unusual sensation or twitching in one limb, before progressing to loss of consciousness and body stiffening, followed by repeated jerking movements of the limbs.

It is important to distinguish this type of seizure from seizures that begin in neural networks distributed across both hemispheres from the outset. The spread of a focal seizure to both sides of the brain does not necessarily mean that the epilepsy is generalized in onset.

Causes of Focal Epilepsy

Focal epilepsy can have several causes. It may be associated with changes or damage in a specific area of the brain that affect the electrical activity of nerve cells. In some cases, it may result from genetic factors or disorders that affect brain development and function. However, the exact cause cannot always be identified, even after appropriate medical investigations.

The following are some of the main causes and risk factors associated with focal epilepsy.

1. Brain Injuries

Severe head injuries may damage brain tissue or cause changes and scarring within it, potentially increasing the likelihood of focal seizures. The level of risk depends on the severity and location of the injury and the extent of damage to the brain tissue.

2. Stroke

A stroke, whether caused by a blockage in a blood vessel or bleeding within the brain, may damage a specific area of brain tissue. The resulting changes may increase the risk of focal seizures, either shortly after the stroke or sometime later.

3. Brain Tumors

Certain brain tumors, whether benign or malignant, can affect the electrical activity of surrounding nerve cells, increasing the likelihood of focal seizures. The risk depends on the tumor's type, location, size, and effect on nearby tissues.

4. Brain Infections

Some infections affecting the nervous system, such as encephalitis or meningitis, may cause damage or changes in brain tissue, increasing the risk of focal epilepsy. In some individuals, a predisposition to seizures may persist even after the infection has resolved, depending on the severity of the inflammation and any resulting complications.

5. Genetic Factors

Some forms of focal epilepsy may be associated with genetic changes that affect how nerve cells function or how the brain develops. These changes may be inherited from a parent or arise for the first time in the affected individual. Therefore, the absence of a family history of epilepsy does not rule out a genetic contribution.

6. Brain Developmental Disorders

Certain differences in brain formation or development during pregnancy or childhood may increase susceptibility to focal seizures. These differences may include malformations of cortical development or abnormalities in the organization of nerve cells. Some can be detected using magnetic resonance imaging (MRI).

7. Immune and Metabolic Disorders

In some cases, focal epilepsy may be associated with autoimmune diseases that affect the brain and cause inflammation, potentially leading to seizures. Certain metabolic disorders may also contribute to seizures. However, acute metabolic disturbances can cause isolated, provoked seizures that do not necessarily indicate chronic epilepsy.

8. Unknown Causes

Despite advances in diagnostic methods, doctors cannot identify a clear cause of focal epilepsy in some patients, even after appropriate investigations, including electroencephalography (EEG) and magnetic resonance imaging (MRI).

This does not necessarily mean that no underlying cause exists. Rather, the changes responsible may be subtle or undetectable using currently available diagnostic methods.

How Is Focal Epilepsy Diagnosed?

The diagnosis of focal epilepsy relies on a combination of medical assessments and diagnostic tests that help determine the nature of the seizures and whether they result from abnormal electrical activity originating in a specific area of the brain. No single test is sufficient to confirm the diagnosis in every case. Instead, the physician considers the patient's medical history, neurological examination, electroencephalography (EEG) results, and medical imaging findings, depending on the individual patient's condition.

1. Medical History and Seizure Description

Understanding the details of the seizures is one of the most important steps in diagnosis. The physician asks the patient or their family members about the symptoms that occurred before, during, and after the episode.

The information the physician may seek includes:

• Symptoms preceding the seizure, such as sudden fear, tingling, or an unusual sense of familiarity.

• The nature, duration, and frequency of any involuntary movements during the seizure.

• Whether the patient remains aware and able to respond to people around them.

• Symptoms following the seizure, such as confusion, fatigue, or weakness in one limb.

• A history of previous head injuries, epilepsy in the family, or other neurological conditions.

• Medications the patient takes and any factors that may be associated with the seizures.

Recording a video of a seizure, when possible without compromising safety or delaying necessary assistance, may help the physician better understand its characteristics. The patient must never be placed at risk for the purpose of recording a video.

2. Medical and Neurological Examination

The physician performs a physical and neurological examination to assess the patient's overall condition and identify signs that may indicate a disorder affecting the nervous system or another possible cause of the symptoms.

Depending on the patient's needs, the examination may include assessments of muscle strength, sensation, balance, motor coordination, reflexes, and cognitive function.

The physician may also request additional tests, such as:

• Blood tests: To detect abnormalities in blood glucose, electrolytes, or other metabolic factors that may cause or contribute to seizures.

• Electrocardiogram (ECG): To help rule out certain heart rhythm disorders that can cause fainting or symptoms resembling epileptic seizures.

The required investigations are determined according to the patient's symptoms, medical history, and clinical examination findings.

3. Electroencephalography (EEG)

Electroencephalography is an important test when focal epilepsy is suspected. It records the brain's electrical activity using electrodes placed on the scalp and helps detect abnormal electrical patterns that may support an epilepsy diagnosis and assist in classifying seizures.

The physician may recommend one of the following types of EEG:

• Routine EEG: Performed over a relatively short period to record the brain's electrical activity.

• Sleep-deprived EEG: May help reveal electrical abnormalities that were not detected during the initial recording. It should be performed according to medical instructions.

• Prolonged EEG monitoring: Records brain activity over an extended period to increase the likelihood of detecting abnormal electrical activity.

• Video EEG monitoring: Combines video recording of the patient's behavior with EEG recording. It may help determine the nature of the episodes and distinguish epileptic seizures from conditions that resemble them.

Important note: A normal EEG does not rule out focal epilepsy, as abnormal electrical activity may not occur during the recording period. Therefore, the physician interprets the results alongside the patient's symptoms, medical history, and other test findings.

4. Brain Magnetic Resonance Imaging (MRI)

Magnetic resonance imaging helps identify structural abnormalities that may be associated with the onset of focal seizures. An epilepsy-specific MRI protocol may be used to obtain more detailed images of relevant brain regions.

MRI may help detect:

• Residual changes from previous brain injuries.

• Certain developmental abnormalities of brain tissue.

• Changes resulting from a previous stroke.

• Some brain tumors or lesions that may be associated with seizures.

• Other structural brain abnormalities that may help explain the symptoms.

Computed tomography (CT) may be used in certain emergency situations or when MRI cannot be performed.

A normal MRI does not necessarily mean that focal epilepsy is absent, as seizures can occur without visible abnormalities on medical imaging.

5. Distinguishing a Single Seizure From a Diagnosis of Epilepsy

Experiencing a single seizure does not necessarily mean that a person has epilepsy. Seizures may occur due to temporary factors, such as severe blood glucose or electrolyte disturbances, or certain acute medical conditions.

According to established diagnostic criteria, epilepsy may be diagnosed in the following circumstances:

• Two unprovoked seizures occurring more than 24 hours apart.

• One unprovoked seizure accompanied by a high estimated risk of further seizures, based on the physician's assessment and accepted medical criteria.

• A diagnosis of a recognized epilepsy syndrome.

The physician determines whether the episode is caused by epilepsy, a temporary underlying factor, or another condition that may produce symptoms resembling epileptic seizures.

When Should You Seek Medical Attention?

A first suspected epileptic seizure requires urgent medical evaluation. Emergency medical assistance should also be sought if a seizure lasts five minutes or longer, if seizures occur repeatedly without the person regaining consciousness between episodes, or if breathing difficulties or a serious injury occur.

Medication Treatment for Focal Epilepsy

First: Medications Used to Treat Focal Epilepsy

Treatment for focal epilepsy involves selecting the appropriate medication based on the patient’s age, seizure type, overall health, other medications they are taking, and the potential for side effects or drug interactions. The goal of treatment is to control seizures and reduce their frequency while maintaining the patient’s quality of life.

Several antiseizure medications are available and may be used alone or in combination with other medications. The neurologist determines the most appropriate option based on the individual patient’s needs.

1. Lamotrigine

Lamotrigine is a commonly used option for treating focal seizures in adults and children, depending on age and medical indication. It can be used as monotherapy or as part of a combination treatment plan.

Benefits and Precautions:

• It is used to control focal seizures and may be a suitable first-line option for many patients.

• The dose must be increased gradually according to the physician’s instructions, as rapid dose escalation may increase the risk of a serious skin rash.

• Possible side effects include dizziness, headache, nausea, and sleep disturbances.

• In rare cases, lamotrigine can cause severe skin reactions. Any new rash requires prompt medical evaluation, particularly if accompanied by fever, facial swelling, sores in the mouth or eyes, or blistering of the skin.

2. Levetiracetam

Levetiracetam is widely used to treat focal seizures. It may be prescribed alone or in combination with another medication if adequate seizure control is not achieved.

Benefits and Precautions:

• It is a common treatment option because it is relatively easy to use and has fewer drug interactions than some other antiseizure medications.

• It may cause drowsiness, dizziness, or fatigue.

• Mood or behavioral changes may occur, including nervousness, irritability, or aggression. Patients should inform their physician if they notice significant changes.

• Patients with impaired kidney function may require a dose adjustment.

• The medication should not be stopped abruptly without medical advice, as doing so may increase seizure frequency.

3. Carbamazepine

Carbamazepine is an effective medication for treating focal seizures. It may be used alone or as part of a treatment plan determined by the physician.

Key Precautions:

• It may cause dizziness, drowsiness, and balance problems, particularly at the beginning of treatment or after a dose increase.

• It may lower blood sodium levels or cause changes in blood cell counts.

• It interacts with several medications and may reduce the effectiveness of some hormonal contraceptives.

• Depending on the physician’s assessment, treatment may require periodic blood tests to monitor liver function, blood cell counts, and sodium levels.

• Carbamazepine may not be suitable for certain other seizure types, so the diagnosis should be confirmed before treatment begins.

4. Oxcarbazepine

Oxcarbazepine is used to treat focal seizures and may be prescribed alone or in combination with another medication, depending on the patient’s response to treatment.

Side Effects and Precautions:

• It may cause dizziness, drowsiness, nausea, and double vision.

• It may lower blood sodium levels, which can require monitoring through blood tests, particularly in patients at increased risk.

• It may affect the effectiveness of some hormonal contraceptives.

• Patients should inform their physician if they develop an unusual severe headache, confusion, or significant weakness, as these symptoms may be associated with low sodium levels.

5. Zonisamide

Zonisamide may be used to treat focal seizures in selected cases, either as monotherapy when indicated or as an add-on treatment.

Benefits and Precautions:

• It may help reduce seizure frequency in some patients.

• Possible side effects include drowsiness, dizziness, reduced appetite, and difficulty concentrating.

• It may increase the risk of kidney stones. Patients should follow their physician’s advice regarding fluid intake unless medically advised to restrict fluids.

• It may reduce sweating and cause an increase in body temperature, particularly in hot weather or during physical activity.

• Depending on the patient’s condition, the physician may monitor kidney function and blood bicarbonate levels.

6. Lacosamide

Lacosamide is used to treat focal seizures. Depending on the patient’s age and response to treatment, the physician may prescribe it alone or in combination with other medications.

Side Effects and Precautions:

• It may cause dizziness, nausea, headache, and balance problems.

• It may affect cardiac electrical conduction in some patients. An electrocardiogram (ECG) may therefore be needed before or during treatment, particularly in patients with heart conditions or those taking medications that affect heart rhythm.

• Patients should inform their physician if they experience fainting, palpitations, or severe dizziness, especially if these symptoms are new.

7. Other Medications for Focal Epilepsy

The physician may select other medications depending on seizure characteristics, treatment response, coexisting medical conditions, and potential side effects. These medications include:

• Topiramate: May be used alone or in combination with other medications. However, it may affect concentration and memory and can cause tingling sensations or kidney stones in some patients.

• Brivaracetam: Used to treat focal seizures. Possible side effects include drowsiness, dizziness, and mood or behavioral changes.

• Perampanel: May be used in selected cases. It can cause dizziness, drowsiness, and balance problems. Severe behavioral changes or aggression require prompt medical evaluation.

No single medication is best for every patient. The choice depends on balancing effectiveness, safety, drug interactions, and each patient’s individual needs.

Second: How Does the Physician Choose the Right Medication?

The physician considers several factors when selecting treatment, including:

1. Seizure type and diagnosis: To ensure that the medication is appropriate for the type of epilepsy.

2. Age and overall health: Including kidney and liver function and, when necessary, heart health.

3. Other medications: To avoid interactions that could affect treatment effectiveness or increase side effects.

4. Pregnancy or plans to become pregnant: Some medications carry risks for the developing fetus, and the treatment plan may need to be adjusted under specialist supervision.

5. Treatment response and tolerability: The physician may adjust the dose or change the medication if seizures continue or troublesome side effects occur.

If the first medication does not provide adequate seizure control, the physician may adjust the dose or switch to another suitable medication. A second medication may be added when necessary.

If seizures continue despite trials of two appropriate, tolerated, and suitably selected antiseizure medication regimens, the patient should be evaluated by an epilepsy specialist to consider advanced treatment options, including assessment for possible epilepsy surgery when appropriate.

Third: Important Guidelines for Taking Medication for Focal Epilepsy

• Take the medication at the prescribed times and follow the recommended dosage.

• Do not increase, reduce, or discontinue treatment without consulting the physician.

• Inform the physician about any new medication or dietary supplement because of the possibility of drug interactions.

• Do not automatically double the next dose after missing one. Instead, follow the physician’s instructions or the medication leaflet.

• Keep a record of seizures, including their timing and associated symptoms, to help assess treatment effectiveness.

• Seek urgent medical attention if a severe skin rash, difficulty breathing, fainting, or severe behavioral changes occur.

Surgical Treatment for Focal Epilepsy

Surgery is an important treatment option for some people with focal epilepsy, particularly when seizures continue despite trials of at least two appropriate, tolerated antiseizure medication regimens. The choice of procedure depends on where the seizures begin, their underlying cause, the results of diagnostic tests, and how close the seizure focus is to brain regions responsible for important functions such as speech, movement, and memory.

Surgery does not necessarily eliminate the need for medication, nor does it guarantee a complete cure for every patient. Each patient should be evaluated at a specialized epilepsy center to determine whether surgery is appropriate and to weigh its potential benefits against its risks.

First: Types of Surgery for Focal Epilepsy

1. Surgical Resection of the Epileptic Focus

This procedure is performed when the medical team can identify the area where seizures originate and determine that it can be removed without causing unacceptable neurological damage.

How Is the Procedure Performed?

• The patient is given anesthesia, usually general anesthesia.

• The neurosurgeon opens a section of the skull to access the targeted area.

• The team uses findings from magnetic resonance imaging (MRI), electroencephalography (EEG), and functional assessments to determine the location and boundaries of the seizure focus.

• The tissue responsible for initiating seizures is removed according to the surgical plan.

• The tissues and skull are closed, and the patient is transferred to the recovery area for monitoring.

In selected cases, intraoperative electrical mapping may be used to help identify the tissue responsible for seizures. The success of the procedure depends on accurately locating the seizure focus and determining whether it can be removed safely.

2. Anterior Temporal Lobectomy

Anterior temporal lobectomy is an established surgical procedure for certain cases of temporal lobe epilepsy, particularly when the symptoms and test results indicate a resectable seizure focus in this region.

How Is the Procedure Performed?

• The medical team identifies the target area based on the presurgical evaluation.

• The surgeon accesses the temporal lobe through an opening in the skull.

• The designated portion of the lobe is removed. Depending on the case, the procedure may include tissue associated with the seizure focus.

• The patient is monitored after surgery for complications or changes in neurological function.

What Are the Potential Risks?

Risks vary depending on the side of the operation and the location of the removed tissue. They may include changes in memory, language, or visual fields, as well as general surgical risks such as bleeding and infection. A detailed assessment of memory and language is therefore performed before surgery when indicated.

3. Amygdalohippocampectomy

This procedure may be used to treat certain cases of mesial temporal lobe epilepsy, particularly when diagnostic findings suggest that the hippocampus and adjacent tissues are involved in seizure onset.

How Is the Procedure Performed?

• The medical team determines the location of the hippocampus and amygdala and their relationship to surrounding structures.

• The surgeon accesses the area through a planned surgical approach.

• The targeted tissue is removed according to the surgical plan.

• Neurological functions, particularly memory, are monitored after surgery.

In some cases, selective amygdalohippocampectomy may be performed, while anterior temporal lobectomy may be more appropriate in others. The decision depends on the location of the seizure focus, the assessment results, the expected benefits, and the potential risks to memory.

4. MRI-Guided Laser Interstitial Thermal Therapy (LITT)

Laser interstitial thermal therapy is less invasive than traditional open-skull surgery and may be used in selected cases, including some involving deep-seated brain lesions or seizure foci.

How Is the Procedure Performed?

• The team identifies the target tissue using imaging and presurgical assessments.

• The surgeon inserts a thin probe through a small opening in the skull.

• Laser energy is used to heat and destroy the targeted tissue in a controlled manner.

• MRI is used to monitor the procedure and temperature, depending on the technology available.

• The probe is removed, and the patient is monitored after the procedure.

Benefits and Limitations

This procedure may reduce incision size and recovery time for some patients, but it is not suitable for every type of focal epilepsy. Outcomes vary according to the location and cause of the seizure focus, and seizures may persist or additional treatment may be required.

5. Surgery Guided by Functional Brain Mapping

When the seizure focus is close to areas responsible for speech, movement, or other important neurological functions, the medical team may use additional techniques to identify and protect these areas as much as possible.

These techniques may include:

• Functional brain mapping: Identifies areas responsible for language, movement, and other functions before surgery.

• Intraoperative electrical stimulation: Helps identify functional brain regions in appropriate cases.

• Awake surgery: The team may keep the patient awake for a specific portion of the procedure to assess speech or movement directly.

Awake surgery is not used for every patient. The decision depends on the location of the seizure focus, the type of procedure, the patient’s condition, and the specialist team’s assessment.

Second: Neuromodulation When Resection Is Not Appropriate

If the seizure focus is located in an area that cannot be safely removed, or if seizures involve multiple neural networks, the medical team may discuss neuromodulation options. These procedures aim to reduce seizure frequency and severity, but they do not guarantee complete seizure freedom.

1. Vagus Nerve Stimulation (VNS)

How Is the Procedure Performed?

• A small device is implanted under the skin in the chest.

• A wire connects the device to the vagus nerve in the neck.

• The device delivers programmed electrical impulses intended to help reduce seizures.

This option may be considered for patients who are not suitable candidates for resective surgery or whose seizures have not been adequately controlled by previous treatments.

2. Responsive Neurostimulation (RNS)

How Is the Procedure Performed?

• A device is implanted to monitor electrical activity in specific brain regions associated with seizures.

• The device detects abnormal activity patterns according to its programming.

• It delivers electrical stimulation in response to detected activity, with the aim of limiting seizure development.

This procedure is used in selected cases, depending on the number and location of seizure foci, eligibility criteria, and regulatory availability of the technology.

3. Deep Brain Stimulation (DBS)

How Is the Procedure Performed?

• Electrodes are implanted in a specific target within the brain.

• The electrodes are connected to a device that generates electrical pulses.

• Stimulation settings are adjusted during medical follow-up according to the patient’s response.

This procedure may help reduce seizures in some patients, but it is not a guaranteed cure, and antiseizure medications may still be required.

Third: How Is a Suitable Candidate for Epilepsy Surgery Identified?

Before a decision is made, the patient generally undergoes a comprehensive evaluation at a specialized epilepsy center. This may include:

1. Video-EEG monitoring: Records seizures and correlates symptoms with the brain’s electrical activity.

2. Epilepsy-protocol MRI: Looks for structural abnormalities that may be responsible for seizures.

3. Neuropsychological assessment: Evaluates memory, attention, language, and cognitive functions.

4. Additional functional imaging: Such as positron emission tomography (PET) or single-photon emission computed tomography (SPECT), when indicated.

5. Intracranial EEG monitoring: Used in selected cases when noninvasive tests are insufficient to locate the seizure focus accurately.