Drug-Resistant Epilepsy

Introduction

If you or a family member has been told that the seizures are not coming under control despite trying medications, the label you may have heard is “drug-resistant epilepsy.” It is also called refractory or intractable epilepsy. The label can feel heavy, but in clinical practice it is mainly a signal — it tells the treating team that standard prescriptions alone are not enough and that care needs to move to a more specialised level.

This is important because the options that open up at this stage are real and varied. They include detailed evaluation at an epilepsy centre, newer anti-seizure medications, surgery to remove or disconnect the part of the brain causing seizures, implanted devices that change abnormal electrical activity, and dietary therapies such as the ketogenic diet. For a substantial proportion of people, one of these approaches reduces seizures meaningfully, and for some it leads to long periods of seizure freedom.

This guide is written for readers who already know epilepsy is part of their life and who are now thinking about what comes next. It explains what drug-resistant epilepsy means, how it is investigated, what treatments are available beyond standard medication, and how to live more safely and confidently with a condition that is still being actively managed.

What Is Drug-Resistant Epilepsy?

Epilepsy is a condition in which the brain has a tendency to produce seizures — sudden bursts of abnormal electrical activity that briefly change movement, awareness, sensation, or behaviour. Most people with epilepsy achieve good seizure control with one or two well-chosen anti-seizure medications. But around a third do not, and this is the group that comes under the label of drug-resistant epilepsy.

The most widely used definition comes from the International League Against Epilepsy (ILAE). It defines drug-resistant epilepsy as the failure of adequate trials of two appropriately chosen, well-tolerated anti-seizure medications — whether taken alone or in combination to achieve sustained seizure freedom. Two points are worth underlining:

• “Appropriately chosen” means the medications must be suitable for the patient’s seizure type and used at the right dose for long enough to judge their effect. A medication that was stopped early because of side effects, or that was wrong for the seizure type, does not count as a true trial.
• “Sustained seizure freedom” typically means going at least three times the longest pre-treatment seizure-free interval, or at least 12 months without seizures, whichever is longer.

The label does not mean treatment has failed. It does mean that the next steps should be guided by specialists experienced in difficult-to-control epilepsy, often at a comprehensive epilepsy centre where advanced testing and the full range of treatment options are available.

Drug-resistant epilepsy can affect children and adults. It can occur in people with a visible cause on brain scans — such as a scar, malformation, or tumour — and in people whose scans look normal. It can occur in well-known epilepsy syndromes and in epilepsy with no clear genetic or structural explanation.

Types and Causes of Drug-Resistant Epilepsy

Drug-resistant epilepsy is not a single disease. It is an outcome that can arise from many different underlying epilepsies. Understanding the underlying type matters because it strongly shapes what treatments are likely to help.

Focal Epilepsy

In focal epilepsy, seizures begin in one specific area of the brain. This area is sometimes called the seizure focus or epileptogenic zone. Focal epilepsies are the most common type of drug-resistant epilepsy in adults. They are also the type for which surgical treatment is most often considered, because identifying and removing or disconnecting the focus can dramatically reduce seizures.

Common underlying causes of focal drug-resistant epilepsy include:

• Mesial temporal sclerosis — a scarring pattern in the inner part of the temporal lobe, often associated with a history of prolonged febrile seizures in childhood
• Focal cortical dysplasia — an area of abnormally developed brain tissue present from birth
• Brain tumours, often slow-growing ones such as low-grade gliomas or gangliogliomas
• Cavernous malformations and other vascular abnormalities
• Post-stroke or post-traumatic scarring
• Old brain infections such as neurocysticercosis, tuberculoma, herpes encephalitis, or meningitis

Generalised Epilepsy

In generalised epilepsy, seizures appear to involve both sides of the brain from the start. Most generalised epilepsies respond well to medication, but a minority do not. When a generalised epilepsy is drug-resistant, treatment focuses on optimising medications, considering dietary therapy, and in some cases neurostimulation devices.

Epileptic Encephalopathies and Developmental Epilepsies

Some severe epilepsies start in infancy or childhood and combine frequent seizures with significant effects on development. Examples include Lennox–Gastaut syndrome, Dravet syndrome, infantile epileptic spasms syndrome (formerly West syndrome), and other genetic developmental and epileptic encephalopathies. These are commonly drug-resistant and often require a combination of medications, dietary therapy, and sometimes surgical procedures such as corpus callosotomy or hemispherotomy. These are discussed further in the paediatric section.

Risk Factors for Becoming Drug-Resistant

It is not always possible to predict who will become drug-resistant, but published series consistently identify several factors associated with higher risk:

• A high seizure frequency before treatment is started
• A history of status epilepticus (prolonged seizures)
• An identifiable structural cause on brain imaging
• Onset of epilepsy in infancy or very early childhood
• Certain known epilepsy syndromes
• Co-existing developmental or intellectual disability
• A poor response to the first medication tried

These factors do not determine the outcome — they simply help clinicians decide who should be referred for specialised evaluation earlier rather than later.

Recognising That Seizures Are Not Well Controlled

Because you are reading this with a diagnosis already in place, this section is not about identifying epilepsy from scratch. It is about recognising patterns that suggest seizures are not well controlled and that the care plan may need to change.

Signs that current treatment is not achieving good control include:

• Seizures continuing at the same frequency, or increasing, despite taking medication as prescribed
• Breakthrough seizures during the day or from sleep
• Injuries during seizures — falls, burns, tongue biting, accidents
• Episodes of confusion, memory loss, or unusual behaviour that may be subtle seizures
• Side effects from medication that are limiting daily life — severe tiredness, mood changes, problems with thinking, unsteadiness
• Clusters of seizures occurring close together
• Any episode of status epilepticus (a seizure lasting more than five minutes or repeated seizures without recovery in between)

If any of these are happening, a reassessment by a neurologist — and ideally an epileptologist, a neurologist with additional training in epilepsy — is appropriate. Earlier referral to an epilepsy centre is favoured by current professional guidelines, rather than waiting many years through repeated medication trials.

Diagnosis and Pre-Surgical Evaluation

When epilepsy is drug-resistant, evaluation becomes more detailed than in the early stages of the condition. The aim is twofold: to confirm that the events really are epileptic seizures (some events that look like seizures are not), and to locate as precisely as possible where they are coming from in the brain.

Re-Examining the Diagnosis

An important first step at a specialist centre is to confirm that the diagnosis is correct. A meaningful proportion of people referred for “drug-resistant epilepsy” turn out to have non-epileptic events — for example, psychogenic non-epileptic seizures, fainting episodes (syncope), or movement disorders — that look similar to seizures but need different treatment. Misdiagnosis is a recognised reason for apparent drug resistance.

EEG and Video EEG Monitoring

An electroencephalogram (EEG) records the brain’s electrical activity through small sensors placed on the scalp. A routine EEG lasts about 20–30 minutes. In drug-resistant epilepsy, longer recordings are usually needed.

Long-term video EEG monitoring records brain activity and video of the patient continuously, often over several days in hospital. The aim is to capture actual seizures, which lets the team see exactly what happens clinically and in the EEG at the same time. This is the single most important test in pre-surgical evaluation. Medications are sometimes reduced during admission to make seizures more likely to occur.

Brain Imaging

An MRI scan performed using an epilepsy-specific protocol is the standard imaging test. Standard general MRI scans can miss subtle abnormalities such as small areas of cortical dysplasia, so review by a neuroradiologist familiar with epilepsy is important.

• PET scan (positron emission tomography) — shows areas of reduced brain metabolism that may correspond to the seizure focus
• SPECT scan (single photon emission computed tomography) — can show changes in blood flow during a seizure when performed at the right moment
• MEG (magnetoencephalography) — available at some specialist centres, detects magnetic fields produced by brain activity
• Functional MRI (fMRI) — maps areas of the brain involved in language, movement, and memory

Neuropsychological Assessment

Detailed testing of memory, language, attention, and other thinking skills helps localise the brain area producing seizures and predicts how surgery might affect cognitive function.

Invasive EEG (Intracranial Monitoring)

When scalp EEG and imaging do not give a clear answer, electrodes may be placed directly on or into the brain to record activity from inside. Two main approaches are used:

• Stereo-EEG (sEEG) — thin electrodes are placed through small holes in the skull into specific brain regions
• Subdural grids and strips — flat electrode arrays placed on the brain surface through a larger opening

Invasive monitoring is only done when it is likely to change the treatment plan, typically to confirm the seizure focus before surgery.

Genetic Testing

Genetic testing is now part of the work-up for many drug-resistant epilepsies, particularly those that begin in infancy or childhood, that occur in the context of developmental delay, or that fit a recognised genetic syndrome. Identifying a genetic cause can guide treatment choices — for example, certain genetic epilepsies respond better to specific medications, and some respond poorly to commonly used drugs.

Treatment and Management

Treatment of drug-resistant epilepsy is individualised. The right combination of approaches depends on the type of epilepsy, the location and number of seizure foci, the patient’s age and other medical conditions, and the family’s priorities. Several options are usually considered together rather than in strict sequence.

Optimising Medications

Medications remain the backbone of care, even when they have not produced seizure freedom. At a specialist epilepsy centre, the medication review typically covers:

• Whether previous drugs were truly trialled at adequate doses and durations
• Whether the chosen medications match the seizure type — some drugs that work well for focal seizures can worsen generalised seizures, and vice versa
• Whether newer anti-seizure medications might be helpful — options such as lacosamide, perampanel, brivaracetam, eslicarbazepine, and cenobamate have expanded what is available
• Whether drug interactions or non-epilepsy medications are interfering with control
• Whether side effects are limiting the dose of an otherwise useful drug

For some specific epilepsies, particular medications have a stronger evidence base. For example, plant-derived purified cannabidiol in pharmaceutical-grade form is approved in many countries for seizures in Dravet syndrome, Lennox–Gastaut syndrome, and tuberous sclerosis complex. Availability and regulatory status of specific newer medications vary by country.

Epilepsy Surgery

Surgery is one of the most effective treatments for selected people with focal drug-resistant epilepsy. The principle is to remove or disconnect the area of brain producing seizures while protecting areas important for movement, language, vision, and memory. Despite strong evidence, epilepsy surgery is still under-used worldwide, partly because of late referral.

Major types of epilepsy surgery include:

• Resective surgery — removing the seizure focus. Anterior temporal lobectomy, the most common epilepsy operation, is performed for temporal lobe epilepsy and produces seizure freedom in a substantial proportion of carefully selected patients. Lesional surgery removes a specific lesion such as a tumour or cortical dysplasia.
• Disconnective surgery — cutting connections rather than removing tissue. Examples include hemispherotomy (used mainly in children with severe one-sided brain disease) and corpus callosotomy (used to reduce drop attacks in severe generalised epilepsies).
• Laser interstitial thermal therapy (LITT) — a minimally invasive technique that uses MRI-guided laser energy to destroy a small target area of brain tissue. It is increasingly used for selected mesial temporal lesions and small focal targets.
• Multiple subpial transections — a less common procedure used when the seizure focus is in an area that cannot safely be removed.

Success rates depend heavily on the underlying cause and the type of surgery. Temporal lobe surgery for clear mesial temporal sclerosis has high rates of long-term seizure freedom. Surgery in normal-MRI epilepsy or extra-temporal epilepsy has lower but still meaningful rates of benefit. The pre-surgical evaluation is designed to estimate this for each individual.

Neurostimulation Devices

When surgery is not suitable — because seizures come from more than one place, because the focus overlaps eloquent brain areas, or because surgery has failed or been declined — implanted devices that modulate brain electrical activity are an option. They rarely produce complete seizure freedom but often reduce seizure frequency and severity over time.

• Vagus nerve stimulation (VNS) — a small device implanted under the skin of the chest delivers regular electrical pulses to the vagus nerve in the neck. It is approved for focal and generalised drug-resistant epilepsies in adults and children. The effect typically builds gradually over months.
• Responsive neurostimulation (RNS) — a device implanted in the skull with electrodes placed at one or two seizure foci. It detects abnormal activity and delivers stimulation in response. RNS is used when surgery is not possible, particularly when seizures arise from two foci or from an eloquent area.
• Deep brain stimulation (DBS) — electrodes placed in the anterior nucleus of the thalamus deliver continuous stimulation. It is used for focal drug-resistant epilepsy that is not surgically resectable.

Availability of RNS and DBS for epilepsy is more limited than VNS and depends on the centre.

Dietary Therapy

Specific medical diets can reduce seizures in some forms of drug-resistant epilepsy. They have been most studied in children but are also used in adults. They are not casual diets — they require dietitian-led planning and monitoring.

• Classical ketogenic diet — very high in fat, very low in carbohydrate, with controlled protein, designed to shift the body into using ketones for fuel. Used particularly in childhood epilepsies including Dravet syndrome, Lennox–Gastaut syndrome, and glucose transporter 1 (GLUT1) deficiency.
• Modified Atkins diet — less restrictive, easier to follow in adolescents and adults.
• Low glycaemic index treatment (LGIT) — another less restrictive option.
• Medium chain triglyceride (MCT) ketogenic diet — a variation using MCT oils that allows somewhat more carbohydrate.

Dietary therapy requires monitoring of growth in children, blood lipids, kidney stones, gastrointestinal effects, and overall nutrition. Many patients see benefit within a few months; if there is no clear benefit by around three months, the diet is usually stopped.

Treating Underlying Causes

In some cases, treating an identifiable underlying cause changes the picture entirely. Examples include surgery for a slow-growing brain tumour, treatment of an autoimmune encephalitis with immunotherapy, treatment of neurocysticercosis, or specific therapy for some metabolic causes of epilepsy.

Managing Co-Existing Conditions

Drug-resistant epilepsy often comes with other conditions — anxiety, depression, sleep problems, learning difficulties, attention problems, or migraine. These can worsen seizure control and quality of life. Treating them is part of comprehensive epilepsy care, not a separate concern.

Lifestyle and Self-Management

Day-to-day choices affect seizure frequency for many people, and a strong self-management routine works alongside medical treatment rather than instead of it.

Medication Adherence

Missed doses are one of the most common reasons for seizure breakthrough. Strategies that help include pill organisers, phone alarms, linking doses to fixed daily activities, keeping a small supply ahead so you do not run out, and discussing schedules that are realistic for shift work or travel.

Sleep

Sleep deprivation is a strong seizure trigger. Regular bed and wake times, adequate sleep duration, and evaluation for sleep disorders such as obstructive sleep apnoea are important.

Alcohol, Recreational Drugs, and Stimulants

Alcohol — particularly heavy or binge drinking and withdrawal — lowers seizure threshold. Recreational drugs can trigger seizures and can interact with anti-seizure medications. Caffeine and energy drinks affect some people.

Stress

Stress is one of the most commonly reported triggers. Approaches that help may include regular exercise, structured relaxation techniques, mindfulness-based programmes, and, when needed, mental health support.

Known Personal Triggers

For some people, specific triggers are clear — flashing lights and certain visual patterns in photosensitive epilepsy, hyperventilation, particular times of the menstrual cycle (catamenial epilepsy), illness with fever, or skipping meals. A seizure diary that records seizures alongside sleep, mood, menstrual cycle, missed doses, and any unusual events helps identify patterns.

Safety at Home and Outdoors

Reducing the harm seizures can cause is as important as reducing their frequency:

• Showers rather than baths, or supervised bathing
• Caution with cooking — back burners, microwave use, avoiding hot oils when alone
• Avoiding swimming alone; using a buoyancy aid where appropriate
• Ladders, heights, and operating heavy machinery require individual risk assessment
• Wearing identification (a medical bracelet or card) that mentions epilepsy and current medications

Driving

Driving regulations for people with active seizures exist in every country and typically require a seizure-free period before a licence can be held or renewed. The specific rules vary; check current local regulations with your treating neurologist.

Work and Education

Workplace and school accommodations — flexible hours after a seizure, breaks during the day, avoiding particular hazards — can make ongoing employment and study sustainable. A frank conversation with an occupational health team or school can help, with appropriate confidentiality.

Monitoring and Long-Term Follow-Up

Drug-resistant epilepsy is a long-term condition and care continues even when seizures improve. Regular follow-up usually covers:

• Seizure frequency, severity, and any pattern changes
• Medication side effects, blood tests where relevant (some medications require periodic checks), and bone health on long-term therapy
• Mood, cognition, and quality of life
• For women of reproductive age: contraception planning, because some anti-seizure medications interact with hormonal contraceptives, and pre-pregnancy planning, because some medications carry higher risks to a developing baby than others
• Bone density in long-term users of certain medications
• Review of whether new treatment options have become appropriate

Periodic re-evaluation is important because the picture can change — new medications become available, new evidence emerges, and a person who was not initially a surgical candidate may become one with better imaging or a different evaluation approach.

Complications and SUDEP

Uncontrolled seizures carry real risks. Honest awareness of these risks is part of managing the condition, not a reason for fear.

• Injuries — falls, burns, fractures, dental and tongue injuries, and road traffic accidents
• Status epilepticus — a prolonged seizure or repeated seizures without recovery, which is a medical emergency
• Cognitive and memory difficulties — from frequent seizures, side effects of medication, or the underlying brain condition
• Mental health — depression and anxiety are more common in people with drug-resistant epilepsy than in the general population, and they affect quality of life as much as seizures themselves
• Sudden unexpected death in epilepsy (SUDEP) — a rare but serious risk, in which a person with epilepsy dies suddenly with no other clear cause, typically during or after a seizure, often during sleep

SUDEP and How It Is Reduced

SUDEP is rare but its risk is higher in drug-resistant epilepsy, especially in people with frequent generalised tonic-clonic seizures. Factors associated with reduced SUDEP risk include better seizure control — particularly fewer night-time tonic-clonic seizures — good medication adherence, and not sleeping alone where possible. Seizure monitors and bed alarms are used by some families. Talking about SUDEP with the treating team is appropriate at any stage of care.

When to Seek Urgent Care

Most seizures are short and self-limiting. Some situations need emergency medical attention:

• A seizure lasting more than five minutes, or repeated seizures without full recovery in between (possible status epilepticus)
• A first-ever seizure of a new type
• Serious injury during a seizure — head injury, suspected fracture, burn, near-drowning
• Difficulty breathing or blue colour that does not resolve as the seizure ends
• A seizure during pregnancy
• An unexplained sudden increase in seizure frequency or a change in seizure character

Drug-resistant epilepsy in children deserves separate attention because the conditions, treatment priorities, and considerations differ from adults.

Common Childhood Drug-Resistant Epilepsies

Some epilepsies that frequently become drug-resistant in childhood include:

• Infantile epileptic spasms syndrome (previously West syndrome) — characterised by clusters of spasms in infants, often with a specific EEG pattern called hypsarrhythmia. Early treatment, often with hormonal therapy (ACTH or oral steroids) or vigabatrin, is important.
• Dravet syndrome — a genetic developmental and epileptic encephalopathy, typically starting in the first year of life. Some commonly used anti-seizure medications can worsen Dravet syndrome, which is why a genetic diagnosis matters.
• Lennox–Gastaut syndrome — multiple seizure types, characteristic EEG, and significant cognitive impact.
• Tuberous sclerosis complex — a genetic condition with multi-organ involvement and a high rate of drug-resistant epilepsy; mTOR inhibitors are used in selected situations.
• Rasmussen encephalitis — a rare progressive condition affecting one hemisphere of the brain.

Why Early Referral Matters

In children, ongoing seizures and the medications used to treat them can affect brain development. For this reason, paediatric epilepsy guidance favours early referral to a specialist centre rather than long sequences of drug trials. Children who are candidates for surgery often do better the earlier surgery is performed.

Treatment Approaches in Children

The treatment options described above — medication optimisation, surgery, neurostimulation, and dietary therapy — all apply to children, with some differences in emphasis:

• Epilepsy surgery in children can include hemispherotomy (functionally disconnecting one hemisphere) for severe one-sided conditions such as hemimegalencephaly, Sturge–Weber syndrome, large strokes, and Rasmussen encephalitis. Children’s brains have considerable capacity to reorganise after early surgery.
• Ketogenic diet is particularly well established in childhood epilepsies and is one of the standard treatments for GLUT1 deficiency syndrome.
• VNS is used in children when surgery is not an option, including in Lennox–Gastaut syndrome.

Wider Considerations

Care for a child with drug-resistant epilepsy includes attention to learning, behaviour, communication, and motor skills. Early educational support, therapy services, and family support are part of comprehensive care, not optional extras. Siblings and parents also benefit from support and information.

Living Well with Drug-Resistant Epilepsy

Drug-resistant epilepsy can be a stable condition that fits around a meaningful life, even when it cannot be cured. Three points are worth holding in view.

First, the goal of treatment is not always full seizure freedom. For some people, seizure freedom is achievable through surgery or a new medication. For others, the goal is fewer seizures, less severe seizures, fewer side effects, and a wider, safer daily life. Both are legitimate aims and both can transform quality of life.

Second, mental health is not separate from epilepsy care. Depression, anxiety, and the strain of living with unpredictable events are common and treatable. Counselling, peer support groups, and where appropriate, medication for mood, are part of overall care.

Third, family and caregivers carry a real load. Their training in seizure first aid, in the use of any rescue medication, and in when to call for help is part of the patient’s safety. Support for caregivers — including respite, peer support, and access to clear information — is part of comprehensive epilepsy care.

Frequently Asked Questions

Does drug-resistant epilepsy mean I will never be seizure-free?

Not necessarily. The label means that two appropriate medications have not produced seizure freedom, but it does not mean further treatment cannot. For people with focal epilepsy and a clear seizure focus, surgery offers a real chance of long-term seizure freedom. For others, newer medications, dietary therapy, or neurostimulation may reduce seizures substantially, and some achieve seizure freedom over time.

Should I keep taking my medications even though seizures are continuing?

Yes, unless your treating neurologist tells you otherwise. Stopping anti-seizure medications suddenly can trigger severe seizures, including status epilepticus. Any change in medication should be planned and supervised.

How do I find out if I am a candidate for epilepsy surgery?

Referral to a comprehensive epilepsy centre is the next step. The centre will perform the detailed evaluation described above — long-term video EEG, specialised MRI, often functional imaging and neuropsychological testing — to determine whether surgery is an option and to estimate the likely benefits and risks for your specific situation.

How long does the pre-surgical evaluation take?

It varies. Some patients complete the evaluation over a few weeks of outpatient visits and one or two hospital admissions for video EEG. Others, especially those who need invasive EEG, take several months. The complexity reflects how carefully the team needs to weigh the benefits and risks for each individual.

Is the ketogenic diet just a low-carbohydrate diet?

No. The classical ketogenic diet is a medical diet with specific ratios of fat, protein, and carbohydrate, designed and monitored by a clinical team that includes a paediatric or adult dietitian experienced in epilepsy. Trying to self-administer it is not advisable; without monitoring, nutritional and metabolic complications can occur.

Can my child outgrow drug-resistant epilepsy?

Some childhood epilepsies do remit with age, although drug-resistant epilepsies are less likely to do so than other epilepsies. Each syndrome has its own typical course. The treating paediatric neurologist can describe what is known about the specific condition.

What is SUDEP and how worried should I be?

SUDEP is sudden unexpected death in epilepsy, a rare event in which a person dies with no other cause found, typically during or after a seizure. The overall risk is low, and it is higher in people with frequent generalised tonic-clonic seizures, especially night-time ones. Reducing this risk is one of the reasons for working towards better seizure control. Talking openly with the treating team about SUDEP is appropriate.

Can women with drug-resistant epilepsy have children?

Yes, most women with epilepsy — including drug-resistant epilepsy — have healthy pregnancies and healthy babies. The key is pre-pregnancy planning: reviewing medications to choose those with the better safety profile in pregnancy where possible, taking high-dose folic acid as advised, and being followed during pregnancy by a team familiar with epilepsy. Stopping medication abruptly because of pregnancy plans is not safe.

Do I need to tell my employer?

This depends on your role, the type of seizures, and local laws. Roles involving driving, heights, machinery, or sole responsibility for vulnerable people may require disclosure for safety. For many other roles it is a personal choice. Occupational health services can advise confidentially.

Are seizure-alert devices worth it?

Various wearable and bedside devices can detect convulsive seizures and alert a carer. Their accuracy varies, particularly for non-convulsive seizures. They are not a substitute for medical treatment but can add a safety layer for some families, especially when seizures occur in sleep.

Conclusion

Drug-resistant epilepsy is not a verdict. It is a turning point in care — the moment at which a different and more specialised set of options becomes appropriate. Detailed evaluation at a centre experienced in difficult epilepsy can clarify what is driving seizures and which combination of treatments is most likely to help: optimised medication, surgery, neurostimulation, dietary therapy, treatment of underlying causes, and structured day-to-day management.

For some people the path leads to long-term seizure freedom. For others it leads to fewer, less severe seizures and a fuller, safer life with epilepsy still present. Both outcomes are worth working towards. With accurate diagnosis, the right specialist team, attention to mental health and to family support, and ongoing review as new options emerge, people with drug-resistant epilepsy have real reasons for hope.