Neurology: Epilepsy

• Diagnosis: What is Epilepsy? | Seizure Types | Epilepsy Syndromes | Blackouts: Seizure, Syncope or Something Else? | Investigating Seizures
• Treatment: Starting Treatment | Choosing an Antiseizure Medicine | Antiseizure Medicines: Side Effects and Interactions | Drug-resistant Epilepsy | Stopping Treatment
• Living with epilepsy: Women, Contraception and Pregnancy | Valproate Safety | Driving and Epilepsy | Safety, SUDEP and Rescue Medication | Older People and Other Groups | Dissociative (Non-epileptic) Seizures
• Revision: Drug Reference Table | Spot the Diagnosis | Exam-style Scenarios | Key Points | Guidelines and Further Reading

⚡ Epilepsy affects about 1 in 100 people in the UK. Getting the diagnosis right matters: misdiagnosis is common (often syncope or dissociative seizures), and the label affects driving, work, pregnancy and insurance. Most people become seizure-free with the right medicine. Status epilepticus and first-seizure assessment in ED are covered in the Neurological Emergencies chapter.
Your four questions for every patient: Was this really an epileptic seizure (eyewitness account)? Was it provoked, or is there an ongoing tendency? Which seizure type or syndrome is it, so the right drug is chosen? What does the patient need to know about driving, safety, pregnancy and SUDEP?

What is Epilepsy?

• Seizure: A brief episode of abnormal, excessive electrical activity in the brain, causing changes in movement, sensation, awareness or behaviour.
• Epilepsy is diagnosed when there is:
  • 2 or more unprovoked seizures more than 24 hours apart, or
  • One unprovoked seizure with a high risk (60% or more) of another - e.g. an epileptiform EEG or a structural brain lesion, or
  • An epilepsy syndrome.
• Provoked (acute symptomatic) seizures are not epilepsy:
  • Alcohol withdrawal.
  • Low sodium, glucose or calcium.
  • Drugs (tramadol, bupropion, ciprofloxacin, cocaine).
  • Acute stroke, head injury or infection.
  • Eclampsia.
• Causes of epilepsy:
  • Structural - stroke (the commonest cause in older people), tumour, head injury, hippocampal sclerosis, malformations of cortical development.
  • Genetic - many generalised epilepsies.
  • Infectious - previous encephalitis, neurocysticercosis.
  • Metabolic.
  • Immune - autoimmune encephalitis.
  • Unknown.

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Seizure Types

Focal seizures start in one part of one hemisphere:

• Focal aware (previously "simple partial") - the patient stays aware. Features depend on the lobe:
  • Temporal - rising stomach sensation, déjà vu, fear, strange smells or tastes.
  • Frontal - jerking spreading up a limb ("Jacksonian march"); bizarre movements, often from sleep.
  • Parietal - tingling.
  • Occipital - coloured flashing lights.
• Focal impaired awareness (previously "complex partial"):
  • Staring, unresponsive.
  • Automatisms - lip smacking, chewing, fiddling with hands.
  • Confusion afterwards; usually no memory of it.
  • Usually temporal lobe.
• Focal to bilateral tonic-clonic (previously "secondary generalised").
• Todd's paresis - temporary weakness after a focal seizure (can mimic stroke).

Generalised seizures involve both hemispheres from the start:

• Tonic-clonic:
  • Stiffening (tonic), then rhythmic jerking (clonic).
  • Tongue biting (side of the tongue).
  • Incontinence.
  • Cyanosis.
  • Confusion, drowsiness and aching muscles afterwards.
• Absence - brief (5–15 seconds) staring spells with abrupt start and end, many times a day, in children. Triggered by hyperventilation.
• Myoclonic - sudden brief jerks, often of the arms, typically in the morning (spilling drinks).
• Tonic (stiffening) and atonic ("drop attacks" - sudden falls with injury).

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Epilepsy Syndromes

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Blackouts: Seizure, Syncope or Something Else?

A witness account (or a phone video) is the most useful diagnostic tool.

⚠️ Safety Pearl: Convulsive syncope is common - brief jerks don't mean epilepsy. Blackouts during exercise, with palpitations, when lying down, or with a family history of sudden death need an ECG and urgent cardiology assessment (long QT, Brugada, HCM, aortic stenosis).

Other mimics:

• Dissociative (non-epileptic) seizures - see below.
• TIA - negative symptoms; no jerking (except "limb-shaking TIA" from severe carotid stenosis).
• Hypoglycaemia.
• Migraine aura - slower spread over minutes.
• Transient global amnesia - hours of repeated questioning with no other deficit; middle-aged or older; benign.
• Sleep disorders - REM sleep behaviour disorder, cataplexy (narcolepsy), night terrors.
• Paroxysmal movement disorders; panic attacks; breath-holding attacks (children).

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Investigating Seizures

• Everyone after a first seizure:
  • 12-lead ECG (long QT, Brugada, heart block, pre-excitation).
  • Bloods - glucose, sodium, calcium, magnesium, U&E, LFTs, FBC; consider a drug screen and prolactin (limited value).
• Specialist referral (NICE NG217): Everyone with a suspected first seizure should be seen by an epilepsy specialist within 2 weeks.
• MRI brain (epilepsy protocol) - for all new epilepsy, unless a typical idiopathic generalised syndrome. It looks for structural causes. CT is used in emergencies.
• EEG:
  • Use it to support the diagnosis and classify the type - not to rule out epilepsy.
  • A routine EEG is normal in about half of people with epilepsy.
  • Sleep-deprived EEG improves yield.
  • Video-EEG telemetry captures attacks - the gold standard for diagnosis (including dissociative seizures).
• Other tests in selected patients:
  • Genetic testing (children, learning disability, syndromes).
  • Autoimmune antibody tests (new-onset epilepsy with cognitive or psychiatric change).
  • LP if infection or inflammation is suspected.

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Starting Treatment

• After a single unprovoked seizure:
  • The risk of another is about 40% over 2 years; higher with an abnormal EEG, a structural lesion, a seizure from sleep, or a neurological deficit.
  • Starting treatment reduces early recurrence but doesn't change long-term outcome.
  • Decide with the patient - consider their job, driving and lifestyle.
• After 2 or more unprovoked seizures: Usually start treatment.
• Principles:
  • One drug (monotherapy), chosen for the seizure type, age, sex, pregnancy plans and other conditions.
  • Start low and go slow (especially lamotrigine - rash risk).
  • If the first drug fails because of side effects or lack of effect, switch to a second drug alone before combining.
• Prognosis:
  • About half become seizure-free on the first drug.
  • About 2 in 3 become seizure-free overall.
  • About 1 in 3 have drug-resistant epilepsy.
• Prescribe by brand for some drugs (category 1 - carbamazepine, phenytoin, phenobarbital, primidone) to avoid switching between products.

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Choosing an Antiseizure Medicine

(NICE NG217, 2022)

💡 Clinical Pearl: Carbamazepine and other sodium-channel drugs can worsen absence and myoclonic seizures - another reason to classify the epilepsy correctly.

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Antiseizure Medicines: Side Effects and Interactions

• Lamotrigine:
  • Rash - risk of Stevens–Johnson syndrome, especially if started too quickly or with valproate. Increase slowly; stop if a rash appears.
  • Insomnia; dizziness.
  • Levels fall with the combined pill and in pregnancy - monitor levels.
• Levetiracetam:
  • Generally well tolerated; few interactions; IV form available.
  • Mood change - irritability, depression, aggression, rarely psychosis. Ask about mood.
  • Reduce the dose in kidney impairment.
• Valproate: See below. Also weight gain, tremor, hair loss, liver toxicity, pancreatitis, raised ammonia (encephalopathy), low platelets. Enzyme inhibitor (raises lamotrigine levels).
• Carbamazepine:
  • Low sodium; dizziness, double vision, ataxia.
  • Rash (HLA-B*1502 in Han Chinese and Thai - screen first).
  • Blood disorders.
  • Strong enzyme inducer - makes the combined pill, warfarin, DOACs and many other drugs less effective.
• Phenytoin:
  • Narrow therapeutic range with non-linear kinetics - small dose changes cause big level changes.
  • Toxicity: ataxia, nystagmus, confusion.
  • Long-term: Gum overgrowth, coarse facial features, hirsutism, osteomalacia, peripheral neuropathy, cerebellar atrophy.
  • Enzyme inducer.
• Topiramate: Word-finding difficulty, weight loss, kidney stones, tingling, angle-closure glaucoma. Teratogenic (pregnancy prevention programme).
• Zonisamide: Weight loss, kidney stones.
• Lacosamide: Dizziness, PR prolongation (check ECG).
• Gabapentin and pregabalin: Sedation, weight gain, dependence and misuse (controlled drugs). Breathing depression with opioids.
• Bone health: Enzyme inducers (and valproate) cause osteoporosis - check vitamin D in long-term use.
• Mood: Depression and suicidal thoughts are more common in epilepsy and with some drugs - ask.

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Drug-resistant Epilepsy

• Definition: Seizures continue despite 2 appropriate, tolerated drugs at adequate doses.
• Check first:
  • Is it really epilepsy (video-EEG)?
  • Right drug for the seizure type?
  • Adherence.
  • Triggers (sleep, alcohol, drugs).
• Refer to a tertiary epilepsy centre for:
  • Epilepsy surgery - e.g. temporal lobectomy for hippocampal sclerosis (60–70% become seizure-free).
  • Vagus nerve stimulation.
  • Ketogenic diet (especially in children).
  • Deep brain stimulation.
  • Newer drugs (e.g. cenobamate, perampanel, brivaracetam; cannabidiol and fenfluramine for specific syndromes).
• Uncontrolled epilepsy carries risks of injury, depression, social isolation and SUDEP - don't accept ongoing seizures as inevitable.

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Stopping Treatment

• Consider stopping after 2 or more years seizure-free, after discussion with a specialist.
• Higher relapse risk with:
  • Juvenile myoclonic epilepsy (usually lifelong).
  • A structural cause.
  • An abnormal EEG.
  • Many seizures before control was achieved.
• Withdraw slowly - usually over at least 2–3 months; benzodiazepines and barbiturates over longer.
• Driving: The DVLA advises not driving during withdrawal and for 6 months after stopping.
• Abrupt stopping can trigger status epilepticus.

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Women, Contraception and Pregnancy

• Contraception:
  • Enzyme-inducing drugs (carbamazepine, oxcarbazepine, phenytoin, phenobarbital, topiramate, eslicarbazepine) make the combined pill, progestogen-only pill and implant unreliable.
  • Use a copper IUD, LNG-IUS (hormonal coil) or the injection.
  • The combined pill lowers lamotrigine levels (risk of seizures), and levels rise in the pill-free week (toxicity).
• Before pregnancy:
  • Plan pregnancies.
  • Folic acid 5 mg daily from before conception (for those on antiseizure medicines).
  • Review the drug: lamotrigine and levetiracetam have the lowest risk of birth defects.
  • Valproate and topiramate carry high risk and must be avoided unless no alternative.
• During pregnancy:
  • Don't stop medicines suddenly - uncontrolled tonic-clonic seizures are dangerous for mother and baby. Epilepsy is a leading cause of indirect maternal death (MBRRACE-UK), often from SUDEP.
  • Lamotrigine and levetiracetam levels fall - monitor and adjust; reduce again after delivery.
  • Joint epilepsy and obstetric care; detailed anomaly scan.
  • Vitamin K for the baby at birth (enzyme inducers).
• After birth:
  • Breastfeeding is encouraged on most antiseizure medicines.
  • Safety: Change nappies on the floor; bathe the baby with someone else present; avoid sleep deprivation where possible.
• Catamenial epilepsy (around periods) - specialist options include intermittent clobazam.

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Valproate Safety

Why it matters: Exposure to valproate in pregnancy causes birth defects in about 1 in 10 babies (neural tube defects, heart defects, cleft lip and palate) and neurodevelopmental problems in up to 4 in 10 (autism, lower IQ, learning difficulties).

• Women and girls:
  • Valproate must not be used in women or girls of childbearing potential unless there is no alternative, and only under the Pregnancy Prevention Programme:
    • Highly effective contraception.
    • Pregnancy tests.
    • An annual specialist review and Annual Risk Acknowledgement Form.
• New patients under 55 (male or female): Since January 2024, starting valproate needs two specialists to agree that there is no suitable alternative (MHRA).
• Men:
  • There is a possible small increased risk of neurodevelopmental problems in children whose fathers took valproate around conception.
  • Men and their female partners should use effective contraception during treatment and for 3 months after stopping.
  • Men already on valproate no longer need a two-specialist review (MHRA 2025).
• Topiramate now has its own pregnancy prevention programme (MHRA 2024).
• Pharmacists dispense valproate in the manufacturer's original pack with warnings.
• Check the latest MHRA guidance - the rules have changed several times.

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Driving and Epilepsy

Patients must tell the DVLA (and doctors must advise them clearly and document it). Always check the current DVLA guidance.

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Safety, SUDEP and Rescue Medication

• SUDEP (sudden unexpected death in epilepsy):
  • About 1 in 1,000 adults with epilepsy each year; much higher with frequent tonic-clonic seizures, especially from sleep and unwitnessed.
  • Discuss with every patient (NICE) - the best prevention is good seizure control.
  • Take medicines regularly; avoid sleep deprivation and binge drinking; consider night-time monitoring devices.
• Everyday safety:
  • Showers rather than baths.
  • Never swim alone.
  • Care with heights, cooking (use the back rings, microwave) and heaters.
  • Occupational advice (machinery, working at heights).
• Rescue medication - for prolonged seizures (5 minutes or more) or clusters, with a written care plan for families and carers:
  • Buccal midazolam 10 mg (adults).
  • Or rectal diazepam 10–20 mg.
  • Call an ambulance if the seizure continues 5 minutes after rescue medication, if it is the first use, or if there are breathing problems or injury.
• First aid:
  • Time the seizure; protect the head; move hazards.
  • Don't put anything in the mouth.
  • Recovery position once the jerking stops.
• Mental health: Depression and anxiety affect about 1 in 3 people with epilepsy - screen and treat (SSRIs are generally safe).

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Older People and Other Groups

• Older people:
  • The commonest age group for new epilepsy.
  • Causes: stroke (including silent), dementia (especially Alzheimer's), tumours, subdural haematoma.
  • Seizures are often focal and subtle - confusion, "funny turns", falls. Often misdiagnosed as TIAs or syncope.
  • Treat with low doses - lamotrigine or levetiracetam are well tolerated.
  • Avoid enzyme inducers (interactions with anticoagulants and statins, bone loss).
  • Watch for falls, sedation, low sodium (carbamazepine) and cognitive effects.
• Post-stroke seizures:
  • Early (within 7 days) - provoked; often don't recur.
  • Late - high recurrence risk; usually treated.
  • Routine prevention isn't recommended.
• Brain tumours: Seizures are common (especially low-grade gliomas). Levetiracetam is often used (few interactions with chemotherapy). No routine prevention without seizures.
• Learning disability: Higher rates of epilepsy and SUDEP; behavioural side effects of drugs; communication of seizures may be harder.
• Alcohol: Withdrawal seizures (6–48 hours after stopping) are provoked - treat the withdrawal, not with long-term antiseizure medicines.

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Dissociative (Non-epileptic) Seizures

What they are: Attacks that look like epileptic seizures but have no abnormal electrical activity. They are a type of functional neurological disorder - genuine and involuntary, not "put on". Up to 1 in 5 people referred with "refractory epilepsy" have them.

Clues (none are diagnostic on their own):

• Eyes closed during the attack (often resisting opening).
• Long duration (often over 5 minutes) with waxing and waning movements.
• Side-to-side head movements; pelvic thrusting; asynchronous limb movements.
• Crying during or after the attack.
• Recall of events during the attack.
• Attacks in front of witnesses, in clinic or in waiting rooms.
• No response to antiseizure medicines; frequent "status".

Diagnosis: Video-EEG capturing a typical attack with a normal EEG. About 1 in 5 also has epilepsy.

Management:

• Explain the diagnosis clearly and positively - what it is, that it is common, and that it can improve.
• Withdraw unnecessary antiseizure medicines (specialist).
• Psychological therapy (e.g. CBT-based, specialist FND services).
• Avoid repeated emergency treatment (IV benzodiazepines, intubation). Have a care plan.
• Driving: DVLA rules depend on the attacks - check guidance.

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Drug Reference Table

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Spot the Diagnosis

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Exam-style Scenarios

1. A 24-year-old woman has had two tonic-clonic seizures and morning jerks. She wants children in the future.
Answer: Likely juvenile myoclonic epilepsy.

• Avoid valproate; use levetiracetam (or lamotrigine - may worsen myoclonus in some).
• Folic acid 5 mg before conception; contraception advice.
• Advise on sleep and alcohol; DVLA - 12 months seizure-free; discuss SUDEP.

2. A 70-year-old has had three episodes of "going blank" for a minute, with fiddling hands, in the 6 months since a stroke.
Answer: Focal impaired awareness seizures - post-stroke epilepsy.

• ECG and bloods; MRI if not recent; EEG to support.
• Low-dose lamotrigine or levetiracetam.
• Check interactions with anticoagulants; advise on driving (DVLA).

3. A woman on carbamazepine for focal epilepsy takes the combined pill.
Answer: Carbamazepine induces liver enzymes and makes the pill unreliable.

• Switch to a copper IUD, hormonal coil or the injection.
• If pregnancy is planned, consider switching to lamotrigine or levetiracetam and start folic acid 5 mg.

4. A 30-year-old man has had one unprovoked tonic-clonic seizure. MRI and EEG are normal. He drives a car for work.
Answer: First unprovoked seizure - recurrence risk about 40% over 2 years.

• Shared decision about treatment (often deferred after a single seizure with normal tests).
• No driving for 6 months; he must tell the DVLA.
• Safety advice; specialist follow-up.

5. A 45-year-old has "seizures" lasting 15–20 minutes, with eyes closed, despite three antiseizure medicines.
Answer: Possible dissociative seizures.

• Video-EEG telemetry to capture attacks.
• If confirmed: clear positive explanation, withdraw unnecessary medicines, psychological therapy, emergency care plan.

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Key Points

• Epilepsy: 2 unprovoked seizures, or 1 with high recurrence risk, or a syndrome. Provoked seizures are not epilepsy.
• A witness account or video is the most useful tool. Convulsive syncope is common.
• ECG for every blackout; exertional collapse is cardiac until proven otherwise.
• A normal EEG doesn't exclude epilepsy; MRI for new epilepsy.
• Focal: lamotrigine or levetiracetam. Generalised: valproate (males), otherwise lamotrigine or levetiracetam. Absence: ethosuximide.
• Carbamazepine worsens absence and myoclonic seizures.
• Valproate: Pregnancy Prevention Programme; two specialists to start under 55; contraception for men too.
• Enzyme inducers make hormonal contraception fail; the pill lowers lamotrigine levels.
• Pregnancy: folic acid 5 mg; lamotrigine and levetiracetam are the safest; don't stop drugs suddenly.
• DVLA Group 1: 6 months after a first unprovoked seizure; 12 months seizure-free for epilepsy.
• Discuss SUDEP with everyone; good control of tonic-clonic seizures is the best prevention.
• Drug-resistant (2 drugs failed): refer for surgery and other options.
• Dissociative seizures: video-EEG, positive explanation, psychological therapy.

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Guidelines and Further Reading

• NICE NG217: Epilepsies in children, young people and adults (2022)
• MHRA Drug Safety Updates: valproate (2024–2025) and topiramate (2024)
• DVLA: Assessing fitness to drive - neurological disorders
• FSRH UK Medical Eligibility Criteria - antiepileptic drugs and contraception
• RCOG Green-top Guideline 68: Epilepsy in pregnancy
• ILAE seizure classification (2017) and syndrome definitions (2022)
• Epilepsy Action; SUDEP Action
• BNF - for current doses

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