Seizures and Epilepsy in Adults

NICE guideline [NG217] Epilepsies in children, young people and adults. Last updated: Jan 2025.

NICE CKS Epilepsy. Last revised: Apr 2025.

Article Last Updated:14/06/2026

Seizure and Epilepsy

Updated UKMLA guide to seizures and epilepsy, including generalised tonic clonic, atonic, myoclonic, absence, and focal seizures.

Overview and Definition

Term	Definition
Seizure	A seizure is a clinical presentation, not a disease or condition. It is a transient episode of signs or symptoms caused by abnormal, excessive or synchronous neuronal activity in the brain.
Status epilepticus	A seizure that lasts ≥5 minutes, or Recurrent seizures occurring without recovery in between
Epilepsy	Epilepsy is characterised by an enduring tendency to have epileptic seizures. According to the ILAE, epilepsy is defined by the presence of ANY of the following At least 2 unprovoked seizures, occurring >24 hours apart 1 Provoked seizure with a high predicted recurrence risk (probability of further seizures similar to the recurrence risk after 2 unprovoked seizures, i.e. ≥60% over the next 10 years) Diagnosis of an epilepsy syndrome, characterised by a recognised pattern of clinical and EEG features, often supported by specific aetiological findings Exam note For exam purposes, the most important definition to remember is: epilepsy = at least 2 unprovoked seizures occurring >24 hours apart. A single acute symptomatic seizure due to a reversible trigger ≠ epilepsy (e.g. due to hypoglycaemia, alcohol withdrawal or severe hyponatraemia)

Term

Definition

Seizure

A seizure is a clinical presentation, not a disease or condition. It is a transient episode of signs or symptoms caused by abnormal, excessive or synchronous neuronal activity in the brain.

Status epilepticus

A seizure that lasts ≥5 minutes, or
Recurrent seizures occurring without recovery in between

Epilepsy

Epilepsy is characterised by an enduring tendency to have epileptic seizures.

According to the ILAE, epilepsy is defined by the presence of ANY of the following

At least 2 unprovoked seizures, occurring >24 hours apart
1 Provoked seizure with a high predicted recurrence risk (probability of further seizures similar to the recurrence risk after 2 unprovoked seizures, i.e. ≥60% over the next 10 years)
Diagnosis of an epilepsy syndrome, characterised by a recognised pattern of clinical and EEG features, often supported by specific aetiological findings

Exam note

For exam purposes, the most important definition to remember is: epilepsy = at least 2 unprovoked seizures occurring >24 hours apart.

A single acute symptomatic seizure due to a reversible trigger ≠ epilepsy (e.g. due to hypoglycaemia, alcohol withdrawal or severe hyponatraemia)

Causes

Epilepsy is one cause of seizures, but not all seizures are due to epilepsy.

Epilepsy refers to an enduring tendency to have epileptic seizures. Therefore, epilepsy is one possible cause of recurrent unprovoked seizures, but not every seizure is due to epilepsy.

Seizure Causes

Seizures can be broadly divided into provoked and unprovoked seizures

A provoked seizure, also known as an acute symptomatic seizure, occurs due to an acute trigger that temporarily lowers the seizure threshold
An unprovoked seizure occurs without an immediate reversible trigger and may suggest an underlying tendency to recurrent seizures, such as epilepsy

Causes of seizures can be remembered using the VITAMIN C mnemonic: ^[Ref]

Category	Specific causes
Vascular	Intracranial haemorrhage (esp. intracerebral haemorrhage) Stroke Cerebral venous sinus thrombosis Hypoxic-ischaemic encephalopathy Eclampsia
Infection	Viral encephalitis Bacterial meningitis Brain abscess HIV and related opportunistic infections (e.g. cryptococcal meningitis, cerebral toxoplasmosis, progressive multifocal leukoencephalopathy)
Trauma	Traumatic brain injury (esp. with depressed skull fractures, penetrating injuries)
Autoimmune / inflammatory	Autoimmune encephalitis (e.g. anti-NMDA encephalitis) Multiple sclerosis (in acute disease relapse) Systemic autoimmune disorders Lupus cerebritis Vasculitis (e.g. Sjögren’s syndrome, GPA, Behcet’s disease) Sarcoidosis
Metabolic	Severe hypoglycaemia Electrolyte disturbances Hyponatraemia and hypernatraemia Hypocalcaemia Hypomagnesaemia Organ failures Renal failure (e.g. uraemic encephalopathy) Liver failure (e.g. hepatic encephalopathy)
Intoxication / iatrogenic / withdrawal	Non-adherence to antiseizure medication Substance withdrawal Alcohol withdrawal seizures Benzodiazepines and barbiturates withdrawal Medications that reduce seizure threshold Antidepressants (e.g. citalopram, bupropion) Antipsychotics (e.g. clozapine) Tramadol High-dose IV ciprofloxacin, imipenem, cefepime Recreational drug use Severe alcohol intoxication Cocaine Amphetamines
Neoplasm	Brain tumours (generally classified as progressive symptomatic seizures)
Congenital	Developmental brain abnormalities Vascular malformations (e.g. AVMs) Neurocutaneous syndrome Tuberous sclerosis Sturge-Weber syndrome Neurofibromatosis

Epilepsy Causes

Common causes include:

Structural – previous stroke, previous TBI, brain tumour, vascular malformation, cortical malformation, neurocutaneous syndrome (tuberous sclerosis, Sturge-Weber syndrome, neurofibromatosis)
Genetic – epilepsy syndromes (e.g. juvenile myoclonic epilepsy), genetic generalised epilepsies
Infectious – chronic CNS infection, post-acute CNS infection, complicated febrile seizures (increases risk of epilepsy)
Metabolic – inherited metabolic disorders (e.g. GLUT1 deficiency, PKU), porphyria
Immune / autoimmune – autoimmune encephalitis-associated epilepsy
Unknown

The same broad disease category can cause seizures in different ways depending on timing.

For example, an acute stroke may cause an acute symptomatic seizure, whereas a previous stroke may leave an epileptogenic scar that causes later unprovoked seizures or epilepsy
Similarly, acute hyponatraemia can provoke a seizure, whereas a persistent inherited metabolic disorder may be contributing to epilepsy

Types and Clinical Features

Generalised Seizures

Generalised seizures are characterised by abnormal neuronal activity originating from both hemispheres

Important types of generalised seizures:

Type	Clinical features
Generalised tonic-clonic seizure (also known as convulsive seizure and grand mal)	Motor symptoms occur in the following order of sequence, usually last ~1-3 min: Tonic phase (→ generalised muscle contractions) Sudden LOC +/- fall (if the patient is standing) Generalised stiffening (bilateral increased tone of the limbs / trunk) Eye rotation / deviation Epileptic cry / ictal cry (a characteristic loud moan caused by respiratory and laryngeal muscle contraction) Possible apnoea and cyanosis Clonic phase: bilateral sustained rhythmic jerking) Post-ictal phase Confusion Fatgiue Focal weakness (Todd’s paresis) Amnesia of the event The presence of the following features is strongly suggestive of generalised tonic-clonic seizure Tongue biting marks (esp. lateral tongue) Urinary and/or bowel incontinence
Tonic seizure	Bilateral increased tone lasting 3 sec to min Often occurs from sleep, may occur in series overnight, and awareness is impaired
Clonic seizure	Bilateral, sustained rhythmic jerking with LOC
Atonic seizure	Classic “drop attack” Sudden loss or reduction of muscle tone, affecting the head / trunk / limb Very brief – usually <2 sec
Myoclonic seizure	May affect a body part or the entire body Sudden jerk-like muscle twitching Non-rhythmic and irregular Often very brief Awareness may be retained
Absence seizure	Absence seizure is a generalised non-motor seizure (all the above-mentioned types are motor) Abrupt onset of blank stare, unresponsiveness Causing interrupted activity / motion Often mistaken as day-dreaming Automatisms Oral: lip smacking, chewing motions, licking lips, swallowing Manual (hand): fidgeting with clothing, rubbing fingers together Ocular: rapid eye blinking, eyelid fluttering, upward rolling of the eye Rapid recovery with amnesia, with NO post-ictal phase If an “absence” lasts >45 seconds or has a post-ictal phase, consider a focal seizure

Focal Seizures (Old: Partial Seizures)

Focal seizures are characterised by abnormal neuronal activity originating from a single hemisphere

Shared features of focal seizures:

Awareness may be preserved or impaired
Clinical features depend on the affected brain region
Amnesia may occur (esp. if awareness is impaired)
Post-ictal symptoms may occur (esp. if awareness is impaired)

The ILAE classification system breaks down focal seizures into 2 tiers: ^[Ref]

1. Level of awareness	Focal aware seizure (old: simple partial seizure): awareness preserved throughout, even if they cannot move or speak Focal impaired awareness seizure (old: complex partial seizure): awareness is impaired at any point of the event
2. Type of onset features	Focal motor onset (e.g. automatisms, muscle contractions) Focal non-motor onset (e.g. sensory, cognitive, emotional, autonomic, behavioural arrest)

Focal seizure may progress to bilateral tonic-clonic seizure (generalisation)

Lobar localisation clues (traditionally how focal seizures are classified):

Lobe	Typical clues
Temporal	Prodromal aura Déjà vu (an intense feeling of familiarity with an unfamiliar setting Jamais vu (a feeling of total unfamiliarity with a deeply familiar person or place) Sudden, unprovoked emotion (often intense fear, panic, anxiety) Olfactory and gustatory hallucinations (sudden, unpleasant smell, often described as burning rubber / metallic taste) Auditory and visual illusions (e.g. muffled buzzing, ringing, distorted voices) Rising epigastric sensation Automatism Oral: lip smacking, chewing motions, licking lips, swallowing Manual (hand): fidgeting with clothing, rubbing fingers together Ocular: rapid eye blinking, eyelid fluttering, upward rolling of the eye Classically caused by: Hippocampal sclerosis Herpes simplex encephalitis Tumours affecting the temporal lobe
Frontal	Motor symptoms Jacksonian march Spreading of muscle contraction from one body part to another Often distal to proximal
Parietal	Sensory symptoms (e.g. paraesthesia, coldness in a limb) Visuospatial symptoms Possible Jacksonian march (spreading of sensory sensation in this case)
Occipital	Visual hallucination Flashing lights Visual loss / blindness

Complications

Risk of progression to status epilepticus

Long-term complications

Reduced quality of life
Mental health comorbidities (depression, anxiety, psychosis are more common in those with epilepsy + higher risk of dying from suicide)
Accidents during seizures (e.g. drowning, fractures, falls, RTAs, head injury, choking)
Sudden unexpected death in epilepsy (SUDEP)
- Defined as sudden, unexpected, unwitnessed, non-traumatic, non-drowning death of a person with epilepsy, with or without a seizure
- Underlying mechanism: early postictal, centrally mediated, severe alteration of respiratory and cardiac function induced by generalised tonic-clonic seizures
- ~60% of cases occur during sleep
- Most common cause of epilepsy-related death in young adults with uncontrolled epilepsy

Developmental and cognitive problems are mainly seen in children and young people

Assessment and Work-Up

Referral Criteria

Refer urgently (appointment within 2 weeks) if:

After a first seizure, or
Seizure recurrence after a period of remission

In the UK, urgent appointments in the context of new-onset seizures are scheduled in first seizure clinics (FSCs).

Investigation and Diagnosis

Standard Workup

A standard workup for suspected epilepsy includes:

Test	Notes
12-lead ECG	To identify arrhythmias or other potential causes of cardiac syncope (which can mimic a seizure)
Blood tests (including glucose and electrolyte levels)	To exclude hypoglycaemia and other electrolyte causes of seizure
Neuroimaging	1st line: MRI 2nd line: CT
Electroencephalogram (EEG)	1st line: awake EEG within 72 hours (+/- provoking manoeuvres during EEG) 2nd line: sleep-deprived EEG 3rd line: ambulatory EEG (up to 48 hours)

Additional Specialised Testing

Test	Indications
Genetic testing (whole genome sequencing)	<2 y/o onset, or Clinical features suggestive of genetic epilepsy syndrome (e.g. Dravet syndrome), or Additional clinical features – learning disability / autism spectrum disorder / structural abnormality (e.g. dysmorphism or congenital malformation) / unexplained cognitive or memory decline
Antibody testing (e.g. anti-NMDA, anti-GABA)	If autoimmune encephalitis is suspected (see the Encephalitis article for more information)

Management

For acute seizure management, including first aid, initial hospital assessment and management, status epilepticus, see the Acute Seizure (Including Status Epilepticus) article.

Conservative / General Management

Advise on the following:

Identify and avoid precipitating factors that may provoke seizures (e.g. sleep deprivation, flashing lights, alcohol consumption, physical exertion)
Adapt activities of daily living to minimise accidents during seizures
- Shower instead of having baths
- Only swim / participate water sports under supervision
- Avoid working at heights
Consider night-time supervision (for those who have seizures during sleep and at higher risk of epilepsy-related death)

Seizure / epilepsy and driving (key important DVLA guidance):

Licence type	DVLA guide
Group 1 (car, motorbike)	1st seizure while awake → Stop driving immediately + license to be revoked Reapplication is only possible after seizure-free for 6 months, provided the DVLA medical advisers consider that there is no high risk of further seizures Epileptic seizure while awake → Stop driving immediately + license to be revoked Reapplication is only possible after seizure-free for 1 year For further guidance (e.g. seizure due to medication / dose change, seizure while asleep, seizures that do not affect consciousness), see this link
Group 2 (bus, coach, lorry)	Regardless, stop driving immediately + license to be revoked Reapplication eligibility: One-off seizure → after seizure-free for 5 years AND did not take any anti-epileptic medication for 5 years >1 seizure →after seizure-free for 10 years AND did not take any anti-epileptic medications for 10 years AND <2% risk of further seizures

Licence type

DVLA guide

Group 1 (car, motorbike)

1st seizure while awake →
- Stop driving immediately + license to be revoked
- Reapplication is only possible after seizure-free for 6 months, provided the DVLA medical advisers consider that there is no high risk of further seizures
Epileptic seizure while awake →
- Stop driving immediately + license to be revoked
- Reapplication is only possible after seizure-free for 1 year

For further guidance (e.g. seizure due to medication / dose change, seizure while asleep, seizures that do not affect consciousness), see this link

Group 2 (bus, coach, lorry)

Regardless, stop driving immediately + license to be revoked

Reapplication eligibility:

One-off seizure → after seizure-free for 5 years AND did not take any anti-epileptic medication for 5 years
>1 seizure →after seizure-free for 10 years AND did not take any anti-epileptic medications for 10 years AND <2% risk of further seizures

Pharmacological Management (Anti-Epileptics)

When to Start Anti-Epileptic Drugs

Consider starting treatment after a first unprovoked seizure if any of the following:

Neurological deficit on examination
Abnormal EEG (unequivocal epileptic activity)
Structural abnormality on neuroimaging
Patient / family / carers consider risk of further seizures unacceptable

Management Principles

Use monotherapy whenever possible

If 1st line monotherapy is unsuccessful → attempt monotherapy with a different medication

Increase the dose of the second medicine slowly while maintaining the dose of the first medicine
If the second medicine is successful, slowly taper off the dose of the first medicine
If still unsuccessful → consider add-on therapy

Choice of Anti-Epileptic Drugs

For exam purposes and non-specialist practice, the key points are to learn the 1st line medications and any contraindications and understand that, if initial monotherapy is ineffective, clinicians usually switch to an alternative monotherapy before adding further medication. Anti-seizure medications should be started under specialist guidance.

Therefore, further 2nd line / add-on treatment options outlined by NICE are omitted here.

1st line anti-epileptic drugs for various types of seizures:

Seizure Type	1st line medication
Generalised tonic-clonic seizure	Monotherapy of: Lamotrigine, or Levetiracetam, or Sodium valproate If unsuccessful, switch to another 1st line option
Focal seizure	Monotherapy of: Lamotrigine, or Levetiracetam
Absence seizure	Monotherapy of ethosuximide Do NOT use the following, as they may exacerbate seizures in absence seizure: Phenytoin Carbamazepine, oxcarbazepine Pregabalin, gabapentin Phenobarbital Tiagabine Vigabatrin
Myoclonic seizure	Monotherapy of: Levetiracetam, or Sodium valproate Do NOT use the following, as they may exacerbate seizures in myoclonic seizure: Phenytoin Carbamazepine, oxcarbazepine Pregabalin, gabapentin Phenobarbital Tiagabine Vigabatrin
Tonic or atonic seizure	Monotherapy of: Lamotrigine, or Sodium valproate

MHRA advises that sodium valproate should NOT be started for the first time in BOTH males AND females who are <55 y/o (this is because valproate is highly teratogenic).

For exam purposes, it might be helpful to think that the other listed medications are generally 1st line, instead of sodium valproate
However, it would be incorrect to say that sodium valproate is no longer 1st line for epilepsy, as it is still a 1st line option but is largely limited by the MHRA safety measures and precautionary advice for sodium valproate
If someone is already taking sodium valproate (and it is contraindicated) → advise NOT to discontinue sodium valproate unless instructed by a specialist

Topiramate is contraindicated and should not be used in girls and women of childbearing potential unless a pregnancy prevention programme is in place

Discontinuing Anti-Epileptic Drugs

Only consider discontinuing anti-epileptic drugs after 2 years of seizure-free

An individualised assessment by a specialist should be done to determine risk of seizure recurrence if medications are discontinued

Anti-epileptic drugs should be stopped gradually:

For most medicines: over at least 3 months
For benzodiazepines and barbiturates, this would typically be over a longer period to reduce the risk of drug-related withdrawal symptoms
For those who take multiple medications: discontinue one at a time

Epilepsy can be defined as resolved if the patient has remained seizure-free for the past 10 years, with no antiseizure medication for at least the past 5 years.