1 Diagnosis and assessment of epilepsy

People have the right to be involved in discussions and make informed decisions about their care, as described in NICE's information on making decisions about your care.

Making decisions using NICE guidelines explains how we use words to show the strength (or certainty) of our recommendations, and has information about prescribing medicines (including off-label use), professional guidelines, standards and laws (including on consent and mental capacity), and safeguarding.

1.1 Referral after a first seizure or remission and assessing risk of a second seizure

Referral after a first seizure

For recommendations on immediate guidance and referral for children under 2 years with suspected or confirmed infantile spasms, see the section on infantile spasms syndrome.

1.1.1 Refer children, young people and adults urgently (for an appointment within 2 weeks) for an assessment after a first suspected seizure:

  • For adults, refer to a clinician with expertise in assessing first seizures and diagnosing epilepsy.

  • For children and young people, refer to a paediatrician with expertise in assessing first seizures and diagnosing epilepsy.

Referral after remission

1.1.2 Refer children, young people and adults urgently (for an appointment within 2 weeks) for an assessment if they have a seizure recurrence after a period of remission.

Assessing the risk of a second seizure

1.1.3 When a child, young person or adult presents with a first seizure, carry out an individualised assessment of their risk of a second seizure.

1.1.4 In adults, assessment should include checking for the following modifiable factors that may increase the risk of a second seizure:

  • an underlying mental health problem (such as depression, anxiety, psychosis and alcohol or substance misuse)

  • vascular risk factors (for example, diabetes, hypertension, atrial fibrillation)

  • sepsis.

1.1.5 Be aware that children presenting with a first afebrile seizure (seizure without a fever) are at an increased risk of further afebrile seizures, especially within 6 to 12 months, compared with children with a febrile seizure (seizure with a fever).

1.1.6 Be aware that children presenting with complicated febrile seizures (febrile seizures that last longer than 10 minutes or febrile seizures associated with other features, such as weakness, on one side of the body) may be at higher risk of epilepsy, especially if other predisposing risk factors for epilepsy are present.

1.1.7 Using a person-centred approach, discuss with the person, and their family and carers if appropriate, their individualised risks for further seizures. This should include any mental, physical and social factors identified as possible risk factors and how these may be modified.

Information and support after a first seizure

1.1.8 After a first seizure, give the person, and their family and carers if appropriate, information about:

  • how to recognise a further seizure

  • first aid and initial safety guidance in case of another seizure (see safety issues in box 1)

  • any changes they can make to reduce their risk of another seizure

  • who they should contact if they have a further seizure while awaiting their appointment for assessment and diagnosis.

1.1.9 After a first afebrile seizure in a child, explain to their parents or carers how to self-refer the child urgently if they have a further seizure.

For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on referral after a first seizure or remission and assessing risk of a second seizure.

Full details of the evidence and the committee's discussion are in:

1.2 Specialist assessment and diagnosis

See also NICE's guideline on transient loss of consciousness ('blackouts') in over 16s for recommendations on initial assessment of people after a suspected transient loss of consciousness. In particular, see the recommendations on performing electrocardiogram (ECG) in the section on obtaining patient history, physical examination and tests and on features suggestive of epileptic seizures in the section on suspected epilepsy.

1.2.1 Take a detailed history from the child, young person or adult after a first suspected seizure, and from their families and carers if appropriate, and carry out a physical examination. If possible, use eyewitness accounts and video footage of the seizure to inform the assessment.

1.2.2 Evaluate people after a first suspected seizure with a 12-lead ECG to help identify cardiac-related conditions that could mimic an epileptic seizure.

1.2.3 Be aware that metabolic disturbance, including hypoglycaemia, can result in seizures.

1.2.4 Offer brain neuroimaging tests if an underlying structural cause is suspected (see also the section on neuroimaging).

Electroencephalogram (EEG)

1.2.5 If the person's history and examination suggests an epileptic seizure, and a diagnosis of epilepsy is suspected, consider a routine EEG carried out while awake to support diagnosis and provide information about seizure type or epilepsy syndrome.

1.2.6 Do not use EEG to exclude a diagnosis of epilepsy.

1.2.7 If an EEG is requested after a first seizure, perform it as soon as possible (ideally within 72 hours after the seizure).

1.2.8 When offering an EEG, discuss the benefits and risks of provoking manoeuvres during EEG, such as hyperventilation and photic stimulation, with the person and their family or carers if appropriate. If agreed, include provoking manoeuvres during routine EEG to assess a suspected first seizure.

1.2.9 If routine EEG is normal, consider a sleep-deprived EEG if agreed with the person, and their family or carers if appropriate, after discussing the benefits and risks.

1.2.10 If routine and sleep-deprived EEG results are normal and diagnostic uncertainty persists, consider ambulatory EEG (for up to 48 hours).

For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on specialist assessment and diagnosis.

Full details of the evidence and the committee's discussion are in evidence review 3: diagnosis of epilepsies.

1.3 Neuroimaging

Initial imaging scans

1.3.1 Offer an MRI scan to children, young people and adults diagnosed with epilepsy, unless they have idiopathic generalised epilepsy or self-limited epilepsy with centrotemporal spikes. The MRI should be carried out:

  • within 6 weeks of the MRI referral and

  • following regionally agreed epilepsy MRI protocols.

1.3.2 If MRI is contraindicated, consider a CT scan for children, young people and adults with epilepsy.

1.3.3 When offering an MRI or CT scan, discuss the risks and benefits with the person with epilepsy (and their families and carers, as appropriate), especially if a general anaesthetic or sedation is needed for the scan.

Reporting and reviewing scans

1.3.4 Ensure that MRI scans are reported by a radiologist with expertise in paediatric or adult neuroradiology, as appropriate.

1.3.5 If seizures are ongoing despite treatment, and diagnosis remains unclear, consider an additional review of MRI scans by a specialist in paediatric or adult neuroradiology within a tertiary centre.

Repeat scanning

1.3.6 Consider an additional MRI scan for children, young people and adults with epilepsy, if:

  • the original scan was suboptimal

  • there are new features to their epilepsy

  • they have idiopathic generalised epilepsy or self-limited epilepsy with centrotemporal spikes that has not responded to first-line treatment

  • surgery is being considered.

Scanning in acute situations

1.3.7 Do not carry out a CT scan for people with established epilepsy presenting at an emergency department after a typical seizure, unless there are other concerns.

For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on neuroimaging.

Full details of the evidence and the committee's discussion are in:

1.4 Genetic testing

1.4.1 Discuss with a neurologist or geneticist any uncertainties about whether to offer genetic testing or which tests to offer to a person with epilepsy.

1.4.2 When making decisions about which tests to offer, refer to the NHS National Genomic Test Directory for rare and inherited disease for information on genetic tests commissioned by the NHS in England.

1.4.3 Before carrying out genetic tests:

  • discuss the purpose of testing and the possible implications of the results with the person with epilepsy, and their family and carers if appropriate

  • obtain informed consent with appropriate genetic counselling in line with the NHS Genomic Medicine Service.

1.4.4 Consider whole-genome sequencing for people with epilepsy of unknown cause who:

  • were aged under 2 years when epilepsy started or

  • have clinical features suggestive of a specific genetic epilepsy syndrome (for example, Dravet syndrome) or

  • have additional clinical features such as:

    • a learning disability

    • autism spectrum disorder

    • a structural abnormality (for example, dysmorphism or congenital malformation)

    • unexplained cognitive or memory decline.

      See also the eligibility criteria that accompany the NHS National Genomic Test Directory.

1.4.5 Consider whole-genome sequencing for people with epilepsy of unknown cause who were aged between 2 and 3 years when epilepsy started, if clinically agreed by a specialist multidisciplinary team.

For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on genetic testing.

Full details of the evidence and the committee's discussion are in evidence review C: effectiveness of genetic testing in determining the aetiology of epilepsy.

1.5 Antibody testing

1.5.1 Consider antibody testing in discussion with a neurologist for people with new-onset epilepsy if autoimmune encephalitis is suspected.

For a short explanation of why the committee made this recommendation and how it might affect practice, see the rationale and impact section on antibody testing.

Full details of the evidence and the committee's discussion are in evidence review D: antibody testing in epilepsy.

  • National Institute for Health and Care Excellence (NICE)