NICE vs SIGN: Management of Epilepsy (2025) - A Clinical Comparison
This guide provides a detailed, factual comparison of the National Institute for Health and Care Excellence (NICE) and the Scottish Intercollegiate Guidelines Network (SIGN) guidelines for the management of epilepsy in adults and children. While both guidelines aim to standardise and improve care across the UK, there are nuanced differences in their recommendations, reflecting their distinct methodologies and update cycles. This comparison is intended to assist clinicians in understanding these differences for practical application within the NHS.
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Diagnosis and Initial Assessment
The cornerstone of both guidelines is the emphasis on rapid, specialist-led assessment following a suspected first seizure.
NICE (NG217, April 2022)
- Referral: Refer urgently (to be seen within 2 weeks) to a specialist (neurologist with an interest in epilepsy) following a first suspected seizure.
- ECG: Strong recommendation for a 12-lead ECG in all patients to rule out cardiogenic syncope.
- Imaging: MRI is recommended as the first-line imaging investigation for patients with a confirmed diagnosis of epilepsy. CT is reserved for emergency situations.
- Classification: Employs the 2017 International League Against Epilepsy (ILAE) classification system.
SIGN (SIGN 143, Updated 2021)
- Referral: Similarly recommends prompt referral to a specialist after a first seizure.
- ECG: Also recommends ECG, aligning with NICE.
- Imaging: Recommends neuroimaging (MRI preferred) for patients with a defined set of criteria, such as focal onset seizure, suggestion of underlying structural pathology, or seizure onset in adulthood. This is a slightly more targeted approach compared to NICE's broader recommendation.
- Classification: Uses the older 1989 ILAE classification, though acknowledges the 2017 update. This is a key practical difference for terminology.
Key Difference: NICE mandates MRI for all new diagnoses, while SIGN recommends it based on specific clinical criteria. NICE uses the current ILAE 2017 classification.
Pharmacological Treatment
Both guidelines are largely aligned on the principles of AED selection based on seizure and epilepsy type, aiming for monotherapy where possible.
NICE (NG217)
- Focal Onset Seizures: Lamotrigine or levetiracetam are recommended as first-line monotherapy. Carbamazepine is offered as a subsequent option.
- Generalised Tonic-Clonic Seizures: Sodium valproate is the first-line recommendation. However, it carries major restrictions in women and girls of childbearing potential (see Special Situations).
- Absence Seizures: Ethosuximide or sodium valproate are first-line.
- Newer AEDs: NICE often incorporates newer evidence, giving stronger recommendations for drugs like levetiracetam.
SIGN (SIGN 143)
- Focal Onset Seizures: Lamotrigine or carbamazepine are first-line. Levetiracetam is typically positioned as a second-line or alternative option.
- Generalised Tonic-Clonic Seizures: Sodium valproate remains first-line, with the same caveats for women.
- Absence Seizures: Ethosuximide or sodium valproate, consistent with NICE.
- Evidence Base: SIGN's 2021 update did not radically overhaul its AED hierarchy, reflecting a more conservative approach to integrating new trial data compared to NICE's 2022 update.
Key Difference: The main divergence is in first-line treatment for focal seizures: NICE strongly recommends levetiracetam alongside lamotrigine, whereas SIGN favours lamotrigine or carbamazepine. This has significant practical implications for prescribing habits.
Special Situations: Women of Childbearing Potential, Surgery, and SUDEP
Women and Girls of Childbearing Potential
This is an area of strong alignment, with both guidelines reflecting heightened safety concerns.
- Valproate: Both NICE and SIGN state that sodium valproate must not be used in women and girls of childbearing potential unless the conditions of the Pregnancy Prevention Programme are met and other treatments are ineffective or not tolerated. This is a critical safety directive.
- Alternative AEDs: Lamotrigine and levetiracetam are preferred alternatives.
Epilepsy Surgery
- NICE: Recommends referral for surgical assessment if seizures continue after trials of two tolerated, appropriately chosen AEDs (drug-resistant epilepsy). This is a proactive, early referral stance.
- SIGN: Also recommends referral for surgery assessment for drug-resistant focal epilepsy, but the language is less explicit about the "two drug" rule, focusing more on the failure of adequate drug trials.
SUDEP (Sudden Unexpected Death in Epilepsy)
Both guidelines mandate discussing SUDEP with patients and their families. NICE provides more structured detail on when and how this discussion should occur, recommending it takes place at diagnosis and during annual reviews.
Key Difference: NICE has a more explicit and earlier referral pathway for epilepsy surgery assessment.
Practical Clinical Flow and Takeaway Points
For a clinician in England, Wales, or Northern Ireland: The NICE guideline (NG217) is the definitive standard. Key practice changes include the universal use of MRI at diagnosis, the promotion of levetiracetam as a first-line option for focal seizures, and the strict "two-drug" rule for surgery referral.
For a clinician in Scotland: The SIGN guideline (143) is the standard, though it is essential to be aware of the NICE updates. The SIGN approach to neuroimaging is more targeted, and the first-line AED choice for focal seizures may differ. The conservative AED hierarchy may be more familiar to established practitioners.
Overarching Takeaway: The most impactful differences are in first-line AED choice for focal seizures and the universal vs. targeted use of MRI. The strict contraindications for valproate in women of childbearing potential are identical and must be adhered to rigorously across the UK.
Frequently Asked Questions (FAQs)
1. Which guideline should I follow if I practice in Scotland?
You should primarily follow the SIGN guideline, as it is commissioned for NHS Scotland. However, being aware of the NICE recommendations, particularly where they are based on newer evidence (e.g., levetiracetam), is prudent for informed practice and discussions with patients.
2. Why is there a difference in first-line treatment for focal seizures?
The difference stems from the interpretation of evidence and the date of the last comprehensive update. NICE's 2022 review incorporated a broader set of comparative effectiveness studies and real-world data that supported the efficacy and tolerability profile of levetiracetam. SIGN's 2021 update was more limited and maintained its previous hierarchy.
3. Is it acceptable to use the 1989 ILAE classification as per SIGN?
While SIGN has not formally adopted the 2017 ILAE classification, the 2017 system is the international standard. For consistency with global practice and research, using the 2017 terminology (e.g., "focal onset" vs. "partial seizure") is recommended, even when applying SIGN's treatment recommendations.
4. How should I manage a patient who has failed their first AED?
Both guidelines agree on trying monotherapy with an alternative suitable AED. The concept of "drug-resistant epilepsy" (failure of two adequate AED trials) is central to both, triggering the need for re-evaluation and consideration of non-pharmacological options like surgery.
5. Are the guidelines for children different?
Both NICE and SIGN integrate paediatric management throughout their guidelines. The principles of diagnosis, investigation, and treatment are similar, with adjustments for syndromic diagnosis (particularly in children) and age-specific dosing. The valproate restrictions apply to girls of all ages.
Source Links
- NICE Guideline NG217 (April 2022) - Epilepsies in children, young people and adults: NICE NG217
- SIGN Guideline 143 (2015, Updated 2021) - Diagnosis and management of epilepsy in adults: SIGN 143 (PDF)
- International League Against Epilepsy (ILAE) Classification: ILAE definition and classification