Neurology

Epilepsy

A disorder of enduring susceptibility to recurrent seizures caused by abnormal, hypersynchronous electrical activity in brain networks; diagnosis is clinical, seizure type determines treatment, and prolonged or repeated seizures are emergencies.

In a nutshell

Epilepsy is an enduring susceptibility to recurrent seizures. Diagnose from the event history and classify the seizure type; EEG and MRI support the diagnosis but cannot replace it. Treatment is seizure-type specific, and convulsive status epilepticus requires immediate emergency treatment.

Classic presentation

A witnessed stereotyped tonic-clonic seizure with loss of consciousness, tonic stiffening, rhythmic jerking and a post-ictal period of confusion or drowsiness; focal seizures may begin with a localising aura or focal motor or sensory symptom.

Key points

Refer a first suspected seizure urgently for specialist assessment within 2 weeks; use witness history, examination, ECG and targeted tests to distinguish epilepsy from syncope and provoked seizures.
EEG supports classification but a normal EEG does not exclude epilepsy; if requested after a first seizure, perform it as soon as possible, ideally within 72 hours. Offer MRI after a diagnosis unless idiopathic generalised or self-limited epilepsy makes it unnecessary.
Convulsive status epilepticus is a convulsion lasting 5 minutes or more: use the emergency plan or give buccal midazolam or rectal diazepam in the community, or IV lorazepam where IV access and resuscitation are available, then follow the local second-line pathway.
First-line therapy depends on seizure type: lamotrigine or levetiracetam for focal seizures; lamotrigine, levetiracetam or sodium valproate for generalised tonic-clonic seizures subject to MHRA safeguards; ethosuximide for typical absence; levetiracetam or sodium valproate for myoclonic seizures.
Sodium valproate has strict initiation and reproductive-safety rules, including two-specialist documentation for first initiation under 55 and the Pregnancy Prevention Programme for women and girls able to become pregnant; do not stop it abruptly.
Discuss adherence, safety, pregnancy, driving and SUDEP from diagnosis. Consider withdrawal only after an individualised review following 2 years seizure-free, with gradual tapering if agreed.

First-line investigation

A detailed eyewitness account with examination and 12-lead ECG, supported by targeted glucose and metabolic testing, specialist-led EEG and MRI when indicated.

Management

Recognise and treat the emergency

Time any convulsion and treat activity lasting 5 minutes or more, or repeated seizures without recovery, as convulsive status epilepticus; use the emergency plan or immediate benzodiazepine pathway.^7,8,9
Protect the airway and from injury, check glucose and escalate to the local second-line and intensive-care pathway if seizures continue.^7,10,13

Confirm the event and classify the seizure

Obtain a detailed witness history or video, examine for focal signs, check glucose and perform a 12-lead ECG to assess mimics such as syncope or arrhythmia.^1,2
Refer a first suspected seizure for specialist assessment within 2 weeks; use EEG to support classification, never to exclude epilepsy, and arrange MRI after diagnosis when indicated.¹

Start seizure-type-specific treatment safely

Use monotherapy where possible: lamotrigine or levetiracetam for focal seizures, lamotrigine, levetiracetam or sodium valproate for generalised tonic-clonic seizures, ethosuximide for typical absence, and levetiracetam or sodium valproate for myoclonic seizures.^{3,14,5,6,13,15}
Apply the MHRA valproate and topiramate safeguards before prescribing, including two-specialist documentation for new valproate initiation under 55 and the Pregnancy Prevention Programme where applicable.^12,16,17,3

Escalate uncontrolled seizures and high-risk situations

Recheck diagnosis, seizure type, adherence, interactions and tolerability; refer promptly to tertiary epilepsy services when appropriate medicines do not control seizures.^4,20
Discuss pregnancy, SUDEP, nocturnal seizures, safety and driving early, and provide a written rescue and escalation plan for people at risk of prolonged or cluster seizures.^4,7,18,19,11

Review long-term control and withdrawal risk

Review adherence, adverse effects, mental health, cognition, work, contraception, pregnancy plans, safety and individual SUDEP risk as part of ongoing care.^4,18,11
After 2 years seizure-free, assess recurrence risk before considering withdrawal; if agreed, taper most medicines gradually over at least 3 months and involve an epilepsy specialist when risk is uncertain.^4,19

Exam traps

A normal EEG does not exclude epilepsy; EEG supports diagnosis and classification but does not rule it out.
Convulsive syncope can include brief jerking; do not diagnose epilepsy from the presence of movements alone, and remember the 12-lead ECG.
Ethosuximide is first-line for typical absence seizures; it is not a suitable monotherapy when other seizure types coexist because it has narrow coverage.
Carbamazepine, oxcarbazepine, phenytoin, gabapentin and pregabalin can worsen myoclonic seizures; lamotrigine can also aggravate myoclonus in some people.
Do not reduce the current MHRA rule to ‘never use valproate under 55’: initiation under 55 requires two-specialist documentation, women and girls who can become pregnant require Pregnancy Prevention Programme safeguards, and men already taking valproate are treated differently from new initiations.
Driving restrictions depend on the seizure pattern and licence group; use current DVLA rules rather than relying on a single universal interval.

Illustrations

Focal vs generalised seizure onsetDiagram of a focal cortical discharge remaining localised or spreading to bilateral cortex, versus a generalised seizure arising simultaneously via bilateral thalamocortical networks.PassFinals · original

EEG in epilepsyEEG trace showing interictal epileptiform spike-and-wave discharges compared with normal background rhythm.Jul059, Wikimedia Commons · CC-BY-SA-2.0

Seizure semiology by cortical regionBrain diagram linking cortical regions such as motor, temporal and occipital cortex to the corresponding seizure symptoms produced when those networks discharge.PassFinals · original

Key sources

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.