Epilepsy
Exam Tips
- In paediatric OSCEs, start with event classification: focal, generalized, or unknown onset; then state whether awareness is impaired and whether focal events evolved to bilateral tonic-clonic.
- A seizure lasting 5 minutes or more is treated as convulsive status epilepticus: this is a time-critical emergency.
- Normal EEG does not rule out epilepsy; diagnosis is primarily clinical and witness history is pivotal.
- Name one high-yield safety point: SUDEP risk rises with uncontrolled tonic-clonic and nocturnal seizures, and falls with better seizure control.
- State key prescribing caution unprompted: avoid or tightly restrict sodium valproate in females of childbearing potential because of major teratogenic risk.
Definition
Epilepsy is a chronic brain disorder with an enduring tendency to generate unprovoked seizures due to abnormal, excessive, and synchronous neuronal activity. Clinically, it is diagnosed by either at least two unprovoked seizures more than 24 hours apart, one unprovoked seizure with a high (about 60% or more) 10-year recurrence risk, or a recognized epilepsy syndrome with characteristic clinical and EEG features.
Pathophysiology
Epileptic seizures arise when cortical networks become hyperexcitable and hypersynchronous because inhibitory-excitatory balance is disrupted (typically reduced GABAergic inhibition, increased glutamatergic drive, or both). At a systems level, seizures may begin in a focal cortical network (focal-onset) or in bilaterally distributed thalamo-cortical circuits (generalized-onset), with possible secondary spread from focal to bilateral tonic-clonic activity. In children, mechanisms commonly include genetic channelopathies, developmental cortical malformations, immune-mediated inflammation, and metabolic defects; repeated uncontrolled seizures can promote network reorganization and drug resistance. See Figure: ILAE-style focal versus generalized seizure network schematic (helpful for viva explanations of semiology-anatomy correlation).
Risk Factors
- Preterm birth and perinatal brain injury
- Congenital cortical malformations and neurocutaneous syndromes (for example tuberous sclerosis, Sturge-Weber syndrome, neurofibromatosis)
- Family history of epilepsy or known genetic epilepsy syndrome (for example Dravet syndrome, Lennox-Gastaut syndrome)
- Previous CNS infection, head injury, intracranial tumour, or prior neurosurgery
- Complicated febrile seizures (prolonged, focal, or with post-ictal weakness)
- Neurodevelopmental disorders (autism spectrum disorder, ADHD, learning disability)
- Stroke and cerebrovascular disease (major risk in older age groups but relevant for lifetime counselling)
- Poor antiseizure medication adherence, alcohol/drug misuse, frequent nocturnal tonic-clonic seizures, and sleeping alone (important SUDEP risk modifiers)
Clinical Features
Symptoms
- Recurrent transient episodes of altered awareness, behaviour, sensation, motor activity, or emotion
- Focal sensory phenomena (for example paraesthesia, visual or auditory aura, epigastric rising sensation)
- Motor jerking, tonic stiffening, atonic drops, or myoclonic jerks
- Absence episodes with brief behavioural arrest and unresponsiveness
- Post-ictal confusion, headache, myalgia, or sleepiness
- Possible tongue biting, urinary incontinence, and amnesia for the event
Signs
- Observed focal onset signs (head/eye deviation, unilateral clonic movements) with or without progression to bilateral tonic-clonic seizure
- Generalized tonic-clonic seizure pattern: tonic phase then rhythmic clonic movements
- Impaired awareness during focal impaired-awareness seizures
- Prolonged convulsive seizure lasting 5 minutes or more (convulsive status epilepticus emergency threshold)
- Lateral tongue bite and prolonged post-ictal phase supporting epileptic rather than syncopal event
- Interictal neurological abnormalities may suggest an underlying structural cause
Investigations
Management
Lifestyle Modifications
- Provide an individualized seizure action plan for home and school, including when to give rescue medication and when to call emergency services
- Safety counselling: supervised bathing/swimming, heights/fire/cooking precautions, cycling helmet use
- Address adherence, sleep deprivation, alcohol/recreational drugs (adolescents), and mental health comorbidity
- Discuss SUDEP risk honestly and proportionately, emphasizing seizure control and nocturnal supervision strategies
- Offer education support and neuropsychology input where cognition/learning are affected
Pharmacological Treatment
Focal-onset seizure maintenance therapy
- Lamotrigine (child specialist titration; typical start 0.3 mg/kg/day, slowly up-titrate to maintenance based on response and co-medication)
- Levetiracetam (usually start 10 mg/kg twice daily; increase every about 2 weeks to up to 30 mg/kg twice daily, max commonly 1.5 g twice daily)
- Carbamazepine (often start about 5 mg/kg/day in divided doses; usual maintenance around 10-20 mg/kg/day)
Choice is syndrome- and comorbidity-dependent. Titrate slowly to limit adverse effects. Check interactions (enzyme induction with carbamazepine).
Generalized tonic-clonic / generalized epilepsies
- Levetiracetam (as above, weight-based titration)
- Lamotrigine (slow titration required; rash risk if escalated too quickly)
- Sodium valproate (typically start 10-15 mg/kg/day, increase by 5-10 mg/kg/week; common maintenance 20-30 mg/kg/day)
Valproate is highly teratogenic; in girls/adolescents who could become pregnant, avoid unless no suitable alternative and strict MHRA pregnancy prevention requirements are met.
Absence seizure therapy
- Ethosuximide (commonly 10-15 mg/kg/day initially, titrated to about 20 mg/kg/day; max often 1.5 g/day)
- Sodium valproate (useful if mixed generalized seizure types coexist)
- Lamotrigine (alternative where ethosuximide/valproate unsuitable)
Match drug to syndrome; ethosuximide is effective for typical absence without prominent tonic-clonic seizures.
Rescue treatment for prolonged convulsive seizures in community
- Buccal midazolam (age-banded: 2.5 mg at 3-11 months, 5 mg at 1-4 years, 7.5 mg at 5-9 years, 10 mg at 10 years and over)
- Rectal diazepam (alternative when buccal route unavailable or ineffective)
Give according to individualized protocol; call emergency services for ongoing seizure, respiratory compromise, or recurrent seizures without recovery.
Hospital treatment of convulsive status epilepticus
- Lorazepam IV 0.1 mg/kg (max 4 mg), repeat once if needed
- Levetiracetam IV 40 mg/kg (max 2.5 g) or phenytoin/fosphenytoin per local protocol if benzodiazepine-refractory
Airway-breathing-circulation first. Continuous monitoring required; watch for respiratory depression and hypotension with sedatives.
Surgical / Interventional
- Epilepsy surgery assessment for drug-resistant focal epilepsy (for example lesionectomy or temporal lobe surgery after specialist multidisciplinary work-up)
- Vagus nerve stimulation when resective surgery is unsuitable or as adjunct in refractory epilepsy
- Ketogenic diet (specialist-led) in selected refractory childhood epilepsies
Complications
- Status epilepticus with significant morbidity and mortality
- Injuries during seizures (falls, fractures, burns, drowning, head injury, road traffic incidents)
- Psychiatric comorbidity (depression, anxiety, psychosis) and increased suicide risk
- Cognitive and developmental impact, especially in complex childhood epileptic encephalopathies
- Social and educational consequences (stigma, school absence, reduced attainment)
- Sudden unexpected death in epilepsy (SUDEP), especially with poorly controlled generalized tonic-clonic or nocturnal seizures
Prognosis
Many individual seizures stop spontaneously, but recurrence risk after a first unprovoked seizure is highest in the first year. Overall recurrence risk is roughly 30-40%, falling to less than 10% after two years in many cohorts; risk is higher with epileptiform EEG changes, structural brain abnormalities, and certain comorbid mental health conditions. Long-term outcome is strongly predicted by early seizure burden and response to the first appropriately chosen antiseizure medicine.
Sources & References
🏥BMJ Best Practice(2)
💊BNF Drug References(50)
- Adrenaline with articaine hydrochloride[cautions]
- Alimemazine tartrate[contraindications]
- Amantadine hydrochloride[contraindications]
- Amifampridine[contraindications]
- Aminophylline[cautions]
- Asenapine[cautions]
- Bethanechol chloride[contraindications]
- Bupivacaine hydrochloride[cautions]
- Buspirone hydrochloride[contraindications]
- Carbetocin[contraindications]
- Cariprazine[cautions]
- Chlorphenamine maleate[cautions]
- Cinnarizine[cautions]
- Ciprofloxacin[cautions]
- Citalopram[cautions]
- Clomipramine hydrochloride[cautions]
- Cycloserine[contraindications]
- Cyproheptadine hydrochloride[cautions]
- Dexamethasone[cautions]
- Dexamfetamine sulfate[cautions]
- Dinoprostone[cautions]
- Droperidol[cautions]
- Epoetin alfa[cautions]
- Epoetin beta[cautions]
- Escitalopram[cautions]
- Fludrocortisone acetate[cautions]
- Fluoxetine[cautions]
- Hydrocortisone[cautions]
- Imipenem with cilastatin[cautions]
- Indoramin[cautions]
- Isoniazid[cautions]
- Lofepramine[cautions]
- Loxapine[cautions]
- Mefloquine[cautions]
- Mepivacaine hydrochloride[cautions]
- Methocarbamol[contraindications]
- Methylprednisolone[cautions]
- Metoclopramide hydrochloride[contraindications]
- Moxifloxacin[cautions]
- Olanzapine embonate[cautions]
- Pilocarpine[cautions]
- Prilocaine hydrochloride[cautions]
- Prochlorperazine[cautions]
- Promethazine hydrochloride[cautions]
- Ropivacaine hydrochloride[cautions]
- Sertraline[cautions]
- Trazodone hydrochloride[cautions]
- Vasopressin[cautions]
- Venlafaxine[cautions]
- Zuclopenthixol[cautions]
✅NICE Guidelines(1)
- Epilepsy[overview]
📖Textbook References(1)
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 967)[context]