Recognise / red flags: Not every episode of loss of consciousness is epilepsy; consider vasovagal or cardiac syncope and functional events. A single suspected seizure needs a focused history and independent witness account.
Investigate / stratify: Check glucose/metabolic causes, medications, substance use, ECG, focal neurology and indicators of intracranial pathology; consider brain imaging and EEG guided by specialist assessment. EEG cannot reliably exclude epilepsy.
Initial management: Refer adults after a first suspected seizure for specialist assessment within 2 weeks. Give interim safety and driving advice in line with current DVLA rules, avoiding high-risk activities until assessed.
Exam pitfall / safety: Avoid quoting a universal recurrence percentage after a first seizure: recurrence depends on cause, EEG, imaging and clinical features. An isolated seizure does not automatically confirm epilepsy.

Source checked 2026-10-30: NICE NG217 (updated Jan 2025). Focused teaching summary only; historical material below has not had a full dose-by-dose review. Use current BNF, local guidelines and specialist advice for individual patients.

ℹ️ About

⚡ A first suspected seizure needs assessment for reversible and structural causes; recurrence risk is individualised rather than a universal lifetime figure.
📊 Epilepsy may be diagnosed after recurrent unprovoked seizures or after a single unprovoked seizure when further recurrence risk and the clinical context meet recognised diagnostic criteria. No fixed 3% progression estimate is appropriate.
🚨 Always consider reversible causes (metabolic, structural, toxic, infectious) before diagnosing epilepsy.

🧬 Aetiology

🧠 Prior ischaemic stroke
🩸 Intracranial haemorrhage
🦠 CNS infections (e.g., meningitis, HSV encephalitis)
🤕 Traumatic brain injury
🧬 Progressive multifocal leukoencephalopathy (PML)
🎗️ Brain tumours
🧩 Alzheimer’s disease
🔄 Autoimmune conditions (e.g., autoimmune encephalitis)

Lateral Tongue Bite compatible with seizure

💊 Drugs That Can Cause Seizures

Antibiotics: Quinolones, Penicillins, Isoniazid
Anticholinesterases: Organophosphates, Physostigmine
Antidepressants: Tricyclics, SSRIs, heterocyclics
Antihistamines: First-gen and some second-gen agents
Antipsychotics: Phenothiazines, Butyrophenones, Atypicals
Chemotherapeutics: Etoposide, Ifosfamide, Cisplatin
Immunosuppressants: Cyclosporine, Tacrolimus
Hypoglycaemics: Insulin, sulphonylureas
Electrolyte disturbance: Hypo-osmolar IV solutions
Lithium: Toxic levels
Local Anaesthetics: Bupivacaine, Lidocaine, Procaine
Methylxanthines: Theophylline, Aminophylline
Narcotics: Fentanyl, Meperidine, Pentazocine
Psychoactive drugs: PCP, Cocaine, Amphetamines, Ecstasy (MDMA)

🧾 Clinical Considerations

📌 Half of “first seizures” may represent undiagnosed epilepsy with prior minor events.
👶 Ask about childhood seizures, febrile convulsions, or developmental issues.
🍷 Screen for alcohol or recreational drug use (withdrawal and intoxication common triggers).
♀️ Consider catamenial epilepsy (menstrual cycle–related seizures).

🔎 Investigations

🩸 Bloods: FBC, U&E, LFTs, Glucose, Calcium, Phosphate, ALP, TFTs
❤️ ECG (rule out arrhythmia mimics); consider CXR if aspiration suspected
🖥️ Imaging: CT head (if acutely unwell/obtunded); outpatient MRI preferred
⚡ EEG: outpatient test to detect epileptiform discharges

📊 Differential Diagnosis

💫 Syncope (with anoxic jerks mimicking seizure)
🎭 Psychogenic non-epileptic seizures (PNES)
⬇️ Hypoglycaemia
⬇️ Hypocalcaemia, hyponatraemia
🫀 Arrhythmias

💊 Management

✅ If patient recovers fully in ED: discharge with safety-netting + seizure advice
🚫 Advise not to drive until cleared by DVLA guidance and a neurologist
🛡️ Avoid high-risk activities (ladders, swimming alone, operating heavy machinery)
👨‍👩 Stay with a responsible adult for first 48–72h; call 999 if seizures recur
🍷 Advise abstinence/reduction in alcohol
📅 Urgent neurology referral: specialist review within 2 weeks
Low-risk patients: (normal neuro exam, MRI & EEG) → recurrence risk ≈ 35% in 5 years → usually no treatment
High-risk patients: (neurological deficits, abnormal MRI or EEG) → recurrence risk ≈ 70% → usually start anti-seizure medication

📌 UK Practice Tip: DVLA guidance requires at least 6 months off driving after a first seizure (12 months if high recurrence risk), depending on neurologist assessment.

📚 References

Additional related clinical topics

First Seizure (OSCE focused)

Candidate Instructions:You are the medical student in the Emergency Department. A 25-year-old man has been brought in after collapsing at home. Take a focused history from the patient (and/or relative if you wish) about the event. Do not examine at this stage. At the end, summarise your findings and tell the examiner what investigations you would request.

Key Areas to Cover ✅

📅 History of the event: Before, during, after (prodrome, ictal, post-ictal).
👀 Witness account: Movements, duration, tongue biting, incontinence, cyanosis.
🧠 Risk factors: Head trauma, meningitis/encephalitis, family history of epilepsy.
💊 Medication & substances: Alcohol withdrawal, recreational drugs, missed medications.
⚠️ Red flags: Prolonged seizure, status epilepticus, focal deficit afterwards (Todd’s paresis).

Examiner Prompts 💬

“How would you differentiate a seizure from a syncopal episode?”
“What investigations would you arrange acutely?”

Differential Diagnoses 🔎

Epileptic seizure (generalised tonic-clonic, focal with secondary generalisation).
Syncope (vasovagal, arrhythmia-related).
Non-epileptic attack disorder (psychogenic seizures).
Metabolic: hypoglycaemia, electrolyte imbalance (Na, Ca, Mg).
Structural brain lesion: tumour, stroke, infection.
Alcohol/drug withdrawal or intoxication.

Mark Scheme (10 points) 📝

Domain	Marks	Details
Event description	3	Clear “before, during, after” structure, including witness account.
Risk factors	2	PMH, FHx, trauma, infection, vascular disease.
Substances/medications	2	Alcohol, drugs, withdrawal, missed meds.
Differentials	2	Considers syncope, metabolic, psychogenic.
Closing	1	Summarises and proposes investigations.

Investigations 🔬

Bedside: glucose, vitals, ECG.
Bloods: FBC, U&E, LFT, Ca, Mg, toxicology if indicated.
Imaging: CT head acutely (exclude bleed, mass); MRI brain if safe.
EEG (not emergency, but part of epilepsy work-up).
Consider lumbar puncture if infection suspected (after imaging).

Management 🩺

If actively seizing: ABC, IV access, O₂, check glucose, give IV lorazepam.
Post-ictal but stable: supportive care, safety (side positioning, airway protection).
Do not start long-term antiepileptics after a single seizure without neurology review (unless high risk).
Advise driving restrictions (UK: no driving for 6 months after first unprovoked seizure).
They must refer themselves to the DVLA for a forma assessment
Arrange urgent neurology referral for outpatient follow-up.

Teaching Commentary 📚

This is a high-yield OSCE: examiners want to see if you can structure a history around an unwitnessed collapse. Always anchor your approach in the “3 phases” (before, during, after). Remember red flags (status, focal neurology, head trauma, infection). For management, your priority is stabilisation and exclusion of reversible causes. The DVLA driving restriction is a classic exam point 🚗❌.

🧑‍⚕️ Case Examples - First Seizure

Case 1 (Generalised Tonic-Clonic Seizure): ⚡ A 22-year-old man collapses at a party with sudden stiffening and generalised jerking movements lasting 90 seconds. He bites his lateral tongue and is confused for 30 minutes afterwards. Blood glucose is normal; CT head clear. Diagnosis: First generalised tonic-clonic seizure. Teaching point: Classic features include tonic–clonic movements, tongue biting, and post-ictal confusion; workup requires EEG and neuroimaging.
Case 2 (Focal Aware Seizure): 🧠 A 30-year-old woman reports recurrent episodes of seeing flashing lights in her right visual field lasting 30 seconds, without loss of awareness. MRI shows an occipital cortical lesion. Diagnosis: First focal aware (simple partial) seizure. Teaching point: Symptoms reflect the cortical origin - visual aura suggests occipital lobe involvement.
Case 3 (Focal Impaired Awareness Seizure with Secondary Generalisation): 🔄 A 35-year-old man experiences a rising epigastric sensation followed by blank staring and lip smacking. Witnesses describe progression into tonic-clonic movements. MRI shows left temporal gliosis. Diagnosis: Focal seizure with impaired awareness, secondarily generalised. Teaching point: Aura + automatisms point to temporal lobe epilepsy; always look for underlying structural pathology.
Case 4 (Provoked Seizure - Alcohol Withdrawal): 🍺 A 45-year-old man with alcohol dependence develops a generalised tonic-clonic seizure 24 hours after stopping drinking. Bloods show hypomagnesaemia. Diagnosis: Alcohol withdrawal seizure. Teaching point: Provoked seizures require treating the underlying cause; benzodiazepines are first-line for withdrawal.
Case 5 (Seizure Mimic - Syncope): ❤️ A 60-year-old man faints while queueing, with brief limb jerks observed. Recovery is rapid, with no post-ictal confusion. ECG reveals complete heart block. Diagnosis: Syncope due to cardiac arrhythmia. Teaching point: Not all "fits" are epileptic; always consider cardiac causes, especially in older adults.

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First Seizure

First suspected seizure — assessment and referral