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This is a clinician-written, evidence-based guide aligned to the MCC Examination Objectives. It is structured by clinical presentation — the way the MCCQE tests and the way patients actually present. Management reflects current Canadian guidelines (CMA, CFPC, CPS). Always cross-reference with institutional protocols and clinical judgment.
Key points
- Active seizure >5 minutes is status epilepticus until proven otherwise: protect airway, check glucose, give benzodiazepine, then load an antiseizure medication
- First seizure evaluation looks for provoked causes: hypoglycaemia, sodium/calcium disturbance, alcohol or benzodiazepine withdrawal, infection, trauma, pregnancy/eclampsia, tumour and stroke
- Epilepsy is generally recurrent unprovoked seizures, or one unprovoked seizure with high recurrence risk; do not diagnose it after a clearly provoked event
- History from witnesses is essential: onset, focal features, duration, cyanosis, injuries, lateral tongue bite, post-ictal phase and recovery
- Canadian counselling must include safety, bathing/swimming/heights, work hazards, medication adherence, pregnancy planning where relevant and driving restrictions/reporting according to provincial rules
Approach to the Presentation
A seizure presentation can be an emergency, a first unprovoked event, a breakthrough event in known epilepsy, or a mimic such as syncope, psychogenic non-epileptic seizure or migraine aura. The MCCQE1 approach begins with the patient in front of you: if actively seizing, treat first. If the event has stopped, obtain witness history, identify provoking factors, perform a neurological and cardiorespiratory examination, and decide whether urgent imaging, lumbar puncture, EEG or admission is required. In known epilepsy, look for missed medication, sleep deprivation, alcohol, infection, pregnancy, metabolic derangement and interacting medicines.
Differential Diagnosis
| diagnosis | likelihood | key features | distinguishing test |
|---|---|---|---|
| Status epilepticus | must-not-miss | Continuous seizure or recurrent seizures without recovery, typically >5 minutes; risk of hypoxia, acidosis, rhabdomyolysis and neuronal injury | Clinical diagnosis; bedside glucose immediately; urgent labs and treatment in parallel |
| Hypoglycaemia or electrolyte-provoked seizure | must-not-miss | Diabetes medications, poor intake, sepsis, alcohol use; hyponatraemia, hypocalcaemia or renal failure may provoke generalized seizures | Point-of-care glucose; electrolytes, calcium, magnesium, renal function |
| CNS infection | must-not-miss | Fever, headache, meningism, altered mental status, immunosuppression; seizure may be presenting feature | Blood cultures, CT before LP if indicated, CSF studies and empiric antimicrobials |
| Intracranial haemorrhage / stroke / tumour | must-not-miss | New focal deficit, severe headache, anticoagulation, cancer history, older age, persistent altered state | Urgent CT head; MRI brain for lesion characterization |
| Eclampsia | must-not-miss | Pregnancy or postpartum with seizure, hypertension, headache, visual symptoms, RUQ pain | BP, urine protein, CBC, creatinine, AST/ALT; obstetric emergency |
| Epilepsy — focal or generalized | common | Recurrent unprovoked stereotyped events; focal aura, automatisms, impaired awareness or generalized tonic-clonic activity | EEG plus MRI epilepsy protocol when appropriate |
| Syncope with convulsive movements | common | Prodrome, standing trigger, pallor, brief myoclonic jerks after LOC, rapid recovery; no prolonged post-ictal confusion | History, orthostatic vitals, ECG; consider Canadian Syncope Risk Score |
| Alcohol or benzodiazepine withdrawal | common | Tremor, autonomic hyperactivity, agitation, hallucinations; seizure within withdrawal window | Clinical history; CIWA-Ar, electrolytes, glucose |
| Febrile seizure | common | Age 6 months to 5 years, brief generalized seizure with fever and rapid recovery; complex if focal, prolonged or recurrent in 24h | Clinical; investigate source of fever rather than routine EEG/imaging in simple febrile seizure |
| Psychogenic non-epileptic seizures | less common | Long fluctuating episodes, eye closure, asynchronous movements, retained awareness or emotional triggers; injuries and lateral tongue bite less typical | Video EEG when diagnosis uncertain; avoid dismissive language |
Red Flags & Key History
Symptoms
Ongoing seizure activity or failure to return to baseline
First seizure with focal deficit, severe headache, trauma, anticoagulation, pregnancy/postpartum or immunosuppression
Fever, meningism or persistent confusion
Lateral tongue bite, shoulder dislocation or prolonged post-ictal confusion
Known epilepsy with missed doses, sleep deprivation or alcohol trigger
Episode only during standing with rapid recovery
Signs
GCS <8 or airway compromise
Focal neurological deficit after recovery
Hypertension/proteinuria in pregnancy or postpartum
Papilloedema or signs of raised ICP
Normal exam after brief provoked event
Approach to Investigation
First-line
ABCs + point-of-care glucoseDo immediately in any active seizure or post-ictal patient; treat hypoglycaemia without delay.
Electrolytes, calcium, magnesium, renal/liver function, CBCIdentify reversible provoked seizure causes and medication toxicity risk.
12-lead ECGAssesses syncope/arrhythmia mimics and QT prolongation.
Pregnancy test where relevantEclampsia and medication choice are critical.
Second-line
CT head urgentlyFirst seizure with focal deficit, trauma, anticoagulation, cancer/immunosuppression, persistent altered mental status, severe headache, age risk or concern for haemorrhage/mass.
MRI brainPreferred outpatient or inpatient imaging for unprovoked first seizure when structural lesion is possible.
EEGSupports seizure classification and recurrence risk; normal EEG does not exclude epilepsy.
Lumbar punctureIf CNS infection or inflammatory process suspected after assessing imaging need.
Specialist
Neurology referralFirst unprovoked seizure, diagnostic uncertainty, abnormal EEG/imaging, refractory epilepsy, pregnancy planning, or occupational/driving implications.
Video EEG monitoringFor suspected psychogenic non-epileptic seizures or unclear paroxysmal events.
Management Principles
Canadian Epilepsy Alliance first aid + Ontario Epilepsy Guidelines1
Active seizure / status epilepticus
- Call for help, protect from injury, lateral position when possible, suction/oxygen, IV access and monitor
- Check glucose; give dextrose after thiamine if malnourished or alcohol use disorder is suspected
- Benzodiazepine first-line: lorazepam IV or midazolam IM/IN if no IV
- Load an antiseizure medication if seizure continues or recurs: levetiracetam, fosphenytoin/phenytoin or valproate depending on context
- Intubation/anaesthesia and ICU for refractory status epilepticus
2
First seizure after recovery
- Identify and correct provoking cause
- Urgent imaging/admission if red flags; otherwise arrange timely EEG, MRI and neurology follow-up
- Do not automatically start long-term antiseizure therapy after a clearly provoked seizure; consider after unprovoked seizure with high recurrence risk
3
Known epilepsy / breakthrough seizure
- Check adherence, recent sleep deprivation, illness, alcohol/drug use, pregnancy, renal function and interacting medications
- Check antiseizure drug levels where clinically useful
- Reinforce rescue plan and follow-up; adjust therapy with neurology if recurrent
4
Counselling
- No driving until medically cleared according to provincial/territorial requirements
- Avoid swimming alone, baths without supervision, heights, open flames and operating heavy machinery until risk is controlled
- Discuss contraception, folic acid and pregnancy planning for people taking teratogenic antiseizure medicines
Complications & Pitfalls
- Delaying benzodiazepines: active seizure beyond 5 minutes should be treated as status epilepticus.
- Diagnosing epilepsy after a provoked seizure: hypoglycaemia, hyponatraemia and withdrawal require cause-directed treatment.
- Missing eclampsia: any seizure in pregnancy or postpartum requires BP, urine protein and magnesium sulphate consideration.
- Ignoring driving duties: MCC questions often test counselling and reporting obligations, not just pharmacology.
- Over-relying on urinary incontinence: it occurs in both seizure and syncope; lateral tongue bite and post-ictal confusion are more discriminating.
MCCQE1 Exam Tips
- 1For an active seizure, the next best step is ABCs, glucose and benzodiazepine — not EEG.
- 2A seizure lasting >5 minutes is status epilepticus in exam practice.
- 3Syncope can have brief jerks; rapid recovery and prodrome favour syncope over epilepsy.
- 4Lateral tongue biting is far more specific for seizure than urinary incontinence.
- 5First unprovoked seizure requires counselling about driving and safety even before a final epilepsy diagnosis.
- 6Known epilepsy with a breakthrough event: ask about missed medication and triggers before escalating treatment.
- 7Pregnancy/postpartum seizure = eclampsia until proven otherwise; magnesium sulphate is central.
Put your reading into practice
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