First Seizure and Status Epilepticus: MCCQE Notes

Was it a seizure?

Distinguish from syncope and from psychogenic non-epileptic seizures. Features favouring seizure: lateral tongue biting, a postictal period of confusion lasting minutes to hours, prolonged duration, cyanosis, and a raised lactate or creatine kinase measured shortly afterwards.

A prolactin taken within 10–20 minutes can support a generalised seizure but a normal level excludes nothing.

Provoked or unprovoked?

This determines everything. Look for an acute cause:

• Metabolic: hypoglycaemia, hyponatraemia, hypocalcaemia, hypomagnesaemia, uraemia, hepatic failure
• Toxic: alcohol withdrawal (classically 6–48 hours after the last drink), benzodiazepine withdrawal, cocaine, tricyclics, tramadol, bupropion
• Structural or infective: stroke, haemorrhage, tumour, meningitis, encephalitis, abscess
• Eclampsia in pregnancy or the puerperium — the treatment is magnesium sulphate and delivery, not a standard antiepileptic

Provoked seizures are treated by correcting the provocation. They do not usually need long-term antiepileptic drugs, and they are not epilepsy.

Work-up of a first unprovoked seizure

• Glucose, electrolytes, calcium, magnesium, renal and liver function, toxicology, pregnancy test
• Neuroimaging — MRI is preferred; CT if urgent
• EEG — supports the diagnosis and helps classify; a normal EEG does not exclude epilepsy
• Lumbar puncture if infection is suspected

Do you start a drug?

Not automatically. Start an antiepileptic after a first unprovoked seizure when recurrence risk is high:

• An epileptiform EEG
• A structural lesion on imaging
• A nocturnal seizure
• A significant prior brain insult

Otherwise many are managed with counselling and observation, since roughly half will not have another. Two unprovoked seizures more than 24 hours apart makes the diagnosis of epilepsy and warrants treatment.

Counsel on driving restrictions (provincially set, typically 3–12 months seizure-free), swimming, bathing, heights and working with machinery — this is nearly always part of the correct answer.

Status epilepticus

Five minutes of continuous seizure activity, or repeated seizures without recovery between them. A timed protocol:

1. 0–5 min — airway, oxygen, IV access, check glucose, thiamine before glucose in suspected alcohol use disorder
2. 5–20 min — benzodiazepine: IV lorazepam, or IM midazolam if there is no access. Under-dosing here is the commonest failure
3. 20–40 min — second-line: levetiracetam, fosphenytoin or valproate. The trial evidence shows these perform similarly, so any is defensible
4. 40+ min — refractory: intubation and infusion of propofol, midazolam or thiopental, with continuous EEG

Look for the cause throughout, and remember non-convulsive status in anyone who does not wake up afterwards.