In a patient known to have epilepsy

Poor compliance with therapy, therapy recently reduced or stopped, or altered drug pharmacokinetics

Drug interaction causing alteration of their normal maintenance level

Intercurrent infection

Alcohol withdrawal

Alcohol or substance use

In a patient not known to have epilepsy

Stroke, especially haemorrhagic stroke

Encephalitis

Brain tumour

Brain abscess (including toxoplasmosis)

Arteriovenous malformation

Meningitis

Acute head injury

Cerebral malaria

Metabolic disorder: cerebral anoxia from cardiac arrest, acute kidney injury, hyponatraemia, hypocalcaemia, hypomagnesaemia, hepatic encephalopathy

Poisoning: alcohol, tricyclics, phenothiazines, theophylline, cocaine, amphetamines, MDMA (‘ecstasy’), heroin

Cerebral vasculitis

Hypertensive encephalopathy

Pre-eclampsia/eclampsia