Eclampsia

Definition

Eclamptic seizure

• A tonic-clonic seizure in the context of a hypertensive disorder of pregnancy is called eclampsia, provided that no other cause is present.
• Possible prodromal symptoms include headache, visual disturbances, upper abdominal pain, and restlessness, as well as hyperreflexia.

• Eclampsia denotes new-onset tonic-clonic, focal or multifocal seizures in hypertensive disorders of pregnancy that are not explained by epilepsy or cerebrovascular events.
• It can also occur without preceding signs of pre-eclampsia such as hypertension or proteinuria.

Classification

• It can occur before, during or after labour; postpartum it typically presents within 48 hours, with the risk remaining raised during the first week.
• New-onset hypertension between 48 hours and 6 weeks after birth is classified as late postpartum pre-eclampsia.

Occurrence & epidemiology

Epidemiology

• Worldwide, eclampsia is reported in about 1.4% of births and pre-eclampsia in 4.6%; rates are higher in developing countries.
• Pre-eclampsia and eclampsia account for up to 14% of all maternal deaths worldwide.

Aetiopathogenesis

Aetiology and risk factors

• Risk factors correspond to those of pre-eclampsia, for example previous pre-eclampsia, multiple pregnancy, renal and autoimmune disease, diabetes mellitus, chronic hypertension, first pregnancy, age 35 years or older, obesity and pre-eclampsia in a first-degree relative.
• Uteroplacental ischaemia releases pro-inflammatory cytokines and anti-angiogenic factors; endothelial dysfunction disrupts the blood-brain barrier and cerebral autoregulation, and oedema and a disturbed neuronal microenvironment trigger the seizures.

Clinical features

Clinical features and complications

• Up to 83% of cases of eclampsia are preceded by prodromal symptoms: severe, frontal or atypical headache, visual disturbances (blurred vision, scotomata, photopsia, diplopia, transient blindness) and right upper quadrant or epigastric pain; however, more than one third occur suddenly without warning.

Diagnosis

• Investigations assess blood pressure, proteinuria and end-organ damage such as pulmonary oedema and impaired liver or kidney function.
• In new-onset seizures, altered mental status or focal deficits, non-contrast CT or MRI of the head is used to detect intracranial causes.

Keep learning in the app

Further reading (selection)

1. StatPearls: Eclampsia (NCBI Bookshelf)
2. MSD Manual Professional Edition: Preeclampsia and Eclampsia
3. DocCheck Flexikon, Eklampsie

Cross-references