Indications and contraindications of thrombolysis

1. Big picture

In acute ischemic stroke, the brain tissue has two zones: the infarct core, which is already irreversibly damaged, and the ischemic penumbra, which is hypoperfused but still salvageable. Thrombolysis aims to reopen the occluded vessel early enough to save the penumbra.

The key exam logic is:

Sudden focal neurological deficit → suspect stroke → determine last-known-well time → urgent non-contrast CT/MRI to exclude hemorrhage → check eligibility and contraindications → give thrombolysis as fast as possible if indicated.

Clinically, ischemic stroke and intracerebral hemorrhage may look identical, so never thrombolyse before brain imaging excludes hemorrhage. Modern criteria generally use 4.5 hours from symptom onset or last-known-well for intravenous thrombolysis in eligible patients, with imaging-selected exceptions in some wake-up/unknown-onset strokes. The AHA inclusion checklist includes disabling symptoms, ability to start treatment within 4.5 hours, and age ≥18 years.