Haemorrhagic stroke
How rupture of a small deep artery bleeds into the brain, how a ruptured aneurysm bleeds around it, and why blood in a closed skull raises pressure and injures the brain.
By the end, you can
- Distinguish intracerebral from subarachnoid haemorrhage by where the blood lies and what usually ruptures.
- Explain how chronic hypertension weakens small penetrating arteries, and name the typical sites of hypertensive haemorrhage.
- Describe where saccular aneurysms form on the cerebral arterial circle and why rupture causes a sudden severe headache.
- Explain how a haematoma causes mass effect, raised intracranial pressure and hydrocephalus.
- Recognise the classic pathology (hyaline arteriolosclerosis and Charcot–Bouchard microaneurysms, amyloid angiopathy, the berry aneurysm and subarachnoid blood), the grading systems and tests, and explain how anticoagulant reversal, blood pressure lowering, securing the aneurysm, nimodipine and surgery act on the mechanism.
What it is
A haemorrhagic stroke is sudden loss of brain function caused by bleeding from a ruptured artery. In intracerebral haemorrhage the blood collects within the brain substance; in subarachnoid haemorrhage it spreads in the subarachnoid space round the brain, most often from a ruptured aneurysm. Together they make up roughly 15% of strokes.
2 types to tell apart
- Intracerebral haemorrhage
- Bleeding into the brain, usually from a small penetrating artery weakened by long-standing hypertension (deep sites) or by amyloid deposits in older people (lobar sites).
- Subarachnoid haemorrhage
- Bleeding into the CSF-filled space between the arachnoid and pia. Outside injury, most are caused by rupture of a saccular (berry) aneurysm on the arterial circle.
US spelling: haemorrhagic → hemorrhagic, haemorrhage → hemorrhage.
Normal function
The brain’s coverings and arteries
The brain sits in a rigid skull inside three membranes. The tough lines the and carries the venous sinuses, such as the . Beneath it the thin bridges over the sulci, and the delicate pia clings to the brain surface.
Between arachnoid and pia lies the subarachnoid space, filled with cerebrospinal fluid (CSF). The large arteries of the cerebral arterial circle and their main branches run in this space, so a leak from them spreads blood through the CSF round the brain.
From these surface arteries, small penetrating arteries plunge into the brain to supply deep structures: the lenticulostriate arteries to the basal nuclei and internal capsule, thalamic branches, and paramedian branches to the pons. They are narrow, arise at right angles from large arteries and so receive high pressure.
Underlying change · Step 1 of 4
A small deep artery ruptures
The full lesson is part of Student Pro
It takes you through all 4 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Underlying change · Step 2 of 4
An aneurysm ruptures into the subarachnoid space
The full lesson is part of Student Pro
It takes you through all 4 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Disrupted function · Step 3 of 4
Blood in a closed box: mass effect
The full lesson is part of Student Pro
It takes you through all 4 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Consequences · Step 4 of 4
What can follow a subarachnoid haemorrhage
The full lesson is part of Student Pro
It takes you through all 4 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Symptoms and signs
Symptoms, signs and findings
The full lesson is part of Student Pro
It takes you through all 4 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Exam detail
Exam detail
The full lesson is part of Student Pro
It takes you through all 4 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Treatment
How treatment works
The full lesson is part of Student Pro
It takes you through all 4 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Recap
Recap
The full lesson is part of Student Pro
It takes you through all 4 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Self-check
Check your understanding
The full lesson is part of Student Pro
It takes you through all 4 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .