Extradural, subdural and subarachnoid haemorrhage in forensic practice
- Finding
Where blood collects inside the skull points to the vessel that bled, the force involved, and whether the person could have stayed awake for a while.
What it is
Bleeding inside the skull is the usual way a head injury kills. Extradural (epidural) haemorrhage lies between bone and dura, usually from a torn meningeal artery under a fracture; the classic victim may wake up and talk before collapsing (the lucid interval). Subdural haemorrhage lies between dura and arachnoid, from torn bridging veins when the head accelerates or decelerates; it is the commonest fatal finding in falls, in older people and in abusive head trauma. Subarachnoid haemorrhage from trauma is usually thin and over contusions; but a massive basal subarachnoid haemorrhage after a blow to the side of the neck or the jaw, often in an intoxicated person who collapses at once, points to a tear of the vertebral artery and needs a special dissection. Each pattern also raises the question of natural disease: aneurysm, hypertension or bleeding disorders.
How to tell it apart
- Heat in a fire can produce a postmortem extradural «heat haematoma»: brown, crumbly, without a fracture across the arterial groove.
- Old subdural collections have a membrane; dating them by histology gives ranges, not exact days.
- A ruptured aneurysm must be excluded in every basal subarachnoid haemorrhage; a traumatic tear may be tiny and only seen under the microscope.
- Alcohol does not cause the haemorrhage, but it delays recognition: the intoxicated patient «sleeping it off» may be deteriorating.
How to recognise it
- Extradural: a firm clot stuck to the inner skull, usually temporal or parietal, often with a fracture line crossing the arterial groove.
- Subdural: a layer of clot over the hemisphere, under the dura, often with little damage to the brain surface.
- Subarachnoid, traumatic: thin film in the sulci over contusions.
- Basal subarachnoid, massive: thick blood around the brainstem and the base of the brain, without aneurysm.
How it forms
- Extradural: the artery bleeds under pressure and strips the dura from the bone; the clot grows over minutes to hours.
- Subdural: rotation or rapid deceleration stretches bridging veins until they tear; venous bleeding grows more slowly.
- Basal subarachnoid: sudden stretching or twisting of the neck tears the vertebral artery near or within the skull.
- In all of them death comes from rising pressure, shift of the brain and compression of the brainstem.
Step by step
- Before opening the skull in a suspected traumatic basal haemorrhage, plan a posterior neck dissection or imaging of the vertebral arteries.
- Measure or weigh each collection and note its side, extent and age.
- Look for the source: fracture across a meningeal groove, torn bridging veins, vertebral artery tear, aneurysm.
- Obtain histology of membranes and vessel walls; record the survival time from the medical record.
Three bleeds in forensic practice
| Type | Usual source | Typical setting | Forensic point |
|---|---|---|---|
| Extradural | Middle meningeal artery under a fracture | Blow or fall with temporal fracture | Lucid interval; heat haematoma as a postmortem mimic |
| Subdural | Bridging veins | Falls, older people, alcohol, infants | Survival time and age of the clot |
| Subarachnoid, traumatic basal | Vertebral artery | Blow to jaw or side of neck, often with alcohol | Special neck dissection before brain removal |
Next step: what to do and document
- Record the time of injury, the time of each neurological assessment and any lucid interval in the patient's words or in witnesses' words.
- Never attribute drowsiness to alcohol alone after a head injury: document the assessment and the decision about imaging.
- If a patient collapses at once after a punch or kick to the head or neck, write the exact site of the blow reported and keep the imaging.
- In a death, report that the case is violent; the medico-legal autopsy will search for the source of the bleeding.
- Keep blood taken at admission: it shows the alcohol level and clotting at the time of the injury.
Common mistakes
- Removing the brain first and cutting the vertebral arteries in a traumatic basal subarachnoid haemorrhage: the tear may then never be found.
- Calling a heat haematoma in a burned body an injury in life.
- Assuming that a lucid interval proves an extradural haematoma.
- Calling a subarachnoid haemorrhage natural without searching for an aneurysm or a traumatic tear.
Test yourself
Think of the answer, then tap the question to see it.
Which vessel is usually torn in an extradural haematoma?
The middle meningeal artery, usually under a fracture of the temporal or parietal bone.
What is the lucid interval and in which haemorrhages can it occur?
A period of apparent recovery before deterioration. It is classic for extradural haematoma but also occurs with subdural bleeding.
A man collapses instantly after a punch to the side of the neck while intoxicated. What should the autopsy look for?
A massive basal subarachnoid haemorrhage from a tear of the vertebral artery, examined by special neck dissection before removing the brain.
What postmortem artefact can mimic an extradural haematoma in a fire death?
The heat haematoma: brown and crumbly blood outside the dura, without a fracture crossing the meningeal groove.
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Educational content on forensic and legal medicine; not legal advice and no substitute for the technical guides of Colombia's National Institute of Legal Medicine and Forensic Sciences. Laws change: each page links the official text and says when it was last checked. For a real case, follow the guide in force and ask the competent authority.
Sources: Epidural Hematoma (StatPearls Publishing (NCBI Bookshelf), 2025); Subdural Hematoma (StatPearls Publishing (NCBI Bookshelf), 2026); Subarachnoid Hemorrhage (StatPearls Publishing (NCBI Bookshelf), 2023); Inconspicuous longitudinal tears of the intracranial vertebral artery in traumatic basal subarachnoid hemorrhage (Journal of Pathology and Translational Medicine (PMC), 2020).
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