QuestionSBA
QuestionChoice
Correct. The bleeding occurs from bridging veins between the dura and arachnoid layers just outside the cortex. This is a low pressure potential space and so blood diffuses around the curve of the brain.
62003
a
Crescent-shaped hyperdense (i.e. appears bright) extra-axial collection that spreads diffusely over the affected hemisphere
QuestionChoice
This is an extradural haemorrhage, between the dura and the skull, which usually are tightly adherent, so the blood forces the layers apart like a balloon.
62005
c
A peripheral, hyperdense (i.e. appears bright), bi-convex (lentiform) collection
QuestionChoice
The collection would be expected to be hyperdense (bright) in the acute phase. The appearance is otherwise correct.
62004
b
Crescent-shaped hypodense (i.e. appears dark) extra-axial collection that spreads diffusely over the affected hemisphere
QuestionChoice
This is a extradural haemmorrhage as above. The collection would also be expected to be hyperdense (bright) in the acute phase.
62006
d
A peripheral, hypodense (i.e. appears dark), bi-convex (lentiform) collection
QuestionChoice
This is an intracerebral haemmorhage: a bleed in the brain itself. This can be related to chronic hypertension or underlying abnormal vasculature or lesions such as tumour or infarct. There is often surrounding hypodense (darker) oedema.
62007
e
A hyperdense (i.e. appears bright) collection of blood within the parenchyma of the brain
Concept
Chapter

### Summary

A subdural haematoma (SDH) is a neurological condition characterized by the accumulation of venous blood between the dura mater and arachnoid mater, often following minor trauma in elderly patients. It can present with a reduced Glasgow Coma Scale (GCS), and is commonly seen in patients with fluctuating GCS. Diagnosis is typically established through a CT scan, with the appearance of the clot varying based on its age. Management strategies largely depend on the stage of the haematoma, with craniotomy indicated for acute haemorrhages, and burr holes recommended for chronic haemorrhages.

### Definition

A subdural haematoma is characterised by the accumulation of venous blood in the potential space between the dura mater and arachnoid mater of the brain.

### Epidemiology

Subdural haematomas typically occur in elderly individuals, particularly those over 65 years of age. It is often a consequence of minor trauma, leading to shearing forces that tear bridging veins between the cortex and dura mater. Risk factors include:

- Advancing age (>65 years old)
- Bleeding disorders or anticoagulant therapy
- Chronic alcohol use
- Trauma.

### Aetiology

The haematoma results from shearing forces that tear the bridging veins between the cortex and dura mater. These forces commonly arise from minor head traumas but can also occur spontaneously in patients with bleeding disorders, anticoagulant therapy, or chronic alcohol use.

### Signs and Symptoms

Clinical presentation of a subdural haematoma varies but may include:

- Headache
- Nausea or vomiting
- Confusion
- Fluctuating GCS
- Behavioural change.


### Differential Diagnosis

Differential diagnoses for subdural haematoma include:

- Epidural haematoma: Characterized by a brief loss of consciousness, followed by a "lucid interval" and then rapid neurological deterioration.
- Traumatic brain injury: Symptoms may include headache, confusion, lightheadedness, dizziness, blurred vision, or tired eyes.
- Stroke: Presents with sudden numbness or weakness, especially on one side of the body, confusion, trouble speaking or understanding, trouble seeing in one or both eyes, and trouble walking, dizziness, or loss of balance or coordination.
- Dementia: Gradual cognitive decline without fluctuating GCS.
- Migraine: Recurrent headaches that might be accompanied by nausea, vomiting, and sensitivity to light and sound.

### Investigations

Diagnosis of a subdural haematoma is primarily established through a CT scan. 

The appearance of the clot varies based on its age:

- Hyperacute phase (<1 hour): The clot may appear isodense, with underlying cerebral oedema.
- Acute phase (<3 days): The clot appears as a crescent-shaped hyperdense extra-axial collection over the affected hemisphere.
- Sub-acute phase (3 days to 3 weeks): The clot appears more isodense compared to the adjacent cortex, making identification more difficult. Contrast-enhanced CT or MRI can aid identification. There may be associated mass effect causing midline shift and sulcal effacement.
- Chronic phase (>3 weeks): The haematoma appears hypodense relative to the adjacent cortex.

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Further investigations may include:

- Routine blood tests including FBC, Renal Profile, Liver Function Tests
-  Clotting profile (to assess for coagulopathy)

### Management

Management of a subdural haematoma depends on the stage, patient’s premorbid baseline, and functional status. Many cases are managed conservatively, especially if there is no midline shift or cerebral oedema. However, for more severe cases, neurosurgical referral is required.

- **Conservative management**: If no significant midline shift or cerebral oedema.
	- For patients taking the DOAC dabigatran, Idarucizumab is a licensed NICE-approval reversal agent which can be given.
- **Surgical management**: In cases where intervention is necessary, options include:
  - **Craniotomy**: Typically for acute haemorrhages.
  - **Burr holes**: Typically for chronic haemorrhages.

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Picture
A subdural haemorrhage.
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Acute on chronic subdural haemorrhage
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Topic
19
Radiology
2443
Subdural Haemorrhage
Topic
57
Geriatrics
12462
A 79 year old male presents to A&E after a fall 2 days ago. He was initially fine but has been increasingly confused since. He complains of mild headache and has vomited twice. CT head shows a subdural haemmorhage.

Which of the following describes the classical appearance of acute SDH on imaging?
a