[3] Subdural Haematoma Flashcards
What is a subdural haematoma?
A collection of blood that forms in the subdural space
What is the subdural space?
The space between the dura mater and the arachnoid mater
What can subdural haematomas be classified as?
- Acute
- Subacute
- Chronic
What is an acute subdural haematoma?
<3 days after injury
What is a subacute subdural haematoma?
3-21 days after injury
What is a chronic subdural haematoma?
> 21 days after injury
What can subdural haematoma be alternatively classified as?
Simple or complicated
What is a simple subdural haematoma?
No associated parenchymal injury
What is a complicated subdural haematoma?
Associated underlying parenchymal injury
What does bleeding in SDH occur from?
Tearing of the bridging veins that cross from the cortex of the dural venous sinuses
What are the bridging veins from the cortex of the dural venous sinuses vulnerable to?
Deceleration injury
What does bleeding from bridging veins in SDH lead to?
Accumulation of blood between the dura and arachnoid
What does the accumulation of blood between the dura and arachnoid lead to in SDH?
Gradual rise in ICP
What can the gradual rise in ICP lead to in SDH if left untreated?
Herniation and brainstem death
What do the majority of SDH occur due to?
Trauma
Can SDH occur in the absence of trauma?
Yes, often as chronic SDHs
What are the risk factors for SDH?
- Increasing age
- Alcohol excess
- Epileptics
- Clotting disorders or on anticoagulation’s
Why is increasing age a risk factor for SDH?
Bridging veins become more vulnerable to tears due to brain atrophy, which causes stretching of these veins
Why is epilepsy a risk factor for SDH?
Prone to falls and head injuries
What are the clinical features of SDH?
- Altered level of consciousness
- Headaches
- Focal neurological signs
- Features of raised ICP
- Seizure activity
What features of raised ICP may be present in SDH?
- Blurred vision
- Worsening headache
How do the symptoms vary between acute and chronic SDH?
Symptoms of acute SDH occur quickly, whereas those with chronic SDH have a latent period of weeks or even months before symptoms appear
What is important to do when children present with SDH?
Survey for other injuries with suspected SDH
Why is it important to survey for other injuries when children present with SDH?
May be signs of non-accidental injury
What routine bloods should be done in SDH?
- FBC
- CRP
- U&Es
- LFTs
- Clotting
- G&S
What is the gold standard imaging modality for suspected SDH?
Non-contrast CT scan of head
What does a non-contrast CT scan of the head show in SDH?
Crescent-shaped collection of blood over one hemisphere, with or without associated midline shift
Why might SDH appear different on CT scanning?
Depending on time of presentation
How does acute SDH appear on CT scanning?
Diffusely hyper dense
How does subacute SDH appear on CT scanning?
Heterogenously hyperdense or isodense
How does chronic SDH appear on CT scanning?
Diffusely hypodense
How does acute-on-chronic SDH appear on CT scanning?
Areas of hyperdensity within a hypodense haematoma
What are the differential diagnoses for acute SDH?
- Extradural haemorrhage
- Subarachnoid haemorrhage
- Intracerebral haemorrhage
- Infarction
What are the differential diagnoses for chronic SDH?
- SOL, e.g. tumor or abscess
- Meningitis or encephalitis
- Dementia
What approach should be taken to SDH in an acute setting?
Systematic A-E assessment, with any concerns of raised ICP being managed appropriately
What should be done if a patient presenting with SDH is on anticoagulants?
They should be reversed appropriately
What might the reversal of anticoagulation of patients presenting with SDH require?
Discussion with haematology
What medication are patients with SDH often started on?
Anti-epileptics
How long are patients on anti-epileptic medications after SDH?
1 week
What should happen in patients who have had SDH following a fall?
They should be investigated for potential underlying reasons for falls
What may be required in the investigation for underlying reasons for falls?
MDT approach with input from geriatricians, physiotherapists, and occupational therapists
What should the management of SDH be based on?
Size and clinical features
When is conservative management appropriate for SDH?
Small acute SDH that do not cause significant midline shift or cisternal encroachment, without significant neurologic impairment
What management options may be used for acute SDHs requiring surgical intervention?
- Trauma craniotomy
- Hemicraniectomy
When might a hemicraniectomy be used in acute SDH?
If there is significant cerebral swelling or associated contusions
What might be involved in the management of chronic SDH?
- Burr hole craniotomy with irrigation
- Twist drill craniotomy with drain placement
Why is a drain used in chronic SDH?
Shown to decrease recurrence rates and mortality without increasing complications
What are the complications of SDH?
- Cerebral oedema and raised ICP
- Seizures
- Herniation
- Persistent vegetative state
- Permanent neurological or cognitive deficits
- Recurrent haematoma formation
