Acute Intracranial Events Flashcards
What is an extradural haemorrhage?
Collection of blood between inner surface of skull, and periosteal dura mater
What causes extradural haemorrhagers?
Nearly always secondary to trauma and/or skull fracture
Who do extradural haemorrhages typically occur in?
Younger patients
What % of extradural haemorrhage cases involve a severed artery?
90%
What artery is most commonly severed in extradural haemorrhages?
Middle meningeal artery
How common is venous involvement in extradural haemorrhages?
Rare
What is venous involvement in extradural haemorrhages usually the rest of?
Torn venous sinus
What % of extradural haemorrhages are supratentorial?
95%
How do patients with extradural haemorrhages present?
Loss of consciousness, due to impact of injury
What happens after the initial loss of consciousness in a patient with an extradural haemorrhage?
- There is a transient recovery with ongoing haemorrhage, known as the lucid interval in 40% of patients
- As haemotoma enlarges, ICP will increase, causing compression of the brain and rapidly deterorating level of consciousness
What might be found on examination in a patient with a progressing extradural haemorrhage?
Cranial nerve palsies
Why might cranial nerve palsies present in patients with extradural haemorrhages?
Due to herniation of brain structures
What is the prognosis of an extradural haemorrhage?
Generally good with early intervention
How is a small extradural haemorrhage managed?
Observed and managed conservatively, with neurological follow up
How is a large extradural haemorrhage managed?
Referral to neurosurgery for craniotomy and clot evacuation
What are the potenital complications of extradural haemorrhages?
- Pernament brain damage
- Coma
- Seizures
- Weakness
- Pseudoaneurysm
- Arteriovenous fistula
What is a subdural haemorrhage?
Collection of blood between meningeal dura mater and arachnoid mater
What age groups can subdural haemorrhages occur in?
All
What are the categories of subdural haemorrhages?
- Acute (<3 days)
- Subacute (3-21 days)
- Chronic (>3 weeks)
Why does bleeding occur in a subdural haemorrhage?
Due to shearing forces on cortical bridging veins
What causes subdural haemorrhages?
Most often associated with trauma, but can be spontaneous
What increases the risk of rupture of subdural haemorrhages?
Cerebral atrophy
What setting do acute subdural haemorrhages usually present?
Head trauma
What % of acute subdural haemorrhage patients present with neurological abnormalities?
Up to 80%
Who is subacute/chronic subdural haemorrhages more common in?
The elderly, with vague or absent history of head trauma
How might subacute/chronic subdural haemorrhages present?
With insidious onset of confusion and general cognitive decline similar to dementia
How do acute subdural haemorrhages appear on CT?
Generally, hyperdense i.e. brighter than brain tissue
What happens to the CT appearance of haemotoma caused by a subdural haemorrhage over time?
It will progressively become hypodense, i.e. darker than brain tissue
How can small chronic haematomas caused by subdural haemorrhages be evaluated?
Serial imaging
What do collect subdural haemorrhages require?
Immediate neurosurgical intervention
How are symptomatic subacute/chronic subdural haemorrhages treated?
Via one or more burr holes
What is the prognosis of subdural haemorrhages?
Relatively poor compared to extradural haemorrhages
What is the mortality in acute subdural haemtomas requiring surgery?
May exceed 50%
What patients have worse outcomes of subdural haemotomas?
Those who are anticoagulated
What % of patients recover fully from subdural haemorrhages?
20%
Describe the shape of an extradural haemorrhage
Lentiform / biconvex, e.g. like a lemon
Describe the shape of a subdural haemorrhage?
Crescent / sickle, e.g. like a banana
What is a subarachnoid haemorrhage?
Collection of blood between the arachnoid mater and the pia mater
In whom do subarachnoid haemorrhages usually occur?
Middle aged patients, <60
What causes subarachnoid haemorrhages?
- Vast majority occur spontaneously, secondary to ruptured berry aneurysms
- May be traumatic
How do patients with a subarachnoid haemorrhages present?
- Sudden onset ‘thunderclap’ headache
- Meningism
- Nausea and vomiting
- Fever
- Focal neurological deficits
- LOC
What are the symptoms of berry aneurysms?
Largely asymptomatic, but symptoms may arise if compressing nearby structures, or during early stages of rupture
What % of the population have one or more berry aneurysm?
Around 3%
What can be done to berry aneurysms with a high risk of rupture?
Surgical clipping and endovascular coiling
What are the risk factors for berry aneurysms?
- Family history
- Hypertension
- Heavy alcohol consumption
- Abnormal connective tissue
Give 4 examples of abnormal connective tissue diseases
- Autosomal dominant polycystic kidney disease
- Erlers-Danlos
- Neurofibromatosis
- Marfan’s disease
What % of berry aneurysms form in the anterior cerebral artery?
40%
What % of berry aneurysms form at the junction of the internal carotid artery with the posterior communicating artery
20%
What % of berry aneurysms form in the middle cerebral artery?
34%
What % of berry aneurysms occur at the bifurcation of the basilar artery?
4%
What is performed to aid diagnosis of a subarachnoid haemorrhage?
Lumbar puncture
What is looked for in the lumbar puncture that might suggest a diagnosis of subarachnoid haemorrhage?
- Presence of RBCs
- Xanthochromia
How are subarachnoid haemorrhages managed?
- Stabilise the patient
- Prevent rebleeding
- Treat cerebral vasospasm
- Correct hyponatraemia
- Neurosurgical intervention if large bleed
What does the prognosis of subarachnoid haemorrhages depend on?
- GCS
- Degree of neurological deficit at the time of presentation
- Co-morbidities
What is the mortality of subarachnoid haemorrhages?
Between 30 and 90%
What are the complications of subarachnoid haemorrhages?
- Hydrocephalus
- Focal neurological deficits
- Coma
- Seizures
- Cognitive decline
- Frequent headaches
- Hypopituitarism
