Head Injury Flashcards
Describe extradural haematomas (definition, common cause, site of trauma)
Bleeding into the space between the dura mater and the skull.
Often results from acceleration-deceleration trauma or a blow to the side of the head.
The majority of epidural haematomas occur in the temporal region where skull fractures cause a rupture of the middle meningeal artery.
Describe subdural haematomas (definition and location, risk factors)
Bleeding into the outermost meningeal layer. Most commonly occur around the frontal and parietal lobes.
Risk factors includeold age, alcoholismand anticoagulation.
Describe Subarachnoid haemorrhages (presentation and aetiology)
Classically causes asudden occipital headache.
Usually occurs spontaneously in the context of a ruptured cerebral aneurysm but may be seen in association with other injuries when a patient has sustained a traumatic brain injury
Describe intracerebral haematomas
Collection of blood within the substance of the brain
Risk factors of intracerebral haematomas
Hypertension
Vascular lesion (e.g. aneurysm or arteriovenous malformation)
Cerebral amyloid angiopathy
Trauma
Brain tumour or infarct (particularly in stroke patients undergoing thrombolysis).
What is a secondary brain injury
Cerebral oedema, ischaemia, infection, tonsillar or tentorial herniation exacerbates the original injury.
Symptoms of a intracranial bleed
Patients will present similarly to an ischaemic stroke (which is why it is crucial to obtain a CT in head in all stroke patients prior to thrombolysis) or with a decrease in consciousness.
What does the following pupil appearance suggest:
Unilateral dilation
Sluggish or fixed light response
3rd nerve compression secondary to tentorial herniation
What does the following pupil appearance suggest:
Bilateral dilation
Sluggish or fixed light response
Poor CNS perfusion
Bilateral 3rd nerve palsy
What does the following pupil appearance suggest:
Unilateral dilated or equal
Marcus-Gunn (cross-reactive)
Optic nerve injury
What does the following pupil appearance suggest:
Bilateral constriction
Opiate overdose
Pontine lesion
Metabolic encephalopathy
What does the following pupil appearance suggest:
Unilaterally constricted with preserved light response
Sympathetic pathway disruption
What requires an immediate CT
GCS < 13 on initial assessment
GCS < 15 at 2 hours post-injury
Suspected open or depressed skull fracture.
Any sign of basal skull fracture (haemotympanum, ‘panda’ eyes, cerebrospinal fluid leakage from the ear or nose, Battle’s sign).
Post-traumatic seizure.
Focal neurological deficit.
More than 1 episode of vomiting
What are the classical appearances on CT head for head injuries
Extradural haematoma - lemon shape
Subdural haematoma - Crescent/banana
