17) Head Trauma and Acute Intracranial Events Flashcards
How can primary head injuries be classified?
Focal or diffuse
What are examples of focal head injuries?
Haematomas
Contusion
What are examples of diffuse head injuries?
Concussion
Diffuse axonal injury
What are the main causes of head injuries?
Assault, falls, surgeries, accidents
What is cerebral contusion?
‘Bruising’ of the brain whereby blood mixes with cortical tissue due to micro-haemorrhages and small BV leaks
What are the types of injury in cerebral contusion?
Coup - brain injured directly under site of impact
Contre-coup - brain injured on the side opposite the impact
What are the complications of cerebral contusion?
Oedema, raised ICP, coma
What is concussion?
Head injury with a temporary loss of brain function
What is the pathophysiology behind concussion?
Trauma -> stretching and injury to axons -> impaired neurotransmission, ion regulation, reduction in cerebral blood flow -> temporary brain dysfunction
What is post concussion syndrome and what are some features?
Set of symptoms that may continue for weeks or months after a concussion
Headaches, dizziness, sleeping abnormalities, cognitive signs
What is diffuse axonal injury?
Shearing of interface between grey and white matter following traumatic acceleration/deceleration or rotational injuries to the brain
What bones could be fractured in a basilar skull fracture?
Temporal, occipital, sphenoid, ethmoid or frontal
What are the signs of a basilar skull fracture?
Raccoon eyes
CSF rhinorrhoea and otorrhoea
Battle sign
Haemotypanum
How should a basilar skull fracture be managed?
ICP control
Treat complication
Elevation of depressed skull fractures
Surgery if persistent CSF leakage
What are the criteria for an urgent head CT?
GCS<13, or <14 for >2hrs
Focal neurological deficit, seizure, LOC
Open/depressed skull fracture
What is an extradural haemorrhage?
Collection of blood between inner surface of skull and perioestal dura mater
What is the likely cause of an extradural haemorrhage and what population are they common in?
Trauma and/or skull fracture - bleeding from middle meningeal artery
Typically in younger patients
How will a patient with an extradural haemorrhage present?
LOC due to impact
Transient recover with ongoing headache (lucid interval)
RICP = CN palsies and brain herniation
What is the management for an extradural haemorrhage?
Craniotomy and clot evacuation
What are the complications of an extradural haemorrhage?
Permanent brain damage, coma, seizures, weakness, more likely to bleed
How does an extradural haemorrhage present on a CT scan?
Lentiform/biconvex haemtoma
Shift of midline
What is a subdural haemorrhage?
Collection of blood between meningeal dura mater and arachnoid mater
Why is there bleeding in a subdural haemorrhage?
Due to shearing forces on cortical bridging veins
What is the likely cause of a subdural haemorrhage and what population are they common in?
Acute SDH - head trauma (acceleration/deceleration)
Subacute/chronic SDH - minor head trauma, more common in elderly
How will a patient with an subdural haemorrhage present?
Gradually increasing headache, confusion and cognitive decline
How does an subdural haemorrhage present on a CT scan?
Crescent/sickle shaped bleed
Midline shift, loss of cerebral architecture
How do acute bleeds differ from longer term bleeds on a CT, and why?
Acute bleeds appear hyperdense
Darken over time (hypodense) due to clot breakdown and liquefying
What is the management for a subdural haemorrhage?
Small, chronic evaluated with serial imaging
Acute - neurosurgical intervention to relieve RICP
Subacute/chronic - burr holes
What is a subarachnoid haemorrhage, and its most common cause?
Collection of blood between arachnoid and pia mater
Rupture berry aneurysm
What population are subarachnoid haemorrhages common in?
Middle aged patients, <60
How would a patient with a subarachnoid haemorrhage present?
Sudden onset, thunderclap headache
Meningism
Vomiting
Fever
How does a subarachnoid haemorrhage present on a CT scan?
Collection of blood in basal cisterns
Blood and CSF mixing giving slightly white colour
What is the management for a subarachnoid haemorrhage?
Lumbar puncture - if no RICP Stabilise Treat cerebral vasospasm Lower systolic BP May need surgical removal of blood
What are the complications of a subarachnoid haemorrhage?
Hydrocephalus, coma, seizures, cognitive decline, headaches, hypopituitarism
What can be done to prevent rupture in high risk berry aneurysms?
Surgical clipping and endovascular coiling
What are some risk factors for berry aneurysms?
FH, HTN, heavy alcohol consumption, ADPKD
Where are the common sites of berry aneurysms?
ACA, MCA, anterior choroidal artery
