Head Injuries Flashcards
5 layers of the scalp
- Surface of skin (abrasions)
- connective layer (lacerations)
- aponeurosis (contusion)
- loose areolar tissue (incision/stab)
- periosteum (firearm)
Sharp force injuries to skull
- slot fractures
- transorbital stabs
Local deformation of skull
- linear fracture
- depressed fracture
- indentation (with or without recoil)
- cephalhaematoma
General deformation of skull
- linear fractures of base and vault
- fractures by diastasis/ bursting of suture lines
Indirect application of force to skulls occurs when:
- condule of mandible into base of skull
- vertebrae upwards into base of skull
Primary events to the meninges
- extradural haematoma
- subdural haematoma
- subarachnoidal haemorrhage
Types of subdural haematoma/collection
- acute
- chronic
- subdural effusions
- subdural hygroma
Primary events to the brain
- diffuse neuronal injury
- diffuse axonal injury
- lacerations
- subpial haemorrhage
- cortical contusions
- intracerebral haemorrhages
Secondary events
- cerebral oedema
- increased intracranial pressure
- secondary infections
- secondary effects on vessels
Complications of cerebral oedema
- herniation
- vascular complications
- cranial nerve damage
- acute anoxic damage
Types of herniation
- subflax
- central downwards
- parahippocampal gyrus herniation
- interior cerebellar or tonsillar herniation
- superior cerebellar herniation
- burr-hole herniation
- cerebral mushroom
Secondary infections
- meningitis
- subdural or epidural abscess
- cerebral abscess
Acutes effects of boxing
- rotational acceleration
- linear acceleration (hyper-extension)
- injury to carotid area
- impact deceleration
Pathological findings in chronic brain damage (punch-drunk syndrome)
- cerebral atrophy with enlarged ventricles
- loss of cells in cerebellum
- loss of nerve cells in substantia nigra
- widespread neuronal damage in cerebral cortex
Types of bleeds (extra vs sub)
Extradural - arterial (MMA)
Subdural - venous
Complications of acute extradural haemorrhage
- transtentorial herniation
- CN III palsy
Mechanisms of injury in acute subdural haemorrhage
- angular acceleration or decel
- tearing of bridging veins between dura and cortical surface of the brain
- child abuse
Mechanisms of injury for subarachnoid haemorrhage
- shear stress with rotational movement
- impact with contusion and laceration
- intracerebral haemorrhage breaking through cortex
- vertebral artery damage
- berry aneurysm
Types of intracerebral haemorrhage
- lobar
- basal ganglia
Associations with basal ganglia hematoma
- diffuse axonal injury
- gliding contusions
- severe hypertension
- decorticate/decerebrate posturing
Where do acute brain contusions occur?
- over the the crest of the gyri
- conical appearance
Clinical presentation of diffuse axonal injury
- immidiate LOC or concussion
- GCS <8
- prolonged vegetative state
Mechanisms of injury in diffuse axonal injury
- diffuse tearing of axons
- shearing forces
- radiologically invisible
- small haemorrhages
Macroscopic features of DAI
- gliding contusions
- small deep grey matter haemorrhage
- punctate hg in corpus callosum
- brainstem hgs
Microscopic features of DAI
retraction balls
Complications of subfalcine herniation
- ipsilateral compression of ventricle
- unilateral obstrucive hydrocephalus
- compresses ACA
Effects of central herniation
- midbrain moves downwards
- effacement of the interpeduncular fossa
- causes brainstem haemorrhages (Duret
- often fatal
Effects of uncal herniation
- CN III down and out
- ipsilat PCA (contralat HH)
- contralat crus cerebri at the Kernohan’s notch (ipsilat paresis)
- aqueduct compression
Effects of cerebelllar herniation
- compression of brianstem
- coma and death
Types of internal herniations
- rostral (SOL in posterior cranial fossa)
- limen insulae (basal aspect of frontal lobe sliding over wing of sphenoid bone
