Head injury and SOL Flashcards
incase u forget SOL =…
Space occupying lesion
Describe the characteristics of a missile injury?
-what occurs with high velocity?
Focal damage
Lacerations, haemorrhage in regional brain damage
High/low velocity means large differences
-pressure waves
Describe the characteristics of non-missile injury?
- causes?
- describe the pathophysiology?
- sudden acceleration of head so the brain moves inside the cranial cavity and makes contact with bony protrusions
- RTAs, falls, assaults
-primary injury (due to impact) secondary injury (evolves after primary injury and is potentially treatable)
Examples of non-missile primary injury? (5)
scalp lesions
Skull fractures
surface contusions/lacerations
diffuse axonal injury/diffuse vascular injury
Scalp lesions:
-give examples? (4)
-bruising
Lacerations
Bleeding
Route for infection
Skull fracture:
- give examples? (4)
- associated with what?
-fissure fracture
Depressed fracture
Compound fracture
base of skull fracture
-higher incidence of intracranial bleeding
Surface contusions and lacerations
- where do these occur?
- types?
-lateral surface of hemispheres
undersurface of temporal and frontal lobes
-Coup: at point of impact
Contracoup: diametrically opposite point of impact
diffuse axonal injury
- occurs when & why?
- can lead to what?
- what measures the clinical feature of this?
- describe the pathophysiology? (4)
- how is this managed acutely?
- occurs at moment of injury: widespread disruption of axons due to shear and tensile strains affecting axons at the time of acceleration/decceleration
- coma and vegetative state
- GCS
-Na channels normally centred around the nodes of ranvier, damage to axon causes redistribution of the Na channels along the length of the axon to demyelinated segments,
get partial restoration of conduction
There is an increased number and distribution to help restore conduction
this increases energy needs of the neurones and so there is an energy failure leading to mitochondrial apoptosis
Then get Ca influx and activation of calpains
results in cytoskeletal disruption and disrupted integrate flow
-prevent Na influx and reduce brain activity: medically induce a coma
Name the 5 conditions in which diffuse axonal injury occurs?
trauma raised intracranial pressure progression of inflammatory disease progression of dementia hypoxia
traumatic intracranial haematoma
-different types? (2, 5)
extra dural
intradural (subdural, subarachnoid, intracerebral/intracerebellar
burst lobe)
traumatic extradural haematomas:
- complication of what?
- what happens if untreated?
- fracture in temparoparietal region that involves middle meningeal artery
- midline shift, compression and herniation
Raised ICP
- normal value?
- how does raised ICP occur?
- compensations?
- causes? (5)
- effects? (4)
- clinical signs? (4)
- 5-13mmHg
- if the brain enlarges and can no longer compensate then the venous sinuses are flattened and there is little or no CSF, any increase in rain size will result in rapid increase in ICP
- blood and CSF escape form the cranial vault
-focal lesion in the brain diffuse lesion in the brain increased CSF increased venous volume Physiological (hypoxia, hypercapnia, pain)
-intracranial shifts and herniations
distortion and pressure on CN and vital centres
reduced level of consciousness
impaired blood flow
-papilloedema
Nausea & vomiting
headache
Neck stiffness
define the following types of cranial shifts/herniations: subfalcine tentorial tonsillar transcalvarium
- unilateral or asymmetric expansion of cerebral hemisphere displaces the cingulate gyrus under the falx cerebri.
- medial aspect of temporal lobe (hippocampal uncus and parahippocampal gyrus) herniates over the tentorium cerebelli.
– displacement of cerebellar tonsils through the foramen magnum (compresses brainstem)
-a swollen brain will herniate through any defect in the dura and skull.
give 4 different examples of space occupying lesion?
tumours
Abscess
Haematoma
localised brain swelling E.g. around infarct
Abscess
-give the causes for single and multiple abscess?
single: focal cause
otitis media, sinusitis, nasal/facial/dental infection, skull fracture, penetrating injury, neurosurgical procedure
Multiple: septicaemia usually
acute bacterial endocarditis, bronchiectasis and lung abscess, cyanotic heart disease, IV drug abuse
