Brain Injury Flashcards
What types of acquired brain injury are there?
TBI
Anoxic (toxic, metabolic)
Stroke
Nutritional (Wernicke’s)
Tumours
Infection
What are the main pathological sequelae of TBI?
Contusions
Diffuse axonal injury
Extradural/subdural haematoma
These can be complicated by increased ICP and anoxia
What is the vascular source of subdural haematoma?
Vein
Low pressure and will accumulate over days/weeks
What is the vascular source of extradural haematoma?
Artery
(often the middle meningeal artery)
High pressure (seen by dura forced away from bone and in concave shape)
Develops rapidly, can be dead in hours
Fracture of the temporal bone from a fall can have this happen easily
What is the first line treatment for extradural haematoma?
Trepanning
What is a typical presentation of a patient with extradural haematoma?
Had a fall in preceding few hours
Drunk or confused
Worsening GCS (should be checked every 15 mins)
How and when do retraction balls form in the white matter?
Over the course of 24h
Damage to the membrane at the point of impact causes disruption of transport through the axon.
Accumulation of products results in balls
Early intervention and delivery of oxygen to the brain can stave this.
What is fractional anisotropy tractography?
Graphical imagery of connectivity in the brain using diffusion tensor imaging
It will show differences in connectivity even when MRI looks normal
What are the key markers of diffuse axonal injury?
Microhaemorrhages (due to being stretch of white matter blood vessels at point of impact)
These have a parafalcine distribution (sagittal)
How are shear microhaemorrhages picked up on MRI?
Gradient echo
Susceptibility weighted imaging
-these images pick up the haemosiderin
What pathology happens in the long term after injury?
Cerebral atrophy
-particularly white matter atrophy
-resultant ventriculomegaly
-thinning of corpus callosum
What are the consequences of bleeding into the brain?
Blood blocks the aqueducts prevent drainage of CSF and causing hydrocephalus
Enlarged ventricles from this should be distinguished from enlargement due to cerebral atrophy.
What happens to the brain when intracranial pressure reduces space in the cranial cavity?
herniation of uncus into post fossa
herniation of cerebellar tonsils into foramen magnum
Damage to midbrain/pons
Ischaemia of brain stem
Squeezing of PCA
What is Duret haemorrhage?
Haemorrhage to the pons or midbrain caused by transtentorial herniation from high intracranial pressure.
There is very low chance of recovery and care is often withdrawn
How would a lumbar puncture reveal SAH?
Blood in CSF indicating bleed into into subarachnoid space
What are the side effects of craniectomy post TBI?
Low CSF
Syndrome of the trephined
What are the presentations of CTE?
Alcohol intolerance
Behavioural change
Concentration and memory difficulties
Movement disorder
Dementia
What are the pathological features of CTE?
Cavum septum pellucidum
Cerebellar scarring
Cerebral atrophy
Neurofibrillary tangles
Tau deposition in the depths of sulci (pathognomonic)
What is a postulated relation of the site of tau accumulation to CTE?
Possible site of shear injury
What are the criteria for traumatic encephalopathy syndrome?
Exposure to repetitive head injuries
Cognitive impairment or behavioural dysregumatiob
Progressive course
No other condition that could account for symptoms
How does CTE differ from TES?
TES is clinical and found in life
CTE is pathological diagnosis