Cerebrovascular Disease and CNS Trauma 2 Flashcards
What are the two major pathogenic mechanisms and one less common mechanism behind haemorrhagic stroke
Major:
- High pressure in normal vessels (e.g. Malignant hypertension)
- Abnormal vessel structure (e.g. Berry aneurysm)
Lesser:
- Bleed easily (e.g. Coagulopathies, anti-coag)
List some causes of haemorrhagic stroke:
- Hypertension
- Ruptured berry aneurysm
- Amyloid angiopathy
- Coagulopathy
Is thrombolytic treatment indicated in haemorrhagic stroke
NOoooooo
What is the major macroscopic differential between ischaemic and haemorrhagic stroke?
Haemorrhagic stroke is red/brown/black
Ischaemic should be pale.
What are the 4 types of intracranial haemorrhage?
- Intracerebral haemorrhage(ICH)
- Sub-arachnoid haemorrhage (SAH)
- Extradural haemorrhage (EDH)
- Sub-dural haemorrhage (SDH)
Association between trauman and intracranial haemorrhage types?
EDH - always trauma
SDH - usually trauma
SAH - sometimes trauma
ICH - rarely trauma
Which types of intracranial haemorrhage are associated with hypertension?
Intracerebral haemorrhage (ICH) and sub-arachnoid haemorrhage (SAH)
Which haemorrhages can lead to haemorrhagic stroke?
ICH always, SAH sometimes
What is ICH and the primary (1) and secondary (3) causes?
Intra-parenchymal bleeding
Primary - HTN
Secondary - Vascular malformation, amyloid angiopathy, trauma
What is SAH and its causes (traumatic and non-traumatic)
Sub-arachnoid bleeding
Sudden onset.
Does NOT cause space occupying lesion - no rise in ICP
Caused by traumatic or non-traumatic (berry aneurysm)
Differences between EDH and SDH
EDH:
- Traumatic
- Arterial bleed (lemon shaped - peels dura away from bone)
- Fast onset of symptoms
SDH:
- Low level trauma
- Venous bleed (banana shaped - under dura)
- Slowly progressive symptoms compared to EDH
What is a vertebral artery dissection and waht does it lead to?
Trauma to the vertebral artery can cause an artery dissection:
- Direct trauma - RIP phil hughes
- Rotational movement
- Minimal trauma- chiro manipulation
Leads to SAH
What is a contusion?
BLunt force trauma without tearing of tissue, but causing compression
What pathological changes can be seen in a contusion injury?
- Bleeding
- Resolution = turns yellow/brown
- Occurs where compressive force was, not necessarily point of trauma
What is coup and contrecoup?
How does head mobility related to this?
Coup = contusin +/- injury at point of impact
Contrecoup = contusion +/- injury at brain surface opposite impact
If head is immobile at point of impact = COUP
If head is mobile = COUP + CONTRECOUP may be found
What is diffuse/traumatic axonal injury?
Movement of one region of the brain relative to another can disrupt axonal integrity.
E.g. rapid deceleration in absence of impact
What pathology is found in traumatic axonal injury?
WIdepsread axonal swelling.
Gliosis.
50% of patients who develop coma after trauma have this
How is concussion assessed?
Glasgow COma Scale (GCS)
What are neurodegenerative diseases (NDDs)?
Umbrella term for disorders that result in loss of neurones. Disorders have cognitive, sensory and motor aspects.
What are the shared features of all NDDs?
- Progressive, relentless
- Loss of neurones
- Associated with aging
- Fatal outcome
What histopathology would you expect in any NDD?
- Neuronal atrophy
- Gliosis (increased astrocytes)
NDDs can be classified based on cognitive vs movement dysfunction. Give examples (4)
Cortical degeneration (cognitive decline)
- Alzheimer’s disease
- Dementia with Lewy bodies
Movement disorders:
- Akinetic syndrome: Parkinson’s disease
- Hyperkinetic syndrome: Huntington’s disease
What protein accumulation causes Alzheimer?
Beta-amyloid and Tau
What protein accumulation causes Parkinsons?
Alpha-synuclein
What causes Huntington disease?
Polyglutamine repeate expansion
What is dementia? Define.
Acquired progressive global dysfunction of intellect, memory, personality without impairment of consciousness.
Reflects dysfunction and cell death in neurones widely distributed through the brain.
Main causes of dementia?
- Alzheimer’s (70%)
- Dementia with Lewy bodies (10%)
- Frontotemporal lobe degeneration (10%)
- Vascular pathology (10%)
What are Lewy bodies?
Accumulation of alpha-synuclein proteins.
ARe toxic to neurones, and cause Lewy body dementia and Parkinsons
What is the common cause of death in Alzheimer patients?
Terminal infection, e.g. pneumonia
What is the gold standard of diagnosis for Alzheimers?
What 5 pathological features would we see?
Gold standard = pathology.
We would expect to see:
- Reduced cerebral weight
- Ventricular effacement (loss of white matter)
- Atrophy of medial temporal lobe
- Atrophy of limbic structures (hippocampus, white matter)
- Symmetrical cerebral atrophy
What histopathological features are expected in Alzheimer’s?
Beta-amyloid accumulation - forms cortical plaques
Tau accumulation - forms neurofibrillary tangles
What is the amyloid hypothesis?
Abnorma accumulation of beta-amyloid protein and reduced clearance thought to play a neurotoxic role in development of dementia/alzheimers.
What genetic factors are involved in development of dementia?
Mostly sporadic - 90% of cases >65
Familial - can see onset from 40-65
Trisomy 21 - Almost all get dementia by age 35 (APP gene on chromosome 21) APP gene codes amyloid precursor protein
What is the ABC score?
Diagnostic criteria for Alzheimer’s:
Look at stains of:
- Amyloid plaques
- Tau neurofibrillary tangles
- Neuritic plaques
What macroscopic and microscopic features would you expect in Lewy body dementia?
Macroscopic - similar to AD
Microscopic features idential to Parkinsons, with Lewy bodies in cortex.
WHat is the mechanism behind parkinsons?
Loss of dopaminergic neruones from substantia nigra - hypokinetic movement disorder.
