Pathology Flashcards
two process that can occur as a result of damage to nerve cells
- rapid necrosis and sudden failure (stroke)
2. slow atrophy with gradual dysfunction (cerebral atrophy)
neuron reaction to hypoxia
red
irreversible cell death
axons reaction to hypoxia
increase protein synthesis and swell
oligodendrocyte reaction to hypoxia
demyelintion
astrocyte response to hypoxia
gliosis
microglial response to hypoxia
proliferate and recruit inflammatory mediators
define cerebrovascular disease
abnormality of the brain caused by pathological blood vessels
two types of cerebral ischaemia
- global
2. focal
define stroke
sudden disturbance in cerebral function of vascular origin that lasts >24 hours
types of stroke
- infarction
2. haemorrhage
causes of infarction stroke
thrombus
emboli
dissection?
risk factors for ischaemic stroke
>70 male hypertension hyperlipidaemia DM smoking
causes of haemorrhagic stroke
BBB disruption
can be caused by thrombolysis
carotid artery lesion presentation
contralateral weakness or sensory loss
MCA presentation
weakness in contralateral face and arm
ACA presentation
weakness in contralateral leg
PCA presentation
pure sensory loss
vertebra-basilar artery presentation
vertigo
ataxia
dysarthria
dysplasia
lacunar presentation
sensory or motor symptoms only to one side of the body with 2/3 areas involved (face, arm, leg)
examples of vascular malformations
arteriovenous malformation
cavernous angiomas
venous angiomas
capillary telangectases
define hydrocephalus
accumulation of CSF in ventricular system
mechanisms of the causes of hydrocephalus
obstruction decreased resorption (SAH, meningitis) overproduction
classification of hydrocephalus
- non-communicating
2. communicating
define non-communicating hydrocephalus
obstruction occurs within the ventricular system
in children tends to be due to aqueduct stenosis
define communicating hydrocephalus
outside ventricular system
what happens if hydrocephalus occurs before closure of cranial sutures?
cranial enlargement
what is hydrocephalus ex vacuo?
dilation of the ventricles occur due to loss of brain parenchyma
presentation of normal pressure hydrocephalus
Parkinson’s symptoms
causes of raised ICP
hydrocephalus SOL oedema increased venous volume physiological (hypoxia, hypercapnia, pain)
effects of raised ICP
herniations
distortion of cranial nerves
impaired blood flow
reduced consciousness
presentation of raised ICP
papilloedema
vomiting
HA
what is a medulloblastoma
primary tumour often in children in the cerebellum (embryonal)
why does a medulloblastoma cause hydrocephalus?
commonly in the midline so disrupts CSF causing hydrocephalus
management of medulloblastoma
radiosensitive
two types of head truma
- penetrating (missile)
2. blunt (non-missile)
what is a contra-coup injury?
damage to the opposite side of impact due to brain moving in the cranial cavity
when does diffuse axonal injury (DAI) occur?
at the moment of injury (balloon axons)
describe extradural haematoma
usually middle meningeal artery
immediate brain damage minimal but untreated causes midline shift
two types of subdural haematoma
- acute
2. chronic
describe acute subdural haematoma
clear history of trauma
elderly
cerebral bridging veins?
describe chronic subdural haematoma
associated with brain atrophy
composed of liquefied blood/yellow- tinged fluid
classification of demyelinating disorders
- primary
2. secondary
primary causes of demyelination
MS
ADEM
AHL
secondary causes of demyelination
viral (JC virus)
metabolic (central pontine myelinosis)
toxic (CO, cyanide)
examples of presentations for MS
optic nerve lesions= unilateral visual impairment
spinal cord lesions= motor or sensory deficit, spasticity, bladder control
brainstem= ataxia, nystagmus, internuclear ophthalmoplegia
pathology specimen for MS
well circumscribed plaques
primary causes of dementia
alzheimer’s
LBD
Pick’s disease (FTD)
Huntington’s
secondary causes of dementia
vascular
infection (HIV, syphilis)
trauma
metabolic
implicated genes in Alzheimer’s
amyloid precursor protein (APP)
presenilin 1
presenilin 2
why is there higher incidence of Alzheimer’s in trisomy 21?
APP gene on chromosome 21
pathological specimen features of Alzheimer’s
gliosis
neurofibrillary tangles (TAU protein)
neuritic plaques= Abeta amyloid plaques
amyloid angiopathy
what is amyloid angiopathy?
stiffening and thickening of blood vessel walls due to eosinophil accumulation
diagnosis of amyloid angiopathy
stains with congo red
what produces Parkinsonism symptoms?
conditions that affect the nigro-striatal dopaminergic pathway
examples of parkinsonism causes
PD LBD drugs (phenothiazine) trauma multisystem atrophy
what happens in Hungtinton’s disease?
atrophy of the basal ganglia (caudate nucleus) with expansion of ventricles
degeneration of neurones leads to loss of inhibition activity
FTD pathological features
atrophy
Pick’s cells (swollen neurones)
Pick bodies (inclusion)
