Pathology Flashcards
Which component of the CNS is most vulnerable to hypoxia?
Neurones
Which cells are the “macrophage cells” of the CNS?
Microglia
Axonal injury involves a reaction in which part of the neurone?
Reaction within cell body
In which direction does the axon damage in response to injury?
Anterograde degeneration of axon distal to site of injury
Which process do astrocytes initiate in response to injury?
Reactive proliferation - gliosis - where cells undergo hyperplasia and hypertrophy
Which process if the most important histopathological indicator of CNS injury, regardless of cause?
Gliosis
Which cells line the ventricular system?
Ependymal cells
The brain receives how much of the cardiac output?
15%
What is the response of vasculature to the brain in hypotension and hypertension?
Constricts in hypertension
Dilates in hypotension
What are the two main sets of arteries supplying blood to the brain?
Branches of internal carotid + vertebral arteries (form anterior + posterior circulations)
Lack of blood supply in the anterior cerebral artery is associated with which dysfunctions?
Frontal lobe dysfunction
Contralateral sensory loss in foot + leg
Paresis of arm + foot
Lack of blood supply in the middle cerebral artery is associated with which dysfunctions?
Hemiparesis
Hemisensory loss
Aphasia/dysphasia
Apraxia
Lack of blood supply in the posterior cerebral artery (vertebrobasilar) is associated with which cerebellar dysfunctions?
Ataxia
Nystagmus
Intention tremor
Pendular reflexes
Lack of blood supply in the posterior cerebral artery (vertebrobasilar) is associated with which occipital lobe dysfunctions?
Homonymous hemianopia with macular sparing
When does gliosis occur following a cerebral infarct?
1-2 weeks
What is the most common cause of a subarachnoid haemorrhage?
Spontaneous rupture of a saccular aneurysm (Berry aneurysm)
List diseases that have increased incidence of Berry aneurysms
Polycystic kidney disease
Fibromuscular dysplasia
Coarctation of aorta
Most berry aneurysms occur where?
90% = arterial bifurcations near internal carotid cartery
10% = vertebrobasilar circulation
At which diameter do berry aneurysms have greatest risk of rupture?
6-10mm
If over 25mm, risk of rupture decreases
Lacunar infarcts can be present in hypertensives. What are they?
Small cavities up to 10mm in diameter found in basal ganglia and pons
What is demyelination?
Destruction of myelin sheath surrounding an axon, either due to breakdown or abnormal production
What disease comes under primary demyelination?
Multiple sclerosis
What is the female:male affected ratio for MS?
2:1
The external appearance of the brain and spinal cord in MS is usually normal. True/False?
True
MS is a grey matter disease. True/False?
False
MS is a white matter disease
Describe the morphology of MS
Well-demarcated plaques in white matter in a non-anatomical distribution
Describe the colour of MS plaques
Acute lesions: soft pink
Chronic lesions: firm pearl-grey
What structures do MS plaques commonly affect?
Optic nerve
Periventricular white matter
Corpus callosum
Brainstem
Spinal cord
Where do chronic inactive MS plaques typically occupy?
Situated around lateral ventricles
Dementia is always pathological. True/False?
True
Neurodegenerative disorder, not just part of ageing!
List diseases classified as primary dementias
Alzheimer’s disease
Huntington’s disease
Pick’s disease
Lewy body dementia
What is the female:male ratio for Alzheimer’s disease?
2:1
List the genes the can be involved in Alzheimer’s disease
Amyloid precursor protein (c21)
Presenilin 1 (c14)
Presenilin 2 (c1)
ApoE (allele e4)
Describe the morphology of Alzheimer’s disease on the brain
Cortical atrophy
Widened sulci
Narrowed gyri
Dilated ventricles
Which lobes are particularly affected in Alzheimer’s disease?
Frontal
Temporal
Parietal
Which protein forms plaques in Alzheimer’s disease?
A-beta amyloid plaques
What colour does amyloid protein stain?
Congo red
Which protein in the brain can become tangled and defective in Alzheimer’s disease?
Tau protein
Which area of the brain is affected in Lewy body dementia (Parkinson’s)?
Substantia nigra
Which protein, when stained, can help detect Lewy bodies?
Ubiquitin
What happens to the caudate nucleus in Huntington’s disease?
Caudate atrophy with loss of neurons
What are the histopathological landmarks of Pick’s disease dementia?
Swollen neurons (Pick’s cells)
Filamentous inclusions (Pick’s bodies)
Which lobes does Pick’s disease usually affect?
Frontal
Temporal
What is the most common type of secondary dementia?
Vascular (infarct) dementia
Examples of acetylcholine esterase inhibitors used to treat dementia?
Donepezil
Galantamine
Rivastigmine
Name the NMDA receptor antagonist used to treat Alzheimer’s?
Memantine
