8.3 Pathology of brain

Question 1

one of the compensatory mechanisms to maintain normal ICP is to reduce blood volume. Is this blood venous or arterial?

Answer 1

venous

Question 2

why is an extradural haemorrhage usually lucid then sudden?

Answer 2

takes time for periosteal dura to split from periosteum of skull, but once split then arterial blood fills the space quickly

Question 3

risk factors for berry aneurysm/SAH

Answer 3

Ehlers danlos
other connective tissue disorders
polycystic kidney disease

Question 4

2 types of cerebral infarcts (ishaemic)

Answer 4

thrombotic occlusion
embolic occlusion

Question 5

why would obstruction of deep penetrating arteries cause significant ant damage? examples of these

Answer 5

no collateral supply

-basal ganglia
-thalamus
-deep white matter

Question 6

where might you get a wedge shaped necrosis in ischaemic stroke?

Answer 6

watered areas (distal artery territories) e.g MCA/ACA border. after a hypotensive episode

Question 7

common sites of thrombotic stroke

Answer 7

carotid bifurcation, MCA origin, basilar artery

Question 8

common sites of spontaneous intracerebral haemorrhage

Answer 8

basal ganglia, pons, cerebellum, thalamus

Question 9

pathophysiology of cerebral amyloid angiopathy

Answer 9

lobar haemorrhages of cerebral cortices, amyloid deposition in walls of small/medium meningeal and cortical vessels, weakness wall

Question 10

arteriovenous malformations

Answer 10

subarachnoid vessels to brain or vessels in brain

tangled vascular channels

Question 11

cavernous malformations

Answer 11

loos vascular channels, distended, thin walled in cerebellum and pons

Question 12

symptoms of CNS tumours

Answer 12

seizures
headaches
focal neurological deficit
raised ICP
N+V

Question 13

identify some primary CNS tumours

Answer 13

gliomas
-astrocytic
-oligdendroglioma

parenchymal
-lymhoma
-germ cell

-meningioma

neuronal
-ganglion cell tumour
-neuroblastoma

Question 14

investigations for meningitis

Answer 14

CT
LP

Question 15

why is glucose decreased in meningitis LP?

Answer 15

requirements of infection

Question 16

how do normal prion proteins become pathological?

Answer 16

normally rich in alpha helices

sporadic mutation/ingested

now beta pleated sheets, resistant to proteolysis

propagates other to beta too

Question 17

creutzfeld Jacob disease features

Answer 17

mostly sporadic

rapidly progressive dementing illness, changes in memory, cerebellar ataxia, brain may look normal

Question 18

variant creutzfeld Jacob disease features

Answer 18

slower progression, younger people, starts with behavioural issues, exposure to prion disease in cattle

Question 19

molecular pathologies in Alzheimer’s

Answer 19

amyloid plaques (alpha beta)

neurofibrillary tangles (hyperphosphorylated tau proteins)

Question 20

huntingtons disease

Answer 20

-autosomal domiannt
-CAG trinucleotide repeat expansion
-hyperkinesia