Neuropathology

Question 1

How do infections enter the CNS? (3 Ways)

Answer 1

direct spread e.g. middle ear, ethmoid bone
Blood-borne, sepsis or infective endocarditis
Iatrogenic -

Question 2

what are the leptomeninges ?

Answer 2

Arachnoid

pia mater

Question 3

what 2 features may be present in meningitis ?

Answer 3

Inflammation of leptomeninges

+/- septicaemia

Question 4

what is a sign of meningococcal septicaemia?

what is its histological appearance ?

Answer 4

non-blanching rash

Neutrophils

Question 5

what are caustive oragnisms in meningitis by age range :
Neonates
2-5
5-30

Answer 5

Neonates – E. coli, L. monocytogenes
• 2-5 years old – H. influenza
• 5-30 years – N. meningitidis

Question 6

what is are features of Chronic Meningitis ?

Answer 6

Photosensitivity
Granulomas
Meningeal fibrosis
Cranial nerve entrapment

Question 7

what are complications of meningitis ?

Answer 7

Death due raised intracranial pressure
Cerebral infarction (stroke)
Cerebral abscess
Subdural empyema
 Epilepsy 
sepsis 
Bilateral adrenal haemorrhage

Question 8

what is the causative organism of Chronic Meningitis ?

Answer 8

M. tuberculosis

Question 9

what is encephalitis ?

what is it classically caused by ?

Answer 9

Inflammation of brain parenchyma not meninges -can occur as a
complication of meningitis
viral

Question 10

what is seen histologically in encephalitis ? why?

Answer 10

intracellular viral
inclusion bodies
neuronal death

Question 11

what affects temporal lobe in encephalitis ?

Answer 11

Herpesviruses

Question 12

what affects spinal lobe in encephalitis ?

Answer 12

Polio

Question 13

what affects Brainstem in encephalitis ?

Answer 13

rabies

Question 14

where are prions found ?

Answer 14

synapses

Question 15

how can PrP turn to PrPsc ?

Answer 15

sporadic mutation,

familial inheritance of mutated gene or following ingestion of PrPsc

Question 16

How would ingested a PrPsc propagate itself ? why is there no immune response ?

Answer 16

PrPsc induced post translational conformational change in normal PrPs
Stable and it is recognised as self protein

Question 17

how do prions (PrPsc) cause damage ?

Answer 17

PrPsc- aggregates which destroy neruones and

cause the grey matter to take on a sponge-like (spongiform) appearance

Question 18

Name 2 Spongiform Encephalopathies

Answer 18

Scrapie in sheep
BSE in cows (‘mad cow’ disease)
Kuru in New Guinean tribes (due to cannibalism and
ingestion of PrPsc)
Creutzfeld Jacob disease (CJD)

Question 19

What is vCJD ? what is it linked with ? difference between vCJD and CJD?

Answer 19

Strongly linked to BSE through ingestion of
prions] higher
prion load associated with earlier age (28) at
death and more prominent psychiatric
symptoms
look at table in lecture

Question 20

what are Koch’s Postulates ?

Answer 20

the Microorganism must be found in abundance in the suffered
Must be isolated and grown in culture
cultured organism must cause disease in healthy individuals
Reisolated from inoculated and identified as same as original host

Question 21

define dementia

Answer 21

Acquired global impairment of intellect, reason and personality without
impairment of consciousness

Question 22

what is the main cause of dementia ?

what are other causes ?

Answer 22

Alzheimer’s

vascular, lewy body and Picks

Question 23

define Alzheimer’s

what is its appearance

Answer 23

loss of cortical neurones
decrease in brain weight
cortical atrophy
narrow gyri and wide sulci

Question 24

what causes Alzheimier’s ?

Answer 24

neurofibrillary tangles and amyloid

plaques

Question 25

what are Neurofibrally tangles ?

Answer 25

Intracellular twisted filaments of Tau that has been hyperphosphorylated - normally bind to stabilise microtubules

Question 26

what are senile plaques ?

Answer 26

Foci of enlarged axons, synaptic terminals and dendrites Amyloid deposition in centre of plaque associated with vessels- central to pathogenesis

Question 27

what syndrome is associated with early onset AD? | what mutations specifically ?

Answer 27

``` Trisomy 21 Down's APP Presenilin -secretase gene leads to incomplete breakdown of APP = amyloid disposition ```

Question 28

what is normal range of ICP ?

Answer 28

0-10mmHg | • Coughing/straining can increase it to 20mmHg

Question 29

What are compensatory mechanisms for ICP? | what is the limit for vascular mechanism ?

Answer 29

Reduce blood volume reduced CSF brain atrophy = chronic <60mmHg

Question 30

what do SoLs do to the brain?

Answer 30

Deforms or destroys surrounding brain Displaces midline structures – loss of symmetry, midline shift Herniation

Question 31

what is a subfalcine herination?

Answer 31

Cingulate gyrus is pushed under the free edge of the | falx cerebri

Question 32

what can subfalcine herination lead to ?

Answer 32

ischaemic due to | compression of anterior cerebral artery leading to infarction

Question 33

what is a tenotrial herination?

Answer 33

Medial temporal lobe (classically the uncus) pushed | down through the tentorial notch

Question 34

why are tentorial herinations often fatal ?

Answer 34

sedondary heamorrhage into brianstem (Duret) leads to resp and CVS control problems common mode of death in those with large tumours and IC heamorrhage

Question 35

what are the symptoms of tentorial herination ? why?

Answer 35

ipsilateral third nerve palsy contralateral UMN signs in limbs- compress ipisilateral oculomotor nerve and ipsilateral cerebral peduncle

Question 36

name 1 benign and 1 malignant Brain tumour

Answer 36

Meningioma | Astrocytoma

Question 37

where do astrocytomas usually mets to ?

Answer 37

spread along nerve through sub arch space to spine - hard to remove

Question 38

what is the most common cause of brain tumours ?

Answer 38

metastasis

Question 39

Name 2 ways tumours can spread in the brain ?

Answer 39

white matter pathways | CSF

Question 40

what is Neurofibroma

Answer 40

tumour of Schwann cells of | peripheral or cranial nerve

Question 41

what are tumours of ependymal cells lining | ventricular system?

Answer 41

Ependymoma

Question 42

what tumours can arise from Non-CNS tissues?

Answer 42

mets | Lymphomas

Question 43

what is a stroke ?

Answer 43

A sudden event producing a disturbance of CNS function due to vascular disease

Question 44

name 2 sources an embolism may come from

Answer 44

Heart (due to AF, mural thrombus) Atheromatous debris (carotids) Thrombus over ruptured plaque Aneurysm

Question 45

where would a thrombus form in a stroke if it did not embolise from somewhere ?

Answer 45

cerebral arteries

Question 46

what s a lacuna stroke ?

Answer 46

Small (less than 1cm area affected) Associated with hypertension Commonly affect basal ganglia and internal capsule

Question 47

what is seen and associated with intracerebral haemorrhage leading to stroke ?

Answer 47

ncreased age, hypertensive vessel damage and amyloid deposition in vessels Charcot-Bouchard aneurysms are seen May be inherited Produces a space occupying lesion

Question 48

what causes subarachnoid haemorrhage ?

Answer 48

Rupture of berry aneurysms, usually found at branch points in circle of Willis  Blood in subarachnoid space can cause secondary spasm of cerebral arteries

Question 49

what are some risk factors for subarachnoid haemorrhage?

Answer 49

Male • Hypertension • Atherosclerosis

Question 50

what are some symptoms of Subarachnoid haemorrhage?

Answer 50

Thunderclap headache • May be preceded by a ‘sentinel’ headache • Loss of consciousness • Often instantly fatal