Neuropathology 2

Question 1

What is PML?

Answer 1

A demyelinating disorder of the CNS characterised by widespread lesions due to infection of oligodendrocytes by JC virus

Question 2

What is sub-acute sclerosing panencephalitis?

Answer 2

Most serious complication of measles

• causes demyelination etc
• always fatal

(because occurs after measles = presents in childhood/adolescence)

Question 3

Where do you often find MS plaques?

Answer 3

Optic nerve
Around the ventricles
Corpus callosum
Brainstem
Spinal cord

Question 4

Where are chronic MS plaques typically situated?

Answer 4

Around the lateral ventricles

Question 5

Primary dementias

Answer 5

Alzheimers
Lewy bodies
Picks
Huntingtons

Question 6

Secondary dementias

Answer 6

Result from vascular, metabolic, infection and trauma

Question 7

Which chromosomal condition increases your chance of alzheimer’s?

Answer 7

Down syndrome

Question 8

Which areas of the brain are affected in alzheimers?

Answer 8

Frontal, temporal and parietal lobes all affected

Brainstem and cerebellum normal

Question 9

Macroscopic pathology in Alzheimers

Answer 9

-decreased size and weight of brain (cortical atrophy)
-widening of sulci
-narrowing of gyri
-compensatory dilatation ventricles, 2° hydrocephalus
-frontal, temporal and parietal lobes affected
-brainstem and
cerebellum normal

Question 10

Severity of brain changes in alzheiemers correlates with what?

Answer 10

Severity of changes correlates with clinical severity

Question 11

Microscopic/histopathological features of alzheimers

Answer 11

intracytoplasmic neurofibrillary tangles

Aß amyloid plaques

amyloid angiopathy

extensive neuronal loss with astrocytosis

Question 12

Amyloid appearance on H&E stain

Answer 12

Eosinophilic appearance

Question 13

Amyloid appearance on x-ray diffraction

Answer 13

Polymerised BETA SHEET

Question 14

Where is amyloid deposited?

Answer 14

Extracellular matrix

Question 15

What type of stain can you use to identify amyloid?

Answer 15

Congo red stain (apple-green birefringence)

Question 16

Amyloid appearance on electron micrography?

Answer 16

Fibrillary appearance (looks like fibrils)
Fibrils are 10-12nm

Question 17

Why is the permanganate reaction test useful?

Answer 17

Differentiates between AA and AL

AA - amyloid A, AL - amyloid light chain

Question 18

Hallmarks of Lewy Body dementia?

Answer 18

Hallucinations and fluctuating levels of attention

but you also have features overlapping with Alzheimer’s disease and features of Parkinsons

Question 19

How can you detect lewy bodies?

Answer 19

Immunochemical staining that looks for the protein ubiquitin

Question 20

Which chromosome affected in Huntington’s disease?

Answer 20

Chromosome 4p

Question 21

Triad in huntington’s disease

Answer 21

Emotional, cognitive and motor disturbance

Question 22

Symptoms in HD

Answer 22

chorea (dance-like movements), myoclonus, clumsiness, slurred speech, depression, irritability and apathy

Develop dementia later

Question 23

Microscopic/histological appearance of Huntington’s disease?

Answer 23

Loss of neurones in the CAUDATE nucleus and cerebral cortex accompanied by REACTIVE FIBRILLARY GLIOSIS

Question 24

When and how does Pick’s disease present?

Answer 24

Presents in middle life (usually 50-60) and characterised by:

• slowly progressing changes in character and social deterioration
• leads to impairment of intellect, memory and language

Question 25

Histological hallmarks of Picks disease?

Answer 25

Picks cells (swollen neurons)

Question 26

Symptoms of Picks disease?

Answer 26

Related to damage to frontal and temporal lobes:

• personality and behavioural change
• speech and communication problems
• changes in eating habits
• reduced attention span

Question 27

Extreme atrophy of the cerebral cortex in frontal and temporal lobes
Brain weight

Answer 27

Pick’s disease

Question 28

What features help to distinguish multi-infarct dementia from Alzheimer’s disease?

Answer 28

• abrupt onset
• stepwise progression
• history of hypertension or stroke
• evidence of stroke will be seen on CT or MRI