Neuropathology 2 Flashcards
What is PML?
A demyelinating disorder of the CNS characterised by widespread lesions due to infection of oligodendrocytes by JC virus
What is sub-acute sclerosing panencephalitis?
Most serious complication of measles
- causes demyelination etc
- always fatal
(because occurs after measles = presents in childhood/adolescence)
Where do you often find MS plaques?
Optic nerve Around the ventricles Corpus callosum Brainstem Spinal cord
Where are chronic MS plaques typically situated?
Around the lateral ventricles
Primary dementias
Alzheimers
Lewy bodies
Picks
Huntingtons
Secondary dementias
Result from vascular, metabolic, infection and trauma
Which chromosomal condition increases your chance of alzheimer’s?
Down syndrome
Which areas of the brain are affected in alzheimers?
Frontal, temporal and parietal lobes all affected
Brainstem and cerebellum normal
Macroscopic pathology in Alzheimers
-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
Severity of brain changes in alzheiemers correlates with what?
Severity of changes correlates with clinical severity
Microscopic/histopathological features of alzheimers
intracytoplasmic neurofibrillary tangles
Aß amyloid plaques
amyloid angiopathy
extensive neuronal loss with astrocytosis
Amyloid appearance on H&E stain
Eosinophilic appearance
Amyloid appearance on x-ray diffraction
Polymerised BETA SHEET
Where is amyloid deposited?
Extracellular matrix
What type of stain can you use to identify amyloid?
Congo red stain (apple-green birefringence)
Amyloid appearance on electron micrography?
Fibrillary appearance (looks like fibrils) Fibrils are 10-12nm
Why is the permanganate reaction test useful?
Differentiates between AA and AL
AA - amyloid A, AL - amyloid light chain
Hallmarks of Lewy Body dementia?
Hallucinations and fluctuating levels of attention
but you also have features overlapping with Alzheimer’s disease and features of Parkinsons
How can you detect lewy bodies?
Immunochemical staining that looks for the protein ubiquitin
Which chromosome affected in Huntington’s disease?
Chromosome 4p
Triad in huntington’s disease
Emotional, cognitive and motor disturbance
Symptoms in HD
chorea (dance-like movements), myoclonus, clumsiness, slurred speech, depression, irritability and apathy
Develop dementia later
Microscopic/histological appearance of Huntington’s disease?
Loss of neurones in the CAUDATE nucleus and cerebral cortex accompanied by REACTIVE FIBRILLARY GLIOSIS
When and how does Pick’s disease present?
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
