Dementia

Question 1

What is dementia?

Answer 1

acquired and persistant generalised disturbance of higher mental function in an otherwise fully alert person

Question 2

What are the 4 primary types of dementia?

Answer 2

Alzhemiers - 60-75%
Lewy Body dementia - 10-15%
Fronto-temporal dementia - <2%
Huntingtons disease

Question 3

What are secondary types of dementia?

Answer 3

multi infarct - vascular dementia - 20%
HIV, syphilis
trauma
metabolic - vit B1 deficiency, paraneoplastic syndromes
intracranial space - SOLs and hydrocephalus
drugs and toxins

Question 4

What are the risk factors for Alzheimers disease?

Answer 4

females>males
most common >85s
if <65 = genetic related
may be familial - amyloid precursor protein or presenillin 1 and 2
increased incidence in trisomy 21

Question 5

What is the presentation of Alzheimers disease?

Answer 5

disorientation
memory loss
aphasia - can be naming, repeating or effortful

Question 6

What is the pathology behind Alzheimers disease?

Answer 6

decreased size and weight of the brain - due to cortical atrophy
normally in frontal, temporal and parietal lobe and hippocampus
sulci widen and gyri narrow
hydrocephalus ex valco occurs - ventricle dilation

Question 7

What can be seen microscopically in Alzheimers disease?

Answer 7

neurofibrillary tangles - often due to disregulated TAU protein
neuronal loss with astrocyte proliferation
Ab amyloid plaques - produced by cleavage of amyloid precursor proteins (APP)

Question 8

Where are amyloid precursor proteins found (APP)?

Answer 8

on chromosone 21

meaning those with down syndrome have a double dose of it so have early onset Alzheimers

Question 9

What do Ab oligomers promote?

Answer 9

mislocation of TAU which leads to Alzheimers

Question 10

What is amyloid angiopathy?

Answer 10

extracellular eosinophillic accumulation
stains congo red
distrupts the BBB by local hypoxia causing excitotoxicity, oedem and serum leaking

Question 11

What investigations are done for Alzheimers disease?

Answer 11

MRI - atrophy of the temporal/parietal lobes
SPECT - tempoparietal decreased metabolism
CSF - decreased amyloid: increased TAU ratio

Question 12

What treatment is given for Alzheimers disease?

Answer 12

acetylcholine boosting treatment - cholinersterase inhibitors (Rivagistimine)
NMDA receptor blocker - mematine

Question 13

What is the presentation of Lewy Body Dementia (LBD)?

Answer 13

frequent visual symptoms
hallucinations
memory affected later on 
fluctuates in severity from day to day
extra pyradimal features of Parkinson's

Question 14

What is the pathology of LBD?

Answer 14

degeneration of the substantia nigra

pallor in the substantia nigra where the preserved dopaminergic neurones run

Question 15

What is seen microscopically in LBD?

Answer 15

loss of pigmented neurones
reactive gliosis
microglial accumulation
remaining neurones show Lewy bodies

Question 16

What are lewy bodies?

Answer 16

aggregates of alpha synuclein and ubiquitin

Question 17

What is the presentation of Huntingtons disease?

Answer 17

35-50yrs
triad of emotional, cognitive and motor disturbances
chorea
myoclonus 
develop dementia later on in the disease

Question 18

What are the investigations for LBD?

Answer 18

reduction of dopamine uptake on the DaT scan

Question 19

What are the treatment options for LBD?

Answer 19

small dose levodopa

cholinesterase inhibitors

Question 20

What are the genes behind Huntingtons disease?

Answer 20

autosomal dominant

huntingtin gene on chromosome 4p - mutant gene has additional CAG repeats

Question 21

What are the investigations for Huntingtons disease?

Answer 21

MRI - loss of caudate heads

Question 22

What is the treatment for Huntingtons disease?

Answer 22

mood stabilisers

Question 23

What is the pathology of Huntingtons disease?

Answer 23

atrophy of basal ganglia esp caudate nucleus and putamen

cortical atrophy of frontal areas - later on

Question 24

What is seen microscopically in Huntingtons disease?

Answer 24

neuronal atrophy of sriatal neurones in the basal ganglia

pronounced astrocytic gliosis

Question 25

What is the presentation of fronto-temporal dementia/picks disease?

Answer 25

50-60years
progressive changes in character and social deterioration
reduced attention span
changes in eating habits with no awareness of abnormal behaviour
loss of social norms

Question 26

What is the pathology behind fronto-temporal dementia/picks disease?

Answer 26

extreme atrophy of the cerebral cortexin the frontal then temporal lobes
neuronal loss and gliosis
picks cells - swollen neurones
picks bodies - intracytoplasmic filamentous inclusions

Question 27

What is the treatment for fronto-temporal dementia/picks disease?

Answer 27

Trazodone

antipsychotics

Question 28

What is multi infarct dementia?

Answer 28

deteriation due to cumulitive damage to the brain due to hypoxia or anoxia as a result of multiple blood clots

Question 29

What is the presentation of multi infarct dementia?

Answer 29

one 50-100mls of the brain is dead - dementia occurs
males > females
>60 or middle aged hypertensive
abrupt onset and stepwise progression of:
reduced attention
slowed processing
executive dysfunction

Question 30

What is the pathology behind multi infarct dementia?

Answer 30

large vessel infarcts spread through the hemispheres due to atheroma of large cerebral arteries
rarer: small vessel/lacunar infarcts

Question 31

What is the treatment of multi infarct dementia?

Answer 31

cholinesterase inhibitor