Dementia Summary

Question 1

most common cause of dementia?

Answer 1

alzheimers

Question 2

biggest risk factors for alzheimers?

Answer 2

age = biggest (increases a lot after 60)
family history
down syndrome
head injury

Question 3

what familial factors can increase risk of alzheimers?

Answer 3

apolipoprotein E4 (ApoE4) increases risk

Question 4

what genetic mutations are associated with early onset alzheimers?

Answer 4

mutations in amyloid precursor protein (APP) or presenilin 1/2

Question 5

histology seen in alzheimers?

Answer 5

excess accumulation of extracellular beta amyloid plaques and intracellular neurofibrilary tangles

Question 6

what are neurofibrillary tangles?

Answer 6

aggregates of tau protein

Question 7

describe the pathology seen in alzheimers

Answer 7

widespread cortical atrophy
narrowing of gyri and widening of sulci
nucleus basalis of meynert, entorhinal cortex and hippocampus are the areas of the brain which can be affected first

Question 8

what is the nucleus basalis of meynert?

Answer 8

source of cholinergic projections to the brain

Question 9

early clinical features of alzheimers?

Answer 9

insidious and progressive onset of worsening memory (particularly episodic)
seen as forgetting appointments, misplacing items and inability to remember recent events
can also have early problems with planning, decision making and working out complex sequences etc

Question 10

how is insight affected in alzheimers?

Answer 10

often lost

- therefore should get collateral history from close friend/relative etc

Question 11

later features of alzheimers?

Answer 11

language difficulties (naming things)
behavioural problems (such as aggression)
depression
disorientation

Question 12

how is alzheimers diagnosed?

Answer 12

generally a clinical diagnosis with several tools (such as MMSE) that assess cognitive function
MRI and SPECT can help differentiate from frontotemporal dementia and lewy body etc
CSF biomarkers show increase in phosphorylated tau protein and decrease in beta amyloid

Question 13

pharmacological management of alzheimers?

Answer 13

acetylcholinesterase (AChE inhibitors) are used in mild to mod alzheimers
N-methyl-D-aspartate (NMDA) receptor antagonists = 2nd line in mod/intolerant to AChE inhibitors or severe alzheimers

Question 14

name 3 AChE inhibitors?

Answer 14

donepazil
galantamine
rivastigmine

Question 15

name an NMDA receptor antagonist?

Answer 15

memantine

Question 16

complicaitons of alzheimers?

Answer 16

haemorrhagic stroke due to beta amyloid deposits in cerebral blood vessels that can weaken them (cerebral amyloid angiopathy)

Question 17

what is frontotemporal dementia?

Answer 17

group of neurodegenerative disorders characterised by relatively focal frontal and temporal cerebral atrophy

Question 18

what is frontotemporal dementia also known as?

Answer 18

picks disease

Question 19

3 broad symptomatic variants of frontotemporal dementia?

Answer 19

behavioural (Most common)
primary progressive aphasia
movement disorders

Question 20

describe the behavioural variant of frontotmporal dementia?

Answer 20

causes loss of inhibition, apathy, repetitive behaviours and difficulty planning
memory is preserved in early disease (behaviour problems more prominent)

Question 21

describe the primary progressive aphasia variant of frontotemporal dementia?

Answer 21

has 2 forms, both with prominent decline in language abilities

• semantic = impaired word comprehansion and object naming, trouble recognising faces and objects
• progressive non-fluent aphasia = slow/hesitant speech, word finding deficits and agrammatism, may have orofacial apraxia which can be tested by coughing/swallowing

Question 22

how is frontotemporal dementia diagnosed?

Answer 22

MRI (can show characteristic changes in frontal and temporal lobes)
lumbar puncture (to distinguish from alzheimers)

Question 23

2nd most common cause of dementia?

Answer 23

vascular dementia

Question 24

what is vascular dementia?

Answer 24

vascular changes secondary to cerebrovascular disease

Question 25

features of vascular dementia?

Answer 25

executive and attentional impairments
behavioural change (disinhibition)
cognitive slowing
focal neurological problems
difficulty walking/falls

Question 26

how does vascular dementia progress?

Answer 26

can have a sudden onset

step-wise decline

Question 27

how is vascular dementia best imaged?

Answer 27

MRI
- shows presence and location of infarcts and commonly shows white matter changes and patchy reduced attenuation in the cortex

Question 28

what is creutzfeldt-jakob disease?

Answer 28

transmissible prion neurodegenerative disease

Question 29

histology in creutzfeldt-jakob disease?

Answer 29

cell death (seen as spongiform changes in the cortex) and astrocytosis

Question 30

how does creutzfeldt-jakob disease present?

Answer 30

rapidly progressing dementia, ataxia and myoclonic jerks

Question 31

best initial test in creutzfeldt-jakob disease?

Answer 31

EEG

- shows characteristic pseudoperiodic sharp wave activity

Question 32

CSF features in creutzfeldt-jakob disease?

Answer 32

elevated 14-3-3 protein