Alzheimer's Disease and Other Dementias

Question 1

What is dementia?

Answer 1

Dementia is an impairment of mental abilities that affects more than one cognitive domain
It is progressive and lasts for more than 6 months
It is severe enough to impact on daily living

Question 2

What is Mild Cognitive Impairment?

Answer 2

Impairment of mental abilities that fails to meet the criteria for dementia. Some patients with MCI may develop dementia later on

Question 3

What is more common form of dementia?

Answer 3

Alzheimers Disease, affecting 1 in 14 people over 65, affecting twice as many women as men

Question 4

What is the cause of AD?

Answer 4

It is idiopathic (no known cause) but there is a familial link in a small number of cases (usually younger onset in these cases)

Question 5

What the risk factors for AD?

Answer 5

Same as stroke: diabetes, stroke, cardivascular disease, high blood pressure, high cholesterol, obesity, depresion, previous head injuries, down syndrome

Question 6

What is the pathology of AD?

Answer 6

accumulation of abnormal proteins around and inside the brain
amyloid plaques - around
neurofibrilary tangles - inside
these interfere with normal cellular function and eventually cause neuronal death

Question 7

What area of the brain is affected first in AD?

Answer 7

hippocampus (in the medial temporal lobe)

Later other areas are affected - typically braun circuits involving the neurotransmitter actylcholine

Question 8

Key Symptom of Early AD?

Answer 8

Key - memory lapses are more apparent to family members and friends than the person themselves. If it is the person themselves it’s generally anxiety

Question 9

Additional symptoms of Moderate AD?

Answer 9

Impaired visuospatial skills
Difficulty concentrating, planning, organising
Need help with complex tasks and personal care
Difficulty learning new skills or information
Behaviour changes - wandering, repeated questions, anxiety

Question 10

Signs of severe AD?

Answer 10

* inactivity and dependence on others 
unaware of time and space 
difficulty recognising family and friends 
difficulty walking 
increase behaviour changes

Question 11

How do you diagnose AD?

Answer 11

No diagnostic test
Exclude reversible causes of cognitive impairment
Exclude depression
Exclude other dementias (e.g. vascular dementia)
Use a cognitive screening tool
Do formal neuropsychological testing
MRI scan (hippocampal atrophy)

Question 12

What are the atypical variants of AD?

Answer 12

posterior cortical atrophy (think occipital and parietal difficulties)
logopenic aphasia (affecting speech output)
Frontal-Variant AD (affects planning and decision making, loss of empathy, socially inappropriate behaviours)

Question 13

What is the treatment for AD?

Answer 13

No disease modifying treatment but drug treatment can temporarily stablize, slow or improve the progression of symptoms
1. Cholineterase Inhibitors: increase ACh by blocking breakdown in synapses
Types: donepezil, rivastigmine, galantamine
side effects: nausea, dizzinesss, loss of appetite
2. Memantime: blocks glutamate effects (which damages neurons)

Question 14

What is the average survival rate for AD?

Answer 14

8-10 years (but variable)

Question 15

What two diseases does Dementia with Lewy Bodies share characteristics with?

Answer 15

Alzheimers Disease and Parkinsons

Question 16

In addition to elements of AD and PD, what are the key features of Dementia with Lewy Bodies?

Answer 16

Fluctuating levels of impairment 
Visual hallucinations 
Delusions 
Visuospatial difficulties 
Sleep disturbances

Question 17

What may be effective in alleviating hallucinations, aggitation or aggressions?

Answer 17

Cholinesterase Inhibitors (also used in AD)

Question 18

What is neuroleptic sensitivity?

Answer 18

It’s a very extreme parkinsonian reaction to some type of antipsychotic medication

Question 19

What is the prognosis for dementia with Lewy Bodies?

Answer 19

6-12 years (but variable)

Question 20

What are the three variants of Frontotemporal Dementia?

Answer 20

Behavioural Variant FTD (most common - ass with changes in personality and behaviour)
Progressive Non-Fluent Aphasia (like slowly progressive Broca’s aphasia)
Semantic Dementia (fluent speech but WFD, loss of vocab and understanding)
End stages of all three look similiar

Question 21

Prognosis of Fronto-temporal Dementia?

Answer 21

2-10 years (average 6-8 years)

Question 22

What are the two types of vascular dementia?

Answer 22

Multi-infarct dementia (series of single infarcts resulting in the accumulation of cognitive impairments - typically stepwise progression of deficits followed by a sudden decline after a new infarct) 
Subcortical Dementia (psychomotor slowness - decrease in the speed of thought processes and actions)

Question 23

What 2 conditions mimic dementia?

Answer 23

1. Delirium (acute confusional syndrome - differentiate by the inability to concentrate on one task/idea)
2. Depression (may co-exist though)