Dementia

Question 1

What is dementia?

Answer 1

An acquired loss in multiple domains of higher mental function.
It is a progressive decline.
Occurring in clear consciousness.

Question 2

Why is mental state important to check in patients with dementia?

Answer 2

Because depression is a differential which is easy to treat.

Question 3

What is the commonest type of dementia?

Answer 3

Alzheimer’s disease

Question 4

What are the stages of Alzheimer’s disease?

Answer 4

It presents in 3 stages:

1. Memory disturbance
2. Global cognitive decline with relatively intact personality
3. Severe global decline with disorders of social behaviour, failure of self care, incontinence and dependence.

Question 5

What is the pathology of Alzheimer’s disease?

Answer 5

There is cerebral atrophy, usually starting in the temporal lobes with characteristic neurofibrillary tangles and senile plaques.
An important constituent of these plaques is amyloid-beta protein.

Question 6

What are the symptoms of Alzheimer’s disease in the beginning? How does this progress?

Answer 6

Forgetfulness. Then formal testing shows evidence of more global impairment of cognitive ability.
30% will then develop depression and 75% personality changes - usually apathy.
Later, in 30-85%, behavioural changes such as verbal and physical aggression, inappropriate sexual behaviour and eating disorders occur.
Hallucinations are less common.
Seizures occur in 10-20%

Question 7

What does examination reveal in Alzheimer’s disease?

Answer 7

Gegenhalten pattern of increased tone.

Release of primitive reflexes.

Question 8

What are the symptoms of diffuse Lewy body dementia?

Answer 8

Marked fluctuations in cognition
Visual hallucinations - often of faces or animals
Behavioural disturbances
Agitation
Some signs of Parkinson’s disease (due to Lewy body)

Question 9

What is the difference in timescale for development of diffuse Lewy body dementia and Alzheimer’s disease?

Answer 9

Diffuse Lewy body dementia progresses more rapidly than Alzheimer’s

Question 10

How are hallucinations in diffuse Lewy body dementia treated?

Answer 10

With cholinesterase inhibitors e.g. rivastigmine.

Question 11

What are the 2 common autosomal dominant familial dementias?

Answer 11

Alzheimer’s disease (5% of AD is familial)

Huntington’s disease

Question 12

How does familial Alzheimer’s disease differ from the sporadic form?

Answer 12

Familial AD is more rapidly progressive than the sporadic form and presentation is usually in 40s/50s. Whereas sporadic form usually presents later in life (300 in 100,000 60-69 years old, 20% at 85 years old).

Question 13

What infections may cause dementia?

Answer 13

AIDs dementia
Syphilis
Subacute sclerosing panencephalitis
CJD