Dementia

Question 1

What is dementia

Answer 1

Dementia is a syndrome with cognitive and behavioural symptoms

Has an insidious onset

Is a chronic condition with slow deterioration

Question 2

Name some congitive symptoms seen in dementia

Answer 2

Impairment of memory

Impariment of orientation

Impariment of learning capacity

Impairment of judgement

Question 3

Name some non-congitive symptoms seen in dementia

Answer 3

Behavioural symptoms - fear of unknown, agitation, aggression, wandering, sexual disinhibition

Depression and anxiety

Psychotic symptoms - visual and auditory hallucinations, persecutory delusions

Sleep symptoms - insomnia, daytime drowsiness

Question 4

Name some differential diagnoses for dementia

Answer 4

Hypothyroidism

Hypercalcaemia

Vit B12 deficiency

Normal pressure hydrocephalus

Question 5

What triad is seen in normal pressure hydrocephalus

Answer 5

Abnormal gait

Incontinence

Reduced cognition

Question 6

What are the types of dementia

Answer 6

Alzheimer’s disease

Vascular dementia

Dementia with Lewy Bodies

Frontotemporal dementia

AIDs dementia complex

Question 7

Describe the changes seen in alzheimer’s disease

Answer 7

Global atrophy of cerebral cortex -> sulcal widening and enlarged ventricles

Senile plaques (alpha-beta protein) - amyloid precursor protein broken down abnormally to alpha-beta protein that aggregates together to cause neuronal damage. Occur in foci of enlarged axons, synaptic terminals and dendrites

Neurofibrillary tangles - hyperphosphorylated Tau proteins that become deranged. Tau proteins normally bind and stabilise microtubules

Question 8

What are the risk factors for vascular dementia/Alzheimer’s

Answer 8

Stroke

Hypertension

Hypercholesterolaemia

Diabetes

Smoking

AF

TIAs

Obesity

Coronary heart disease

Question 9

How does vascular dementia present and how does it progress

Answer 9

Vascular dementia either has a sudden onset or comes on slowly over time

Patient progresses in a step-wise manner - suffer deterioration in cognition -> stable -> deteriorate

Question 10

Describe dementia with lewy bodies including where the bodies are deposited and how it is defined in relation to Parkinson’s

Answer 10

Dementia with lewy bodies is caused by aggregations of alpha-synuclein protein within the neurone cytoplasm

In DLB the bodies are deposited in substantia nigra, frontal lobe, temporal lobe, cingulate gyrus amoung others

If patient has Parkinson’s -> develops dementia they have Parkinson’s with dementia

If patient has congitive features first (i.e. dementia) -> develop Parkinson’s then it is dementia with lewy bodies

Question 11

Describe the presentation of DLB

Answer 11

Fluctuating cognition and alertness

Vivid visual hallucinations

Spontaneous features of Parkinson’s

Repeated falls due to festinating gait

Question 12

What syndrome are patients with DLB susceptible to and what are the signs

Answer 12

Neuroleptic malignant syndrome - side effect of anti-psychotics caused by a sudden drop in dopamine. Signs:

Fever

Encephalopathy

Vital signs instability - tachycarida, tachypnoea, fluctuating BP

Elevated enzyme - creatinine phosphokinase

Rigidity

Question 13

Describe frontotemporal dementia and the main syndromes of frontotemporal dementia

Answer 13

Have lobar atrophy of frontal and temporal lobes with symptoms based on lobe dysfunction

Three main syndromes:

• Behavioural varient
• Progressive non-fluent aphasia
• Semantic

Question 14

Name some symptoms of frontotemporal dementia

Answer 14

Loss of inhibition

Inappropraite social behaviour

Loss of motivation without depression

Repetitive/ritualistic behaviours

Non-fluent aphasia

Question 15

Desribe AIDs dementia complex and the clinical features seen with it

Answer 15

AIDs dementia complex - HIV infected macrophages enter brain where HIV causes indirect damage to neurones

Rapid progression

Features: cognitive impairment, psychomotor retardation, tremor, ataxia, dysarthria, incontinence

Question 16

Name some pharmacological methods of treating dementia

Answer 16

Acetylcholinesterase inhibitors - decrease ACh breakdwon to increase ACh for transmission. Good for improving cognition. E.g. donepezil, rivastigmine

NMDA antagonists - reduce overstimulation of NMDA and are used in patients who are agitated or aggressive (caused by overstimulation of NMDA). E.g. memantine

Question 17

Deposition of which protein is central to the pathogenesis of Alzheimer’s and which gene mutations increase the deposition of this protein

Answer 17

Amyloid deposition is key to pathogenesis of Alzheimer’s - seen in Down’s syndrome as well

Mutations of amyloid precursor protein gene or presenilin genes 1 and 2 can lead to incomplete breakdown of amyloid precursor protein and amyloid deposition