Dementia

Question 1

What is definition of dementia

Answer 1

Syndrome caused by group of brain disorders that cause decline in higher cortical function

Syndrome of:
Cognitive impairment
Psychiatric/behavioural changes
Difficulties with Activities of daily living

Decline must be progressive from previously higher level of cognitive functioning, and without impairment of consciousness

Question 2

What are the common causes of dementia

Answer 2

Alzheimer’s disease (65%)
Vascular dementia (25%)
Dementia with Lewy Body (15%)
Frontotemporal dementia (5%)

Question 3

What are the general symptoms of dementia

Answer 3

Memory: typically short term, progress to long term
Language: anomic aphasia (expressive), difficulty understanding
Other cognitive: orientation, problem-solving, calculation
Behavioural: personality change, emotional control, social behaviour
Difficulty with ADLs: driving, dressing, shopping
Apraxia (difficulty with motor planning to perform tasks when asked)

Question 4

What is diagnosis of dementia based on

Answer 4

Comprehensive history
Neurological exam
Screen for cognitive impairment: MMSE
CAM score: rule out delirium
Bloods: TFTs, B12, folate (rule out organic causes)
CT/MRI: confirm diagnosis, rule out SOLs
Specialist assessment: determine subtype of dementia, in memory clinic

Question 5

What is CAM score

What features are assessed

Answer 5

Confusion assessment method, tool for identifying delirium

1. Acute onset/Fluctuating mental state
2. Inattention
3. Altered state of consciousness
4. Disorganised thinking

Question 6

What are the possible findings on ct scan

Answer 6

Dilated ventricles

Generalised cortical atrophy

Question 7

What is Alzheimer’s disease

Answer 7

Brain disorder causing progressive degeneration of cerebral cortex
It is most common cause of dementia

Question 8

What are macroscopic pathological features of AD

Answer 8

Wide sulci
Narrow gyri
Ventricular dilatation

Question 9

What are microscopic features of AD

Answer 9

Neurofibrillary tangles: intracellular fibrils of tau protein
Amyloid beta plaques: extracellular deposits of amyloid beta protein

Question 10

What is the pathophysiology of AD

Answer 10

Neuronal damage + loss due to Neurofibrillary tangles and amyloid beta plaques
Tau proteins phosphorylated, become stable, aggregate on microtubules
Build up of Amyloid beta proteins lead to abnormal extracellular deposition

Question 11

Why do you get early onset dementia with Down’s syndrome

Answer 11

Chromosome 21 mutation
Upregulation of amyloid beta protein precursor + Mutation of enzymes for proteolysis
Build up of amyloid beta protein

Question 12

What is the presentation of AD

Answer 12

Insidious onset, gradual progression of symptoms

Mild:
2-4 years
Short term memory loss
Independent ADLs

Intermediate: 
2-10 years
Confusion 
Behavioural changes 
Assistance with ADLs 

Severe:
1-3 years
Long term memory loss (loss of self) 
Psychiatric: depression, hallucinations 
Behavioural: withdrawal, aggression, disinhibition 
Physical: dysphagia, incontinence, falls

Question 13

What is vascular dementia

Answer 13

Group of syndromes of cognitive impairment caused by different mechanisms of ischaemia/haemorrhage secondary to cerebrovascular disease

Question 14

What are the different rates of decline for different causes of dementia

Answer 14

AD: gradual decline
VD: stepwise decline (sudden, episodic)
DwLB: fluctuating decline

Question 15

What is the pathophysiology of VD

Answer 15

Multi-infarct dementia: series of small strokes resulting in dementia
Single infarct dementia: single larger stroke resulting in dementia

Small vessel disease

Question 16

What is the pattern of presentation of VD

Answer 16

Stepwise abrupt decline in cognitive function, with period of stability between each cerebrovascular accident

Question 17

What is dementia with Lewy bodies

Answer 17

Type of dementia characterised by Lewy bodies in neocortex and brainstem

Question 18

What are Lewy Bodies

Answer 18

Eosinophilic intracytoplasmic neuronal inclusion bodies

Question 19

What is the presentation of DwLB

Answer 19

Fluctuating cognitive decline 
Parkinsonism
Visual hallucinations
Frequent falls
Sleep disorders - restless leg syndrome, R.E.M. sleep disorder

Question 20

What is frontotemporal dementia

Answer 20

Group of conditions that cause dementia by affecting frontal and/or temporal lobes

Question 21

What is the pathophysiology of FTD

Answer 21

Atrophy of frontal and temporal lobes

Protein inclusions in neurones: Intracellular Protein aggregates

Question 22

What are the clinical syndromes of FTD

Answer 22

Behavioural: early signs unlike in AD
Semantic: language impairment
Progressive non-fluent aphasia