Dementia

Question 1

What is the commonest cause of dementia?

Answer 1

Alzheimer’s disease (AD) (and vascular dementia)

Question 2

What is the age cut-off between young onset and late onset dementia?

Answer 2

65 years old

Question 3

What are potentially reversible causes of dementia/things that mask dementia?

Answer 3

• depression
• alcohol related brain damage
• endocrine
• B1/B12/B6 deficiency
• benign tumours
• normal pressure hydrocephalus
• infections- HIV/syphilis
• limbic encephalitic
• inflammatory (vasculitis, MS, sarcoid)

Question 4

What mix of molecules/neuropathologies can be responsible for Alzheimer’s disease?

Answer 4

• neuronal tau
• amyloid beta
• TDP-43
• alpha-synuclein
• vessel wall pathology
• parenchymal ischaemic changes

Question 5

What do you need to ask patients who have been referred for potential dementia?

Answer 5

N.B. ask partner/children also
- memory, esp. short term
- language
- numerical skills
- executive skills
- visuospatial skills
- neglect phenomena?
- visual perception
- route finding and landmark identification
- personality and social conduct
- sexual behaviour
- eating
- mood
- motivation/apathy
- anxiety/agitation
- delusions/hallucinations
- activities of daily living
and chronology

Question 6

What is the definition of dementia?

Answer 6

severe loss of memory and other cognitive abilities which leads to impaired daily function (regardless of underlying cause)

Question 7

What examinations would you carry out for a potential dementia patient?

Answer 7

neurological exam: cranial nerves 2-12, upper limb+lower limb gaits, focus tests e.g. frontal lobe function
and mental state exam (MMSE, ACE)

Question 8

What investigations would you carry out in a potential dementia patient?

Answer 8

• neuropsychological/cognitive exam
• bloods to exclude other causes
• structural MRI scan
• PET scan

Question 9

What key features of Alzheimer’s disease can be seen on an MRI?

Answer 9

• narrowed gyri
• widened sulci
• dilated/enlarged ventricles
• medial temporal volume loss bilaterally
• hippocampus volume loss
• more CSF (black on scan)

Question 10

What does a PET scan show in a person with Alzheimer’s?

Answer 10

high levels of amyloid in brain

Question 11

How would you manage a patient with Alzheimer’s?

Answer 11

• acetylcholinesterase inhibitors
• watch and wait for successive deterioration over 6 months-2 years
• treat behavioural, psychological symptoms–> inc. care support, antidepressants
• refer to OT, social services or specialists

Question 12

How would you rule in/out the cause of dementia/not dementia?

Answer 12

• delirium?
• depression?
• Alzheimer’s: subtle, insidious amnestic/non-amnestic presentations
• Vascular dementia: related to cerebrovascular diseases w/ step-wise deterioration +multiple strokes
• dementia w/ Lewy bodies: cognitive impairment before/within 1 year of Parkinsonian symptoms, visual hallucinations and fluctuating cognition
• FTD: behaviour, semantic dementia, progressive non-fluent aphasia
• rapidly progressing dementias

Question 13

What is the head-turning sign?

Answer 13

when a patient turns their head to their partner because they don’t know the answer or aren’t sure of it

Question 14

What is episodic memory?

Answer 14

• memory for particular episodes in life

- dependent on medial temporal lobes, inc. the hippocampus

Question 15

What biomarkers are used for Alzheimer’s diagnosis?

Answer 15

• decreased CSF concentrations of amyloid-beta 42

- elevations in tau species

Question 16

What causes dementia with Lewy bodies?

Answer 16

aggregation of alpha synuclein monomers–> eventually become Lewy bodies–> causes internal symptoms