Lecture 40: Dementia

Question 1

What is dementia and when is young onset compared to late onset

Answer 1

Dementia is an umbrella term for a group of symptoms caused by many different diseases- it is a multidomain cognitive or behavioural impairment severe enough to affect daily function which is a decline from previous level of function
- Including: memory, reasoning, language, behaviour, visuospatial.

YOD: <65 yo (4-9%)
LOD: 65+

Question 2

What are the four most common causes of Late onset dementia- irreversable and what are the special features of their presentation

Answer 2

1. Alzheimers disease: 60%, insidious, amnestic presentation
2. Vascular dementia: 20%, sudden onset, cerebrovascular disease on CT/MRI
3. Dementia with Lewy bodies: 15%, Alzheimer like presentation but with Parkinsonism
4. Fronto-temporal dementia: <5%, behavioural or language presentation (memory spared), onset 55-65yo

Question 3

What is the genetic causes of Dementia- can undergo testing if significant family history

Answer 3

Can be directly caused by mutation in
-AlzD: presenilin 1,2.Amyloid precursor gene
-FrontoTD: c9orf72, progranulin, Tau gene
Generally seen in YOD

Some genes also increase risk of developing dementia
-In AlzD: Apolipoprotein E isoforms: E4 increases risk while E2 decreases risk

Question 4

What is the general epidemiology of dementia: risk factors, numbers, survival

Answer 4

~62k Expected to increase with aging population
More common with increasing age
Average age of survival is 2-9 years
About the same in men and women but women live longer

Question 5

How is dementia diagnosed- steps

Answer 5

1. Comprehensive history from patient + collateral person
2. clinical and neurological exam
3. cognitive screen- mACE test
4. have to exclude depression and delirium
5. blood tests to exclude physical factors vit B12 deficiency
6. Referral to Neurologist if under 65, then geriatricin if 65+ where they will do
   - neuroimaging to find atrophy, location, evidence of vascular disease
   - neuropsychological assessment by clinical psychologist

Question 6

What are the types of treatment and management available for dementia

Answer 6

Goal is symptom management
1. enhance cognition/ delay decline in early dementia: using acetylcholinesterase inhib. Does have parasymp side effects

2. stop glutamate excitotoxicity in moderate -late dementia
   NMDA antagonist
3. Cognitive stimulation therapy: as early as possible, run by Dementia related organisations: social interaction
4. Treat other symptoms with medication
   a) LDopa for LwyBD + Alz Parkinsonism
   b)Agitation/psychosis: antipsychotics
   (don’t give any dopamine stuff for FrontoD)
   c) Depression: anti depressants

Treat cerebrovascular disease in all types

5. improve quality of life with Nonpharmacological management: behavioural, SLT, OT, PT

Question 7

What are some future planning things that need to be considered for patients of dementia

Answer 7

• Advanced care planning, power of attorney
• Consider driving safety: driving assessment
• Mate Wareware: Maori understanding is different from western, wairua and whanau have to be considered. Generally younger at diagnosis.

Question 8

What are the neuropathological features of dementia related to the causes

Answer 8

Common feature of Alz, LwyB and FrontoT dementia is the presence of pathological protein aggregates. the affected region determines the functional deficit

1. Alz: amyloid B, tau
2. LwyB: a-synuclein (amyloid B, tau)
3. Ft: Tau, TDP43 but won’t have both

However a lot of other diseases will also present the same protein aggregates as well