14 - Dementia Syndromes

Question 1

What is the definition of dementia syndromes?

Answer 1

Decline of memory and (or) other cognitive abilities from a previous level of function, which must be sufficiently severe to cause impairment in occupational or social functioning

Change from previous level of functioning
Multiple cognitive/behaviour domains affected

Question 2

What are the cognitive domains that are affected by dementia syndromes?

Answer 2

Memory
Language
Visuo-perceptual skills
Praxis
Attention
Executive Functions

Question 3

Describe the distribution of dementia syndromes

Answer 3

70% Alzheimers
17% Vascular Dementia, due to multiple strokes normally
13% other dementias

Question 4

What are the changes from DSM-IV to the DSM-V for Alzheimer’s disease?

Answer 4

Re-terms dementia into major neurocognitive disorder

The same as DSM-IV, but doesn’t require memory impairment, as long as evidence of genetic mutation known to cause Alzheimer’s

Acknowledges existence of “atypical” variants

Question 5

What’s required when diagnosing dementia?

Answer 5

Clinical history of decline in cognitive function and impairment of daily livings

Objective evidence of cognitive and/or behavioural impairment on neuropsychological testing

Deficits and presentation can’t be explained by another condition

Preferable: evidence of progressive decline across repeated neuropsychological testing

Associated biomarkers

Question 6

What is the typical presentation of Alzheimer’s disease?

Answer 6

After age 60

Memory impairment often the first presenting complaint (both failure to encode and store)

As disease advances, language, visuo-spatial and executive functions compromised

General demeanour and personality preserved until late in disease

Neurofibrillary tangles and amyloid plauqes. Atrophy in mesial temporal lobe (including hipp.), partietal lobes and dorsolateral prefrontal cortex

Question 7

Describe atypical variants of Alzheimer’s disease

Answer 7

Earlier onset
Memory is usually not compromised in early stages

Visual Variant AD or Posterior Cortical Atrophy

• visuo-spatial impairments (judging spatial locations)
• visual agnosia (impaired object recognition)
• apraxia (assembling, dressing)
• significant changes in parietaland occipital lobes

Frontal Variant AD

• executive dysfunction (poor planning and organisation, impaired mental flexibility)
• personality change
• significant changes in frontal lobe

Question 8

Describe Fronto-Temporal Dementia

Answer 8

• Called Pick’s disease for a long time
• Disease concentrated in frontal and temporal lobes
• Different pathology: Pick bodies

Earlier onset, 40-50s
Various variants; behavioral, semantic, progressive non-fluent aphasia

Question 9

Describe the Behavioural Variant of Fronto-Temporal dementia

Answer 9

Frontal lobe atrophy

Personality and behaviour change (disinhibition, apathy, emotional blunting, over-eating)

Executive dysfunction on neuropsychological testing

• Mental inflexibility
• Concrete thinking
• Planning problems

Memory and visuo-perceptual skills relatively spared

Question 10

Describe the Semantic Variant of Fronto-Temporal dementia

Answer 10

Anterior-Lateral temporal lobe atrophy (more commonly left)

Progressive loss of semantic knowledge

Visuo-perceptual skills, memory, personality preserved

Question 11

Describe the Progressive Non-Fluent Aphasia Variant of Fronto-Temporal dementia

Answer 11

Frontal and temporal lobe atrophy

Non-fluent speech

Agrammatic

Visuo-perceptual skills, memory, personality preserved

Question 12

Describe Vascular (Multi-Infarct) Dementia

Answer 12

Second most common dementia

Caused by hypertension, leading to multiple strokes in the brain. Symptom onset usually related to cerebro-vascular events.

Progression more step-wise, with periods of plateau.

Distribution of lesions varies widely, and so does the neuropsychological picture

A more “subcortical” neuropsychological picture.

• Slow speed of processing
• Attention problems
• Memory problems secondary to; attention and difficulties initiating memory search
• Motor and other neurological problems can be present

Question 13

Describe dementia in Parkinson’s disease

Answer 13

Apathy, difficult in “getting going”
Slowed mental processing
Attention impairments, especially shifting impairments
Visuo-spatial impairments
Visual hallucinations
Memory; problems with recall
cognitive impairments occur after motor disorder