HC11: Assessment
The importance of neuropsychological assessment
The roles in dementia assessment and care:
Serve as biomarker
Predictor for development of dementia
Capture different influences disease trajectory
Proxies for functional deficits
Insight into intervention targets
Biomarker for illness
Biomarker = characteristic that is objectively measures as an indicator of a biological
process, whether that is normal or pathological. Think about neuropathology: plaques,
tangles.
Neuropsychological profile: distinguish between underlying pathologies because different
brain areas affect different neuropsychological profiles. We have seen a bunch of examples
the last couple of weeks of why biomarkers can be useful to distinguish different types of
dementia.
Hutchinson & Mathias (2007): meta-analysis 94 studies comparing FTD and AD
o Best discrimination FTD and AD:
Memory tests: FTD better than AD
Language/verbal ability tests: FTD poorer than AD
204 bvFTD, 674 AD, 126 age-matched HC (Ranasinghe et al., 2016):
o Memory: AD < bvFTD < HC
o Language: naming, lexical fluency – bvFTD < AD
Fireman et al. (2006) – DLB versus AD
o Lower scores AVLT (auditory verbal learning Test) and BNT (Boston Naming
Test) – diagnosis DLB less likely
o Lower scores TMT-A and RCFT – diagnosis DLB more likely
Meta-analysis neuropsychological differences DLB and AD (Gurnani & Gavett, 2017)
– 14 studies included autopsy confirmed DLB (n=155) or AD (n=431)
o AD memory worse
o DLB visuospatial worse
Raminez-Gomez et al. (2017) autopsy diagnosis confirmed VAD or AD
o AD: memory poorer than EF
Meta-analysis (Mathias & Burke, 2009)
o 81 studies comparing cognitive performance in persons diagnosed with AD
and VAD
Episodic memory more impaired in AD than VAD: confirmed
Emotional recognition test: VAD worse than AD
Delayed story recall: VAD better than AD
These are all examples of why different neuropsychological profiles can help to distinguish
between different forms of dementia.
, Predictor development of dementia
Poorer cognition years before diagnosis could represent an increased risk to develop
dementia. For example, there were already lower episodic memory scores at least 6 years
before diagnosis. This means that memory score is an extremely early predictor! This is the
same in aMCI and naMCI. In particular, the aMCI is more likely to be a risk factor for AD
whereas naMCI is more likely to be a risk factor for DLB. This does not mean that everyone
with naMCI will continue to develop dementia.
Capture different influences on disease
trajectory
Knowing where the tangles and plaques are, will
not necessarily tell you how severe the
symptoms are. Biomarkers can give you more
information about the severity of the disease,
plus other factors that influence performance:
e.g., compensation, cognitive reserve. Cognitive
functioning is only partially explained by the
extent of neuropathology.
The neuropsychological assessment can show a
different pattern of the progression of the
disease than simply looking at the ongoing
neuropathology.
Proxies for functional deficits
Functional deficit – what person can or can no longer do in daily life (e.g., wash, dress, shop,
drive). This matters most to person and their family, then purely the cognitive impairment or
the neuropathology. Neuropsychological measures can try to help estimate functional
outcomes. This can estimate how well a person can cope in daily life, something which isn’t
noticeable from neuroimaging. The neuroimaging can say something about the stage of the
disease but can’t say something about the severity of the symptoms.
Insight intervention targets
Neuropsychological measures can identify residual strengths/spared functions and use
those for possible target interventions. One approach in non-pharmacological interventions
like cognitive training or compensation strategies is trying to use the spared functions to
compensate for the impairments. One study focused on training a relatively spared function,
in this case procedural memory, to train episodic memory. Neuropsychological assessment
can help with identifying these spared functions.
To make valuable contribution
The neuropsychological tests must be of sufficient quality: validity and sensitivity,
reliability.
Not screening tools only: e.g., MMSE.
Multiple measures are needed to assess a particular domain. E.g., memory, EF,
visuospatial functioning, language etc.
The importance of neuropsychological assessment
The roles in dementia assessment and care:
Serve as biomarker
Predictor for development of dementia
Capture different influences disease trajectory
Proxies for functional deficits
Insight into intervention targets
Biomarker for illness
Biomarker = characteristic that is objectively measures as an indicator of a biological
process, whether that is normal or pathological. Think about neuropathology: plaques,
tangles.
Neuropsychological profile: distinguish between underlying pathologies because different
brain areas affect different neuropsychological profiles. We have seen a bunch of examples
the last couple of weeks of why biomarkers can be useful to distinguish different types of
dementia.
Hutchinson & Mathias (2007): meta-analysis 94 studies comparing FTD and AD
o Best discrimination FTD and AD:
Memory tests: FTD better than AD
Language/verbal ability tests: FTD poorer than AD
204 bvFTD, 674 AD, 126 age-matched HC (Ranasinghe et al., 2016):
o Memory: AD < bvFTD < HC
o Language: naming, lexical fluency – bvFTD < AD
Fireman et al. (2006) – DLB versus AD
o Lower scores AVLT (auditory verbal learning Test) and BNT (Boston Naming
Test) – diagnosis DLB less likely
o Lower scores TMT-A and RCFT – diagnosis DLB more likely
Meta-analysis neuropsychological differences DLB and AD (Gurnani & Gavett, 2017)
– 14 studies included autopsy confirmed DLB (n=155) or AD (n=431)
o AD memory worse
o DLB visuospatial worse
Raminez-Gomez et al. (2017) autopsy diagnosis confirmed VAD or AD
o AD: memory poorer than EF
Meta-analysis (Mathias & Burke, 2009)
o 81 studies comparing cognitive performance in persons diagnosed with AD
and VAD
Episodic memory more impaired in AD than VAD: confirmed
Emotional recognition test: VAD worse than AD
Delayed story recall: VAD better than AD
These are all examples of why different neuropsychological profiles can help to distinguish
between different forms of dementia.
, Predictor development of dementia
Poorer cognition years before diagnosis could represent an increased risk to develop
dementia. For example, there were already lower episodic memory scores at least 6 years
before diagnosis. This means that memory score is an extremely early predictor! This is the
same in aMCI and naMCI. In particular, the aMCI is more likely to be a risk factor for AD
whereas naMCI is more likely to be a risk factor for DLB. This does not mean that everyone
with naMCI will continue to develop dementia.
Capture different influences on disease
trajectory
Knowing where the tangles and plaques are, will
not necessarily tell you how severe the
symptoms are. Biomarkers can give you more
information about the severity of the disease,
plus other factors that influence performance:
e.g., compensation, cognitive reserve. Cognitive
functioning is only partially explained by the
extent of neuropathology.
The neuropsychological assessment can show a
different pattern of the progression of the
disease than simply looking at the ongoing
neuropathology.
Proxies for functional deficits
Functional deficit – what person can or can no longer do in daily life (e.g., wash, dress, shop,
drive). This matters most to person and their family, then purely the cognitive impairment or
the neuropathology. Neuropsychological measures can try to help estimate functional
outcomes. This can estimate how well a person can cope in daily life, something which isn’t
noticeable from neuroimaging. The neuroimaging can say something about the stage of the
disease but can’t say something about the severity of the symptoms.
Insight intervention targets
Neuropsychological measures can identify residual strengths/spared functions and use
those for possible target interventions. One approach in non-pharmacological interventions
like cognitive training or compensation strategies is trying to use the spared functions to
compensate for the impairments. One study focused on training a relatively spared function,
in this case procedural memory, to train episodic memory. Neuropsychological assessment
can help with identifying these spared functions.
To make valuable contribution
The neuropsychological tests must be of sufficient quality: validity and sensitivity,
reliability.
Not screening tools only: e.g., MMSE.
Multiple measures are needed to assess a particular domain. E.g., memory, EF,
visuospatial functioning, language etc.
