Memory and language disorders in dementia

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Memory and language disorders in dementia
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Types of dementia
Alzheimers disease
Vascular dementia
Frontotemporal dementia
Dementia with Lewy bodies
Other
Early Onset (before 65)
Late Onset (after 65)
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Frontotemporal Dementia

• Semantic dementia (progressive fluent aphasia)
• Anomia, impaired comprehension loss of semantic
  knowledge, progresses to mutism
• Progressive nonfluent aphasia
• effortful, distorted, agrammatic speech with
  phonological errors, progressing to mutism
• Frontal variant FTD
• Changes in personality and social behaviour (lack
  of emphathy, increased risk-taking, poor social
  understanding)

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MRI scans
Semantic dementia (SD)
Control
Alzheimers Disease (AD)
Frontal variant frontotemporal dementia (fvFTD)
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Semantic dementia
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Picture Naming
48
40
32
24
Total Correct
cat dog horse mouse cat squirrel cat ra
bbit little cat cow dog camel horse rhinoceros
elephant kangaroo horse tiger dog
crocodile fish
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8
0
1
2
3
4
5
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Test Session (1994-1996)
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Semantic associations
Bozeat et al (2000)
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Colour knowledge
Rogers et al (2007)
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(No Transcript)
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Simons et al (2002)
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Key site of damage temporal lobe

• Strong correlation between performance on
  semantic memory tasks and degree of atrophy to
  anterior temporal lobe regions

Williams et al (2005)
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Progressive nonfluent aphasia
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Progressive NonFluent Aphasic Speech

• Experimenter Whats troubling you about your
  speech?
• Patient Getting twisted, you know, spoozerism
• Experimenter When you want to speak, what
  happens?
• Patient When Ive constracted it...

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• Fluent PA SD NonFluent PA
• Semantics ? ?
• Phonology ? ?
• Syntax ? ?

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PFA/SD
PNFA
dog
dog
horse
camowa
nice dog
kokeroo
elvelo
box
big box
busbin
little thing
escato
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PET Imaging

• Poor glucose metabolism in the left anterior
  insula/frontal opercular region
• Some support that the breakdown in speech is due
  to a motor articulatory problem (speech apraxia)

Nestor et al (2003)
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Frontal variant frontotemporal dementia
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Cognitive deficits..??

• Impairment on risk-taking tasks and reversal
  learning (inhibit response to previously rewarded
  item)
• Deficits on social cognition - understanding
  other peoples perspectives, poor moral
  reasoning, emotion processing and empathy

Jeanette bought her friend Ann a crystal bowl
for a wedding gift. Ann had a big wedding and
there were a lot of presents to keep track of.
About a year later, Jeanette was over one night
at Annes for dinner. Jeanette dropped a wine
bottle by accident on the crystal bowl, and the
bowl shattered. Im really sorry, Ive broken
the bowl said Jeanette. Dont worry said Anne
I never liked it anyway. Someone gave it to me
for my wedding.
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Memory vs Faux Pas
Jeanette bought her friend Ann a crystal bowl
for a wedding gift. Ann had a big wedding and
there were a lot of presents to keep track of.
About a year later, Jeanette was over one night
at Annes for dinner. Jeanette dropped a wine
bottle by accident on the crystal bowl, and the
bowl shattered. Im really sorry, Ive broken
the bowl said Jeanette. Dont worry said Anne
I never liked it anyway. Someone gave it to me
for my wedding
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0.9
0.8
Faux Pas
Memory
0.7
0.6
0.5
fvFTD
AD
Controls
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Temporal source monitoring
Set 1
Set 2
Test
Did you see the picture in Set 1, Set 2, or not
at all?
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Item recognition
Set 1
Set 2
S1/S2
N
Test
Discriminating familiar (regardless of set) vs
novel foils
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Source memory
Set 1
Set 2
S2
S1
Test
Accurately identifying items as in Set 1 or Set 2
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AD vs FvFTD
A. Graham, Hodges K. Graham (unpublished data)
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Pattern of frontal atrophy in fvFTD
Moderate disease (MMSE 23.2)
Mild disease (MMSE 27.7)
Perry et al (2006)
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Alzheimers disease
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Object-location learning
11/42 QD ? AD Sensitivity (? AD) 82 Specificity
(no AD) 96
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Posterior cingulate involvement in MCI
Nestor et al (2003) Pengas et al (2008)
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Parallels across imaging
Scene Memory Taylor et al (2007)
Scene Oddity Lee et al (2008)
FDG-PET in MCI Nestor et al (2003)
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Our current research themes

• Large scale studies of the sensitivity of spatial
  memory and discrimination tasks in the diagnosis
  of dementia
• Imaging studies to pin down the anatomical cause
  of the early memory impairments in Alzheimers
  disease (use of a functional marker of
  posterior cingulate)
• Contrasting neuropsychological and imaging
  profiles across different dementias who perform
  differentially on spatial tasks (Alzheimers
  disease vs semantic dementia, Lee et al, 2006)

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Conclusions

• Improved understanding of cognitive deficits in
  dementia
• AD - deficit in learning and remembering new
  information
• SD - loss of factual knowledge (semantic memory)
• PNFA - speech articulatory difficulties
• fvFTD - personality changes source memory
  deficit
• Use this information to build multi-domain tests
  of memory for use in the clinic
• To target key early cognitive deficits that map
  onto the earliest structural and functional brain
  changes