Neurocognitive  and  Language  Function  in  Aging  and  Dementia  Vanessa  Taler,  Ph.D.  University  of  Ottawa  Élisabeth  Bruyère  Research  Institute  

The  aging  brain  

•  lower  volumes  of  grey  matter  resulting  from  reduced  synaptic  densities  • some  regions  are  more  affected  than  others  •  e.g.,  prefrontal  cortex  • medial  temporal  structures  

images  from  http://www.cse.buffalo.edu/,  http://www.mybrainnotes.com/  

Changes  in  white  matter  

Effects  of  aging  on  cognitive  function  

• With  normal  aging,  we  see  declines  in:  •  processing  speed  •  episodic  memory  • working  memory  •  executive  function  

• these  declines  are  associated  with  brain  changes  (e.g.,  prefrontal  volume,  white  matter  integrity)  

Intelligence  

•  Fluid  intelligence:  ability  to  think  and  reason  abstractly  and  solve  problems    •  Correlated  with  volume  of  prefrontal  cortex    

�  Crystallized  intelligence:  the  ability  to  use  skills,  knowledge,  and  experience    

�  Preserved  in  normal  aging  

Language  changes  with  age  

• Language  function  remains  largely  intact  • However,  it  can  be  afffected  by  other  changes  with  age  (e.g.,  in  processing  speed,  working  memory)  • Discourse  comprehension  is  affected  by  both  processing  deficits  and  increases  in  language  experience  related  to  age:  • working  memory  (integration  of  concepts,  maintenance  of  thematic  information  over  multiple  sentences).    •  topdown  influences  (real  world  knowledge)  

Considerations  

• Many  common  health  problems  can  have  a  deleterious—and  additive—effect  on  cognition  • Medications  can  affect  cognitive  function  • Sensory  acuity  (visual  and  hearing  function)  is  an  important  predictor  of  cognitive  performance  • Cross-­‐sectional  vs.  longitudinal  studies  give  different  results  

What  is  dementia?  

• Significant  loss  of  intellectual  abilities  such  as  memory  capacity,  severe  enough  to  interfere  with  social  or  occupational  functioning.    • Criteria  for  the  diagnosis  of  dementia  include:  •  impairment  of  attention,  orientation,  memory,  judgment,  language,  motor  and  spatial  skills,  and  function  •  by  definition,  dementia  is  not  due  to  major  depression  or  schizophrenia.  

What  causes  dementia?  

• Most  common  causes  include:  • Alzheimer’s  disease  (AD)  –  64%  of  cases  

•  vascular  dementia  (VaD)  –  up  to  20%  of  cases  

•  Lewy  body  dementia  (LBD)  –  5-­‐15%  of  cases  

•  frontotemporal  dementia  (FTD)  –  2-­‐5%  of  cases  

•  atrophy  •  senile  plaques:  buildup  of  beta-­‐amyloid  may  interfere  with  neuronal  communication.  •  neurofibrillary  tangles:  threads  of  tau  protein  become  twisted.    

image  from  http://alzheimer.ca/  

Memory  in  AD  • Memory  impairment  +  impairment  in  one  other  cognitive  domain  • Affects  primarily  declarative  memory  (not  procedural)  • Declarative  memory  =  memory  for  what  •  semantic  memory  (world  knowledge,  knowledge  about  the  meaning  of  things)  •  episodic  memory  (personal  memories)  

• Procedural  memory  =  memory  for  how  (e.g.,  how  to  ride  a  bike)  • Often  remote  memories  are  better  recalled  

Other  cognitive  domains  in  AD  

•  Impairments  are  also  seen  in:  •  executive  function    •  judgment,  decision  making  •  calculations  •  visuoperceptual  function  •  language  function  

Other  dementias  

• Lewy  body  dementia:    •  both  AD-­‐like  and  Parkinsonian  symptoms  (rigidity;  tremors;  stooped  posture;  slow,  shuffling  movements.);  visual  hallucinations  

• Vascular  dementia:    •  often  co-­‐occurs  with  AD  and  manifests  similarly  •  stroke  is  a  common  cause;  symptoms  vary  depending  on  brain  regions  affected  

• Frontotemporal  dementia:  •  behavioural  variant  (frontal)  •  language  variant  (temporal)  

Language  deficits  in  AD  

• Word-­‐finding  difficulty  • Gradual  loss  of  knowledge  about  word  meaning  • Deficits  in  standardized  language  tests:  • Naming  •  Verbal  fluency,  especially  semantic  fluency  

• Language  production  •  semantically  impoverished  discourse  that  is  lacking  in  coherence  

Communication  in  dementia  

• Communication  is  profoundly  affected  in  dementia,  and  has  a  major  impact  on  quality  of  life  

• Declining  communication  function  leads  to:  •  increased  stress  

•  loneliness,  and  social  withdrawal  

•  earlier  institutionalization  

How  do  we  improve  communication?  

• Learning  about  dementia,  its  progression,  and  how  it  affects  individuals.  • Believing  that  communication  is  possible.  • Focusing  on  remaining  abilities  and  skills.  • Reassuring  the  individual  with  dementia  and  being  positive.  • Meeting  people  with  dementia  where  they  are  and  accepting  their  reality.  

(Alzheimer  Society  of  Canada)  

Strategies  for  communication  cont.  

• Eliminate  distractions  (TV,  radio,  etc.)  

• Use  body  language  and  non-­‐verbal  communication  

• Letting  the  person  see  your  face  helps  them  understand  you  

• One  thing  at  a  time  

• Don’t  use  elderspeak!  

The  effects  of  bilingualism  

• The  number  of  bilinguals  in  Canada  is  large  and  increasing  • Bilingualism  affects  neuropsychological  assessment,  especially  since  most  tasks  are  administered  verbally.  • Bilingual  patients  prefer  care  in  the  native  language,  and  caregiving  in  the  second  language  reduces  apparent  competence  and  quality  of  life.  

• Bilingualism  may  delay  the  onset  of  dementia.    • Why?...  

What  is  “cognitive  reserve”?  

• Cognitive  reserve  (CR)  is  the  brain's  capacity  to  cope  with  cerebral  damage  to  minimize  clinical  manifestations.    • Researchers  do  not  yet  fully  understand  what  CR  is  but  some  factors  may  include:  •  education  •  occupation  •  social  interactions  •  physical  activity    

• “Use  it  or  lose  it”  –  bilingualism  may  be  a  form  of  “using  it”  

Looking  after  your  brain  

• Stay  intellectually  engaged  • At  best,  mental  activity  seems  to  protect  against  age-­‐related  declines  and  progression  to  AD.  • At  worst,  it  increases  an  individual’s  baseline  level  so  that  age-­‐related  declines  begin  to  affect  everyday  functioning  later  in  life.  •  Enriched  environments  stimulate  neurogenesis  in  aged  rats,  indicating  a  possible  mechanism  for  the  benefits  of  cognitive  stimulation.  

Looking  after  your  brain  cont.  

• Maintain  cardiovascular  physical  activity  

•  Exercise  appears  to:  

•  aid  executive  function  

•  reduce  declines  in  tissue  density  in  frontal,  parietal  and  temporal  cortex  

Looking  after  your  brain  cont.  

• Minimize  chronic  stressors  •  Proneness  to  distress  is  associated  with  increased  risk  of  AD  and  a  faster  rate  of  cognitive  decline  •  Increased  glucocorticoid  levels,  which  accompany  stress,  might  damage  hippocampal  neurons  over  the  lifespan  

Thanks  to:  

• Alzheimer  Society  of  Canada  

• Canadian  Institutes  of  Health  Research  

• Élisabeth  Bruyère  Research  Institute  

• All  the  members  of  my  lab!