EFFECTIVENESS OF REHABILITATION FOR EXECUTIVE IMPAIRMENTS

1
EFFECTIVENESS OF REHABILITATION FOR EXECUTIVE
IMPAIRMENTS
Jonathan Evans Oliver Zangwill Centre MRC
Cognition and Brain Sciences Unit
2
Acknowledgement
Dr Tom Manly MRC Cognition and Brain Sciences
Unit, Cambridge.
3
EFFECTIVENESS OF REHABILITATION FOR EXECUTIVE
IMPAIRMENTS

• Some (obvious, but brief) introductory comments
• The Question
• The Answer
• The Justification
• Summary Conclusions

4
The problem of executive impairment

• We know from clinical experience and from
  research (e.g. Crepeau and Scherzer 1993) that
  impairments in executive functioning cause social
  dysfunction, and restrict participation in
  pre-injury activities.
• A huge number of types of difficulty have been
  associated with frontal lobe or executive
  dysfunction

5
Executive functions

• Programming, regulation and verification of
  activity (Luria 1966)
• Goal formulation, planning, and carrying out
  goal-directed plans effectively (Lezak 1983)
• Problem-solving behaviour, trying out hypotheses
  and learning from failed attempts (Shallice 1988)
• May be able to work along routine lines, but have
  difficulties in new situations (Baddeley and
  Wilson 1988)

6
Adapted from Shallice and Burgess (1996)
Problem Orientation Phase
Delayed Intention Marker Realisation
Level of Aspiration Setting
Contention Scheduling
Goal Setting Process
Strategy Generation Phase
Progressive Deepening Phase
Episodic Memory Retrieval
Spontaneous Schema Generation
Solution Checking Phase
Behaviour
Intention Marker Activation
Assessment and verification of new
schema Monitoring Rejection of Schema
Implementation of temporary new schema Special
Purpose Working Memory
7
The Question
Is there evidence that executive impairments can
be effectively treated?
More specifically, is there evidence that the use
of carefully selected exercises can promote
recovery in damaged neural circuits and hence
restore executive functioning?
8
The Answer
Yesbut

• Yes, but
• There is some evidence that interventions focused
  on training problem solving skills can be
  effective, but that evidence is very limited
• We do not know what the active ingredients are in
  the rehabilitation interventions
• Only a sub-group of people with brain injury are
  likely to benefit from current interventions
• We cannot conclude with any certainty that the
  interventions promote recovery of damaged neural
  circuits and as a result restore ability in
  executive function

9
Rehabilitation studies

• Three types
• Studies that attempt through a series of
  exercises or tasks to re-train executive
  functioning - problem solving/goal management
  training.
• Acquired brain injury
• Schizophrenia
• Studies where attempts have been made to target
  interventions at one specific impaired process or
  component of executive functioning.
• Studies where pharmacological compounds have been
  used with the aim of enhancing executive
  functioning.

10
Problem-solving or goal management training

• There really arent that many studies!
• So we can afford to look at individual, key
  studies...

11
Problem-solving or goal management training

• von Cramon and colleagues (1991, 1992)
• Problem-solving therapy
• .providing patients with techniques enabling
  them to reduce the complexity of a multi-stage
  problem by breaking it down into more manageable
  portions. A slowed down, controlled and stepwise
  processing of a given problem should replace the
  unsystematic and often rash approach these
  patients spontaneously prefer" (1991, p46).

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Problem-solving or goal management training

• Problem-solving therapy
• Group based programme, over six weeks with an
  average of 25 sessions per patient.
• Exercises focused on
• Problem orientation
• Problem definition and formulation
• Generating potential alternative solutions
• Decision making concerning the best approach
• Solution implementation
• Solution verification

13
Problem-solving or goal management training

• Does Problem-solving Therapy work?
• von Cramon, Matthes-von Cramon and Mai (1991)
  compared a PST group (N20) with a control
  'memory therapy' (MT) group (N17).

14
problem solving educational groupvon Cramon,
Matthes-von Cramon Mai (1991)
Tower of Hanoi (number of moves - optimal 30)
P lt 0.01
ns
15
problem solving educational groupvon Cramon,
Matthes-von Cramon Mai (1991)
Planning Test Scheduling visits/appointments
(median scores)
P lt 0.01
ns
16
problem solving educational groupvon Cramon,
Matthes-von Cramon Mai (1991)
Rating Goal directed ideas
Problem solving therapy
Memory training
17
problem solving educational groupvon Cramon,
Matthes-von Cramon Mai (1991)
Rating Problem solving ability
18
problem solving educational groupvon Cramon,
Matthes-von Cramon Mai (1991)
Rating Action style
19
Problem-solving or goal management training

• von Cramon, Matthes-von Cramon Mai (1991)
• Well controlled
• Improvement in both tests and functional ratings
• But no evidence for maintenance of improvement
  over time.
• Selected client group - the more able
• We should admit that our PST is currently more
  of an art than a scientifically sound procedure.
  Thus, success depended heavily on the therapists
  expertise in carrying out the training (p.61)
• Did the treatment restore executive functioning
  or provide patients with a structure or different
  way of approaching that helps their functioning?

20
Problem-solving or goal management training

• Von Cramons PST fits well with Lurias (1963,
  1969) notion of extended programming.
• Ben Yishay and Prigatano (1990) discussed
  extended programming, indicating that what Luria
  meant by this was that the training task (e.g.
  problem solving), should be broken down into a
  series of highly articulated routines and
  sub-routines..Patients cannot, on their own,
  perceive the subtle gradations and transitions in
  the chain of reasoning that are implicit in the
  usually more condensed ways in which most
  nonimpaired individuals solve problems..The
  extended programming principleis the idea that
  the retraining should follow the logical course
  of the origins of the reasoning chain, before it
  became condensed (p.396)

21
Problem-solving or goal management training

• Rath, Simon, Langenbahn, Sherr and Diller (2001)
• 60 outpatients, all at least 1 year post-injury
• Conventional group neuropsychological
  rehabilitation vs. problem solving group.
• Assessed on
• Cognitive tests (inc. WCST)
• Psychosocial functioning (e.g. SIP, CIQ, RSES)
• Problem-solving questionnaires (self-appraised)
• Observer ratings of role-played scenarios.

22
Rath, Simon, Langenbahn, Sherr and Diller
(submitted)
60 outpatients
Problem-solving group n27 One, 2 hour
session, per week for 24 sessions
Conventional treatment n19 24 sessions, 2-3
hours per week
Cognitive remediation Psychosocial components
Problem orientation 12 sessions Affective
reactions Attitude Motivation
Problem-solving skills 12 sessions Problem
definition Generating alternatives Decision
making Solution implementation and verification
23
Rath, Simon, Langenbahn, Sherr and Diller
(submitted)

• Results
• P/S group (and not conventional group) improved
  on
• WCST
• problem solving self-appraisal
• self-appraised clear thinking
• self-appraised emotional regulation
• Observer ratings of role played scenarios
• Gains maintained at 6-month follow-up.

24
Rath, Simon, Langenbahn, Sherr and Diller
(submitted)

• Limitations
• Lack of evidence for gains in functional outcome
  (clients real life, other than self-rated).
• Test gain limited to examination on WCST.

25
Goal Management Training

• Levine et al (2000)
• Study of effectiveness of Robertsons (1996) Goal
  Management Training
• Derived from Duncans concept of Goal Neglect as
  the core executive deficit.
• A set of paper and pencil training exercises are
  used, with participants being taught to follow a
  set of five stages of goal management

26
Goal Management Training

• STOP! What am I doing? Check the mental
  blackboard
• DEFINE The main task
• LIST The steps
• LEARN The steps
• DO IT!
• CHECK Am I doing what I planned?

27
Goal Management Training

• Levine et al (2000)
• Group study (n30) of GMT vs control Motor Skills
  Training
• Measured on performance on paper and pencil tasks
  (largely similar to training tasks)
• GMT group improved on paper/pencil tasks, but
  control group did not.
• Further single case showed improvement on cooking
  task with GMT, plus checklists.
• But, lack of generalisation evidence for group
  study and lack of control in single case for
  impact of checklist.

28
Insights from Schizophrenia

• Cognitive deficits, and in particular executive
  deficits, have been described as the core deficit
  in schizophrenia.
• In recent years several studies have examined the
  impact of cognitive remediation therapy (CRT),
  targeting executive skills, on neuropsychological
  and social functioning.
• Wykes et al (1998, 1999, 2002)
• Penades et al (2002)
• Bell et al (2001)

29
Insights from Schizophrenia

• Wykes (1998, 1999, 2002)
• Cognitive Remediation Therapy (CRT)
• Developed by Delahunty and Morice (1993)
• Exercises focused on
• cognitive flexibility (set shifting)
• working memory
• planning
• 1 hour individual session on 40 days (3-5 days
  per week)

30
Insights from Schizophrenia

• Wykes (1998, 1999, 2002)
• Group studies, comparing CRT with Intensive OT
• Evidence for greater improvement for CRT group on
  some, but not all executive tasks (WCST/Six
  Elements/Digit Span), and self-esteem.
• No overall difference between groups on social
  functioning measure, but CRT group more likely to
  reach a threshold of cognitive performance that
  appeared to be necessary for change in social
  functioning.

31
Insights from Schizophrenia

• Wykes (2002)
• fMRI study of impact of CRT on cognitive tasks,
  (cognitive flexibility and working memory, but
  sadly not planning), social and brain functioning
• Focus on working memory (n-back task) for brain
  activation study
• Comparison of CRT, intensive OT and healthy
  control)

32
Insights from Schizophrenia

• Wykes (2002)
• No benefit of CRT for cognitive flexibility.
• Benefit of CRT for working memory.
• No change in symptoms or disability, but increase
  in self-esteem for CRT group.
• Evidence for increase in activation on WM task
  for CRT group in right inferior frontal gyrus and
  visual cortex bilaterally.
• Activation increase related to improved
  performance on other WM tasks.

33
Insights from Schizophrenia

• So, some evidence of improvement on tests
• Some exciting evidence of changes in brain
  functioning, (unless the change is interpreted as
  a index of effort?)
• Limited impact on social functioning, though may
  be threshold dependent.
• But is schizophrenia a good model for acquired
  brain injury?

34
Rehabilitation studies

• Three types
• Studies that attempt through a series of
  exercises or tasks to re-train executive
  functioning - problem solving/goal management
  training.
• Acquired brain injury
• Schizophrenia
• Studies where attempts have been made to target
  interventions at one specific impaired process or
  component of executive functioning.
• Studies where pharmacological compounds have been
  used with the aim of enhancing executive
  functioning.

35
Impairment specific interventions

• Improving monitoring and reducing goal neglect

36
Adapted from Shallice and Burgess (1996)
Problem Orientation Phase
Delayed Intention Marker Realisation
Level of Aspiration Setting
Contention Scheduling
Goal Setting Process
Strategy Generation Phase
Progressive Deepening Phase
Episodic Memory Retrieval
Spontaneous Schema Generation
Solution Checking Phase
Behaviour
Intention Marker Activation
Implementation of temporary new schema Special
Purpose Working Memory
Assessment and verification of new
schema Monitoring Rejection of Schema
37
Impairment specific interventions

• Improving monitoring and reducing goal neglect
• Manly, Hawkins, Evans, Woldt and Robertson (2002)
• Hotel task, 2 versions

38
The Hotel Task
39
Manly, Hawkins, Evans, Woldt and Robertson (2002)

• Manly et al (2002)
• 10 clients with TBI
• 24 participants in control group matched for age,
  sex and IQ
• Periodic non-contingent alerting vs no alert
  conditions, in counterbalanced order.

40
Manly, Hawkins, Evans, Woldt and Robertson (2002)
41
Manly, Hawkins, Evans, Woldt and Robertson (2002)
42
Impairment specific interventions

• Previous research (Dritschel et al 1998) has
  shown that people with TBI are less likely to use
  prior experience to help plan in unstructured
  situations (e.g. how would you go about planning
  a holiday or finding a new house).

43
Adapted from Shallice and Burgess (1996)
Problem Orientation Phase
Delayed Intention Marker Realisation
Level of Aspiration Setting
Contention Scheduling
Goal Setting Process
Strategy Generation Phase
Progressive Deepening Phase
Episodic Memory Retrieval
Spontaneous Schema Generation
Solution Checking Phase
Behaviour
Intention Marker Activation
Implementation of temporary new schema Special
Purpose Working Memory
Assessment and verification of new
schema Monitoring Rejection of Schema
44
Impairment specific interventions

• Hewitt, Evans and Dritschel (2000)
• 30 participants, with TBI
• Performance on Everyday Descriptions Tasks
  before and after training measured
• Control group (Group 1 no training) vs.
  Autobiographical cueing group (Group 2).
• 15 in each

45
Impairment specific interventions
Effectiveness of problem-solving rating
46
Impairment specific interventions

• Other examples of specific impairment focused
  studies
• Cicerones (1987) self-instructional training for
  impulsivity.
• Alderman, Fry and Youngsons (1995)
  self-monitoring training.

47
Rehabilitation studies

• Three types
• Studies that attempt through a series of
  exercises or tasks to re-train executive
  functioning - problem solving/goal management
  training.
• Acquired brain injury
• Schizophrenia
• Studies where attempts have been made to target
  interventions at one specific impaired process or
  component of executive functioning.
• Studies where pharmacological compounds have been
  used with the aim of enhancing executive
  functioning.

48
Pharmacological treatment of executive impairment

• A relatively unexplored option in acquired brain
  injury.
• Dopaminergic and noradrenergic neurotransmitter
  systems implicated in modulation of the
  pre-frontal cortex.
• Evidence (Mehta, Sahakian and Robbins 2001) for
  improvement in attention and executive
  functioning (working memory, planning) in ADHD,
  though the use of Methylphenidate, which
  increases level of DA and NE.

49
Pharmacological treatment of executive impairment

• Some evidence for improvement in executive
  functioning (working memory tests) in normal
  controls and people with TBI with Bromocriptine
  (McDowell et al 1998), and Amantadine (Kraus and
  Maki 1997), both of which increase levels of
  available dopamine.
• Some evidence (Coull et al 1996) for improvement
  in planning and fluency tasks for cases of
  frontal dementia with Idazoxan, an alpha2
  antagonist, which acts pre-synaptically to
  increase NA.

50
Pharmacological treatment of executive impairment

• But
• The evidence in relation to acquired brain injury
  amounts to small number of cases.
• Focus of cases on test results, with little or no
  functional measures.
• The rationale for the use of the compounds where
  gross lesions are present is less clear
• Nevertheless, this remains an area that requires
  more systematic investigation.

51
Summary Conclusions

• So, is there evidence that executive impairments
  can be effectively treated?
• In terms of research evidence, there is not much
  more than some tantalising hints that we really
  can help people with the devastating disabilities
  associated with executive impsirments to improve
  their functioning and maybe even change their
  brains?
• Clinical experience would suggest that learning
  problem solving or goal management strategies
  can, with some people, have a very significant,
  positive effect on functioning. But we have not
  restored damaged circuits.

52
Summary Conclusions

• We have a long, long way to go.
• But we are now in a good position, with a range
  of interventions available, some of which clearly
  have a basis in sound theory of executive
  functioning, to step-up our efforts to identify
  what works, and for whom it works.

• So, lets get on with it...