1. Forensic Neuropsychology in Personal Injury Cases II
Russell M. Bauer, Ph.D.
July 17, 2008

2. Summary from Last Week Persistent deficits after mTBI are rare
Even when present, severity of deficits is small (<.5 SD)
NP impairment is often the only “objective” indicator of abnormality
What to make of this?
IMPORTANT REMINDER: SOME PATIENTS DO SUFFER RESIDUAL DEFICITS!!

3. “Noninjury” Contributors to Neuropsychological Impairment in MHI
Adversarial patient-examiner relationship
Expectation/attributional processes
Diagnosis threat, role stereotypes
Exaggeration or poor effort
Impairment as communication
Frank malingering for gain; financial incentives
Factitious disorders
Fatigue, pain, other physical factors
Psychiatric/behavioral disturbance (e.g., psychosis, anxiety, depression)
Cogniform disorder/cogniform condition
Pre-existing factors affecting neuropsychological performance (e.g., learning disability, limited education)
Occupational/life experience factors

4. Assessment of Malingering and Poor Effort
Issues/problems with definition
Intentional (intention)
Fabrication or exaggeration (action)
For purposes of gain (motive)
Explanatory models (Rogers, 1997)
Pathological (mental disorder)
Criminological (fake)
Adaptational (meeting adversarial demands)
Cognitive vs. Somatic Malingering

5. Diagnosis Threat (Suhr & Gunstad, 2002)
37 MHI (17 in “diagnosis threat” condition)
Diagnosis threat: told selected because of a MHI history; “a growing number of studies show that many individuals with head injury show cognitive deficits in neuropsychological tests”

6. Suhr & Gunstad, 2002

7. *
Suhr & Gunstad, 2002

8. Cogniform Disorder/Cogniform Condition
Patients with excessive cognitive complaints
Difficulties with existing diagnostic options
Symptom specificity
Intentionality
Presence of external incentive

9. COGNIFORM PRESENTATION

10. Pain and NP Performance
Pain itself associated with mild NP performance decrements
Pain medications
Opioids: attention/concentration (on dose escalations)
Neurobiological systems
ACC, NA, extended amygdala
Pain ALONE would not explain a -2SD discrepancy in severity
Block & Cianfrini Neurorehabilitation, 2013; Moriarty, et al Prog Neurobiol, 2011.

11. Depression and NP
Moderate effect sizes in executive function, memory and attention (-.34 to -.65)
After treatment/remission,
Executive/attention: to -.61 in patients with depression relative to controls (sig)
Memory: -.22 to -.54 (nonsig)
Suggests that “poor” cognition is a central, core feature
Rock, et al., Psychological Medicine, 2013

12. Lim et al, Int Psychogeriatr, 2013
Meta-analysis of a total of 22 trials involving 955 MDD patients and 7,664 healthy participants. MDD < healthy:
Digit Span, CPT (attention)
TMT-A, Digit Symbol (processing speed)
Stroop, WCST, Verbal Fluency (exec)
Immed verbal memory (memory)MDD
Other tests did not differentiate

13. Larrabee & Rohling, 2013

14. Effort, Motivation, & Response Styles
Frederick et al., 2000

15. Malingering Algorithms: Slick (1999)
Considers evidence from NP and self report
4 criteria
Presence of incentive
Evidence from NP
Evidence from self-report
Not better accounted for by….

16. Slick et al. (1999; cont’d) NP criteria
Definite (below chance) or probable (low) response bias on FC measures
Discrepancies/inconsistencies between
NP data and patterns of brain functioning
NP data and observed behavior
NP data and reliable collateral reports
NP data and past history

17. Slick et al. (1999; cont’d) Self-report criteria
Self-report discrepant with history
Self-report discrepant with known patterns of brain functioniong
Self-report discrepant with behavioral observations
Self-report discrepant with collateral information
Evidence of exaggerated or fabricated psychological dysfunction

18. Slick et al, 1999 (cont’d) DEFINITE MND
Presence of financial incentive
Definite negative response bias
Behaviors that meet criteria for negative response bias that are not fully accounted for by psychiatric, neurological, or developmental factors
PROBABLE MND
Presence of financial incentive
Two or more types of evidence from NP, excluding definite response bias, or one piece of evidence from NP and one from self-report

19. Malingering Research Literature
Case study
Simulation studies
Interpretive issues
Appropriate designs
Differential prevalence design
contrasting high and low baserate groups (e.g., groups with and without financial incentives)
Valuable mostly for determining average performances
Known-groups design
Selecting groups on the basis of malingering criteria (e.g., Slick, et al)
Examining differences between the groups

20. Selecting Specialized Cognitive Effort Tests
Ease of use
Credibility of rationale
Operating Characteristics
Incremental validity
TBI vs. PPCS
Coaching issues
There is not likely to be a “best” test in all circumstances

21. Commonly Used Specialized Tests
Portland Digit Recognition
Digit Memory Test
Computerized Assessment of Response Bias (CARB)
Word Memory Test (WMT)
Victoria Symptom Validity Test
Test of Memory Malingering
Validity Indicator Profile
Rey 15-Item Test
Dot Counting Test

22. Detecting Anomalous Results with Embedded Measures and Performance Patterns
Measures within standard NP tests that signify noncredible or ‘suspect’ performance
Identification of such measures can be “rational” or “empirical”
May be less subject to coaching than separate measures

23. Pattern Analysis Pattern Analysis
With HRNB, DFA outperforms clinicians (80-90% v %)
Most DFA’s multivariate , consisting of attention and memory measures
Generally, malingers score better on hard measures
DFA’s exist for WMS-R, WMS-III, WAIS-R, WAIS-III and other tests
Before using, investigate whether the DFA was validated/cross validated with known groups or simulators
Iverson & Binder, 2000; Larrabee, 2005

24. Common “suspect” neuropsychological signs on NP testing
Recognition << recall (hits, discriminability)
Extremely poor DS in the context of normal auditory comprehension (RDS)
Motor slowing (e.g., reduced tapping) relative to overt motor disability
Excessive failures-to-maintain-set on WCST
Discrepancies between test level and level during informal interaction
Other “impossible” signs

25. Embedded Measures – Motor, Sensory, and Perceptual-Motor
Perceptual-motor pseudoabnormality should not be overlooked b/c of emphasis on “higher” cognitive disabilities
Approaches
Neurologic exam
Sensorimotor impairments on NP exam
Findings
RCFT copy 50% sensitive with lots of FP
Malingering groups favor memory over visuoconstructive impairment (e.g. memory trials of RCFT discriminate better)
Generally large grip strength effect size in K-G designs
Reduced FT speed in the context of MHI

26. Embedded Cognitive Measures
WMS-R/WMS-III
Malingerers: Attention/Concentration < General Memory
Opposite pattern is more typical of head injury
Rarely-missed index on LM delayed recognition trials
WAIS-R/WAIS-III: Digit Span
Malingerers: Low digit span performance (ACSS < 5)
Reliable Digit Span (sum of longest correct span for both trials < 8)
Vocabulary – Digit Span (low digit span while vocabulary is high)
CVLT
Malingerers: Low recognition (hits & forced-choice)
Cutoff scores for recall trials produce variable false-positive rates
Variable results with most widely used cutoffs (Millis et al): Total < 35, LDCR <7, delayed recognition <11, discriminability < 81; sensitivity in question, not specificity

27. Malingering Patterns in NΨ Tests
Pattern Analysis
Word Memory Test
Malingerers: Inconsistent responding, poor initial recognition
Pattern should reflect severity of impairments
Category Test
Malingerers: Poor performance on first 2 subtests
Wisconsin Card Sorting Task
Malingerers: Poor ratios of categories completed compared to both perseverative errors and failure to maintain set
Iverson & Binder, 2000; Larrabee, 2005

29. Why being a knowledgeable neuropsychologist is important
You know likely patterns of impairment
You know psychometric relationships among tests
You know course of recovery
You know about contributory factors (e.g., LD, depression, etc.)
You can compare what you see to what you expect

30. Some Take Home Messages
Use multiple measures (forced choice, embedded, etc.)
Clarify your goals: sensitivity, specificity, etc.
Be aware of correlations among malingering measures
Look for emerging research on sensitivity/specificity of multiple indicators

31. Symptom Exaggeration Self-Report of Symptoms MMPI-2
May be exaggerated due to other variables (depression, pain, stress)
e.g., Post-Concussive Syndrome persisting for more than 3 months
MMPI-2
Malingerers tend to show elevations in clinical scales 1, 2, 3, 7, and 8, the Fake Bad Scale (FBS), VRIN, TRIN, the Infrequency-Psychopathology Scale [F(p)].
The F Scale and F – K does not appear to be as sensitive, and therefore “valid” profiles may be obtained.
Caution should be given to interpreting the clinical scales and F Scale derivatives, as these can be easily influenced by psychiatric comorbidities.
Iverson & Binder, 2000; Larrabee, 2005

32. Detecting Somatic Malingering
Symptom report, as well as cognitive performance, can be controlled by the litigant
Use of MMPI-2
F-scale, F(p)
VRIN, TRIN
Subtle-Obvious
F-K index
Revised Dissimulation Scales
These scales may not be sufficiently sensitive to TBI-related claims, despite neuro-psychological differences

33. MMPI Measures
FBS: 43 items – honest with bad injury; Originally the “Fake Bad Scale” and now the “Symptom Validity Scale” (FBS)
Response Bias Scale (RBS): 28 items that predicted failure on CARB and WMT
Henry-Heilbronner Index (HHI): 15 items sensitive to neurocognitive complaints in the months following head trauma

34. FBS Model of goal-directed behavior: Want to appear honest
Want to appear psychologically normal except for the influence of injury
Avoid admitting longstanding problems
Minimize pre-existing complaints
Minimizing pre-injury antisocial or illegal behavior
Presenting plausible injury severity

35. Lees-Haley FBS (cont’d)
18 “True” , 25 “False”
Does not correlate very strongly with F-scale derivatives
Most scale items overlap with “neurotic” side of MMPI
Cut-off mid 20’s, with varying false positive rates; increasing security with scores > 25-27

36. FBS Operating Characteristics
Most frequently failed indicator of MND (Larrabee)
FBS > 27 has Sn=.46 , Sp=.96, better than F or Fb (Greve et al)
Sensitive to symptom exaggeration in personal injury, not just litigation
Cutoffs determine TP, FP rate

37. Critical Studies Butcher et al (2003) Bury & Bagby (2002)
Unacceptably high FP of FBS (24% of males, 37.9% of females exceeded cutoffs)
Psychiatric, corrections, medical, pain, VA, personal injury litigants
No measures of symptom validity external to the MMPI
No report of who was litigating
Can’t compute specificity or sensitivity without this information
Bury & Bagby (2002)
PTSD vs. students (standard and exaggeration instructions)
F family produced best overall classification rates
Entire PTSD sample were being evaluated for workplace disability
Mean PTSD FBS was 26.31
No independent measures of malingering or exaggeration

38. RBS Sensitivity low (.34), specificity high (.96-.98)
Specifically designed to predict SVT failure
Outperforms F-family and FBS in doing this
Seems to measure more “cognitive” than “somatic” factors

39. HHI Neurocognitive complaints in the immediate postinjury period.
9 items overlap with FBS, 4 with original “Pseudoneurologic Scale; PNS)
Sensitivity 80%, Specificity 89% with a cutoff of > 8

40. Classification Accuracy of FBS, RBS, and HHI
Participants were referred to a private practice for neuropsychological testing between 1999 and Patients were evaluated
regarding a head injury in the context of litigation. Institutional Review Board approval was obtained and the study was
in compliance with the ethical treatment of human participants. Archival data were extracted and de-identified. Participants
were included if their files contained data for all 567 MMPI-2 items and at least three effort indicators. Using a criterion-groups
design, participants were identified who appeared to exaggerate neurocognitive dysfunction. Criteria for inclusion and exclusion
within noncredible and credible groups are described subsequently, including the use of performance measures of response
bias for group assignment.
Probable Negative Response Bias Group
In total, 37 participants (age: M ¼ 44.5, SD ¼ 11.9; education: M ¼ 12.1, SD ¼ 1.8; Full-Scale Intelligence Quotient
[FSIQ]: M ¼ 88.2, SD ¼ 9.0; 19 men and 30 women; 97.3% Caucasian and 2.7% African American) met the Slick and colleagues
(1999) criteria for Probable Negative Response Bias (PNRB; Criterion B2). Used Rey-15, FTT total score, TOMM, WMT, and BCT (Booklet Category Test) Bolter infrequently missed items
Although information regarding the severity of head injury was often not available, 25
participants reported post-traumatic amnesia congruent with mild head injury (,1 h). The Glasgow ratings for eight participants
were mild (at least 13 points) and one was moderate (9–12 points). The reported length of time the participants were
unconscious due to their head injury indicates 17 to be in the mild range (length of unconsciousness ≤30) and 5 to be in
the moderate-to-severe range (length of unconsciousness .30 min). Nineteen participants reported their head injuries to be
due to motor vehicle accidents (51.4%), eight reported injuries caused by a fall (21.6%), nine reported injuries due to work
related accidents (24.3%), and one reported injury due to an assault (2.7%). Sixteen participants were evaluated within 6
months to a year post-injury (43.2%), 12 were within 1- to 3-year post-injury (32.4%), five were within 3- to 5-year post-injury
(13.5%), one was within 5- to 7-year post-injury (2.7%), two were within 7- to 10-year post-injury (5.4%), and one was tested
more than 10-year post-injury (2.7%). In regards to psychiatric comorbidity, two participants were diagnosed with depression
and three were diagnosed with an adjustment disorder.
Presumed Valid Group
The presumed valid (PV) group consists of 42 participants (age: M ¼ 43.3, SD ¼ 11.5; education: M ¼ 12.2, SD ¼ 2.1;
FSIQ: M ¼ 90.9, SD ¼ 16.0; 25 men and 17 women; 95.2% Caucasian, 2.4% African American, and 2.4% Native
American). All were involved in litigation; however, none of the participants had a failure on any effort measure. Although
information regarding the severity of head injury was often not available, 22 participants reported post-traumatic amnesia congruent
with mild head injury (,1 h). The Glasgow ratings for 12 participants were mild (at least 13 points) and one was moderate
(9–12 points). The reported length of time the participants were unconscious due to their head injury indicates 26 to be in
the mild range (length of unconsciousness ≤30 min). Twenty-six participants reported their head injuries to be due to motor
vehicle accidents (61.9%), six reported injuries caused by a fall (14.3%), four participants reported injuries due to work-related
accidents (9.5%), four reported their injury as other (9.5%), one reported injury due to an assault (2.4%), and one reported
injury due to sports and recreation (2.4%). Nineteen participants received evaluations within 6 months to a year post-injury
(45.2%), 18 were within 1- to 3-year post-injury (42.9%), three were within 3- to 5-year post-injury (7.1%), and two were
within 7- to 10-year post-injury (4.8%). In regards to psychiatric comorbidity, one participant was diagnosed with a posttraumatic
stress disorder and three with an adjustment disorder.
Dionysus et al., Arch Clin Neuropsychol, 2011