forensic neuropsychology in personal injury cases i
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RUSSELL M. BAUER, PH.D.JUNE 30 , 2014
Forensic Neuropsychology in Personal Injury Cases I
Compensation for Mental Injury
law in this area is called “tort” law in the case of civil proceedings
governs compensation of individuals whose interests have been violated
recognizes potential fault or negligence of injured party
Neuropsychologists generally not concerned with liability; “damages” is the focus
personal injury vs. worker’s compensation
Tort Law vs. Worker’s Compensation
WC handled administratively; tort law handled judicially
WC regulated by legislature; tort law by the courts
WC compensates according to fixed injury schedule according to earning capacity; tort law is theoretically limitless (e.g., pain and suffering, loss of consort, etc.)
Worker’s Compensation
designed to compensate injured workers for losses, incurred during the course of employment, in their wage-earning power
actually the result of a different set of guidelines than “tort” law
designed to allow workers to circumvent frequently used employer defenses: contributory negligence you assumed the risk another employee (who can’t pay you salary and
benefits) was responsible
Worker’s Compensation Criteria
an injury or disability affecting wage-earning capacity facial disfigurement, loss of sexual potency
doesn’t countarising out of or in the course of, employment
assumes causal relationship positional risk (injury would not have occurred
“but for employment”)which is “accidental”
some nonaccidents are compensable
Procedures for WC Claims
Employee serves noticeMedical examinationProceeding for Adjustment and Compensation
administrative hearing before hearing officer once settled, claimant can’t take case to court for
further action
Mental Injury
Physical Trauma Causing Mental InjuryMental Stimulus Causing Physical InjuryMental Stimulus Causing Mental Injury
Key Elements of Tort Law
act or omission + causation + fault + protected interest + damage = liability
existence of duty owed the plaintiff by the defendant
violation of duty by the defendantan injury “proximately caused” by the
violation, andthe injury is compensable
Duty
“an obligation, to which the law will give recognition, to conform to a particular standard of conduct toward another”
we have certain duties, for example, when we Drive a car Handle firearms Maintain our homes Etc.
Obligation
Something you MUST do because of a law, rule, promise, etc.
Not fulfilling obligation (violation) can be by act (commission) or by omission
can be intentional or negligentnegligence is “conduct which falls below the
standard of care established by law for the protection of others against reasonable risk of harm”
Proximate Cause
given the actions of A, could one reasonably foresee the consequences that occurred?
alternative: but for the actions/omissions of A, event/consequences would not have occurred
most psychological theories have elaborate cause-effect chains
courts will generally recognize only certain aspects in the chain of events as proximate causes
Compensable Damages
an invasion of “legally protected interests”“feeling of harm” not sufficient; law must define
interests as sufficiently important or worthy of protection to hold the person causing harm liable for damages
major importance of neuropsychological testimony is in this area; extent of neuropsychological injury
Compensatory damages: replace what is lostPunitive damages: punish offender as a deterrent
for future action
Mental Injury and Tort Law
reluctance to compensate “mental injuries” without some physical manifestation
basic mental injury torts: tort of intentional infliction (e.g., slander) tort of negligent infliction (e.g., residents
emotionally affected by flood damage)the “predisposed plaintiff”the “as they are” principle
Predisposed Plaintiff: Aggravation
Castillo v. Young – plaintiff with TMJ injury and pre-existing TMJ condition from previous injury
Physician testimony: “There are patients – it's like a truck. If you rear end a truck that’s full of bricks, you’re probably
[not] going to hurt your truck – you’re going to hurt yourself, not the truck. If you rear end a truck full of eggs, you’re more likely to do damage than if you rear end a truck full of bricks. Unfortunately I think in [Castillo’s] case, they rear-ended her being full of eggs. She was fragile. . . . Any time you’ve had injury to a joint that would cause fracture of that bone, there has to be consequence to the system, whether there [are] symptoms provoked at that time or not.”
Eggshell jury instructions proposed (but denied): There is evidence that the Plaintiff had broken her jaw in 1983 and experienced a disk
displacement in her jaw prior to the December 20, 2000, accident. The Defendant(s) is liable only for any damages that you find to be proximately caused by the Defendants' negligence relating to the December 20, 2000, accident. If you cannot separate damages caused by the pre [sic] existing broken jaw from those caused by the accident of December 20, 2000, then the Defendant(s) are liable for all of those damages.
Plaintiff awarded $13,058.67. Appealed to State Supreme Court, which opined that the eggshell jury instructions SHOULD have been given, and remanded the case for retrial
Issues in Evaluation
potential examiner bias (in both directions)retrospective analysis of prior mental
functioning often critically importantissue in damages: can the individual
function “as s/he was”?impact of mental/emotional reactions, some
of which are, themselves, compensableeffects of litigation, distortions, malingering
Definition of Mild TBI
Traumatically induced physiological disruption of brain function
At least one of the following:1. any period of loss of consciousness 2. any loss of memory for events immediately before or after the
accident 3. any alteration of mental state at the time of accident (e.g., feeling
dazed, disoriented, or confused) 4. Focal neurological deficit(s) that may or may not be transient
Exclusion Criteria:1. loss of consciousness exceeding approximately 30 minutes 2. after 30 minutes, a GCS falling below 13 3. post-traumatic amnesia (PTA) persisting longer than 24 hours
American College of Rehabilitative Medicine, 1993
Common Case Scenario in “Mild Head Injury”
• minor MVA with no or questionable LOC, PTA, but some indication of possible orthopedic injury
• normal ED evaluation• delayed development of “de novo” cognitive
problem (e.g., memory, concentration difficulty) • subsequent referral to a neurologist-
neuropsychologist • neuropsychological exam reveals abnormal
neuropsychological or neuropsychiatric test findings indicative of “brain damage”
What does the literature on MHI say What does the literature on MHI say about longabout long--term outcome?term outcome?
Dikmen, et al. (1995): studied 1-year outcome in 436 head injured and 121 general trauma controls– MHT has good outcome in vast majority (95%) of
patients Binder, Rohling & Larrabee (1997)
– used “d” - control group SD– used “g” - pooled SD of both groups– found very small effects of MHT
Effect Sizes in Prospective and Effect Sizes in Prospective and QuasiQuasi--Prospective NP StudiesProspective NP Studies
STUDY d Effect Hedges gEffect
MHTSample
ContSample
TSI
Ewing .737 .737 10 10 2.2yAlterman -.181 -.208 25 25 remoteHugenholz .466 .371 22 22 3mRuff 89 .260 .187 16 26 3mRuff 89 -.411 -.461 06 12 3mRuff 89 .317 .112 10 18Montgomery -.154 -.228 26 26 6mBornstein .278 .223 24 24 15yDikmen .019 .023 161 121 1yCremona-Meteyard 1
.821 .523 06 09 1y
Cremona-Meteyard 2
.444 .245 08 09 1y ormore
Binder, Rohling, & Larrabee, 1997 (JCEN, 19, 421-431)
P ossible P P V and N P V of N P D iagnosis P ossible P P V and N P V of N P D iagnosis --T B I P revalence of .05T B I P revalence of .05
Sensitivity Specificity P P V N P V.80 .88 .26 .99.90 .70 .14 .99.90 .90 .32 .99.70 .90 .27 .98.70 .80 .16 .98.70 .70 .11 .98
B inder, R ohling, & L arrabee, 1997 (JCEN, 19, 421-431)
Conclusions
Severe long-term sequelae of mild TBI are rare (<10%)
Mild TBI results in NP effect sizes that average less than .5 SD
NP evals in MHT have low PPVTherefore, some NP evaluations lead to “false
positive” diagnoses
Caveats (Bigler, 2001)
The “lesion” is always larger than visualizedNormal scans may not signify absence of
pathologyDOI scans may not be enoughLong-term sequelae (e.g., accelerated aging)
“Noninjury” Contributors to Neuropsychological Impairment in MHI
Adversarial patient-examiner relationshipExaggeration or poor effort
Impairment as communication Frank malingering for gain; financial incentives Factitious disorders
Fatigue, pain, other physical factorsPsychiatric disturbance (e.g., psychosis, anxiety,
depression)Pre-existing factors affecting neuropsychological
performance (e.g., learning disability, limited education)Occupational/life experience factors
Financial Incentives and Disability
Binder & Rohling (AJP, 1996, 153, 7-10) Meta-analytic review of financial incentives and
symptoms 18 study groups, 2,353 subjects Weighted mean effect size of difference between
groups with and without financial incentives was 0.47 More late-onset symptoms in groups seeking
compensation
Checks against False Positives: Consistency Analysis
Consistency of results between/within domains
Consistency with known syndromes example: “hemi-anomia”
Consistency with injury severityConsistency with other aspects of
behavior e.g. memory abilities during vs. apart from formal
testing
Post-Concussion Syndrome
Post-Concussion Syndrome: DSM-IV Definition
“acquired impairment in cognitive functioning, accompanied by specific neurobehavioral symptoms, that occurs as a consequence of closed head injury of sufficient severity to produce a significant cerebral concussion” (LOC, PTA, etc.)
Symptoms, cognition, balance
PCS: DSM-IV Criteria
A Hx of head trauma that has caused significant cerebral concussion
B Evidence from NP testing or quantified cognitive assessment of difficulty in attention or memory
C Three (or more) of the following occur shortly after trauma and last at least 3 months: easy fatigue disordered sleep headache dizziness/vertigo irritability or aggression with little/no provocation anxiety, depression, or affective lability changes in personality apathy or lack of spontaneity
PCS: DSM-IV Criteria (cont’d)
D. Symptoms begin after head trauma or else represent a worsening of pre-existing symptoms
E. Significant impairment in social or occupational function; decline from previous functional level
F. Do not meet criteria for dementia and are not better accounted for by another mental disorder
PCS-Like Complaints of NP Dysfunction
CommonNonspecific Potentially related to non-neurological factors
(anxiety, depression, fatigue, stress)Correlate better with distress than with
objective indicators of CNS injuryEasy to feign or exaggerate
Complaints as “Evidence”
In the absence of objective neuro-psychological deficit, complaints are often taken to indicate the existence of occult disease
There is a difference between symptoms (subjective evidence) and signs (objective evidence) of illness
Symptom reports subject to cognitive distortions and attributional processes
“She reports feeling tired, moving slowly, losing her balance, tripping over things, and feeling weak and dizzy. She also reported increased sensitivity to noise, altered perception of the ambient temperature (feeling warm when others are comfortable), poor concentration, forgetfulness, finding once routine activities now complicated, diminished sexual functioning, sleep problems, fatigue and low energy level, anxiety and nervousness, “panic attacks”, lack of patience, decline in handling household chores, fear of certain situations, decline in recreational activities, concerns and worried about her health, depressed mood, decline in her ability to work, diminished interest in pleasurable activities, weight gain of 55 pounds, feelings of worthlessness and guilt, difficulty with language and word-finding, difficulty with concentration and thought processing, difficulties with making conversation and understanding it, writing slowly and illegibly, finding it difficulty to get started on things, trouble making decisions, difficulty pronouncing words, forgetting people’s names, getting her mind off certain thoughts, misplacing things, and becoming easily distracted. Scattered and confused behavior permeates all aspects of her life. She also reports periods of time where she becomes completely disoriented to her place and purpose. She experiences severe headaches, shoulder, neck, back, and leg problems, severe depression and cognitive dysfunction”.
Complaints (N=45) as “Evidence”
Problems with Using Complaints as Evidence of MHI
Mittenberg et al. (1992, 1997): “expectation as etiology” ‘imaginary concussion’ produces symptom complaint
cluster identical to that reported by patients with ‘real’ head injury
patients with minor TBI significantly underestimate degree of pre-injury problems
Major PCS Symptoms
“Imaginary
concussion”
produces a pattern of symptom
reports virtually identical
to that seen after
MHI
MHT patients
significantly underestimate preinjury
symptoms compared to
a noninjured
control group
Base Rates of Post-Concussion Symptoms (Base Rates of Post-Concussion Symptoms (LarrabeeLarrabee,,1997, based on Lees-Haley & Brown, 1993)1997, based on Lees-Haley & Brown, 1993)
Symptoms Medical Controls Non-CNS Litigantsa
Headaches 62% 88%Fatigue 58% 79%Dizziness 26% 44%Blurred Vision 22% 32%Bothered by Noiseb 18%c 29%c
Bothered by Light - -Insomniab 52%d 92%d
Poor Concentration 26% 78%Irritability 38% 77%Loss of Temper - -Memory Problemsb 20% 53%Anxiety 54% 93%
aNon CNS Litigants: in litigation for emotional or industrual stress, but not for CNSinjuries, bsignificant difference from controls at 1m, but not 1y in Dikmen et al.,1986; c”hearing problems in Lees-Haley & Brown, 1993;d”sleeping problems in Lees-Haley & Brown, 1993
Conclusions
You don’t have to have had a head injury to have post-concussion symptoms
Once something bad has happened to you, you tend to attribute more of your problems to it
Complaints reflect the subjective, not necessarily the objective, consequences of MTBI
Implications for Understanding PCS5-8% of MHI patients have persistent deficitsPhysiogenic causes likely operative in the
first 1-3 monthsPsychogenic causes important (though
probably not exclusively so) thereafterComplaints have low specificity for MHIBaserate issues importantAttributional processes importantSuggests need for a scientific approach to
assessing persistent complaints after MHT
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