Forensic Neuropsychology in Personal Injury Cases I

1. Forensic Neuropsychology in Personal Injury Cases I Russell M. Bauer, Ph.D. July 13, 2006

2. 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 • personal injury and worker’s compensation

3. 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.)

4. 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 was responsible

5. Worker’s Compensation Criteria • an injury or disability • affecting wage-earning capacity • facial disfigurement, loss of sexual potency doesn’t count • arising out of or in the course of, employment • assumes causal relationship • positional risk • which is “accidental” • some nonaccidents are compensable

6. Procedures for WC Claims • Employee serves notice • Medical examination • Proceeding for Adjustment and Compensation • administrative hearing before hearing officer • once settled, claimant can’t take case to court for further action

7. Mental Injury • Physical Trauma Causing Mental Injury • Mental Stimulus Causing Physical Injury • Mental Stimulus Causing Mental Injury

8. Elements of Tort Law • existence of duty owed the plaintiff by the defendant • Violation of duty by the defendant • an injury “proximately caused” by the violation, and • the injury is compensable

9. Duty • “an obligation, to which the law will give recognition, to conform to a particular standard of conduct toward another”

10. Obligation • violation can be by act or by omission • can be intentional or negligent • negligence is “conduct which falls below the standard of care established by law for the protection of others against reasonable risk of harm”

11. Proximate Cause • given the actions of A, could one reasonably foresee the consequences that occurred? • most psychological theories have elaborate cause-effect chains • courts will generally recognize only certain aspects in the chain of events as proximate causes

12. 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

13. 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 • the “predisposed plaintiff” • the “as they are” principle

14. Issues in Evaluation • examiner bias (in both directions) • retrospective analysis of prior mental functioning often critically important • issue in damages: can the individual function “as s/he was”? • impact of mental/emotional reactions, some of which are, themselves, compensable • effects of litigation, distortions, malingering

15. Definition of Mild TBI • Traumatically induced physiological disruption of brain function • At least one of the following: • any period of loss of consciousness • any loss of memory for events immediately before or after the accident • any alteration of mental state at the time of accident (e.g., feeling dazed, disoriented, or confused) • Focal neurological deficit(s) that may or may not be transient • Exclusion Criteria: • loss of consciousness exceeding approximately 30 minutes • after 30 minutes, a GCS falling below 13 • post-traumatic amnesia (PTA) persisting longer than 24 hours American College of Rehabilitative Medicine, 1993

16. 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”

19. (JCEN, 19, 421-431)

20. (JCEN, 19, 421-431)

21. Conclusions • Severe long-term sequelae of mild TBI are rare (5%) • Mild TBI results in NP effect sizes that average less than .5 SD • NP evals in MHT have low PPV • Therefore, some NP evaluations lead to “false positive” diagnoses

22. Caveats (Bigler, 2001) • The “lesion” is always larger than visualized • Normal scans may not signify absence of pathology • DOI scans may not be enough • Long-term sequelae (e.g., accelerated aging)

23. “Noninjury” Contributors to Neuropsychological Impairment in MHI • Adversarial patient-examiner relationship • Exaggeration or poor effort • Impairment as communication • Frank malingering for gain; financial incentives • Factitious disorders • Fatigue, pain, other physical factors • Psychiatric disturbance (e.g., psychosis, anxiety, depression) • Pre-existing factors affecting neuropsychological performance (e.g., learning disability, limited education) • Occupational/life experience factors

24. 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 compensation-seeking groups

25. Checks against False Positives: Consistency Analysis • Consistency of results between/within domains • Consistency with known syndromes • example: “hemi-anomia” • Consistency with injury severity • Consistency with other aspects of behavior • e.g. memory abilities during vs. apart from formal testing

26. Post-Concussion Syndrome

27. 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.)

28. PCS: DSM-IV Criteria • Hx of head trauma that has caused significant cerebral concussion • Evidence from NP testing or quantified cognitive assessment of difficulty in attention or memory • 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

29. PCS: DSM-IV Criteria (cont’d) • Symptoms begin after head trauma or else represent a worsening of pre-existing symptoms • Significant impairment in social or occupational function; decline from previous functional level • Do not meet criteria for dementia and are not better accounted for by another mental disorder

30. PCS-Like Complaints of NP Dysfunction • Common • Nonspecific • Potentially related to non-neurological factors (anxiety, depression, fatigue, stress) • Correlate better with distress than with objective indicators of CNS injury • Easy to feign or exaggerate

31. 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

33. 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 significantlyunderestimatedegree of pre-injury problems

34. Major PCSSymptoms “Imaginary concussion” produces a pattern of symptom reports virtually identical to that seen after MHI

35. MHT patients significantly underestimate preinjury symptoms compared to a noninjured control group

37. 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

38. Implications for Understanding PCS • 5% of MHI patients have persistent deficits • Physiogenic causes likely operative in the first 1-3 months • Psychogenic causes important thereafter • Complaints have low specificity for MHI • Baserate issues important • Attributional processes important • Suggests need for a scientific approach to assessing persistent complaints after MHT