Wounds of War: Traumatic Brain Injury

1. Wounds of War:Traumatic Brain Injury Rex M. Swanda, Ph.D., ABPP-CN Neuropsychology Program New Mexico VA Healthcare System

2. Traumatic Brain Injury (TBI) Brain injury caused by an external mechanical force such as a blow to the head, concussive forces, acceleration-deceleration forces, or projectile missile (e.g., bullet).

3. CONCLUSIONS • TBI does not typically occur in isolation • Emotional and psychosocial stressors • Reported TBI most frequently involves mild TBI • Credible research indicates that full cognitive recovery is the norm in mild TBI (e.g., LOC < 30 minutes) • Important to identify TREATABLE symptoms • No direct treatments for TBI • Associated psychological symptoms are associated with subjectively reported TBI symptoms that ARE highly treatable • Depression, PTSD, Substance Abuse

4. Incidence of TBI 500,000 to 2,000,000 per year (civilian) Poorly defined Poorly documented

5. Risk Factors Associated with TBI • Age • 15 to 24 years of age • First 5 years of life • Elderly • Males outnumber Females 2:1 • Except over age 75

6. Risk Factors Associated with TBI • Lower Socio-Economic Status • Unemployment • Lower Education • Prior History of a Medical Condition Affecting the Central Nervous System • Alcoholism or Substance Abuse • History of Prior Head Injury

7. Frequent Causes of TBI • Falls • Motor Vehicle Accidents • Interpersonal Violence

8. Classification of TBI • Closed Head Injury • Skull intact, Brain tissue not exposed • 90% of civilian head injury • Diffuse effects are common • Attention / Executive Penetrating Head Injury (Open Head Injury) • Skull and dura are penetrated • Focal injury is more common

9. High Risk Areas for Contusion

10. Long-Term Consequences of TBI • Cognitive consequences • Emotional consequences • Social consequences

11. Indicators of Severity for all types of head injury • Loss of Consciousness (Loss of Awareness) • Coma • (operationalized by Dikmen, et al. as Time to Follow Commands) • Post Traumatic Amnesia (PTA) • Signs of Intracranial Injury

12. Glasgow Coma Scale • 15 point scale measures presence, degree, and duration of coma • Based on • Eyes Opening response (1 – 5 pts) • Best Verbal response (1 – 5 pts) • Best Motor response (1 – 6 pts)

13. Post-traumatic Amnesia A period of anterograde amnesia in which new memories cannot be consistently made and recalled that follows recovery of consciousness in head injury or other neurological trauma. The duration of PTA is often used as a predictor of the degree of recovery.

14. Classification of Head Injury • Mild Head Injury • Glasgow Coma Scale 13 – 15 • PTA 5 – 60 minutes • Moderate Head Injury • Glasgow Coma Scale 9 – 12 • PTA up to 24 hours • Moderate to Severe Head Injury • Glasgow Coma Scale 3 – 8 • PTA 1 to 7 days or longer

15. What does empirical research tell us about the consequences of Traumatic Brain Injury • Dikmen, S.S., Machamer, J.E., Winn, R., & Temkin, N.R. (1995). Neuropsychological outcome at 1-year post head injury. Neuropsychology, 9, 80-90. Dikmen, S., Machamer, J., & Temkin, N. (2001). Mild Head Injury: Facts and Artifacts. Journal of Clinical and Experimental Neuropsychology, 23, 729-738.

16. What does empirical research tell us about the consequences of Traumatic Brain Injury • Hoge, C.W., McGurk, D., Thomas, J.L., et al (2008) Mild traumatic brain injury in U.S. soldiers returning from Iraq. New England Journal of Medicine.358, no. 5, 453-463.

17. Outcome Research: Mild TBI • Appropriately designed research studies indicate that virtually 100% mild head injured subjects show no cognitive impairment within about 3 months to a year (outside) post-injury • EXCELLENT Prognosis for Mild Head Injury

18. TBI Outcome Research: Surreya Dikmen, Ph.D. • Studies date from 1986 • Follow patients and controls over time • Prospective Design • Consecutive hospital admissions of well-defined Head Injury patients • Harborview Medical Center (Seattle, WA), a Level I Trauma Center

19. TBI Outcome Research: Dikmen • Study minimized selection bias • Large demographically representative group • English-speaking only (for testing criteria) • Did NOT screen out preexisting conditions • Unusually high rates of follow-up • 85% followed up after one year

20. Outcome Research: Dikmen • Pre-existing conditions included: • Prior significant head injury • Alcoholism receiving treatment • History of cerebral disease • Psychiatric disorder (schizophrenia, bipolar disorder)

21. Outcome Research: Dikmen • Broad spectrum of head injury severity • Minimum injury criteria include: • Any period of loss of consciousness • Post-traumatic amnesia of at least 1 hour • Other objective evidence of head trauma (e.g., hematoma) • Injury severe enough to hospitalize • Survival to complete at least 1 month follow-up for neuropsychological assessment baseline

22. Outcome Research: Dikmen • Trauma Control Subjects • recruited from ER after trauma to parts of body, other than head • Controls matched head-injured on • age • sex • education

23. Outcomes Following TBI • Dose-Response Relationship • Dikmen, et al. (1995) found a significant relationship between length of coma (Time to Follow Commands) and level of performance on sensitive neuropsychological measures at 1 year post-injury • Greater cognitive impairment is associated with longer periods of coma

24. Outcomes Following TBI • Mild head injured patients (TFC < 1 hour) were indistinguishable from trauma controls at one year post-injury on sensitive measures of cognitive functioning

25. Outcomes Following TBI Although there were no significant differences on cognitive testing, premorbid characteristics and risk factors were more powerful than head injury in explaining persistent psychosocial symptoms at one year post-injury (Dikmen, et al. 2001)

26. Contributing Risk Factors Account for Persistent Symptoms in cases of Mild Closed Head Injury • Age • Education • Pre-existing conditions • Treatment for alcohol or substance abuse • CNS disorder (prior head injury) • Psychiatric condition (including PTSD) • Somatoform-Spectrum diagnoses

27. Dikmen’s Conclusion “It is equally unusual for mild head injury to produce deficits after 1 year as it is for severe head injury to produce no deficits after 1 year.” (Dikmen, et al., 1995)

28. Recent Study of Soldiers Returning from Iraq • Hoge, et al (2008, in NEJM) studied 2525 U.S. soldiers returning from Iraq. • 124 (4.9%) reported injuries with LOC • 43% of these met criteria for PTSD • 260 (10.3%) reported altered Mental Status • 27.3% of these met criteria for PTSD • 435 (17.2%) reported other injuries • 16.2% of these met criteria for PTSD • 1760 reported no injury • 9.1% of these met criteria for PTSD

29. Recent Study of Soldiers Returning from Iraq • Although the relationship is associative and not necessarily causal…… • …“after adjustment for PTSD and depression, mild traumatic brain injury was no longer significantly associated with these physical health outcomes or symptoms, except for headaches.” • Consistent with Dikmen’s research

30. So, how do we account for subjective complaints of lasting symptoms following TBI ?

31. Postconcussion SyndromeICD-10 Diagnostic Criteria • A. History of head trauma with loss of consciousness precedes symptoms onset by maximum of four weeks

32. Postconcussion SyndromeICD-10 Diagnostic Criteria • B. Symptoms in 3 or more of the following categories: • Headache, dizziness, malaise, fatigue, noise tolerance • Irritability, depression, anxiety, emotional lability • Subjective concentration, memory, or intellectual difficulties without neuropsychological evidence of marked impairment • Insomnia • Reduced alcohol tolerance • Preoccupation with above symptoms and fear of brain damage with hypochondriacal concern and adoption of sick role.

33. Misattribution of Symptoms • Why do patients, families – even providers – “misattribute” symptoms, such as memory problems, “loss” of cognitive abilities, or declining cognitive performance – to brain injury?

34. Psychological Theories for Understanding Postconcussion Syndrome and “Misattribution of Symptoms” • “Good Old Days” Hypothesis • “Nocebo” Effect • Diathesis-Stress Model • Expectation as Etiology

35. “Good Old Days” Hypothesis • Gunstad & Suhr (2001) • Tendency of people to recall past symptoms and functioning more favorably than was actually the case • Suggests that, following any negative event, people tend to attribute all symptoms to that negative event, regardless of a preexisting history of that very problem or any other factors that may be influencing that problem.

36. Nocebo Effect • Hahn (1997) • The notion that expectations of sickness and associated emotional distress cause the sickness in question • Suggests that response expectations are “anticipations of automatic reactions to particular situational cues” and are outside both volition and conscious thought.

37. Diathesis-Stress Model • Wood (2004) • Examines the interaction between physiologic and psychological factors that generate and maintain postconcussional symptoms. • Suggests that iatrogenic forces can influence a patient’s recovery after MTBI, especially if health care providers inadvertently reinforce misperceptions of symptoms or insecurities about recovery

38. Diathesis-Stress Model • In McCrea (2008, p. 176) • “an unfortunate scenario unfolds when a patient with vague symptom complaints and no clear indication of significant head trauma is told he has “brain damage” and will never make a complete neurologic, symptom, or functional recovery.” • “The long-term damage of creating that perception for a patient is most difficult to undo.”

39. Expectation as Etiology • Mittenberg et al (1992) • Suggests that the incidence and persistence of PCS may be explained by the degree to which an individual misattributes common complaints to a prior head injury • Examine in detail as an example of “normal” tendencies to misattribute symptoms

40. Misattribution of Symptoms • Poor understanding that many common symptoms represent a “final common endpoint” of many overlapping diagnoses and disorders • Poor understanding of mechanisms of brain processing, injury, and recovery • Poor understanding of base rates of symptoms among “normal” individuals

41. Symptoms Overlap Across DiagnosesFrom: McCrea (2007) Mild Traumatic Brain Injury and Postconcussion Syndrome p. 160, Table 161

42. Poor Understanding of Brain Mechanisms Involved in Memory • “Memory” complaints are among most common symptoms associated with postconcussion syndrome • Information Processing Model of Memory helps clarify the role that “psychological factors” can play in memory complaints • Example of the important role that basic education plays as a therapeutic intervention

43. Information Processing Model of Memory

44. Base Rates and Misattribution of Symptoms • Base Rates: The frequency with which abnormal neuropsychological findings are observed among “normal” individuals. • It is “normal” to perform in the impaired range on some cognitive measures • Heaton, Grant, and Matthews norms indicate that very few healthy individuals complete a neuropsychological protocol without any impaired scores, while as many as 38% of “normals” perform in the impaired range on 6 or more discrete scores in a 40-score battery.

45. Percent of “normal” individuals who score in the impaired range on 0 to 6 or more measures in a battery of 40 measures

46. Expectation as Etiology • Mittenberg, et al. (1992) • 223 volunteers • 100 pts with closed head injuries • Average 1.7 years after injury • Average reported LOC = 23 minutes • 30-symptom checklist of items • Affective • Somatic • Memory

47. Examples of symptom checklist • Forgets where car is parked • Forgets why they entered a room • Loses items around the house • Sensitivity to bright light • Blurry or double vision • Concentration difficulty • Depression

48. Control Subjects • Which symptoms do you (healthy volunteers) currently experience? • ….Now imagine an MVA-related head injury 6 months before, in which you were knocked out, hospitalized for a week or two. Respond to the symptoms that you think you would have after an accident like this.

49. Patients with head injuries • Identify the symptoms you think you would have had before the accident (how you used to be) • Then identify symptoms that you notice now, after the accident (how you are now)

50. No difference between the incidence of Post-concussion Symptoms expected by controls and those reported by head injury patients. Control Group M = 14.8 s.d. = 7.6 Head Injured M = 13.8 s.d. = 8.3