Esther Bay PhD ACNS BC, Clinical Associate Professor, School of Nursing &

1. Determinants of subjective memory complaints in community-dwelling adults with traumatic brain injury Esther Bay PhD ACNS BC, Clinical Associate Professor, School of Nursing & Bruno Giordani, Associate Professor, Department of Psychiatry, & Claire Kalpakjian, Assistant Professor, Department of Physical Medicine & Rehabilitation University of Michigan Ann Arbor

2. Acknowledgements This project was supported by Award Number T32HD007422 from the Eunice Kennedy Shriver National Institute of Child Health & Human Development to Dr. Denise Tate in the Department of Physical Medicine & Rehabilitation where Dr. Bay was a post-doctoral fellow. The content is solely the responsibility of the authors and does not necessarily represent the official views of the Eunice Kennedy Shriver National Institute of Child Health & Human Development of the National Institutes of Health

3. What are subjective memory complaints? (SMC) Defined: voiced by the patient, without objective memory deficits, no known cause for the memory deficit, yet can yield daily disruption in occupational and social activity

4. Why study subjective memory complaints (SMC)? • Circular effects: Vicious cycle with stress and anxiety • Present in over 50% of the population >age 65 • May be a precursor to dementias • Metternich, Kosch, Kriston, Harter & Hull, 2010

5. Memory dysfunction after TBI • Overall the memory dysfunction associated with mild-to-moderate TBI is resolved by 12 weeks after injury for most • Attention, working memory, short-term memory, verbal memory and reasoning typically involved • Impairment is associated with frontal and temporal areas of the brain • These same memory structures are involved in stress circuitry • Herman, et al, 2003; Stulemeijer, et al, 2010; Belanger, 2008

6. Stress, memory and the brain

7. Clinical significance of protracted SMC after TBI • Is there an organic origin? • Consistent with Post-concussion syndrome • Could reflect emotional, sleep or stress issues • Present in persons engaged in litigation? • Explained by medication side effects? • Wood, 2004

8. What is known about SMC after TBI? • For those with mild TBI, 20% will experience protracted recovery that is poorly explained • Those with more chronic TBI and increased SMC reported more distress and fatigue compared to those with less SMC Wood, 2004; Stulemeijer, etal. 2010

9. Purpose of the study? • SMC may reflect chronic stress and strain on cognitive brain structures • This strain may be more significant in older versus younger persons with TBI • Depressive symptoms may also be associated with SMC • Purpose: To what extent is SMC associated with chronic stress, depression, and neurobehavioral consequences of mild-to-moderate TBI

10. Study hypotheses • Compared to younger persons (18-39), older adults (40-60) with mild-to-moderate TBI will reported increased SMC, after controlling for covariates • There will be a positive and significant relationship between chronic stress and SMC; the effect of age on this relationship will be determined by interactions between age group and depression severity • Increase SMC will be associated with increased time-since-injury, age, chronic stress, somatic and depressive symptoms

11. Design • Observational • Cross-sectional

12. Participants • 18-65 y/o participants who were community dwelling and within 3 years of their mild-to-moderate TBI • Eligibility criteria (N=159) • Without pre-injury neurological impairments • Absence of severe TBI on admission to ED • Hospitalized for the TBI • Without psychosis • Able to read & speak English

13. Procedures for data collection • Original permission sought by admitting neuropsychologist • Human subjects approval obtained at all institutions • Recruitment from outpatient rehabilitation clinics affiliated with Level I & 2 health systems in southeastern MI • In person assessment obtained within the clinic setting • EMR data was abstracted by trained personnel

14. Measures

15. Data analysis procedures • SPSS v 18.0 • Descriptive statistical analysis • ANOVA and Multiple regression analyses

16. Study variables by age *p<.05, ** P<.01, *** P<.001

17. Results H1:Age & SMC • Older persons (those 40 & over) showed significantly greater frequencies of SMC than those younger (p<.008). • Time-since-injury showed a significant main effect on SMC, not premorbid psychiatric hx

18. Results H2: Age, Stress, & SMC • No significant group differences in depression severity • Using ANOVA and the CESD cut-off score for depression, SMC was significantly explained by increased age, chronic stress, time-since-injury, as well as the presence of mental health history and the severity group of depressive symptoms (Adjusted R2 = 53%) • Chronic stress significantly impacted those in the “no depression” or “severe depression” group

19. Results H3: Full model • SMC was explained by premorbid psychiatric history and increased age, time-since-injury, chronic stress, somatic symptoms, and communication difficulties • Importantly, depressive symptoms were not associated with SMC • Adjusted R2=.783*, F=72.13 (df = 8, 150), p<.001 *Standardized regression coefficient

20. Final model & results of H3

21. Implications of study findings • SMC were significantly associated with • Increased age • Increased time-since-injury • Worse self-reported chronic stress • Heightened somatic symptoms and communication difficulties • SMC were not associated with • Motor complaints • Depressive symptoms

22. Implications for research • Being over age 40 and having a TBI is important!! • Stress and SMC matters! • Stress and symptom management delivered early after injury may mitigate chronic problems and circular patterns of stress, anxiety & SMC • Promoting healthy brain activity after TBI is a new direction of research

23. Study limitations • Cross sectional observation of problems that may evolve over time • Study was conducted in specialized clinics and may not be applicable to others with TBI who were not treated in such clinics • There may be participant bias in sampling since we don’t know about the characteristics of those who refused to participate

24. Value of our findings • Continued support that chronic stress has negative impact on post-TBI outcomes • Continued support that Allostatic Load Stress theory could guide longitudinal and intervention studies for mild-to-moderate TBI • Findings from healthy aging studies • Factors other than the brain injury may be worsening memory complaints

25. Questions

26. Thank you!