Early Brain Changes of Non-Amyloid Pathways

1. Early Brain Changes of Non-Amyloid Pathways Charles DeCarli, MD Victor and Genevieve Orsi Chair in Alzheimer's Research Director University of California at Davis, Alzheimer’s Disease Center

2. Acknowledgements • Funded in part by Grant R13 AG030995 from the National Institute on Aging • The views expressed in written conference materials or publications and by speakers and moderators do not necessarily reflect the official policies of the Department of Health and Human Services; nor does mention by trade names, commercial practices, or organizations imply endorsement by the U.S. Government.

3. Outline • Brain Aging: cognition and structural imaging • Potential Causes of heterogeneity • Amyloidosis (brief) • Vascular risk factors • Time course of vascular risk on brain • Inflammation and brain aging

4. Cross-sectional and Longitudinal Memory Performance Wilson et al,Psychology and Aging, 2002 Wilson et al, Arch Neuro, 1999

5. Clinical Consequences Mungas, et al. Psychology and Aging, 2010

6. MRI Measures of Atrophy

7. Variability in Brain Aging

8. Summary • Brain aging is heterogeneous • Cognition • Brain structure

9. Outline • Brain Aging: cognition and structural imaging • Potential Causes of heterogeneity • Amyloidosis (brief) • Vascular risk factors • Time course of vascular risk on brain • Inflammation and brain aging

10. Percent PiB+ with Age Morris et al, Annals of Neuro, 2010

11. Time Dependent Differences Jack, et al. JAMA Neurology, 2015

12. Framingham Heart Study, unpublished data

13. Prevalence of Vascular Risk Factors among the Framingham Offspring DeCarli, et al. Neurobiology of Aging, 2005

14. Women Future Risk of Stroke or Dementia at Age 65 Men Seshadri, S. et al. Stroke 2006;37:345-350

15. Spectrum of CVD Stroke MRI Infarction White Matter Hyperintensities Brain Atrophy

16. MRI Examples of WMH and SBI Normal WMH Extensive WMH Silent MRI Infarct Debette et al, Stroke, 2010

17. Age-Specific Prevalence of SBI DeCarli, et al. Neurobiology of Aging, 2005

19. Aging White Matter Disease 0.30 0.29 0.25 0.23 0.20 Vascular Risk DeCarli, et al. Neurobiology of Aging, 2005

20. Quantification of age-related differences in WMH • Define Large WMH as 1 sd above age-related mean WMH

21. Vascular Risk and WMH

23. Risk Factors, Age and Brain Volume

24. Cognitive Consequences

26. Middle Life Vascular Risk Factors and Dementia Risk Whitmer, et al, Neurology, 2005

27. Increasing odds of Dementia with number of Risk Factors* *~74% Caucasian Whitmer, et al, Neurology, 2005

28. Dementia Risk with MRI Vascular Measures Debette et al, Stroke, 2010

29. Impact of Vascular Risk (VR) on White Matter Integrity and Gray Matter Atrophy 0 VR 1 VR 2 VR • Significant change in FA • Significant negative Jacobians • Both 3 VR Maillard et al, Neurobiology of Aging, 2015

30. Significant Atrophy /year Significant FA loss /year ** ** * * ** Number of VR

31. Annual change in hippocampus volume *** * * Number of Vascular Risk Factors

32. Summary II • Vascular risk factors are common • Vascular risk factors affect the brain • Silent brain infarctions • WMH • Cerebral Atrophy • Vascular risk factors affect cognition and brain structure in a dose dependent fashion

33. Outline • Brain Aging: cognition and structural imaging • Potential Causes of heterogeneity • Amyloidosis (brief) • Vascular risk factors • Time course of vascular risk on brain • Inflammation and brain aging

34. Impact of Vascular Disease may begin early Maillard, et al, Lancet Neurology, 2013

35. Neurology, 2015

36. Diabetes and Brain Aging

37. Cognitive Consequences

38. Hypothetical Model of Vascular Disease and Brain Atrophy

39. Hypothetical Consequences Cognition VRF VBI SNAP?

40. Summary III • Advancing age is associated with co-morbid diseases • Alzheimer’s pathology • Cerebrovascular pathology • Vascular injury may begin early in life • The number of vascular risk factors appears additive to later life dementia risk • Vascular risk may contribute to neurodegeneration in SNAP

41. Outline • Brain Aging: cognition and structural imaging • Potential Causes of heterogeneity • Amyloidosis (brief) • Vascular risk factors • Time course of vascular risk on brain • Inflammation and brain aging

42. Atheroscler, Thromb, Vasc, Bio, 2011

44. Inflammation in Younger Individuals Interaction p-value indicates significant differences by younger versus older

46. Inflammation and Cognition

47. GDF-15 in Brain Immunostaining of human cortex from individual who had mixed dementia (AD+vascular dementia). Blue=cell nuclei stained with DAPI. Green=microglia stained with IBA-1. Red =immunostaining for GDF15. Colocalization of GDF15 is noted in microglia (arrows). Bar = 20um.

48. Model of Inflammation and Brain Pathology in Aging

49. Summary IV • Aging and atherosclerosis lead to increasing inflammation • Inflammation can lead to brain injury and cognitive decline independent of vascular risk factors • Inflammation may lead to microglial activation with release of harmful cytokines

50. Conclusions • Brain aging is heterogeneous • Vascular risk factors cause subtle brain injury and cognitive impairment in a dose dependent manner • Cerebral atrophy is a common consequence of vascular risk • Inflammation secondary to systemic atherosclerosis may mediate some of the atrophic process