We strive to have substantial rural (~30%) and African-American or other Non-White (~20%) enrollment in both cohorts and our goal is for each cohort to be fairly evenly balanced between men and women. In each cohort, we aim for approximately two-thirds of participants to have a known APOE4 gene and/or a family history of Alzheimer’s disease in a first-degree relative (or in a grandparent, in the case of the Young Cohort).

Cohorts

• Memory and Aging Study (MAS) Cohort (Ages 45 to 80)

  MAS will develop and maintain a prospectively followed cohort of 420 research participants, ages 45 to 80 and this will enable us to observe key transition periods related to AD risk, including menopause, onset of comorbidities, and the transition to MCI and dementia. To accomplish these goals, the cohort design will collect from two different groups based on affection. The first group will consist of 320 participants who are cognitively normal at entry and roughly equal in age distribution. The second group will include 100 participants symptomatic at entry (MCI or early dementia).

• Young Cohort (Ages 25 to 44)

  The Young Cohort (n=120) will consist of participants ages 25-44 who will undergo a one-time evaluation and biomarker collection. The availability of this unique comparison group will enable investigators to evaluate the degree to which novel biomarkers or signatures associated with AD in older cohorts are linked to other contributing factors, such as age or genetic risk.

• Each participant contributes UDS-based medical, neurologic, psychiatric, and neuropsychological evaluations.
• We also collect blood, urine, and cerebrospinal fluid specimens.
• During the baseline visit, we collect motor-sensory assessments, and imaging:
  • brain MRI (T1, T2 FLAIR, diffusion-weighted, fMRI resting-state, susceptibility)
  • retinal imaging

    Retinal imaging protocol

    Corrected distance visual acuity on Snellen chart

    Zeiss Cirrus HD-5000 AngioPlex retinal and optic nerve imaging device

    • Optical coherence tomography (OCT)
      • macular cube
        • measures ganglion cell inner plexiform layer thickness, central subfield thickness
      • HD21 raster scan
        • measures subfoveal choroidal thickness
      • optic disc cube
        • measures retinal nerve fiber layer thickness
    • Optical coherence tomography angiography (OCTA)
      • 3x3mm OCTA scan centered on macula
        • images the superficial capillary plexus of the retina
        • measures foveal avascular zone area, vessel density, and perfusion density
      • 6x6mm OCTA scan centered on macula
        • images the superficial capillary plexus of the retina
        • measures vessel density and perfusion density
      • 4.5x4.5mm OCTA scan centered on optic disc
        • images the superficial capillary plexus of the retina
        • measures capillary perfusion density and capillary flux index

    Optos California Scanning Laser Ophthalmoscopy Camera

    • Ultrawidefield color fundus photographs (~220 degrees)
      • can measure vessel width gradient, vessel tortuosity, fractal dimension
    • Ultrawidefield fundus autofluorescence (~220 degrees)

     
• Up to 100 participants in the MAS cohort who are unable or unwilling to undergo lumbar puncture may be consented to undergo a PET image of their brain, rather than contributing cerebrospinal fluid via lumbar puncture.
• The participant’s amyloid and tau status is determined either from cerebrospinal fluid or a PET image.
• Participants who are peri-menopausal women also contribute a set of questionnaires about menopause symptoms and extra blood for tests related to menopause.

Specimens

• CSF:  ~300 samples (86 with AD; 209 with other neurologic diseases such as MCI, DLB and others; and 41 from healthy controls).
• Plasma:   ~300 samples (81 with AD, 218 with other neurologic diseases such as MCI, DLB and others; and 14 from normal controls)