Development of Clinical Methods to Evaluate Neural Function in Aging
Condition: Aging
Study type: Observational

Summary: 
      A primary focus of the University of Florida (UF) Claude D. Pepper Older Americans
      Independence Center (OAIC) is to build a comprehensive understanding of the causes and
      consequences of declining physical function and disability development among older adults. To
      date investigators have largely focused on sarcopenia, the age-related decline in skeletal
      muscle mass and strength, as the primary contributor to physical decline. However, recent
      findings indicate that changes in the central and/or peripheral nervous systems may play a
      larger role than previously thought in the development of functional limitations. These
      fields hold extensive promise for identifying novel contributors to age-related functional
      decline. Therefore, the overarching aim of this project is to develop the ability of RC1 to
      assess novel neural contributors to mobility and overall physical function. Importantly, the
      development of these techniques will provide the RC1 with the tools to evaluate the potential
      involvement of the central and peripheral nervous systems in age-related functional decline
      and disablement. The primary aim of this project is to develop techniques for quantifying
      peripheral motor unit number and size as well as spinal cord integrity.
    

Detailed description: 
      As part of participation, the subjects will attend up to 4 visits. During the visits the
      following testing may occur:

        -  Vital signs (heart rate, blood pressure), height and weight will be measured.

        -  Tests that assess your mobility and questions about physical function. These tests are
           listed below and will not be conducted in a particular order, and will take
           approximately 1.5 hours to complete.

             -  Walking tests,

             -  Tests of physical ability that include:

                  1. Standing up from chairs of different height

                  2. Lying on the floor and rising to a standing position

                  3. Kneeling on the floor and rising to standing position

                  4. Climbing a flight of stairs

                  5. Lift a weighted laundry basket and placing it on a shelf

             -  Muscle strength tests will be performed on the legs and arms.

             -  Questionnaires that address physical function.

             -  Muscle and nerve testing will be done.

             -  During the above testing, sensors will be worn on the forehead that use invisible
                light to indirectly measure blood flow and blood oxygen content of the brain. In
                addition, sensors may be worn the fingers that measure how the skin conducts
                electricity. A chest strap that measures heart beats will also be worn. These
                measures are safe and provide information about the nervous system responds to
                physical and/or mental challenges.

        -  Tests will be done that measure memory, attention, vocabulary, problem solving, and
           planning skills.

        -  A bone density and body composition measured (scanned) by the machine called DEXA. DEXA
           scans, like x-rays, are painless, and involve exposure to very small amounts of
           radiation.

        -  Images of the brain will be taken using magnetic resonance imaging (MRI). Magnetic
           resonance imaging (MRI) is a procedure that allows doctors to look inside the body by
           using a scanner that sends out a strong magnetic field and radio waves.

      All of these test are done for this study and will not be used to diagnose or treat any
      medical problems.

      The expected length of participation is approximately six hours total, over the course of 4
      separate visits.
    

Intervention name(s): High-functioning older adults; Lower-functioning older adults; Young adults
Intervention type(s): Other; Other; Other
Intervention description(s): Participants with a SPPB score ≥ 11 will be categorized as high-functioning. The following test will be performed: Health and Quality of Life questionnaires, Mobility Assessments, Accelerometry, Body Composition (DEXA scan), Strength assessments, Neuromuscular stimulation, and Magnetic resonance imaging (MRI).; Participants with a SPPB score ≤ 8 will be categorized as lower-functioning. The following test will be performed: Health and Quality of Life questionnaires, Mobility Assessments, Accelerometry, Body Composition (DEXA scan), Strength assessments, Neuromuscular stimulation, and Magnetic resonance imaging (MRI).; Participants between the 20 - 30 years of age. The following test will be performed: Health and Quality of Life questionnaires, Mobility Assessments, Accelerometry, Body Composition (DEXA scan), Strength assessments, Neuromuscular stimulation, and Magnetic resonance imaging (MRI).
Observational model: Case-Control
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        We propose to recruit 30 persons over 60 years of age who are classified as either high- or
        low functioning based on performance on the Short Physical Performance Battery (SPPB).
        Participants with a SPPB score ≥ 11 will be categorized as high-functioning, while the
        low-functioning group will include participants with a SPPB score ≤ 8. We will also recruit
        15 persons between 20-30 years of age. We will target cognitively intact (3MSE > 80) older
        adults who are free of overt neuromuscular impairments (no dementias, brain tumors, major
        depression, history of stroke, etc.).