Impact of Age on Cardiovascular, Cerebrovascular and Cognitive Health in Spinal Cord Injury
Condition: Spinal Cord Injury
MeSH terms: Spinal Cord Injuries; Wounds and Injuries
Study type: Observational

Summary: 
      As the spinal cord injured population ages, these individuals are being exposed to an
      increased prevalence of age-associated diseases, which coupled with the secondary
      complications of the injury may contribute to the reduced life expectancies. Decentralized
      autonomic regulation in persons with SCI results in a multitude of cardiovascular changes,
      which may contribute to accelerated aging. Adverse cardiovascular changes may have
      deleterious effects on cerebral blood flow dynamics and an increase in cerebral vascular
      resistance index in individuals with SCI during cognitive testing. Deficits in memory and
      processing speed in individuals with SCI may relate to cardiovascular and cerebrovascular
      dysfunction. Identifying the associations between healthy aging versus premature or
      accelerated aging in organ system function in the SCI population is an important first step
      towards prevention and amelioration of these changes. Therefore the study objectives are to
      compare, among individuals with SCI, age-matched non-SCI and older non-SCI individuals
      arterial stiffness and cerebral vascular resistance index; memory, processing speed, and
      executive function; and volume of white matter hyperintensities. 60 individuals with SCI, 30
      age-matched non-SCI controls, and 20 older non-SCI controls will be recruited for this study.
      All potential subjects will undergo a two-part screening process which consists of an initial
      screening via telephone and a detailed, in-person screening. Eligible subjects will be
      invited to participate in a 4 hour laboratory visit during which their arterial stiffness,
      blood pressure, heart rate, respiration rate and, blood flow to the brain will be monitored
      at rest and during a comprehensive series of cognitive tests. A subset of the participants
      will be asked to take part in an MRI brain imaging session: 40 persons with SCI, 10
      age-matched non-SCI and 10 older non-SCI. Eligible subjects will be asked to participate in a
      1 hour MRI/functional magnetic resonance imaging(fMRI) session.

      We hypothesize that arterial stiffness and cerebral vascular resistance index will be
      increased in the SCI group compared to the age-matched non-SCI but will be comparable to the
      older non-SCI groups. In addition, we hypothesize that the prevalence of mild to moderate
      cognitive impairments in memory, processing speed, and executive function will be increased
      in the SCI individuals compared to the age-matched non-SCI but will be comparable to the
      older non-SCI individuals.
    

Detailed description: 
      The cognitive test battery will consists of the tests listed below, administered in the order
      given.

        1. Digit Span

        2. California Verbal Learning Test

        3. Symbol Digit Modalities Test

        4. Letter Number Sequencing

        5. California Verbal Learning Test Delay

        6. Paced Auditory Serial Addition Test

        7. D-KEFS Verbal Fluency

        8. D-KEFS Color-Word

        9. WASI Vocabulary

       10. WASI Matrix Reasoning
    

Observational model: Case-Control
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        60 subjects with SCI, 30 age-matched non-SCI controls and 20 older non-SCI controls will be
        recruited from out-patient clinics at Kessler Institute for Rehabilitation. This includes
        subjects who have completed various protocols in the Cardiovascular autonomic testing
        laboratory or patients referred by their physicians following routine physical
        examinations. Physicians will be informed of the inclusion and exclusion criteria for this
        study and will be able to provide us with the assurance that the patient is an appropriate
        candidate for the study and that he/she was willing to speak with the study coordinators.
      
Keywords: spinal cord injury; autonomic dysreflexia; baroreceptor integrity; sympathetic integrity; vagal integrity; autonomic integrity; arterial stiffness; cognitive function; traumatic brain injury; cerebral blood flow; white matter hyperintensities; cerebral vascular resistance index