Rationale: As the population of the world ages, age-related cognitive decline is becoming an ever-increasing problem. However, the changes in brain structure that accompany normal ageing, and the role they play in cognitive decline, remain to be fully elucidated.
Aims: This study aims to characterize changes in brain structure in old age, and to investigate relationships between brain ageing and cognitive decline using the Lothian Birth Cohort 1936 (LBC1936). Here, we report the rationale, design and methodology of the brain and neurovascular imaging protocol developed to study this cohort.
Design: An observational, longitudinal study of the LBC1936, which comprises 1091 relatively healthy individuals now in their 70's and living in the Edinburgh area. They are surviving participants of the Scottish Mental Survey 1947, which involved a test of general intelligence taken at age 11 years. At age 70 years the LBC1936 undertook detailed cognitive, medical and genetic testing, and provided social, family, nutritional, quality of life and physical activity information. At mean age 73 years they are undergoing detailed brain MRI and neurovascular ultrasound imaging, repeat cognitive and other testing. The MRI protocol is designed to provide qualitative and quantitative measures of grey and white matter atrophy, severity and location of white matter lesions, enlarged perivascular spaces, brain mineral deposits, microbleeds and integrity of major white matter tracts. The neurovascular ultrasound imaging provides velocity, stenosis and intima-media thickness measurements of the carotid and vertebral arteries.
Study: This valuable imaging dataset will be used to determine which changes in brain structural parameters have the largest effects on cognitive ageing. Analysis will include multimodal image analysis and multivariate techniques, such as factor analysis and structural equation modelling. Especially valuable is the ability within this sample to examine the influence that early life intelligence has on brain structural parameters in old age, and the role of genetic, vascular, educational and lifestyle factors.
Outcomes: Final outcomes include associations between early and late life cognition and integrity of key white matter tracts, volume of grey and white matter, myelination, brain water content, and visible abnormalities such as white matter lesions and mineral deposits; and influences of vascular risk factors, diet, environment, social metrics, education and genetics on healthy brain ageing. It is intended that this information will help to inform and develop strategies for successful cognitive ageing.
- Lothian Birth Cohort
- vascular disease
- brain imaging