Brain atrophy associations with white matter lesions in the ageing brain: the Lothian Birth Cohort 1936
Cerebral atrophy and white matter lesions (WMLs) are common in older people with common risk factors, but it is unclear if they are related. We investigated whether and to what degree they are related in deep and superficial structures using both volumetric and visual ratings.
The intracranial, total brain tissue (TBV), cerebrospinal fluid (CSF), ventricular superficial subarachnoid space (SSS), grey matter, normal-appearing white matter, WMLs, and combined CSF, venous sinuses and dural volumes were measured. WMLs were also rated using the Fazekas scale.
Amongst 672 adults (mean age 73 ± 1 years), WMLs were associated with global brain atrophy (TBV, β = −0.43 mm3, P < 0.01) and specifically with deep (ventricular enlargement, β = 0.10 mm3, P = 0.03) rather than superficial (SSS, β = 0.09 mm3, P = 0.55) atrophy. A 1 mm3 increase in WML volume was associated with a 0.43 mm3 decrease in TBV and 0.10 mm3 increase in ventricular volume. WMLs were associated with combined CSF + Venous Sinuses + Meninges volumes, but not CSF volume alone. Some of the associations were attenuated after correcting for vascular risk factors. The associations were similar for visually scored WMLs.
WMLs are associated with brain atrophy, primarily with deep brain structures. Measures of brain atrophy should include all intracranial structures when assessing brain shrinkage.
• Increasing age-related white matter lesions (WML) are modestly associated with brain atrophy.
• Most associated atrophy affects deep structures (white matter, basal ganglia, etc.).
• This is true whether WMLs are assessed volumetrically or visually scored.
• Precise evaluation of brain atrophy requires assessment of all intracranial tissues.
KeywordsBrain atrophy White matter lesions Leukoaraiosis Magnetic resonance imaging WML
BSA, NAR, SMM and MCVH are supported by The Disconnected Mind (http://www.disconnectedmind.ed.ac.uk/) funded by Age UK and the UK Medical Research Council. JMW was supported by the Scottish Funding Council (SFC) through the SINAPSE Collaboration (Scottish Imaging Network. A Platform for Scientific Excellence, http://www.sinapse.ac.uk). MCVH is also supported by Row Fogo Charitable Trust. We thank the radiographers and administrative staff of the Brain Research Imaging Centre, Edinburgh, (http://www.bric.ed.ac.uk/), part of the SINAPSE Collaboration (http://www.sinapse.ac.uk/), where the subjects were scanned and the imaging data were analysed. We thank the Lothian Birth Cohort 1936 team for data collection and data entry; the nurses and other staff at the Wellcome Trust Clinical Research Facility (http://www.wtcrf.ed.ac.uk/) and the staff at Lothian Health Board. The work was undertaken within The University of Edinburgh Centre for Cognitive Ageing and Cognitive Epidemiology (http://www.ccace.ed.ac.uk/), part of the cross council Lifelong Health and Wellbeing Initiative (G0700704/84698). Funding from the Biotechnology and Biological Sciences Research Council (BBSRC), Engineering and Physical Sciences Research Council (EPSRC), Economic and Social Research Council (ESRC) and Medical Research Council (MRC) is gratefully acknowledged.
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