Progression in WMH volume is accompanied by higher gray matter loss: One‐year follow‐up MRI study in TATA Longitudinal Study on Aging Cohort of India

Abstract

AbstractBackgroundSmall vessel disease pathologies such as white matter hyperintensity (WMH) and loss in neuroanatomical volumes with aging have been investigated across various cross‐ sectional and longitudinal‐aging studies in different parts of world. However, it is yet not extensively investigated whether the changes in WMH kinetics over the period impacts the neuroanatomical health? Here, we have measured changes in WMH and neuroanatomic‐volumes, in an ongoing longitudinal study on aging in India called TATA longitudinal study on aging (TLSA), at the baseline and one‐year‐follow‐up visit. The TLSA‐study is a prospective, community‐based, cohort study that comprises of cognitively healthy, educated, and multilingual individuals of both genders aged ≥45 years. The subjects are recruited from urban‐Bangalore, a large metropolitan city in southern India.MethodMRI measurements were conducted on 3T whole‐body‐scanner. MRI study performed close to the first clinical and cognitive‐examination is termed as baseline visit (V0), while MRI close to one‐year follow‐up is termed as V1. T2w‐FLAIR, 3D‐MPRAGE and DWI MRI were performed at both V0‐ and V1‐visits. WMH was quantified using T2w‐FLAIR and MPRAGE‐T1w images. Anatomical volumes were determined using Freesurfer. The volumes were normalized to the total‐intracranial‐volume. Changes in WMH and anatomic volume were calculated as (Volume at V1 – Volume at V0).ResultChanges in WMH and neuroanatomic volumes were evaluated for 128‐subjects who had MRI at both the visits, V0 and V1. Quantification of change in WMH (Delta‐WMH) in the TLSA‐subjects revealed that 65% of the subjects showed progression in WMH‐volume while another 35% did not show WMH‐progression. This indicated that there is a subset of cohorts that showed progression in WMH volume (+0.5‐7.9 ml) while another subset of subjects had no change in WMH over the period. Segmentation of neuroanatomical‐volume showed that the subset of the cohort that showed WNH‐progression over the one‐year period had significantly larger reduction in gray‐matter and increase in CSF volume at V1 compared to another subset that did not had changes in WMH.ConclusionProgression in WMH may be associated with increased vascular insult to the brain resulting in substantial gray‐matter loss and ventricular increase. Increase in WMH volume may fasten the neuroanatomic deteriorations with aging.