Subcortical diagnostic indicators for Dementia: evidence from volumetric alterations of grey matter

Dementia as a progressive and debilitating syndrome inevitably impacts one's self-sufficiency and life expectancy, yet, the associated brain structural changes are not comprehensively addressed nor are brain volumetric signature associated with Dementia fully documented. Given the involvement of subcortical areas in deterioration of cognitive abilities, we investigated the volumetric alterations of subcortical grey matter, as potential diagnostic biomarkers for Dementia, using T1-weighted structural brain scans data of 152 Dementia patients and 152 healthy individuals from the UK Biobank; we focused on the volumes of the Brain Stem, the Thalamus, the Caudate, the Putamen, the Amygdala, the Hippocampus, and the Pallidum and performed a multifactor MANOVA. We observed that in Dementia patients, there was significant shrinkage of the grey matter volumes (GMVs) in the Brain Stem, the left and right Amygdala, and Hippocampus, but higher GMVs in the left and right Caudate and Pallidum. That is, our investigation into the GMVs of subcortical areas revealed that in Dementia patients not only the atrophy of the grey matter but also the inflammation of brain tissue characterizes pathological volumetric alterations, uncovering the consequences of sustained neuroinflammation and the resulting pathogenesis of Dementia. To examine the diagnostic indications for Dementia based on the volumes of the subcortical areas, we also performed Receiver Operating Characteristic curve analysis; according to our findings, the diagnostic accuracy of this model in discriminating the Dementia patients from the healthy participants is at the considerable rate of 82%. Therefore, the alterations of the GMVs of subcortical areas serve as a reliable biomarker for early detection and diagnosis of Dementia in clinical settings, facilitating timely interventions.