Regional amyloid burden and lacune in pure subcortical vascular cognitive impairment

We investigated the amyloid and vascular burden in Pittsburgh compound B (PiB)-negative subcortical vascular mild cognitive impairment (svMCI) and PiB-negative subcortical ischemic vascular dementia (SIVD) to elucidate the potential roles of amyloid deposition and small vessel disease (SVD). Thirty-eight svMCI patients and 42 SIVD patients were enrolled. The regional PiB uptake values and SVD markers were obtained and compared between groups. Additionally, correlations among amyloid burden, SVD, and cognition were made. Patients with PiB-negative SIVD showed more amyloid deposition than those with PiB-negative svMCI, particularly in the cuneus, lingual gyrus, supramarginal, and angular gyri. Despite subthreshold levels for amyloid deposition, our findings showed a marked regional difference in amyloid uptake between svMCI and SIVD, particularly in posteriorly located brain areas. However, lacune, a proxy for vascular burden, showed a broader association with cognition and had more impacts on developing dementia than amyloid burden. The topographical pattern of amyloid deposition and its impact on clinical status in pure subcortical vascular cognitive impairment were different from those in Alzheimer's disease.