Authors: Ashleigh F Parker, Lisa Ohlhauser, Vanessa Scarapicchia, Colette M Smart, Jodie Gawryluk
Published: 2020-12-07
DOI: 10.1002/alz.047606
Source: Full article
AbstractBackgroundIndividuals with subjective cognitive decline (SCD), who self‐report changes in cognition, but are within the normal range on neuropsychological testing, are thought to be the earliest along the cognitive continuum between healthy aging and Alzheimer’s disease (Jessen et al., 2014). This study aimed to synthesize findings of neuroimaging studies using various modalities to investigate changes in the brain in those with SCD.MethodPubMed and PsycINFO databases were searched for neuroimaging studies of individuals with SCD. Quality assessment was completed using the Appraisal tool for Cross‐Sectional Studies (Downes, Brennan, Williams, & Dean, 2016).ResultIn total, 108 neuroimaging studies investigating SCD samples were identified. Specifically, 45 studies used MRI, 8 used EEG, 5 used MEG, 3 used CT, 26 used PET, 2 used SPECT, and 19 studies used multi‐modal neuroimaging methods. Many studies investigated differences between healthy controls and those with SCD. Across imaging modalities, findings revealed significant differences in brain structure and function between these groups.ConclusionIt is valuable to synthesize the results of studies found in this area to identify neuroimaging biomarkers present in those with SCD. Identifying changes in the brain using objective and physiologically based measures at this early clinical stage will help to characterize the progression of Alzheimer’s disease. In future neuroimaging investigations of SCD, it would be useful for studies to include larger sample sizes, examine groups longitudinally, and use multi‐modal neuroimaging methods. Incorporating these components in future studies could provide a better understanding of changes in the brain that are associated with subsequent conversion to mild cognitive impairment or Alzheimer’s disease.