Investigation of patterns and associations of neuroinflammation in cognitive impairment.

Neuroinflammation has been identified as an important pathological component of cognitive impairment, and translocator protein imaging has become a valuable tool for assessing its patterns. We aimed to obtain the exact distribution of neuroinflammation in cognitive impairment and its underlying mechanisms with amyloid-beta. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, two investigators searched literature databases for studies that measured translocator protein binding levels. This measurement was performed between healthy controls and subjects with mild cognitive impairment or Alzheimer's disease via voxel-based positron emission tomography image analysis at the whole-brain level. This meta-analysis was performed with the anisotropic effect-size based algorithm. Neuroinflammation in patients with mild cognitive impairment was mainly concentrated in the left middle temporal gyrus and left amygdala. In Alzheimer's disease patients, the brain regions involved were the left inferior temporal gyrus, left calcarine fissure/surrounding cortex, left parahippocampal gyrus, right lingual gyrus, and right middle temporal gyrus. In addition, neuroinflammation in patients with cognitive impairment was highly correlated with amyloid-beta deposition in the cortex. This study deepens our understanding of the patterns of neuroinflammation in patients with cognitive impairment and its interaction with amyloid-beta, providing potential insights for therapeutic approaches targeting neuroinflammation in Alzheimer's disease.