Florbetaben PET imaging to detect amyloid beta plaques in Alzheimer's disease: phase 3 study.

BACKGROUND: Evaluation of brain ß-amyloid by positron emission tomography (PET) imaging can assist in the diagnosis of Alzheimer disease (AD) and other dementias. METHODS: Open-label, nonrandomized, multicenter, phase 3 study to validate the (18)F-labeled ß-amyloid tracer florbetaben by comparing in vivo PET imaging with post-mortem histopathology. RESULTS: Brain images and tissue from 74 deceased subjects (of 216 trial participants) were analyzed. Forty-six of 47 neuritic ß-amyloid-positive cases were read as PET positive, and 24 of 27 neuritic ß-amyloid plaque-negative cases were read as PET negative (sensitivity 97.9% [95% confidence interval or CI 93.8-100%], specificity 88.9% [95% CI 77.0-100%]). In a subgroup, a regional tissue-scan matched analysis was performed. In areas known to strongly accumulate ß-amyloid plaques, sensitivity and specificity were 82% to 90%, and 86% to 95%, respectively. CONCLUSIONS: Florbetaben PET shows high sensitivity and specificity for the detection of histopathology-confirmed neuritic ß-amyloid plaques and may thus be a valuable adjunct to clinical diagnosis, particularly for the exclusion of AD. TRIAL REGISTRATION: ClinicalTrials.govNCT01020838.

The neural correlates of mindful awareness: a possible buffering effect on anxiety-related reduction in subgenual anterior cingulate cortex activity.

BACKGROUND: Human personality consists of two fundamental elements character and temperament. Character allays automatic and preconceptual emotional responses determined by temperament. However, the neurobiological basis of character and its interplay with temperament remain elusive. Here, we examined character-temperament interplay and explored the neural basis of character, with a particular focus on the subgenual anterior cingulate cortex extending to a ventromedial portion of the prefrontal cortex (sgACC/vmPFC). METHODS: Resting brain glucose metabolism (GM) was measured using [(18)F] fluorodeoxyglucose positron emission tomography in 140 healthy adults. Personality traits were assessed using the Temperament and Character Inventory. Regions of interest (ROI) analysis and whole-brain analysis were performed to examine a combination effect of temperament and character on the sgACC/vmPFC and to explore the neural correlates of character, respectively. RESULTS: Harm avoidance (HA), a temperament trait (i.e., depressive, anxious, vulnerable), showed a significant negative impact on the sgACC/vmPFC GM, whereas self-transcendence (ST), a character trait (i.e., intuitive, judicious, spiritual), exhibited a significant positive effect on GM in the same region (HA ß = -0.248, p = 0.003; ST: ß = 0.250, p = 0.003). In addition, when coupled with strong ST, individuals with strong HA maintained the sgACC/vmPFC GM level comparable to the level of those with low scores on both HA and ST. Furthermore, exploratory whole-brain analysis revealed a significant positive relationship between ST and sgACC/vmPFC GM (peak voxel at x = -8, y = 32, z = -8, k = 423, Z = 4.41, corrected p (FDR) = 0.030). CONCLUSION: The current findings indicate that the sgACC/vmPFC might play a critical role in mindful awareness to something beyond as well as in emotional regulation. Developing a sense of mindfulness may temper exaggerated emotional responses in individuals with a risk for or having anxiety and depressive disorders.