Hippocampal shape across the healthy lifespan and its relationship with cognition.

The study of the hippocampus across the healthy adult lifespan has rendered inconsistent findings. While volumetric measurements have often been a popular technique for analysis, more advanced morphometric techniques have demonstrated compelling results that highlight the importance and improved specificity of shape-based measures. Here, the MAGeT Brain algorithm was applied on 134 healthy individuals aged 18-81 years old to extract hippocampal subfield volumes and hippocampal shape measurements, namely: local surface area (SA) and displacement. We used linear-, second- or third-order natural splines to examine the relationships between hippocampal measures and age. In addition, partial least squares analyses were performed to relate volume and shape measurements with cognitive and demographic information. Volumetric results indicated a relative preservation of the right cornus ammonis 1 with age and a global volume reduction linked with older age, female sex, lower levels of education and cognitive performance. Vertex-wise analysis demonstrated an SA preservation in the anterior hippocampus with a peak during the sixth decade, while the posterior hippocampal SA gradually decreased across lifespan. Overall, SA decrease was linked to older age, female sex and, to a lesser extent lower levels of education and cognitive performance. Outward displacement in the lateral hippocampus and inward displacement in the medial hippocampus were enlarged with older age, lower levels of cognition and education, indicating an accentuation of the hippocampal "C" shape with age. Taken together, our findings suggest that vertex-wise analyses have higher spatial specifity and that sex, education, and cognition are implicated in the differential impact of age on hippocampal subregions throughout its anteroposterior and medial-lateral axes. This article is part of the Virtual Special Issue titled COGNITIVE NEU- ROSCIENCE OF HEALTHY AND PATHOLOGICAL AGING. The full issue can be found on ScienceDirect at https://www.sciencedirect.com/journal/neurobiology-of-aging/special-issue/105379XPWJP.

Hippocampal subfield volumes across the healthy lifespan and the effects of MR sequence on estimates.

The hippocampus has been extensively studied in various neuropsychiatric disorders throughout the lifespan. However, inconsistent results have been reported with respect to which subfield volumes are most related to age. Here, we investigate whether these discrepancies may be explained by experimental design differences that exist between studies. Multiple datasets were used to collect 1690 magnetic resonance scans from healthy individuals aged 18-95 years old. Standard T1-weighted (T1w; MPRAGE sequence, 1 mm3 voxels), high-resolution T2-weighted (T2w; SPACE sequence, 0.64 mm3 voxels) and slab T2-weighted (Slab; 2D turbo spin echo, 0.4 × 0.4 × 2 mm3 voxels) images were included. The MAGeT Brain algorithm was used for segmentation of the hippocampal grey matter (GM) subfields and peri-hippocampal white matter (WM) subregions. Linear mixed-effect models and Akaike information criterion were used to examine linear, second or third order natural splines relationship between hippocampal volumes and age. We demonstrated that stratum radiatum/lacunosum/moleculare and fornix subregions expressed the highest relative volumetric decrease, while the cornus ammonis 1 presented a relative volumetric preservation of its volume with age. We also found that volumes extracted from slab images demonstrated different age-related relationships compared to volumes extracted from T1w and T2w images. The current work suggests that although T1w, T2w and slab derived subfield volumetric outputs are largely homologous, modality choice plays a meaningful role in the volumetric estimation of the hippocampal subfields.

Impact of cognitive-behavioral interventions on weight loss and psychological outcomes: A meta-analysis.

OBJECTIVES: To examine the effects of cognitive-behavioral therapy weight loss (CBTWL) interventions on weight loss, psychological outcomes (eating behaviors [cognitive restraint, emotional/binge eating], and depressive/anxiety symptoms) in adults with overweight or obesity. METHODS: To be included, studies had to (a) be randomized controlled clinical trials of a CBTWL intervention versus a comparison intervention; (b) include weight loss and psychological outcomes; and (c) include patients who were at least overweight to obese. This review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement (Moher, Liberati, Tetzlaff, & Altman & the PRISMA Group, 2009). RESULTS: Twelve studies (6,805 participants) were included. The average weight loss difference between arms was -1.70 kg (95% confidence interval [CI]: -2.52 to -0.86, I2 = 1%) in favor of CBTWL. The standardized mean difference on cognitive restraint was 0.72 (95% CI: 0.33 to 1.09; I2 = 81%) and -0.32 (95% CI: -0.49 to -0.16; I2 = 0%) for emotional eating in favor of CBTWL. The reduction in depressive symptoms was not statistically different between the groups (-0.10 [95% CI: 0.21 to 0.02], I2 = 36%). Meta-analyses were not possible for anxiety and binge eating. CONCLUSIONS: In addition to weight loss, current evidence suggests that CBTWL is an efficacious therapy for increasing cognitive restraint and reducing emotional eating. However, CBTWL does not seem to be superior to other interventions for decreasing depressive symptoms. Future studies should focus on understanding how psychological factors impact weight loss and management. (PsycINFO Database Record

Pharmacodynamically Guided Levofloxacin Dosing for Pediatric Community-Acquired Pneumonia.

BACKGROUND.: Oral levofloxacin is recommended as a preferred treatment for infection with Streptococcus pneumoniae with a penicillin minimum inhibitory concentration (MIC) of ≥4 µg/mL and as an alternative for infection with S pneumoniae with a penicillin MIC of ≤2 µg/mL. To investigate the current dosing recommendations and create a pharmacodynamically guided regimen, a Monte Carlo simulation was performed. METHODS.: The simulation included a previously published 1-compartment model, and incorporated a formula that takes into account age-appropriate weights for hospitalized patients. Three different dosing regimens, including community-acquired pneumonia guideline dosing, inhalational anthrax dosing, and a pharmacodynamically guided regimen, were assessed. The probability of target attainment was described as the proportion of patients who achieve an unbound-drug area under the concentration-time curve over 24 hours divided by the MIC above 33.7 µg/mL per hour. Microbiologic data from 2 stand-alone pediatric tertiary care centers were included. RESULTS.: Guideline-recommended doses of levofloxacin seem to produce suboptimal exposure in patients aged 5-14 years for pneumococci with an MIC of 1 µg/mL. Anthrax dosing was suboptimal in patients aged <5 years and in those aged >15 years. The pharmacodynamically guided regimen maintained a probability of target attainment of >90% for all age groups without producing peak concentrations higher than those previously described. None of the regimens attained the pharmacodynamic targets for a levofloxacin MIC of 2 µg/mL. CONCLUSIONS.: Current dosing recommendations were found to be suboptimal for specific age groups. A pharmacodynamically guided levofloxacin dosing regimen was determined, but it will need to be studied clinically for safety and tolerability.