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Quantitative maps of rotating frame relaxation (RFR) time constants are sensitive and useful magnetic resonance imaging tools with which to evaluate tissue integrity in vivo. However, to date, only moderate image resolutions of 1.6 x 1.6 x 3.6 mm3 have been used for whole‐brain coverage RFR mapping in humans at 3 T. For more precise morphometrical examinations, higher spatial resolutions are desirable. Towards achieving the long‐term goal of increasing the spatial resolution of RFR mapping without increasing scan times, we explore the use of the recently introduced Transform domain NOise Reduction with DIstribution Corrected principal component analysis (T‐NORDIC) algorithm for thermal noise reduction. RFR acquisitions at 3 T were obtained from eight healthy participants (seven males and one female) aged 52 ± 20 years, including adiabatic T1ρ, T2ρ, and nonadiabatic Relaxation Along a Fictitious Field (RAFF) in the rotating frame of rank n = 4 (RAFF4) with both 1.6 x 1.6 x 3.6 mm3 and 1.25 x 1.25 x 2 mm3 image resolutions. We compared RFR values and their confidence intervals (CIs) obtained from fitting the denoised versus nondenoised images, at both voxel and regional levels separately for each resolution and RFR metric. The comparison of metrics obtained from denoised versus nondenoised images was performed with a two‐sample paired t‐test and statistical significance was set at p less than 0.05 after Bonferroni correction for multiple comparisons. The use of T‐NORDIC on the RFR images prior to the fitting procedure decreases the uncertainty of parameter estimation (lower CIs) at both spatial resolutions. The effect was particularly prominent at high‐spatial resolution for RAFF4. Moreover, T‐NORDIC did not degrade map quality, and it had minimal impact on the RFR values. Denoising RFR images with T‐NORDIC improves parameter estimation while preserving the image quality and accuracy of all RFR maps, ultimately enabling high‐resolution RFR mapping in scan times that are suitable for clinical settings. [ABSTRACT FROM AUTHOR]

BackgroundSleep disturbances are reportedly common among persons infected with human immunodeficiency virus (HIV), but recent data, including comparisons with HIV-uninfected persons, are limited.MethodsWe performed a cross-sectional study among early-treated HIV-infected military beneficiaries (n = 193) to determine the prevalence and factors associated with insomnia (Pittsburgh Sleep Quality Index [PSQI]) and daytime sleepiness (Epworth Sleepiness Scale [ESS]). Data were compared with HIV-uninfected persons (n = 50) matched by age, sex, race or ethnicity, and military rank.ResultsForty-six percent of HIV-infected persons had insomnia (PSQI >5), and 30% reported daytime drowsiness (ESS ≥10). The prevalence of insomnia and daytime sleepiness was not significantly higher compared with the HIV-uninfected group (38% [P = .30] and 20% [P = .18], respectively). In the multivariate model, factors associated with insomnia among HIV infected patients included depression (odds ratio [OR], 16.8; 95% confidence interval [CI], 2.0-142.1; P = .01), increased waist size (OR, 2.7; 95% CI, 1.4-5.1; P = .002), and fewer years of education (OR, 0.8; 95% CI, .7-.95; P = .006). Neurocognitive impairment (diagnosed in 19% of HIV-infected participants) was not associated with insomnia; however, HIV-infected persons with insomnia were 3.1-fold more likely to have a decline in activities of daily living than those without insomnia (23% vs 9%; P = .01). Only 18% of HIV-infected persons reported using a sleep medication at least weekly.ConclusionsHIV-infected persons have a high prevalence of insomnia, but among an early-treated cohort this rate was not significantly higher compared with HIV-uninfected persons. Factors associated with insomnia among HIV-infected patients include depression and increased waist size. Prompt diagnosis and treatment of sleep disturbances are advocated and may improve quality of life.

Objective: To determine sex differences in the neurochemical concentrations measured by in vivo proton magnetic resonance spectroscopy (1H MRS) of healthy mice on a genetic background commonly used for neurodegenerative disease models. Methods: 1H MRS data collected from wild type mice with C57BL/6 or related genetic backgrounds in seven prior studies were used in this retrospective analysis. To be included, data had to be collected at 9.4 tesla magnetic field using advanced 1H MRS protocols, with isoflurane anesthesia and similar animal handling protocols, and a similar number of datasets from male and female mice had to be available for the brain regions analyzed. Overall, 155 spectra from female mice and 166 spectra from male mice (321 in total), collected from six brain regions (brainstem, cerebellum, cortex, hippocampus, hypothalamus, and striatum) at various ages were included. Results: Concentrations of taurine, total creatine (creatine + phosphocreatine), ascorbate, glucose and glutamate were consistently higher in male vs. female mice in most brain regions. Striatum was an exception with similar total creatine in male and female mice. The sex difference pattern in the hypothalamus was notably different from other regions. Interaction between sex and age was significant for total creatine and taurine in the cerebellum and hippocampus. Conclusion: Sex differences in regional neurochemical levels are small but significant and age-dependent, with consistent male-female differences across most brain regions. The neuroendocrine region hypothalamus displays a different pattern of sex differences in neurochemical levels. Differences in energy metabolism and cellular density may underlie the differences, with higher metabolic rates in females and higher osmoregulatory and antioxidant capacity in males. [ABSTRACT FROM AUTHOR]

Objective: Spinocerebellar ataxia type 3 (SCA3) is the most common dominantly inherited ataxia, and biomarkers are needed to noninvasively monitor disease progression and treatment response. Anti‐ATXN3 antisense oligonucleotide (ASO) treatment has been shown to mitigate neuropathology and rescue motor phenotypes in SCA3 mice. Here, we investigated whether repeated ASO administration reverses brainstem and cerebellar neurochemical abnormalities by magnetic resonance spectroscopy (MRS). Methods: Symptomatic SCA3 mice received intracerebroventricular treatment of ASO or vehicle and were compared to wild‐type vehicle‐treated littermates. To quantify neurochemical changes in treated mice, longitudinal 9.4T MRS of cerebellum and brainstem was performed. Acquired magnetic resonance (MR) group means were analyzed by 2‐way analysis of variance mixed‐effects sex‐adjusted analysis with post hoc Sidak correlation for multiple comparisons. Pearson correlations were used to relate SCA3 pathology and behavior. Results: MR spectra yielded 15 to 16 neurochemical concentrations in the cerebellum and brainstem. ASO treatment in SCA3 mice resulted in significant total choline rescue and partial reversals of taurine, glutamine, and total N‐acetylaspartate across both regions. Some ASO‐rescued neurochemicals correlated with reduction in diseased protein and nuclear ATXN3 accumulation. ASO‐corrected motor activity correlated with total choline and total N‐acetylaspartate levels early in disease. Interpretation: SCA3 mouse cerebellar and brainstem neurochemical trends parallel those in patients with SCA3. Decreased total choline may reflect oligodendrocyte abnormalities, decreased total N‐acetylaspartate highlights neuronal health disturbances, and high glutamine may indicate gliosis. ASO treatment fully or partially reversed select neurochemical abnormalities in SCA3 mice, indicating the potential for these measures to serve as noninvasive treatment biomarkers in future SCA3 gene silencing trials. ANN NEUROL 2023;94:658–671 [ABSTRACT FROM AUTHOR]

To better communicate and improve post-visit outcomes, a remote patient monitoring (RPM) program was implemented for patients discharged from emergency departments (ED) across 10 hospitals. The solution was offered to patients at the time of ED discharge and staffed by a group of care coordinators to respond to questions/urgent needs. Of 107,477 consecutive patients offered RPM, 28,425 patients (26.4%) engaged with the program. Activated patients with RPM were less likely to return to the ED within 90 days of their index visit [19.8% compared to 23.6%, p<.001]. While activation rates were modest, we observed fewer return visits to the ED in patients using RPM, with a 16.2% lower hazard of returning in the next year. Future research is needed to understand methods to improve RPM activation, any causal effects of RPM activation on return ED visits, and external validation of these findings. [ABSTRACT FROM AUTHOR]