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The HEALthy Brain and Child Development (HBCD) Study, a multi-site prospective longitudinal cohort study, will examine human brain, cognitive, behavioral, social, and emotional development beginning prenatally and planned through early childhood. The acquisition of multimodal magnetic resonance-based brain development data is central to the studys core protocol. However, application of Magnetic Resonance Imaging (MRI) methods in this population is complicated by technical challenges and difficulties of imaging in early life. Overcoming these challenges requires an innovative and harmonized approach, combining age-appropriate acquisition protocols together with specialized pediatric neuroimaging strategies. The HBCD MRI Working Group aimed to establish a core acquisition protocol for all 27 HBCD Study recruitment sites to measure brain structure, function, microstructure, and metabolites. Acquisition parameters of individual modalities have been matched across MRI scanner platforms for harmonized acquisitions and state-of-the-art technologies are employed to enable faster and motion-robust imaging. Here, we provide an overview of the HBCD MRI protocol, including decisions of individual modalities and preliminary data. The result will be an unparalleled resource for examining early neurodevelopment which enables the larger scientific community to assess normative trajectories from birth through childhood and to examine the genetic, biological, and environmental factors that help shape the developing brain.

Neurological disease due to single-gene defects represents a targetable entity for adeno-associated virus (AAV)-mediated gene therapy. The delivery of AAV-mediated gene therapy to the brain is challenging, owing to the presence of the blood–brain barrier. Techniques in gene transfer, such as convection-enhanced intraparenchymal delivery and image-guided delivery to the cerebrospinal fluid spaces of the brain, have led the field into highly accurate delivery techniques, which provide correction of genetic defects in specific brain regions or more broadly. These techniques commonly use magnetic resonance imaging (MRI), computed tomography, and fluoroscopic guidance. Even more, the neuroimaging changes evaluated by MRI, MR spectroscopy, diffusion tensor imaging, and functional MRI can serve as important biomarkers of therapy effect and overall disease progression. Here, we discuss the role of neuroimaging in delivering AAV vectors and monitoring the effect of gene therapy. [ABSTRACT FROM AUTHOR]

Objective: E2730, an uncompetitive γ‐aminobutyric acid (GABA) transporter‐1 (GAT‐1) inhibitor, has potent anti‐seizure effects in a rodent model of chronic temporal lobe epilepsy, the kainic acid status epilepticus (KASE) rat model. In this study, we examined purported neuroimaging and physiological surrogate biomarkers of the effect of E2730 on brain GABAergic function. Methods: We conducted a randomized cross‐over study, incorporating 1‐week treatments with E2730 (100 mg/kg/day subcutaneous infusion) or vehicle in epileptic post‐KASE rats. KASE rats underwent serial 9.4 T magnetic resonance spectroscopy (MRS) measuring GABA and other brain metabolites, [18F]Flumazenil positron emission tomography (PET) quantifying GABAA receptor availability, quantitative electroencephalography (qEEG) and transcranial magnetic stimulation (TMS)–mediated motor activity, as well as continuous video‐EEG recording to measure spontaneous seizures during each treatment. Age‐matched, healthy control animals treated with E2730 or vehicle were also studied. Results: E2730 treatment significantly reduced spontaneous seizures, with 8 of 11 animals becoming seizure‐free. MRS revealed that E2730‐treated animals had significantly reduced taurine levels. [18F]Flumazenil PET imaging revealed no changes in GABA receptor affinity or density during E2730 treatment. The power of gamma frequency oscillations in the EEG was decreased significantly in the auditory cortex and hippocampus of KASE and control rats during E2730 treatment. Auditory evoked gamma frequency power was enhanced by E2730 treatment in the auditory cortex of KASE and healthy controls, but only in the hippocampus of KASE rats. E2730 did not influence motor evoked potentials triggered by TMS. Significance: This study identified clinically relevant changes in multimodality imaging and functional purported biomarkers of GABAergic activity during E2730 treatment in epileptic and healthy control animals. These biomarkers could be utilized in clinical trials of E2730 and potentially other GABAergic drugs to provide surrogate endpoints, thereby reducing the cost of such trials. [ABSTRACT FROM AUTHOR]

Proton MRS is used clinically to collect localized, quantitative metabolic data from living tissues. However, the presence of baselines in the spectra complicates accurate MRS data quantification. The occurrence of baselines is not specific to short‐echo‐time MRS data. In short‐echo‐time MRS, the baseline consists typically of a dominating macromolecular (MM) part, and can, depending on B0 shimming, poor voxel placement, and/or localization sequences, also contain broad water and lipid resonance components, indicated by broad components (BCs). In long‐echo‐time MRS, the MM part is usually much smaller, but BCs may still be present. The sum of MM and BCs is denoted by the baseline. Many algorithms have been proposed over the years to tackle these artefacts. A first approach is to identify the baseline itself in a preprocessing step, and a second approach is to model the baseline in the quantification of the MRS data themselves. This paper gives an overview of baseline handling algorithms and also proposes a new algorithm for baseline correction. A subset of suitable baseline removal algorithms were tested on in vivo MRSI data (semi‐LASER at TE = 40 ms) and compared with the new algorithm. The baselines in all datasets were removed using the different methods and subsequently fitted using spectrIm‐QMRS with a TDFDFit fitting model that contained only a metabolite basis set and lacked a baseline model. The same spectra were also fitted using a spectrIm‐QMRS model that explicitly models the metabolites and the baseline of the spectrum. The quantification results of the latter quantification were regarded as ground truth. The fit quality number (FQN) was used to assess baseline removal effectiveness, and correlations between metabolite peak areas and ground truth models were also examined. The results show a competitive performance of our new proposed algorithm, underscoring its automatic approach and efficiency. Nevertheless, none of the tested baseline correction methods achieved FQNs as good as the ground truth model. All separately applied baseline correction methods introduce a bias in the observed metabolite peak areas. We conclude that all baseline correction methods tested, when applied as a separate preprocessing step, yield poorer FQNs and biased quantification results. While they may enhance visual display, they are not advisable for use before spectral fitting. [ABSTRACT FROM AUTHOR]

Objective: The associations between the ratio of blood high-sensitivity C-reactive protein (hs-CRP) to high-density lipoprotein cholesterol (HDL-C) (hs-CRP/HDL-C ratio) and outcomes in patients with acute ischemic stroke (AIS) have yet to be established. This study is the first to examine the relationship between the hs-CRP/HDL-C ratio and three-month unfavorable outcomes in patients with AIS. Methods: This secondary analysis utilized data from a prospective cohort study involving 1559 AIS patients recruited at a South Korean hospital between January 2010 and December 2016. We constructed a binary logistic regression model to explore the association between the hs-CRP/HDL-C ratio and unfavorable outcomes in patients with AIS. An attempt was made to use a generalized additive model (GAM) with smooth curve fitting to elucidate potential nonlinear interactions. Furthermore, inflection points were identified via a recursive method, and binary logistic regression models were developed for each side of these inflection points. Ultimately, a log-likelihood ratio test was used to identify the most appropriate model for explaining the connection between the hs-CRP/HDL-C ratio and unfavorable outcomes in patients with AIS. Results: The incidence of unfavorable outcomes was 24.5%, with a median hs-CRP/HDL-C ratio of 3.64. After accounting for other factors, the binary logistic regression model revealed a statistically significant positive association between the hs-CRP/HDL-C ratio and the likelihood of poor outcomes in AIS patients (OR = 1.013, 95% CI: 1.005–1.022; P = 0.002). A nonlinear relationship was observed, with the first inflection point of the hs-CRP/HDL-C ratio at 42.74. Each 1-unit increase in the hs-CRP/HDL-C ratio was associated with a 2.4% greater risk of unfavorable outcomes (OR = 1.024, 95% CI: 1.011–1.038, P < 0.001). Conclusion: This study provides evidence of a positive and nonlinear correlation between the hs-CRP/HDL-C ratio and poor three-month functional outcomes in AIS patients. When the hs-CRP/HDL-C ratio was less than 42.74, a positive association was observed with the risk of unfavorable outcomes. This finding offers a reference for optimizing early individualized therapy and aids in clinical counseling for patients with AIS. [ABSTRACT FROM AUTHOR]

Background: The carotid artery stenosis (CAS) is a notable risk element for ischemic stroke, accounting for 10 to 20% of such cases. There is a deficiency in research studies exploring the prognostic impact of CAS specifically in the anterior circulation acute ischemic stroke (AIS). Therefore, we conducted this study to evaluate the prognostic impact of CAS in individuals with anterior circulation AIS. Patients were categorized into two groups, patients with both anterior circulation AIS and CAS in comparison to patients with anterior circulation AIS without CAS (control group). We compared patient characteristics, neuroimaging, and outcome evaluations using a modified Rankin Scale (mRS) and the National Institute Health Stroke Scale (NIHSS) in both groups. P-value < 0.05 meaning statistical significance. Results: Fifty patients were involved in the current study; of them, 25 patients with both anterior circulation AIS and CAS and 25 patients with anterior circulation AIS without CAS. Both groups were comparable concerning age, gender, co-morbidities of diabetes, hypertension, smoking, and dyslipidemia with p-value > 0.05. The mean NIHSS was significantly elevated the CAS group compared to the control group (p = 0.037). Our results showed that patients with CAS ≥ 70% were associated with an mRS > 2 and a significantly higher NIHSS compared to control. The regression analysis showed that occlusion > 1/3, CAS ≥ 70%, and higher NIHSS score were considered independent predictors of mRS > 2. The mortality rate was significantly elevated in the CAS group versus the control group (p < 0.05). Both bilateral and unilateral CAS groups were comparable regarding NIHSS and mRS values. Conclusion: Patients with anterior circulation AIS who had CAS of 70% or more, whether unilateral or bilateral, showed a higher likelihood of increased mortality and more severe strokes, as evidenced by elevated NIHSS and mRS scores. [ABSTRACT FROM AUTHOR]

Introduction: Canavan disease (CD) is a rare autosomal recessive neurodegenerative disorder caused by a deficiency of aspartoacylase A, an enzyme that degrades N-acetylaspartate (NAA). The disease is characterized by progressive white matter degeneration, leading to intellectual disability, seizures, and death. This retrospective study aims to describe the full spectrum of magnetic resonance imaging (MRI) findings in a large case series of CD patients. Materials and methods: MRI findings in 18 patients with confirmed CD were investigated, and the full spectrum of brain abnormalities was compared with the existing literature to provide new insights regarding the brain MRI findings in these patients. All the cases were proven based on genetic study or NAA evaluation in urine or brain. Results: Imaging analysis showed involvement of the deep and subcortical white matter as well as the globus pallidus in all cases, with sparing of the putamen, caudate, and claustrum. The study provides updates on the imaging characteristics of CD and validates some underreported findings such as the involvement of the lateral thalamus with sparing of the pulvinar, involvement of the internal capsules and corpus callosum, and cystic formation during disease progression. Conclusion: To our knowledge, this is one of the largest case series of patients with CD which includes a detailed description of the brain MRI findings. The study confirmed many of the previously reported MRI findings but also identified abnormalities that were previously rarely or not described. We speculate that areas of ongoing myelination are particularly vulnerable to changes in CD. [ABSTRACT FROM AUTHOR]

The neuronal tricarboxylic acid and glutamate/glutamine (Glu/Gln) cycles play important roles in brain function. These processes can be measured in vivo using dynamic 1H–[13C] MRS during administration of 13C‐labeled glucose. Proton‐observed carbon‐edited (POCE) MRS enhances the signal‐to‐noise ratio (SNR) compared with direct 13C‐MRS. Ultra‐high field further boosts the SNR and increases spectral dispersion; however, even at 7 T, Glu and Gln 1H‐resonances may overlap. Further gain can be obtained with selective POCE (selPOCE). Our aim was to create a setup for indirect dynamic 1H–[13C] MRS in the human brain at 7 T. A home‐built non‐shielded transmit–receive 13C‐birdcage head coil with eight transmit–receive 1H‐dipole antennas was used together with a 32‐channel 1H‐receive array. Electromagnetic simulations were carried out to ensure that acquisitions remained within local and global head SAR limits. POCE‐MRS was performed using slice‐selective excitation with semi‐localization by adiabatic selective refocusing (sLASER) and stimulated echo acquisition mode (STEAM) localization, and selPOCE‐MRS using STEAM. Sequences were tested in a phantom containing non‐enriched Glu and Gln, and in three healthy volunteers during uniformly labeled 13C‐glucose infusions. In one subject the voxel position was alternated between bi‐frontal and bi‐occipital placement within one session. [4‐13C]Glu‐H4 and [4‐13C]Gln‐H4 signals could be separately detected using both STEAM‐POCE and STEAM‐selPOCE in the phantom. In vivo, [4,5‐13C]Glx could be detected using both sLASER‐POCE and STEAM‐POCE, with similar sensitivities, but [4,5‐13C]Glu and [4,5‐13C]Gln signals could not be completely resolved. STEAM‐POCE was alternately performed bi‐frontal and bi‐occipital within a single session without repositioning of the subject, yielding similar results. With STEAM‐selPOCE, [4,5‐13C]Glu and [4,5‐13C]Gln could be clearly separated. We have shown that with our setup indirect dynamic 1H–[13C] MRS at 7 T is feasible in different locations in the brain within one session, and by using STEAM‐selPOCE it is possible to separate Glu from Gln in vivo while obtaining high quality spectra. [ABSTRACT FROM AUTHOR]

Magnetic resonance spectroscopy (MRS) thermometry offers a noninvasive, localized method for estimating temperature by leveraging the temperature‐dependent chemical shift of water relative to a temperature‐stable reference metabolite under suitable calibration. Consequentially, this technique has significant potential as a tool for postmortem MR examinations in forensic medicine and pathology. In these examinations, the deceased are examined at a wide range of body temperatures, and MRS thermometry may be used for the temperature adjustment of magnetic resonance imaging (MRI) protocols or for corrections in the analysis of MRI or MRS data. However, it is not yet clear to what extent postmortem changes may influence temperature estimation with MRS thermometry. In addition, N‐acetylaspartate, which is commonly used as an in vivo reference metabolite, is known to decrease with increasing postmortem interval (PMI). This study shows that lactate, which is not only present in significant amounts postmortem but also has a temperature‐stable chemical shift, can serve as a suitable reference metabolite for postmortem MRS thermometry. Using lactate, temperature estimation in postmortem brain tissue of severed sheep heads was accurate up to 60 h after death, with a mean absolute error of less than 0.5°C. For this purpose, published calibrations intended for in vivo measurements were used. Although postmortem decomposition resulted in severe metabolic changes, no consistent deviations were observed between measurements with an MR‐compatible temperature probe and MRS thermometry with lactate as a reference metabolite. In addition, MRS thermometry was applied to 84 deceased who underwent a MR examination as part of the legal examination. MRS thermometry provided plausible results of brain temperature in comparison with rectal temperature. Even for deceased with a PMI well above 60 h, MRS thermometry still provided reliable readings. The results show a good suitability of MRS thermometry for postmortem examinations in forensic medicine. [ABSTRACT FROM AUTHOR]

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic medical condition with no specific pharmacological treatment. Creatine, a nutrient essential for maintaining energy homeostasis in the cells, is a candidate for interventions in ME/CFS. Methods: Fourteen participants with ME/CFS received supplementation with 16 g creatine monohydrate for 6 weeks. Before starting creatine and on the last day of treatment, participants underwent brain magnetic resonance spectroscopy (MRS) scanning of the pregenual anterior cingulate cortex (pgACC) and dorsolateral prefrontal cortex (DLPFC), followed by symptom, cognition, and hand-grip strength assessments. Results: Eleven participants completed the study. Creatine treatment increased creatine concentration in both the pgACC and DLPFC (p = 0.004 and 0.012, respectively), decreased fatigue and reaction time (RT) on congruent and incongruent trials of the Stroop test (p = 0.036 and 0.014, respectively), and increased hand-grip strength (p = 0.0004). There was a positive correlation between increases in pgACC creatine and changes in RT on Stroop congruent and incongruent trials (p = 0.048 and p = 0.022, respectively). Creatine was well tolerated, and none of the participants stopped treatment. Conclusion: Creatine supplementation over six weeks in ME/CFS patients increased brain creatine and improved fatigue and some aspects of cognition. Despite its methodological limitations, this study encourages placebo-controlled investigations of creatine treatment in ME/CFS. [ABSTRACT FROM AUTHOR]

The presence of fat within a lesion in the brain is not only easy to identify on both CT/MRI but also can help narrow the differential. The purpose of this paper is to illustrate the spectrum of common and rare fat-containing lesions in the brain that are encountered in clinical practice. This paper intends to discuss 15 such lesions which are confirmed by MRI findings and histopathological correlation. We divided the spectrum of fat-containing lesions into lesions with adipose cells, lesions with cholesterol-rich content and tumours with lipomatous differentiation/transformation. Knowledge of these common and rare fat-containing lesions is essential for making the right diagnosis or narrowing the differential diagnosis. [ABSTRACT FROM AUTHOR]

Stroke is a sudden cerebral root neurologic collapse, a major cause for global morbidity and death, necessitates the use of neuroprotectants to prevent further damage to ischemic decline. Citicoline and piracetam are widely used as neuro-protectives, however their benefits in Acute Ischemic Stroke have not yet been established. This prospective, quasi-experimental study compared the effectiveness of citicoline (Group A) and citicoline with piracetam combination (Group B) in moderate-to-severe patients. 75 patients were divided into two groups (25 in Group A and 50 in Group B) and followed for a period of 90 days. Their cognitive and functioning events were examined using National Institute of Health Stroke Scale (NIHSS), modified Rankin Scale (mRS) and Barthel Index (BI). There is no discernible difference (p > 0.05) amongst the two groups by NIHSS whereas, there was a significant difference (p<0.05) in mRS and BI. After 90 days, Group A patients significantly progressed in terms of overall functional and cognitive improvement. The administration of citicoline within the first 24 hours of a stroke helps to prevent further sequelae and minimizes the severity of AIS. This study concludes that citicoline alone responds better than piracetam combination, but its neuroprotective properties have not been proven. [ABSTRACT FROM AUTHOR]

Background/Objectives: Despite the role of metabolism in breast cancer metastasis, we still cannot predict which breast tumors will progress to distal metastatic lesions or remain dormant. This work uses metabolic imaging to study breast cancer cell lines (4T1, 4T07, and 67NR) with differing metastatic potential in a 3D collagen gel bioreactor system. Methods: Within the bioreactor, hyperpolarized magnetic resonance spectroscopy (HP-MRS) is used to image lactate/pyruvate ratios, while fluorescence lifetime imaging microscopy (FLIM) of endogenous metabolites measures metabolism at the cellular scale. Results: HP-MRS results showed no lactate peak for 67NR and a comparatively large lactate/pyruvate ratio for both 4T1 and 4T07 cell lines, suggestive of greater pyruvate utilization with greater metastatic potential. Similar patterns were observed using FLIM with significant increases in FAD intensity, redox ratio, and NAD(P)H lifetime. The lactate/pyruvate ratio was strongly correlated to NAD(P)H lifetime, consistent with the role of NADH as an electron donor for the glycolytic pathway, suggestive of an overall upregulation of metabolism (both glycolytic and oxidative), for the 4T07 and 4T1 cell lines compared to the non-metastatic 67NR cell line. Conclusions: These findings support a complementary role for HP-MRS and FLIM enabled by a novel collagen gel bioreactor system to investigate metastatic potential and cancer metabolism. [ABSTRACT FROM AUTHOR]

The prevalence of frailty is increasing, and it is associated with increased risk of diseases and adverse outcomes. Although substantial research has focused on post-stroke frailty, understanding of pre-stroke frailty remains limited. Our aim was to synthesize literature on pre-stroke frailty and stroke risk to explore their relationship and impact on prognosis. A systematic search of multiple databases was conducted to identify cohort studies published until October 28, 2023. Meta-analysis was conducted using a random effects model. Heterogeneity was assessed with the I² statistic, and publication bias was evaluated using Begg's test. Finally, we included 11 studies (n = 1,660,328 participants). The pooled hazard ratios (HRs) for stroke risk associated with pre-stroke frailty compared to non-frail individuals was 1.72 (95% confidence interval, CI: 1.46–2.02, p = 0.002, I2 = 69.2%, Begg's test: p = 0.536). The pooled HRs for mortality and the pooled relative risk (RRs) modified Rankin Scale (mRs) associated with pre-stroke frailty were 1.68 (95% CI: 1.10–2.56, p = 0.136, I2 = 49.9%, Begg's test: p = 0.296) and 3.11 (95% CI: 1.77–5.46, p = 0.192, I2 = 39.4%, Begg's test: p = 1.000), respectively. In conclusion, pre-stroke frailty is strongly associated with stroke risk and impacts its prognosis, irrespective of the measurement method. Future research should focus on prospective studies to assess the effects of early intervention for frailty. This has significant implications for primary healthcare services and frailty management. [ABSTRACT FROM AUTHOR]

Cognitive flexibility represents the capacity to switch among different mental schemes, providing an adaptive advantage to a changing environment. The neural underpinnings of this executive function have been deeply studied in humans through fMRI, showing that the left inferior frontal cortex (IFC) and the left inferior parietal lobule (IPL) are crucial. Here, we investigated the inhibitory– excitatory balance in these regions by means of γ-aminobutyric acid (GABA+) and glutamate + glutamine (Glx), measured with magnetic resonance spectroscopy, during a cognitive flexibility task and its relationship with the performance level and the local task-induced blood oxygenation level-dependent (BOLD) response in 40 young (18–35 years; 26 female) and 40 older (18–35 years; 21 female) human adults. As the IFC and the IPL are richly connected regions, we also examined whole-brain effects associated with their local metabolic activity. Results did not show absolute metabolic modulations associated with flexibility performance, but the performance level was related to the direction of metabolic modulation in the IPL with opposite patterns in young and older individuals. The individual inhibitory–excitatory balance modulation showed an inverse relationship with the local BOLD response in the IPL. Finally, the modulation of inhibitory–excitatory balance in IPL was related to whole-brain effects only in older individuals. These findings show disparities in the metabolic mechanisms underlying cognitive flexibility in young and older adults and their association with the performance level and BOLD response. Such metabolic differences are likely to play a role in executive functioning during aging and specifically in cognitive flexibility. [ABSTRACT FROM AUTHOR]

Hyperoxia has been suggested as a mechanism for secondary injury following adult traumatic brain injury (TBI), but its effects have not been well described in pediatric patients. Pediatric (≤18yo) TBI patients were identified in a prospective institutional registry from October 2008 to April 2022. The first, highest, and the Area Under the Curve (AUC) PaO2 in the first 24 hours were collected and calculated for each patient from arterial blood gas reports after admission to the ICU. Neurological outcome after 6 months was measured using dichotomized modified Rankin Scale (mRS) and Glasgow Outcome Scale – Extended (GOS-E). Multivariable logistic regression models were used to determine if the three measurements for hyperoxia predicted an unfavorable outcome after controlling for well-established clinical and imaging predictors of outcome. We identified 98 pediatric patients with severe accidental TBI during the study period. Hyperoxia (PaO2 > 300 mmHg) occurred in 33% of the patients. The presence of elevated PaO2 values, determined by all three evaluations of hyperoxia, was not associated with unfavorable outcome after 6 months. Utilizing multiple methods to assess exposure, hyperoxia was present in a substantial number of patients with severe TBI but was not associated with an unfavorable outcome. [ABSTRACT FROM AUTHOR]

Proton magnetic resonance spectroscopy (1H-MRS) has shown inconsistent alterations in the brain metabolites of individuals with chronic pain. We used 3T 1H-MRS to investigate the brain metabolites in the anterior cingulate cortex and thalamus of 22 patients with chronic mild pain and no gait disturbance and 22 healthy controls. The chronic-pain group included patients with chronic low back pain and/or osteoarthritis but none suffering from hypersensitivity. There were no significant between group-differences in glutamate, glutamate plus glutamine (Glx), N-acetylaspartate, glycerophosphorylcholine (GPC), glutamine, creatine plus phosphocreatine, or myo-inositol in the anterior cingulate cortex, but the patients showed a significant decrease in GPC, but not other metabolites, in the thalamus compared to the controls. The GPC values in the patients' thalamus were significantly correlated with pain components on the Short-Form McGill Pain Questionnaire (SF-MPQ-2) and affective empathy components on the Questionnaire of Cognitive and Affective Empathy (QCAE). The GPC in the patients' anterior cingulate cortex showed significant correlations with cognitive empathy components on the QCAE. Myo-inositol in the controls' anterior cingulate cortex and Glx in the patients' thalamus each showed significant relationships with peripheral responsivity on the QCAE. These significances were not significant after Bonferroni corrections. These preliminary findings indicate important roles of GPC, myo-inositol, and Glx in the brain of patients with chronic mild pain. [ABSTRACT FROM AUTHOR]

Purpose: In vivo quantification of lactate has numerous applications in studying the pathology of both cerebral and musculoskeletal systems. Due to its low concentration (~0.5–1 mM), and overlap with lipid signals, traditional 1H MR spectra acquired in vivo using a small voxel and short echo time often result in an inadequate signal to detect and resolve the lactate peak, especially in healthy human volunteers. Methods: In this study, using a semi‐LASER acquisition with long echo time (TE = 288 ms) and large voxel size (80 × 70 × 20 mm3), we clearly visualize the combined signal of lactate and threonine. Therefore, we call the signal at 1.33 ppm Lac+ and quantify Lac+ concentration from water suppressed spectra in healthy human brains in vivo. Four participants (22–37 years old; mean age = 28 ± 5.4; three male, one female) were scanned on four separate days, and on each day four measurements were taken. Intra‐day values are calculated for each participant by comparing the four measurements on a single day. Inter‐day values were calculated using the mean intra‐day measurements. Results: The mean intra‐participant Lac+ concentration, standard deviation (SD), and coefficient of variation (CV) ranged from 0.49 to 0.61 mM, 0.02 to 0.07 mM, and 4% to 13%, respectively, across four volunteers. The inter‐participant Lac+ concentration, SD, and CV was 0.53 mM, ±0.06 mM, and 11%. Conclusion: Repeatability is shown in Lac+ measurement in healthy human brain using a long echo time semi‐LASER sequence with a large voxel in about 3.5 min at 3 T. [ABSTRACT FROM AUTHOR]

Abstract Objective The associations between the ratio of blood high-sensitivity C-reactive protein (hs-CRP) to high-density lipoprotein cholesterol (HDL-C) (hs-CRP/HDL-C ratio) and outcomes in patients with acute ischemic stroke (AIS) have yet to be established. This study is the first to examine the relationship between the hs-CRP/HDL-C ratio and three-month unfavorable outcomes in patients with AIS. Methods This secondary analysis utilized data from a prospective cohort study involving 1559 AIS patients recruited at a South Korean hospital between January 2010 and December 2016. We constructed a binary logistic regression model to explore the association between the hs-CRP/HDL-C ratio and unfavorable outcomes in patients with AIS. An attempt was made to use a generalized additive model (GAM) with smooth curve fitting to elucidate potential nonlinear interactions. Furthermore, inflection points were identified via a recursive method, and binary logistic regression models were developed for each side of these inflection points. Ultimately, a log-likelihood ratio test was used to identify the most appropriate model for explaining the connection between the hs-CRP/HDL-C ratio and unfavorable outcomes in patients with AIS. Results The incidence of unfavorable outcomes was 24.5%, with a median hs-CRP/HDL-C ratio of 3.64. After accounting for other factors, the binary logistic regression model revealed a statistically significant positive association between the hs-CRP/HDL-C ratio and the likelihood of poor outcomes in AIS patients (OR = 1.013, 95% CI: 1.005–1.022; P = 0.002). A nonlinear relationship was observed, with the first inflection point of the hs-CRP/HDL-C ratio at 42.74. Each 1-unit increase in the hs-CRP/HDL-C ratio was associated with a 2.4% greater risk of unfavorable outcomes (OR = 1.024, 95% CI: 1.011–1.038, P

Abstract Background The carotid artery stenosis (CAS) is a notable risk element for ischemic stroke, accounting for 10 to 20% of such cases. There is a deficiency in research studies exploring the prognostic impact of CAS specifically in the anterior circulation acute ischemic stroke (AIS). Therefore, we conducted this study to evaluate the prognostic impact of CAS in individuals with anterior circulation AIS. Patients were categorized into two groups, patients with both anterior circulation AIS and CAS in comparison to patients with anterior circulation AIS without CAS (control group). We compared patient characteristics, neuroimaging, and outcome evaluations using a modified Rankin Scale (mRS) and the National Institute Health Stroke Scale (NIHSS) in both groups. P-value 0.05. The mean NIHSS was significantly elevated the CAS group compared to the control group (p = 0.037). Our results showed that patients with CAS ≥ 70% were associated with an mRS > 2 and a significantly higher NIHSS compared to control. The regression analysis showed that occlusion > 1/3, CAS ≥ 70%, and higher NIHSS score were considered independent predictors of mRS > 2. The mortality rate was significantly elevated in the CAS group versus the control group (p

Background: Choline, a vital nutrient, and lipids play pivotal roles in liver function and overall metabolic homeostasis. Magnetic resonance spectroscopy (MRS) offers a non-invasive and highly sensitive method for assessing hepatic choline and lipid levels in vivo. This study aims to investigate the correlation between liver choline and lipid levels among young Saudi women. Methods and Results: This cross-sectional research explored the relationship between liver choline and fat levels, employing MRS to estimate these levels. A total of 29 healthy female students from the radiological sciences department, aged between 18 and 25 years, participated in the study. MRS scans were conducted using a 1.5 tesla Philips scanner using single volume sequence (SVS). The SVS spectroscopy sequence used in this study indicated the presence of lipid peaks within the frequency range of 0.9-1.2 ppm and choline peaks at 3.2 ppm. The Pearson correlation test revealed a statistically significant association between choline and lipid levels in the liver (r=0.367, P=0.025). Conclusion: Investigating the relationship between liver lipids and choline levels is crucial for understanding liver health, identifying metabolic dysregulation, informing diagnostic and therapeutic strategies, promoting personalized medicine, and advancing scientific research in the field of metabolism and liver diseases.

Supplemental Digital Content is Available in the Text. Using magnetic resonance spectroscopy, region-specific changes in glutamate and gamma-aminobutyric acid were measured at varying time points outside and during attacks in children and adolescents with migraine. In patients with migraine, an excitation–inhibition imbalance that fluctuates relative to attack onset has been proposed to contribute to the underlying pathophysiology of migraine, but this has yet to be explored in children and adolescents. This prospective, observational, cohort study examined glutamate and gamma-aminobutyric acid (GABA) levels across the phases of a migraine attack and interictally in children and adolescents using magnetic resonance spectroscopy. Macromolecule-suppressed GABA (sensorimotor cortex and thalamus) and glutamate (occipital cortex, sensorimotor cortex, and thalamus) were measured in children and adolescents (10-17 years) with a migraine diagnosis with or without aura 4 times over 2 weeks. Linear mixed-effects models examined changes in glutamate and GABA during the 72 hours leading up to, and after the onset of an attack. We found significant region-specific changes in glutamate and GABA. Specifically, sensorimotor GABA significantly increased leading up to the headache phase, whereas glutamate significantly decreased following the headache onset in the occipital cortex and the thalamus. Post hoc analyses examined the 24 hours leading up to or following the onset of the headache phase. In the 24 hours before the headache onset, sensorimotor glutamate, occipital glutamate, and thalamic GABA decreased. In the 24 hours post headache onset, sensorimotor glutamate continued to decrease. Our results suggest changes in glutamate and GABA that are consistent with the thalamocortical dysrhythmia hypothesis. These findings provide insight into developmental migraine pathophysiology and may open future avenues for treatment targets specific to children and adolescents. [ABSTRACT FROM AUTHOR]

Background: MR spectroscopy (MRS) is a noninvasive tool for evaluating biochemical alterations, such as glutamate (Glu)/gamma‐aminobutyric acid (GABA) imbalance and depletion of antioxidative glutathione (GSH) after traumatic brain injury (TBI). Thalamus, a critical and vulnerable region post‐TBI, is challenging for MRS acquisitions, necessitating optimization to simultaneously measure GABA/Glu and GSH. Purpose: To assess the feasibility and optimize acquisition and processing approaches for simultaneously measuring GABA, Glx (Glu + glutamine (Gln)), and GSH in the thalamus, employing Hadamard encoding and reconstruction of MEscher–GArwood (MEGA)‐edited spectroscopy (HERMES). Study Type: Prospective. Subjects: 28 control subjects (age: 35.9 ± 15.1 years), and 17 mild TBI (mTBI) patients (age: 32.4 ± 11.3 years). Field Strength/Sequence: 3T/T1‐weighted magnetization‐prepared rapid gradient‐echo (MP‐RAGE), HERMES. Assessment: We evaluated the impact of acquisition with spatial saturation bands and post‐processing with spectral alignment on HERMES performance in the thalamus among controls. Within‐subject variability was examined in five controls through repeated scans within a week. The HERMES spectra in the posterior cingulate cortex (PCC) of controls were used as a reference for assessing HERMES performance in a reliable target. Furthermore, we compared metabolite levels and fitting quality in the thalamus between mTBI patients and controls. Statistical Tests: Unpaired t‐tests and within‐subject coefficient‐of‐variation (CV). A P‐value <0.05 was deemed significant. Results: HERMES spectra, acquired with saturation bands and processed with spectral alignment, yielded reliable metabolite measurements in the thalamus. The mean within‐subject CV for GABA, Glx, and GSH levels were 18%, 10%, and 16% in the thalamus (7%, 9%, and 16% in the PCC). GABA (3.20 ± 0.60 vs 2.51 ± 0.55, P < 0.01) and Glx (8.69 ± 1.23 vs 7.72 ± 1.19, P = 0.03) levels in the thalamus were significantly higher in mTBI patients than in controls, with GSH (1.27 ± 0.35 vs 1.22 ± 0.28, P = 0.65) levels showing no significant difference. Data Conclusion: Simultaneous measuring GABA/Glx and GSH using HERMES is feasible in the thalamus, providing valuable insight into TBI. Level of Evidence: 2 Technical Efficacy: Stage 2 [ABSTRACT FROM AUTHOR]

We aim to assess a straightforward technique to enhance spectral quality in the brain, particularly in the cerebellum, during 7 T MRI scans. This is achieved through a wireless RF array insert designed to mitigate signal dropouts caused by the limited transmit field efficiency in the inferior part of the brain. We recently developed a wireless RF array to improve MRI and 1H‐MRS at 7 T by augmenting signal via inductive coupling between the wireless RF array and the MRI coil. In vivo experiments on a Siemens 7 T whole‐body human scanner with a Nova 1Tx/32Rx head coil quantified the impact of the dorsal cervical array in improving signal in the posterior fossa, including the cerebellum, where the transmit efficiency of the coil is inherently low. The 1H‐MRS experimental protocol consisted of paired acquisition of data sets, both with and without the RF array, using the semi‐LASER and SASSI sequences. The overall results indicate that the localized 1H‐MRS is improved significantly in the presence of the array. Comparison of in vivo 1H‐MRS plots in the presence versus absence of the array demonstrated an average SNR enhancement of a factor of 2.2. LCModel analysis reported reduced Cramér–Rao lower bounds, indicating more confident fits. This wireless RF array can significantly increase detection sensitivity. It may reduce the RF transmission power and data acquisition time for 1H‐MRS and MRI applications, specifically at 7 T, where 1H‐MRS requires a high‐power RF pulse. The array could provide a cost‐effective and efficient solution to improve detection sensitivity for human 1H‐MRS and MRI in the regions with lower transmit efficiency. [ABSTRACT FROM AUTHOR]

Background and Aims: Tenecteplase is used as the standard of care treatment for thrombolysis in acute ischemic stroke (AIS) patients within 4.5 h of symptom onset. Documented reports were less certain to claim the benefits of it in an extended window period. EAST-AIS (CTRI/2022/03/040718) trial is designed to determine the success rate of thrombolysis in an extended window period for good clinical outcomes. Study Design: It is a randomized, placebo-controlled trial of tenecteplase administered within 4.5–24 h of stroke onset (with or without large vessel occlusion) based on evidence of salvageable tissue through baseline computed tomography perfusion (CTP) or magnetic resonance imaging (MRI) scan. Criteria of patient inclusion are as follows: patients of both genders (male and female), age >18 years, pre-stroke modified Ranking Scale (mRS) 5, CTP showing penumbra–ischemic core ratio >1.8, absolute difference in volume >10 ml, and ischemic core volume

Abstract Gamma-aminobutyric acid (GABA), the most important inhibitory neurotransmitter in the human brain, has long been considered essential in human behavior in general and learning in particular. GABA concentration can be quantified using magnetic resonance spectroscopy (MRS). Using this technique, numerous studies have reported associations between baseline GABA levels and various human behaviors. However, regional GABA concentration is not fixed and may exhibit rapid modulation as a function of environmental factors. Hence, quantification of GABA levels at several time points during the performance of tasks can provide insights into the dynamics of GABA levels in distinct brain regions. This review reports on findings from studies using repeated measures (n = 41) examining the dynamic modulation of GABA levels in humans in response to various interventions in the perceptual, motor, and cognitive domains to explore associations between GABA modulation and human behavior. GABA levels in a specific brain area may increase or decrease during task performance or as a function of learning, depending on its precise involvement in the process under investigation. Here, we summarize the available evidence and derive two overarching hypotheses regarding the role of GABA modulation in performance and learning. Firstly, training-induced increases in GABA levels appear to be associated with an improved ability to differentiate minor perceptual differences during perceptual learning. This observation gives rise to the ‘GABA increase for better neural distinctiveness hypothesis’. Secondly, converging evidence suggests that reducing GABA levels may play a beneficial role in effectively filtering perceptual noise, enhancing motor learning, and improving performance in visuomotor tasks. Additionally, some studies suggest that the reduction of GABA levels is related to better working memory and successful reinforcement learning. These observations inspire the ‘GABA decrease to boost learning hypothesis’, which states that decreasing neural inhibition through a reduction of GABA in dedicated brain areas facilitates human learning. Additionally, modulation of GABA levels is also observed after short-term physical exercise. Future work should elucidate which specific circumstances induce robust GABA modulation to enhance neuroplasticity and boost performance.

Abstract Background Schizophrenia is a prevalent psychiatric disorder that affects 1% of the global population. Schizophrenia frequently begins in late adolescence or early adulthood, causing significant educational, social, and economic costs for people and society. Functional neuroimaging research on schizophrenia physiopathology has been beneficial. Arterial spin labelling (ASL) is one of functional magnetic resonance imaging (fMRI) technologies that assess brain function without radiation. ASL uses magnetic resonance (MR) imaging to quantify tissue-level brain perfusion non-invasively. Arterial spin labelling (ASL) is one of the functional magnetic resonance imaging (fMRI) technologies that assess the brain function without radiation hazards. ASL uses magnetic resonance (MR) imaging to quantify tissue-level brain perfusion non-invasively. Many publications were performed on role of different advanced MRI techniques in schizophrenia, but our study insisted on the added value of combined ASL and MRS over the conventional MRI in schizophrenic Egyptian population sample. Aim of the work The purpose of this work was to evaluate the added value of combined ASL-perfusion MRI and MRS in schizophrenic patients. Methods This prospective case–control study was carried out on two groups: First group was 30 patients who were diagnosed clinically as schizophrenic patients, and second group was 20 healthy volunteers as a control group for comparison in the period from August 2021 till July 2022. Results The majority of newly diagnosed cases had significant higher positive symptoms than chronic cases. According to arterial spin labelling (ASL) data, rCBF was noticed to be reduced in anterior cingulate, frontal lobe, and parietal lobe of both patients’ subgroups but more significant in chronically ill patients. Convergent results of decreased rCBF were also found in the parietal lobe and occipital lobe. Magnetic resonance spectroscopic analysis showed that NAA was decreased in the anterior cingulate cortex, thalami and basal ganglia of the newly diagnosed cases more than chronic cases. The ASL-MRI perfusion accurately detected the hypo-perfusion of different brain regions with sensitivity 100%, specificity 66.67%, positive predictive value 96.43%, negative predictive value 100%, and accuracy 96.67%, while MR spectroscopy showed sensitivity 100%, specificity 33.33%, positive predictive value 93.10%, negative predictive value 100%, and accuracy 93.33% in evaluation of changes of brain metabolites. Conclusion ASL is a promising functional MRI technique that can produce together with MRS quantitative information about the metabolites of different brain regions. The ASL-MRI appears as a reliable non-invasive technique to measure cerebral blood flow and identify decreased rCBF without any contrast administration, and it could be repeatable which helps in early diagnosis as well as follow-up of the progression of the disease.

Abstract Background Dyslipidemia is one of the main modifiable risk factors for cardiovascular diseases, which accounts for one third of total deaths worldwide. Statin is considered the cornerstone therapy for treating dyslipidemic patients. H1 Cardiac magnetic resonance spectroscopy (MRS) is a special non-invasive, non-irradiating method for assessing myocardial lipid content in vivo in both health and disease. Aim To compare dyslipidemic patients and healthy individuals, and to detect the efficacy of statin on the myocardial lipid content in dyslipidemic patients to detect if there will be changes 6 months after starting statin therapy. Methods Laboratory lipid profile and myocardial lipid content had been measured by H1 MRS in thirty dyslipidemic patients and fifteen healthy matched age and sex individuals as a control group, then dyslipidemic patients were followed up 6 months after statin therapy at Cardiovascular Medicine and Radiology departments; Mansoura University Hospitals, Dakahlia Governorate, Egypt, during the period from January 2020 to October 2022. Results A total of thirty dyslipidemic patients were screened for lipid profile, myocardial lipid content by H1 MRS; 56.67% were male, with a mean age of 49 ± 9.19 years, and compared with fifteen healthy matched age and sex individuals as a control group. Laboratory lipid profile, and triglyceride lipid concentration by MRS were significantly higher in dyslipidemic group before initiating statin therapy compared to control group (p value, 0.001, 0.019 respectively). Median LDL levels were 161.10 ± 30.28 mg/dl before the start of statin therapy and were 114.27 ± 48.33 mg/dl after statin therapy (p

Gamma-aminobutyric acid (GABA), the most important inhibitory neurotransmitter in the human brain, has long been considered essential in human behavior in general and learning in particular. GABA concentration can be quantified using magnetic resonance spectroscopy (MRS). Using this technique, numerous studies have reported associations between baseline GABA levels and various human behaviors. However, regional GABA concentration is not fixed and may exhibit rapid modulation as a function of environmental factors. Hence, quantification of GABA levels at several time points during the performance of tasks can provide insights into the dynamics of GABA levels in distinct brain regions. This review reports on findings from studies using repeated measures (n = 41) examining the dynamic modulation of GABA levels in humans in response to various interventions in the perceptual, motor, and cognitive domains to explore associations between GABA modulation and human behavior. GABA levels in a specific brain area may increase or decrease during task performance or as a function of learning, depending on its precise involvement in the process under investigation. Here, we summarize the available evidence and derive two overarching hypotheses regarding the role of GABA modulation in performance and learning. Firstly, training-induced increases in GABA levels appear to be associated with an improved ability to differentiate minor perceptual differences during perceptual learning. This observation gives rise to the 'GABA increase for better neural distinctiveness hypothesis'. Secondly, converging evidence suggests that reducing GABA levels may play a beneficial role in effectively filtering perceptual noise, enhancing motor learning, and improving performance in visuomotor tasks. Additionally, some studies suggest that the reduction of GABA levels is related to better working memory and successful reinforcement learning. These observations inspire the 'GABA decrease to boost learning hypothesis', which states that decreasing neural inhibition through a reduction of GABA in dedicated brain areas facilitates human learning. Additionally, modulation of GABA levels is also observed after short-term physical exercise. Future work should elucidate which specific circumstances induce robust GABA modulation to enhance neuroplasticity and boost performance. [ABSTRACT FROM AUTHOR]

Background: Evidence from animal and human studies suggests glutamatergic dysfunction in posttraumatic stress disorder (PTSD). The purpose of this study was to investigate glutamate abnormalities in the dorsolateral prefrontal cortex (DLFPC) of individuals with PTSD using 7T MRS, which has better spectral resolution and signal-to-noise ratio than lower field strengths, thus allowing for better spectral quality and higher sensitivity. We hypothesized that individuals with PTSD would have lower glutamate levels compared to trauma-exposed individuals without PTSD and individuals without trauma exposure. Additionally, we explored potential alterations in other neurometabolites and the relationship between glutamate and psychiatric symptoms. Methods: Individuals with PTSD (n = 27), trauma-exposed individuals without PTSD (n = 27), and individuals without trauma exposure (n = 26) underwent 7T MRS to measure glutamate and other neurometabolites in the left DLPFC. The severities of PTSD, depression, anxiety, and dissociation symptoms were assessed. Results: We found that glutamate was lower in the PTSD and trauma-exposed groups compared to the group without trauma exposure. Furthermore, N -acetylaspartate (NAA) was lower and lactate was higher in the PTSD group compared to the group without trauma exposure. Glutamate was negatively correlated with depression symptom severity in the PTSD group. Glutamate was not correlated with PTSD symptom severity. Conclusion: In this first 7T MRS study of PTSD, we observed altered concentrations of glutamate, NAA, and lactate. Our findings provide evidence for multiple possible pathological processes in individuals with PTSD. High-field MRS offers insight into the neurometabolic alterations associated with PTSD and is a powerful tool to probe trauma- and stress-related neurotransmission and metabolism in vivo. [ABSTRACT FROM AUTHOR]

Background: Schizophrenia is a prevalent psychiatric disorder that affects 1% of the global population. Schizophrenia frequently begins in late adolescence or early adulthood, causing significant educational, social, and economic costs for people and society. Functional neuroimaging research on schizophrenia physiopathology has been beneficial. Arterial spin labelling (ASL) is one of functional magnetic resonance imaging (fMRI) technologies that assess brain function without radiation. ASL uses magnetic resonance (MR) imaging to quantify tissue-level brain perfusion non-invasively. Arterial spin labelling (ASL) is one of the functional magnetic resonance imaging (fMRI) technologies that assess the brain function without radiation hazards. ASL uses magnetic resonance (MR) imaging to quantify tissue-level brain perfusion non-invasively. Many publications were performed on role of different advanced MRI techniques in schizophrenia, but our study insisted on the added value of combined ASL and MRS over the conventional MRI in schizophrenic Egyptian population sample. Aim of the work: The purpose of this work was to evaluate the added value of combined ASL-perfusion MRI and MRS in schizophrenic patients. Methods: This prospective case–control study was carried out on two groups: First group was 30 patients who were diagnosed clinically as schizophrenic patients, and second group was 20 healthy volunteers as a control group for comparison in the period from August 2021 till July 2022. Results: The majority of newly diagnosed cases had significant higher positive symptoms than chronic cases. According to arterial spin labelling (ASL) data, rCBF was noticed to be reduced in anterior cingulate, frontal lobe, and parietal lobe of both patients' subgroups but more significant in chronically ill patients. Convergent results of decreased rCBF were also found in the parietal lobe and occipital lobe. Magnetic resonance spectroscopic analysis showed that NAA was decreased in the anterior cingulate cortex, thalami and basal ganglia of the newly diagnosed cases more than chronic cases. The ASL-MRI perfusion accurately detected the hypo-perfusion of different brain regions with sensitivity 100%, specificity 66.67%, positive predictive value 96.43%, negative predictive value 100%, and accuracy 96.67%, while MR spectroscopy showed sensitivity 100%, specificity 33.33%, positive predictive value 93.10%, negative predictive value 100%, and accuracy 93.33% in evaluation of changes of brain metabolites. Conclusion: ASL is a promising functional MRI technique that can produce together with MRS quantitative information about the metabolites of different brain regions. The ASL-MRI appears as a reliable non-invasive technique to measure cerebral blood flow and identify decreased rCBF without any contrast administration, and it could be repeatable which helps in early diagnosis as well as follow-up of the progression of the disease. [ABSTRACT FROM AUTHOR]

Background Persistent cognitive deficits and functional impairments are associated with bipolar disorder (BD), even during the euthymic phase. The dysfunction of default mode network (DMN) is critical for self-referential and emotional mental processes and is implicated in BD. The current study aims to explore the balance of excitatory and inhibitory neurotransmitters, i.e. glutamate and γ -aminobutyric acid (GABA), in hubs of the DMN during the euthymic patients with BD (euBD). Method Thirty-four euBD and 55 healthy controls (HC) were recruited to the study. Using proton magnetic resonance spectroscopy (1 H-MRS), glutamate (with PRESS sequence) and GABA levels (with MEGAPRESS sequence) were measured in the medial prefrontal cortex/anterior cingulate cortex (mPFC/ACC) and the posterior cingulate gyrus (PCC). Measured concentrations of excitatory glutamate/glutamine (Glx) and inhibitory GABA were used to calculate the excitatory/inhibitory (E / I) ratio. Executive and attentional functions were respectively assessed using the Wisconsin card-sorting test and continuous performance test. Results euBD performed worse on attentional function than controls (p = 0.001). Compared to controls, euBD had higher E / I ratios in the PCC (p = 0.023), mainly driven by a higher Glx level in the PCC of euBD (p = 0.002). Only in the BD group, a marginally significant negative association between the mPFC E / I ratio (Glx/GABA) and executive function was observed (p = 0.068). Conclusions Disturbed E/I balance, particularly elevated Glx/GABA ratio in PCC is observed in euBD. The E / I balance in hubs of DMN may serve as potential biomarkers for euBD, which may also contribute to their poorer executive function. [ABSTRACT FROM AUTHOR]

Clozapine is the only antipsychotic approved for treating treatment-resistant schizophrenia (TRS), characterized by persistent positive symptoms despite adequate antipsychotic treatment. Unfortunately, clozapine demonstrates clinical efficacy in only ~30–60 % of patients with TRS (clozapine-responders; ClzR+), while the remaining ~40–70 % are left with no pharmacological recourse for improvement (clozapine-resistant; ClzR−). Mechanism(s) underlying clozapine's superior efficacy remain unclear. However, in vitro evidence suggests clozapine may mitigate glutamatergic dysregulations observed in TRS, by modulating astrocyte activity in ClzR+, but not ClzR−. A factor that if proven correct, may help the assessment of treatment response and development of more effective antipsychotics. To explore the presence of clozapine-astrocyte interaction and clinical improvement, we used 3 T proton-magnetic resonance spectroscopy to quantify levels of myo-Inositol, surrogate biomarker of astrocyte activity, in regions related to schizophrenia neurobiology: Dorsal-anterior-cingulate-cortex (dACC), left-dorsolateral-prefrontal-cortex (left-DLPFC), and left-striatum (left-striatum) of 157 participants (ClzR− = 30; ClzR+ = 37; responders = 38; controls = 52). Clozapine treatment was assessed using clozapine to norclozapine plasma levels, 11–12 h after last clozapine dose. Measures for symptom severity (i.e., Positive and Negative Symptoms Scale) and cognition (i.e., Mini-Mental State Examination) were also recorded. Higher levels of myo-Inositol were observed in TRS groups versus responders and controls (dACC (p < 0.001); left-striatum (p = 0.036); left-DLPFC (p = 0.023)). In ClzR+, but not ClzR−, clozapine to norclozapine ratios were positively associated with myo-Inositol levels (dACC (p = 0.004); left-DLPFC (p < 0.001)), and lower positive symptom severity (p < 0.001). Our results support growing in vitro evidence of clozapine-astrocyte interaction in clozapine-responders. Further research may determine the viability of clozapine-astrocyte interactions as an early marker of clozapine response. [ABSTRACT FROM AUTHOR]

Background: Dyslipidemia is one of the main modifiable risk factors for cardiovascular diseases, which accounts for one third of total deaths worldwide. Statin is considered the cornerstone therapy for treating dyslipidemic patients. H1 Cardiac magnetic resonance spectroscopy (MRS) is a special non-invasive, non-irradiating method for assessing myocardial lipid content in vivo in both health and disease. Aim: To compare dyslipidemic patients and healthy individuals, and to detect the efficacy of statin on the myocardial lipid content in dyslipidemic patients to detect if there will be changes 6 months after starting statin therapy. Methods: Laboratory lipid profile and myocardial lipid content had been measured by H1 MRS in thirty dyslipidemic patients and fifteen healthy matched age and sex individuals as a control group, then dyslipidemic patients were followed up 6 months after statin therapy at Cardiovascular Medicine and Radiology departments; Mansoura University Hospitals, Dakahlia Governorate, Egypt, during the period from January 2020 to October 2022. Results: A total of thirty dyslipidemic patients were screened for lipid profile, myocardial lipid content by H1 MRS; 56.67% were male, with a mean age of 49 ± 9.19 years, and compared with fifteen healthy matched age and sex individuals as a control group. Laboratory lipid profile, and triglyceride lipid concentration by MRS were significantly higher in dyslipidemic group before initiating statin therapy compared to control group (p value, 0.001, 0.019 respectively). Median LDL levels were 161.10 ± 30.28 mg/dl before the start of statin therapy and were 114.27 ± 48.33 mg/dl after statin therapy (p < 0.001). There was a statistically significant reduction in triglyceride lipid concentration in dyslipidemic patients after 6 months of statin therapy: from 0.011 (0.001–0.55 (mmol/l), to 0.0025 (0.001–0.04 mmol/l) with a p value < 0.001. Conclusions: Increased myocardial lipid content as measured by magnetic resonance spectroscopy was demonstrated in dyslipidemic patients in our study that decreased after 6 months of statin therapy. [ABSTRACT FROM AUTHOR]

Background and Aims: Tenecteplase is used as the standard of care treatment for thrombolysis in acute ischemic stroke (AIS) patients within 4.5 h of symptom onset. Documented reports were less certain to claim the benefits of it in an extended window period. EAST-AIS (CTRI/2022/03/040718) trial is designed to determine the success rate of thrombolysis in an extended window period for good clinical outcomes. Study Design: It is a randomized, placebo-controlled trial of tenecteplase administered within 4.5-24 h of stroke onset (with or without large vessel occlusion) based on evidence of salvageable tissue through baseline computed tomography perfusion (CTP) or magnetic resonance imaging (MRI) scan. Criteria of patient inclusion are as follows: patients of both genders (male and female), age >18 years, pre-stroke modified Ranking Scale (mRS) <2, baseline NIHSS >5, CTP showing penumbra--ischemic core ratio >1.8, absolute difference in volume >10 ml, and ischemic core volume <70 ml. The sample size for the study is 100 patients: 50 in the tenecteplase arm (0.25 mg/kg body weight; maximum- 25 mg) and 50 in the placebo arm (controls). Study Outcomes: The study's primary objective is safety endpoints along with the efficacy of tenecteplase assessed using the mRS score at 90 days of stroke onset. Conclusion: The result obtained from EAST-AIS will determine the safety and efficacy of tenecteplase injection administered 4.5-24 h following the symptom onset for AIS patients within the territory of Internal Carotid Artery (ICA), Middle Cerebral Artery (MCA), or Anterior Cerebral Artery (ACA) occlusion. [ABSTRACT FROM AUTHOR]

Background and Purpose: Transcranial Doppler (TCD) identifies acute stroke patients with arterial occlusion where treatment may not effectively open the blocked vessel. This study aimed to examine the clinical utility and prognostic value of TCD flow findings in patients enrolled in a multicenter prospective study (CLOTBUST‐PRO). Methods: Patients enrolled with intracranial occlusion on computed tomography angiography (CTA) who underwent urgent TCD evaluation before intravenous thrombolysis was included in this analysis. TCD findings were assessed using the mean flow velocity (MFV) ratio, comparing the reciprocal ratios of the middle cerebral artery (MCA) depths bilaterally (affected MCA‐to‐contralateral MCA MFV [aMCA/cMCA MFV ratio]). Results: A total of 222 patients with intracranial occlusion on CTA were included in the study (mean age: 64 ± 14 years, 62% men). Eighty‐eight patients had M1 MCA occlusions; baseline mean National Institutes of Health Stroke Scale (NIHSS) score was 16, and a 24‐hour mean NIHSS score was 10 points. An aMCA/cMCA MFV ratio of <.6 had a sensitivity of 99%, specificity of 16%, positive predictive value (PV) of 60%, and negative PV of 94% for identifying large vessel occlusion (LVO) including M1 MCA, terminal internal carotid artery, or tandem ICA/MCA. Thrombolysis in Brain Ischemia scale, with (grade ≥1) compared to without flow (grade 0), showed a sensitivity of 17.1%, specificity of 86.9%, positive PV of 62%, and negative PV of 46% for identifying LVO. Conclusions: TCD is a valuable modality for evaluating arterial circulation in acute ischemic stroke patients, demonstrating significant potential as a screening tool for intravenous/intra‐arterial lysis protocols. [ABSTRACT FROM AUTHOR]

To compare the GABA+/Glx (glutamate-glutamine) ratio in the prefrontal lobe under non-rapid eye movement sleep between patients with narcolepsy type 1 (NT1) and normal controls and explore the correlation between this difference and abnormal cognitive function, using synchronous electroencephalography-functional magnetic resonance spectroscopy (EEG-fMRS). MRS measurements of GABA+ and Glx concentrations as well as synchronous EEG data were obtained from 26 medication-naive patients with NT1 and 29 sex- and age-matched healthy community volunteers. Cognition was appraised with the Beijing version of the Montreal Cognitive Assessment, and daytime sleepiness was measured using the Epworth Sleepiness Scale. All subjects recorded a 2-week sleep log as well as an overnight polysomnography within 1 week before MR scanning to understand their sleep habits and determine sleep stages. After PSG, they also underwent multiple sleep latency trials. Patient/control group differences in the individual measurements of GABA+ and Glx and the GABA+/Glx ratio and their relationship with cognition were assessed. The GABA+/Glx ratio and GABA + levels of patients with narcolepsy were higher than those of the control group (P＜0.0001 and P = 0.0008, respectively). However, there was no significant difference in Glx levels (P = 0.6360). The GABA+/Glx ratio negatively correlated with abnormal cognitive function (r = −0.6710, P = 0.0002). Moreover, GABA + levels were inversely proportional to rapid eye movement sleep latency (REML) in patients with narcolepsy (r = −0.5019, P = 0.0106). The GABA+/Glx ratio in the prefrontal lobe was higher in NT1 patients during N2 sleep than in normal controls, mainly caused by GABA + levels; this ratio was negatively related to abnormal cognitive function. In addition, GABA + levels were inversely proportional to REML. • Narcolepsy type 1 affects GABA+ and Glx levels in the medial prefrontal cortex. • GABA+/Glx ratio is higher during the N2 sleep phase in patients with narcolepsy. • GABA+/Glx ratio is correlated with abnormal cognitive function in narcolepsy. • GABA + levels are inversely proportional to rapid eye movement sleep latency in patients with narcolepsy. [ABSTRACT FROM AUTHOR]

Several studies have suggested that atypical social processing in neurodevelopmental conditions (e.g. autism) is associated with differences in excitation and inhibition, through changes in the levels of glutamate and gamma‐aminobutyric acid (GABA). While associations between baseline metabolite levels and behaviours can be insightful, assessing the neurometabolic response of GABA and glutamate during social processing may explain altered neurochemical function in more depth. Thus far, there have been no attempts to determine whether changes in metabolite levels are detectable using functional MRS (fMRS) during social processing in a control population. We performed Mescher–Garwood point resolved spectroscopy edited fMRS to measure the dynamic response of GABA and glutamate in the superior temporal sulcus (STS) and visual cortex (V1) while viewing social stimuli, using a design that allows for analysis in both block and event‐related approaches. Sliding window analyses were used to investigate GABA and glutamate dynamics at higher temporal resolution. The changes of GABA and glutamate levels with social stimulus were largely non‐significant. A small decrease in GABA levels was observed during social stimulus presentation in V1, but no change was observed in STS. Conversely, non‐social stimulus elicited changes in both GABA and glutamate levels in both regions. Our findings suggest that the current experimental design primarily captures effects of visual stimulation, not social processing. Here, we discuss the feasibility of using fMRS analysis approaches to assess changes in metabolite response. [ABSTRACT FROM AUTHOR]

Purpose: To understand how macromolecular content varies in the human brain with age in a large cohort of healthy subjects. Methods: In‐vivo 1H‐MR spectra were acquired using ultra‐short TE STEAM at 7T in the posterior cingulate cortex. Macromolecular content was studied in 147 datasets from a cohort ranging in age from 19 to 89 y. Three fitting approaches were used to evaluate the macromolecular content: (1) a macromolecular resonances model developed for this study; (2) LCModel‐simulated macromolecules; and (3) a combination of measured and LCModel‐simulated macromolecules. The effect of age on the macromolecular content was investigated by considering age both as a continuous variable (i.e., linear regressions) and as a categorical variable (i.e., multiple comparisons among sub‐groups obtained by stratifying data according to age by decade). Results: While weak age‐related effects were observed for macromolecular peaks at ˜0.9 (MM09), ˜1.2 (MM12), and ˜1.4 (MM14) ppm, moderate to strong effects were observed for peaks at ˜1.7 (MM17), and ˜2.0 (MM20) ppm. Significantly higher MM17 and MM20 content started from 30 to 40 y of age, while for MM09, MM12, and MM14, significantly higher content started from 60 to 70 y of age. Conclusions: Our findings provide insights into age‐related differences in macromolecular contents and strengthen the necessity of using age‐matched measured macromolecules during quantification. [ABSTRACT FROM AUTHOR]

Ischemic stroke is a significant public health concern, with its incidence expected to double over the next 40 years, particularly among individuals over 75 years old. Previous studies, such as the DAWN trial, have highlighted the importance of correlating clinical severity with ischemic stroke volume to optimize patient management. Our study aimed to correlate the clinical severity of ischemic stroke, as assessed by the NIHSS score, with ischemic stroke volume measured using DWI, and short-term prognosis quantified by the mRS score at discharge. Conducted at the largest hospital in Gorj County from January 2023 to December 2023, this study enrolled 43 consecutive patients with acute ischemic stroke. In our patient cohort, we observed a strong positive correlation between NIHSS score and ischemic stroke volume (Spearman correlation coefficient = 0.982, p < 0.01), and a strong negative correlation between ASPECTS-DWI score and mRS score (Spearman correlation coefficient = −0.952, p < 0.01). Multiple linear regression analysis revealed a significant collective relationship between ASPECTS score, ischemic stroke volume, and NIHSS score (F(1, 41) = 600.28, p < 0.001, R2 = 0.94, R2adj = 0.93). These findings underscore the importance of DWI in assessing ischemic stroke severity and prognosis, warranting further investigation for its integration into clinical practice. [ABSTRACT FROM AUTHOR]

Background: Comprehensive stroke centers (CSC) offer state-of-the-art stroke care in metropolitan centers. However, in rural areas, sufficient stroke expertise is much scarcer. Recently, telemedical stroke networks have offered instant consultation by stroke experts, enabling immediate administration of intravenous thrombolysis (IVT) on-site and decision on thrombectomy. While these immediate decisions are made during the consult, the impact of the network structures on stroke care in spoke hospitals is still not well described. Aims: This study was performed to determine if on-site performance in rural hospitals and patient outcome improve over time through participation and regular medical staff training within a telemedical stroke network. Methods: In this retrospective study, we analyzed data from stroke patients treated in four regional hospitals within the telemedical Neurovascular Network of Southwest Bavaria (NEVAS) between 2014 and 2019. We only included those patients that were treated in the regional hospitals until discharge at home or to neurorehabilitation. Functional outcome (modified Rankin scale) at discharge, mortality rate and periprocedural intracranial hemorrhage served as primary outcome parameters. Door-to-imaging and door-to-needle times were secondary outcome parameters. Results: In 2014–2019, 5,379 patients were treated for acute stroke with 477 receiving IVT. Most baseline characteristics were comparable over time. For all stroke patients, door-to-imaging times increased over the years, but significantly improved for potential IVT candidates and those finally treated with IVT. The percentage of patients with door-to-needle time <30 min increased from 10% to 25%. Clinical outcome at discharge improved for all stroke patients treated in the regional hospitals. Particularly for patients treated with IVT, good clinical outcome (modified Rankin scale 0–2) at discharge increased from 2014 to 2019 by 19% and mortality rates dropped from 13% to 5%. Conclusions: 24-h/7-day telemedical support and regular on-site medical staff training within a structured telemedicine stroke network such as NEVAS significantly improve on-site stroke care in rural areas, leading to a considerable benefit in clinical outcome. Data access statement: The data that support the findings of this study are available upon reasonable request and in compliance with the local and international ethical guidelines. [ABSTRACT FROM AUTHOR]

Simple Summary: Cervical cancer is the fourth most prominent cancer in women worldwide. Early cancer detection, timely treatment, and prognostic marker identification are vital to ensure that patients have improved outcomes. Magnetic resonance spectroscopy (MRS) is a powerful tool for detecting metabolites in vivo. This review article covers the role of MRS for cervical cancer for diagnosis, treatment response evaluation, and future applications of this technology. This review article investigates the utilization of MRS in the setting of cervical cancer. A variety of different techniques have been used in this space including single-voxel techniques such as point-resolved spectroscopy (PRESS) and stimulated echo acquisition mode spectroscopy (STEAM). Furthermore, the experimental parameters for these acquisitions including field strength, repetition times (TR), and echo times (TE) vary greatly. This study critically examines eleven MRS studies that focus on cervical cancer. Out of the eleven studies, ten studies utilized PRESS acquisition, while the remaining study used STEAM acquisition. These studies generally showed that the choline signal is altered in cervical cancer (4/11 studies), the lipid signal is generally increased in cervical cancer or the lipid distribution is changed (5/11 studies), and that diffusion-weighted imaging (DWI) can quantitatively detect lower apparent diffusion coefficient (ADC) values in cervical cancer (2/11 studies). Two studies also investigated the role of MRS for monitoring treatment response and demonstrated mixed results regarding choline signal, and one of these studies showed increased lipid signal for non-responders. There are several new MRS technologies that have yet to be implemented for cervical cancer including advanced spectroscopic imaging and artificial intelligence, and those technologies are also discussed in the article. [ABSTRACT FROM AUTHOR]

The latest research into the pathophysiology of Alzheimer's Disease (AD) has included several cognitive deficits related to hippocampal functioning. However, current clinical research fails to consider the full extent of the heterogeneous cognitive spectrum of AD, resulting in a lack of the specific methods required to draw definitive diagnostic and therapeutic conclusions. This also includes in-vivo metabolic measurements for tailoring the diagnostic and therapeutic regimens in humans with AD. Magnetic resonance spectroscopy and repetitive transcranial magnetic stimulation (rTMS) are two novel diagnostic and therapeutic approaches that must be modified to treat AD. In the present study, we aimed to investigate the underlying therapeutic role of rTMS in humans with AD by evaluating the in-vivo hippocampal metabolites before and after rTMS treatment. Based on the data obtained using the fMRI data in our previous study and on the references reported in the literature, in the present study, we decided to use hippocampal NAA data after rTMS stimulation and found a significant increase in NAA levels. To the best of our knowledge, no other study has evaluated the effect of rTMS on hippocampal metabolites in humans with AD. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Melkersson–Rosenthal syndrome can cause recurring bilateral facial paralysis. When steroids fail, surgical decompression of facial nerve is recommended, with endoscopic trans‐canal decompression as a safe, minimally invasive, and effective option. Melkersson–Rosenthal syndrome (MRS) is a rare neuro‐mucocutaneous disorder, clinically diagnosed by a triad of orofacial swelling, recurrent facial palsy, and fissured tongue. Due to the lack of a comprehensive understanding of MRS, there is no accepted standard of care. In this study we report a 30‐year‐old female patient, who was referred to the otolaryngology clinic of Rasool Akram Hospital, with classical triad of MRS that was managed by endoscopic trans‐canal facial nerve decompression. Bilateral endoscopic trans‐canal facial nerve decompression was done when we did not find any improvement with systemic steroids. Endoscopic trans‐canal facial nerve decompression could be a safe, reliable minimal invasive treatment of facial paralysis in MRS patients. It needs no external incision or temporal bone drilling which makes this method more convenient for patients with shorter recovery time. [ABSTRACT FROM AUTHOR]

We are developing transflective LCD displays for signage that have good outdoor visibility and super‐low power consumption. This panel adopts a design that incorporates our technologies such as TFT, twisted‐VA technology, and MRS structure that can be driven at super‐low frequencies using IGZO technology. We would like to report that we have developed a 54.5‐inch transflective LCD. [ABSTRACT FROM AUTHOR]

Purpose: Dynamic (2D) MRS is a collection of techniques where acquisitions of spectra are repeated under varying experimental or physiological conditions. Dynamic MRS comprises a rich set of contrasts, including diffusion-weighted, relaxation-weighted, functional, edited, or hyperpolarized spectroscopy, leading to quantitative insights into multiple physiological or microstructural processes. Conventional approaches to dynamic MRS analysis ignore the shared information between spectra, and instead proceed by independently fitting noisy individual spectra before modeling temporal changes in the parameters. Here, we propose a universal dynamic MRS toolbox which allows simultaneous fitting of dynamic spectra of arbitrary type. Methods:Asimple user-interface allows information to be shared and precisely modeled across spectra to make inferences on both spectral and dynamic processes. We demonstrate and thoroughly evaluate our approach in three types of dynamic MRS techniques. Simulations of functional and edited MRS are used to demonstrate the advantages of dynamic fitting. Results: Analysis of synthetic functional ¹H-MRS data shows a marked decrease in parameter uncertainty as predicted by prior work. Analysis with our tool replicates the results of two previously published studies using the original in vivo functional and diffusion-weighted data. Finally, joint spectral fitting with diffusion orientation models is demonstrated in synthetic data. Conclusion: A toolbox for generalized and universal fitting of dynamic, interrelated MR spectra has been released and validated. The toolbox is shared as a fully open-source software with comprehensive documentation, example data, and tutorials. [ABSTRACT FROM AUTHOR]

BackgroundAlthough proton magnetic resonance spectroscopy (MRS) has been used to study metabolite alterations in stimulant (methamphetamine and cocaine) substance use disorders (SUDs) for over 25 years, data-driven consensus regarding the nature and magnitude of these alterations is lacking.MethodIn this meta-analysis, we examined associations between SUD and regional metabolites (N-acetyl aspartate (NAA), choline, myo-inositol, creatine, glutamate, and glutamate+glutamine (glx)) in the medial prefrontal cortex (mPFC), frontal white matter (FWM), occipital cortex, and basal ganglia as measured by 1 H-MRS. We also examined moderating effects of MRS acquisition parameters (echo time (TE), field strength), data quality (coefficient of variation (COV)), and demographic/clinical variables.ResultsA MEDLINE search revealed 28 articles that met meta-analytic criteria. Significant effects included lower mPFC NAA, higher mPFC myo-inositol, and lower mPFC creatine in SUD relative to people without SUD. mPFC NAA effects were moderated by TE, with larger effects at longer TEs. For choline, although no group effects were observed, effect sizes in the mPFC were related to MRS technical indicators (field strength, COV). No effects of age, sex, primary drug of use (methamphetamine vs. cocaine), duration of use, or duration of abstinence were observed. Evidence for moderating effects of TE and COV may have implications for future MRS studies in SUDs.ConclusionsThe observed metabolite profile in methamphetamine and cocaine SUD (lower NAA and creatine with higher myo-inositol) parallels that observed in Alzheimer's disease and mild cognitive impairment, suggesting these drugs are associated with neurometabolic differences similar to those characterizing these neurodegenerative conditions.

ObjectiveThis study aimed to determine whether brain volume at the time of ischemic stroke injury is a better biomarker for predicting functional outcomes than brain atrophy.BackgroundBrain parenchymal fraction (BPF) has been used as a surrogate measure of global brain atrophy and a neuroimaging biomarker of brain reserve in studies evaluating clinical outcomes after brain injury. Brain volume itself is affected by natural aging, cardiovascular risk factors, and biological sex, among other factors. Recent studies have shown that brain volume at the time of injury can influence functional outcomes, with larger brain volumes being associated with better outcomes.MethodsAcute ischemic stroke cases at a single center between 2003 and 2011, with neuroimaging obtained within 48 h of presentation were eligible for the study. Functional outcomes represented by the modified Rankin Scale (mRS) score at 90 days post-admission (mRS score ≤ 2 deemed a favorable outcome) were obtained through patient interviews or per chart review. Deep learning–enabled automated segmentation pipelines were used to calculate brain volume, intracranial volume, and BPF on the acute neuroimaging data. Patient outcomes were modeled through logistic regressions, and a model comparison was conducted using the Bayes information criterion (BIC).ResultsA total of 467 patients with arterial ischemic stroke were included in the analysis, with a median age of 65.8 years and 65.3% of the participants being male. In both models, age and a larger stroke lesion volume were associated with worse functional outcomes. Higher BPF and a larger brain volume were associated with favorable functional outcomes; however, a comparison of both models suggested that the brain volume model (BIC = 501) better explains the data than the BPF model (BIC = 511).ConclusionThe extent of global brain atrophy (and its surrogate biomarker BPF) has been regarded as an important biomarker for predicting functional post-stroke outcomes and resilience to acute injury. In this study, we demonstrate that a higher global brain volume at the time of injury better explains favorable functional outcomes, which can be directly measured in a clinical setting.