Although specific risk factors for brain alterations in bipolar disorders (BD) are currently unknown, obesity impacts the brain and is highly prevalent in BD. Gray matter correlates of obesity in BD have been well documented, but we know much less about brain white matter abnormalities in people who have both obesity and BD. We obtained body mass index (BMI) and diffusion tensor imaging derived fractional anisotropy (FA) from 22 white matter tracts in 899 individuals with BD, and 1287 control individuals from 20 cohorts in the ENIGMA-BD working group. In a mega-analysis, we investigated the associations between BMI, diagnosis or medication and FA. Lower FA was associated with both BD and BMI in six white matter tracts, including the corpus callosum and thalamic radiation. Higher BMI or BD were uniquely associated with lower FA in three and six white matter tracts, respectively. People not receiving lithium treatment had a greater negative association between FA and BMI than people treated with lithium in the posterior thalamic radiation and sagittal stratum. In three tracts BMI accounted for 10.5 to 17% of the negative association between the number of medication classes other than lithium and FA. Both overweight/obesity and BD demonstrated lower FA in some of the same regions. People prescribed lithium had a weaker association between BMI and FA than people not on lithium. In contrast, greater weight contributed to the negative associations between medications and FA. Obesity may add to brain alterations in BD and may play a role in effects of medications on the brain.
- MeSH
- Anisotropy MeSH
- White Matter * pathology diagnostic imaging metabolism MeSH
- Bipolar Disorder * pathology metabolism MeSH
- Adult MeSH
- Body Mass Index MeSH
- Middle Aged MeSH
- Humans MeSH
- Brain pathology MeSH
- Obesity * pathology metabolism complications MeSH
- Gray Matter MeSH
- Diffusion Tensor Imaging methods MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
Glymphatic dysfunction potentially contributes to Parkinson's disease (PD) via impaired clearance of metabolic waste products. Obstructive sleep apnea (OSA) can disturb sleep, which is necessary for proper glymphatic function, and is frequent in PD. We investigated the glymphatic function in de novo PD and its relation to OSA. Fifty-four PD patients (mean age 58.9 ± 12.2 years) and 32 controls (mean age 59.4 ± 8.3 years) underwent polysomnography and 3 T magnetic resonance imaging of the brain. Diffusion tensor imaging along the perivascular space (DTI-ALPS) was calculated using atlas-based automatic regions of interest selection. In PD, ALPS-index negatively correlated with apnea-hypopnea index (rho = -0.41; p = 0.002), oxygen desaturation index (rho = -0.38; p = 0.006), sleep stage N1 (rho = -0.42; p = 0.002), and arousal index (rho = -0.24; p = 0.018), while in controls, no such correlations were observed. Glymphatic dysfunction is related to OSA severity in de novo PD but not in controls. We suggest that OSA may contribute to neurodegeneration via glymphatic impairment in PD.
- Publication type
- Journal Article MeSH
Diffusion tensor image analysis along the perivascular space (DTI-ALPS) is a potential non-invasive marker of glymphatic function that typically relies on manual region of interest (ROI) placement. This study compared ALPS indices in treatment-naïve, de novo diagnosed patients with Parkinson's disease (PD), patients with isolated REM behavior disorder (iRBD), and healthy controls using both manual and automatic approaches to the ROI selection used in ALPS-index calculation. ALPS indices were analyzed bilaterally and correlated with clinical severity (MDS-UPDRS) and nigrostriatal denervation (DAT-SPECT). ANCOVA revealed significant inter-group differences using both manual (p = 0.018) and automatic (p = 0.002) ROI selection methods. The automatic ROI selection approach showed significantly lower ALPS indices in PD compared to controls (p = 0.001) and iRBD (p = 0.009). ALPS indices correlated with symptom severity and nigrostriatal denervation. These findings underscore the reliability of the automatic ROI placement approach for ALPS index calculation and may indicate early glymphatic alterations in Parkinson's disease.
- Publication type
- Journal Article MeSH
BACKGROUND AND PURPOSE: The primary objective was to compare diffusion tensor imaging (DTI) scalar parameters of peripheral nerves between subjects with type 2 diabetes mellitus (T2DM) and those without diabetes. Secondarily, we aimed to correlate DTI scalar parameters with nerve morphometric properties. METHODS: Median, tibial, and sural nerves were harvested from 34 male cadavers (17 T2DM, 17 nondiabetic). Each nerve was divided into three segments. The initial segment was scanned using 9.4 Tesla MRI system (three-dimensional pulsed-gradient spin-echo sequence). DTI scalars were calculated from region-average diffusion-weighted signals. Second segment was optically cleared, acquired with optical projection tomography (OPT), and analyzed for morphometrical properties. Toluidine-stained sections were prepared from last segment, and axon- and myelin-related properties were evaluated. RESULTS: DTI scalar parameters of median and tibial nerves were comparable between the groups, while sural nerves of T2DM exhibited on average 41% higher mean diffusivity (MD) (p = 0.03), 38% higher radial diffusivity (RD) (p = 0.03), and 27% lower fractional anisotropy (FA) (p = 0.005). Significant differences in toluidine-evaluated parameters of sural nerves were observed between the groups, with a positive correlation between FA with fiber density (p = 0.0001) and with myelin proportion (p < 0.0001) and an inverse correlation between RD and myelin proportion (p = 0.003). OPT-measured morphometric properties did not correlate with DTI scalar parameters. CONCLUSIONS: High-field DTI shows promise as an imaging technique for detecting axonal and myelin-related changes in small sural nerves ex vivo. The reduced fiber density and decreased myelin content, which can be observed in T2DM, likely contribute to observed FA reduction and increased MD/RD.
- MeSH
- Diabetes Mellitus, Type 2 * diagnostic imaging pathology MeSH
- Diabetic Neuropathies diagnostic imaging pathology MeSH
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Cadaver * MeSH
- Median Nerve diagnostic imaging pathology MeSH
- Sural Nerve * diagnostic imaging pathology MeSH
- Tibial Nerve diagnostic imaging pathology MeSH
- Reproducibility of Results MeSH
- Aged MeSH
- Sensitivity and Specificity MeSH
- Diffusion Tensor Imaging * methods MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged MeSH
- Publication type
- Journal Article MeSH
BACKGROUND AND PURPOSE: White matter changes assessed by DTI typically reflect tract functionality. This study aimed to investigate DTI parameter alterations in important regions pre- and postshunt implantation in patients with idiopathic normal pressure hydrocephalus (iNPH), alongside assessing the relationship between DTI parameters and clinical improvement. MATERIALS AND METHODS: Patients with probable iNPH underwent prospective preoperative MRI and comprehensive clinical work-up between 2017-2022. Patients with clinical symptoms of iNPH, positive result on a lumbar infusion test, and/or gait improvement after 120-hour lumbar drainage were diagnosed with iNPH and underwent shunt-placement surgery. Fractional anisotropy and mean diffusivity values for individual regions of interest were extracted from preoperative and postoperative MRI. These values were correlated with the clinical picture of individual patients. RESULTS: A total of 32 patients (73.59 ± 4.59 years) with definite iNPH were analyzed. Preoperative DTI characteristics of internal capsule and corona radiata correlated with the 1-year improvement in the Dutch Gait Scale postoperatively (all P < .036). Cognitive domain improvement after surgery in memory and psychomotor speed correlated with preoperative DTI values of cingulate gyrus (P = .050), uncinate fasciculus (P = .029), superior longitudinal fasciculus (P = .020), or corpus callosum (P < .045). CONCLUSIONS: DTI characteristics of white matter regions reflect clinical improvement after shunt surgery in patients with iNPH. They tend to improve toward physiologic DTI values, thus further accentuating the benefit of shunt surgery in both clinical and radiologic pictures.
- MeSH
- Anisotropy MeSH
- White Matter diagnostic imaging MeSH
- Middle Aged MeSH
- Humans MeSH
- Hydrocephalus, Normal Pressure * surgery diagnostic imaging MeSH
- Prospective Studies MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Cerebrospinal Fluid Shunts * MeSH
- Treatment Outcome MeSH
- Diffusion Tensor Imaging * methods MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
OBJECTIVE: The clinical diversity of schizophrenia is reflected by structural brain variability. It remains unclear how this variability manifests across different gray and white matter features. In this meta- and mega-analysis, the authors investigated how brain heterogeneity in schizophrenia is distributed across multimodal structural indicators. METHODS: The authors used the ENIGMA dataset of MRI-based brain measures from 22 international sites with up to 6,037 individuals for a given brain measure. Variability and mean values of cortical thickness, cortical surface area, cortical folding index, subcortical volume, and fractional anisotropy were examined in individuals with schizophrenia and healthy control subjects. RESULTS: Individuals with schizophrenia showed greater variability in cortical thickness, cortical surface area, subcortical volume, and fractional anisotropy within the frontotemporal and subcortical network. This increased structural variability was mainly associated with psychopathological symptom domains, and the schizophrenia group frequently displayed lower mean values in the respective structural measures. Unexpectedly, folding patterns were more uniform in individuals with schizophrenia, particularly in the right caudal anterior cingulate region. The mean folding values of the right caudal anterior cingulate region did not differ between the schizophrenia and healthy control groups, and folding patterns in this region were not associated with disease-related parameters. CONCLUSIONS: In patients with schizophrenia, uniform folding patterns in the right caudal anterior cingulate region contrasted with the multimodal variability in the frontotemporal and subcortical network. While variability in the frontotemporal and subcortical network was associated with disease-related diversity, uniform folding may indicate a less flexible interplay between genetic and environmental factors during neurodevelopment.
- MeSH
- Anisotropy MeSH
- White Matter pathology diagnostic imaging MeSH
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Magnetic Resonance Imaging MeSH
- Brain * pathology diagnostic imaging MeSH
- Schizophrenia * pathology diagnostic imaging MeSH
- Gray Matter pathology diagnostic imaging MeSH
- Diffusion Tensor Imaging MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Meta-Analysis MeSH
White matter (WM) development has been studied extensively, but most studies used cross-sectional data, and to the best of our knowledge, none of them considered the possible effects of biological (vs. chronological) age. Therefore, we conducted a longitudinal multimodal study of WM development and studied changes in fractional anisotropy (FA) in the different WM tracts and their relationship with cortical thickness-based measures of brain aging in young adulthood. A total of 105 participants from the European Longitudinal Study of Pregnancy and Childhood (ELSPAC) prenatal birth cohort underwent magnetic resonance imaging (MRI) at the age of 23-24, and the age of 28-30 years. At both time points, FA in the different WM tracts was extracted using the JHU atlas, and brain age gap estimate (BrainAGE) was calculated using the Neuroanatomical Age Prediction using R (NAPR) model based on cortical thickness maps. Changes in FA and the speed of cortical brain aging were calculated as the difference between the respective variables in the late vs. early 20s. We demonstrated tract-specific increases as well as decreases in FA, which indicate that the WM microstructure continues to develop in the third decade of life. Moreover, the significant interaction between the speed of cortical brain aging, tract, and sex on mean FA revealed that a greater speed of cortical brain aging in young adulthood predicted greater decreases in FA in the bilateral cingulum and left superior longitudinal fasciculus in young adult men. Overall, these changes in FA in the WM tracts in young adulthood point out the protracted development of WM microstructure, particularly in men.
- MeSH
- Anisotropy MeSH
- White Matter * diagnostic imaging growth & development MeSH
- Adult MeSH
- Humans MeSH
- Longitudinal Studies MeSH
- Young Adult MeSH
- Brain * growth & development diagnostic imaging anatomy & histology MeSH
- Aging * physiology MeSH
- Diffusion Tensor Imaging methods MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
OBJECTIVE: The potential of magnetization transfer imaging (MTI) and diffusion tensor imaging (DTI) for the detection and evolution of new multiple sclerosis (MS) lesions was analyzed. METHODS: Nineteen patients with MS obtained conventional MRI, MTI, and DTI examinations bimonthly for 12 months and again after 24 months at 1.5 T MRI. MTI was acquired with balanced steady-state free precession (bSSFP) in 10 min (1.3 mm3 isotropic resolution) yielding both magnetization transfer ratio (MTR) and quantitative magnetization transfer (qMT) parameters (pool size ratio (F), exchange rate (kf), and relaxation times (T1/T2)). DTI provided fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD). RESULTS: At the time of their appearance on MRI, the 21 newly detected MS lesions showed significantly reduced MTR/F/kf and prolonged T1/T2 parameters, as well as significantly reduced FA and increased AD/MD/RD. Significant differences were already observed for MTR 4 months and for qMT parameters 2 months prior to lesions' detection on MRI. DTI did not show any significant pre-lesional differences. Slightly reversed trends were observed for most lesions up to 8 months after their detection for qMT and less pronounced for MTR and three diffusion parameters, while appearing unchanged on MRI. CONCLUSIONS: MTI provides more information than DTI in MS lesions and detects tissue changes 2 to 4 months prior to their appearance on MRI. After lesions' detection, qMT parameter changes promise to be more sensitive than MTR for the lesions' evolutional assessment. Overall, bSSFP-based MTI adumbrates to be more sensitive than MRI and DTI for the early detection and follow-up assessment of MS lesions. CLINICAL RELEVANCE STATEMENT: When additionally acquired in routine MRI, fast bSSFP-based MTI can complement the MRI/DTI longitudinal lesion assessment by detecting MS lesions 2-4 months earlier than with MRI, which could implicate earlier clinical decisions and better follow-up/treatment assessment in MS patients. KEY POINTS: • Magnetization transfer imaging provides more information than DTI in multiple sclerosis lesions and can detect tissue changes 2 to 4 months prior to their appearance on MRI. • After lesions' detection, quantitative magnetization transfer changes are more pronounced than magnetization transfer ratio changes and therefore promise to be more sensitive for the lesions' evolutional assessment. • Balanced steady-state free precession-based magnetization transfer imaging is more sensitive than MRI and DTI for the early detection and follow-up assessment of multiple sclerosis lesions.
AIMS: Mild Traumatic Brain Injury (mTBI) is the most common type of craniocerebral injury. Proper management appears to be a key factor in preventing post-concussion syndrome. The aim of this prospective study was to evaluate the effect and safety of selected training protocol in patients after mTBI. METHODS: This was a prospective study that included 25 patients with mTBI and 25 matched healthy controls. Assessments were performed in two sessions and included a post-concussion symptoms questionnaire, battery of neurocognitive tests, and magnetic resonance with tractography. Participants were divided into two groups: a passive subgroup with no specific recommendations and an active subgroup with simple physical and cognitive training. RESULTS: The training program with slightly higher initial physical and cognitive loads was well tolerated and was harmless according to the noninferiority test. The tractography showed overall temporal posttraumatic changes in the brain. The predictive model was able to distinguish between patients and controls in the first (AUC=0.807) and second (AUC=0.652) sessions. In general, tractography had an overall predictive dominance of measures. CONCLUSION: The results from our study objectively point to the safety of our chosen training protocol, simultaneously with the signs of slight benefits in specific cognitive domains. The study also showed the capability of machine learning and predictive models in mTBI patient recognition.
- MeSH
- Adult MeSH
- Brain Concussion * MeSH
- Middle Aged MeSH
- Humans MeSH
- Magnetic Resonance Imaging MeSH
- Young Adult MeSH
- Neuropsychological Tests MeSH
- Post-Concussion Syndrome * MeSH
- Prospective Studies MeSH
- Case-Control Studies MeSH
- Diffusion Tensor Imaging MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
Cíl: Vytvořit souhrnný přehled možností zobrazovacích metod při diagnostice pudendální neuralgie. Metodika: Literární rešerše. Závěr: Pudendální neuralgie je chronický bolestivý stav, který je obtížně diagnostikovatelný. Od prvních obtíží až ke správně stanovené diagnóze uplyne průměrně 5 let. Diagnostika se opírá o symptomy popsané pacientkou, neuropelveologické fyzikální vyšetření a přítomnost pěti Nantes kritérií. Zobrazovací metody, zejména ultrazvuk a magnetická rezonance pudendálního nervu, mohou pomoci s diagnostikou obtíží a s vyloučením ostatních patologií, které mohou být příčinou obtíží.
Objective: To create a comprehensive overview of imaging methods for diagnosing pudendal neuralgia. Methodology: Literature review. Conclusion: Pudendal neuralgia is a chronic pain condition that is difficult to diagnose. On average, it takes 5 years from the onset of symptoms to the correct diagnosis. Diagnosis is based on symptoms described by the patient, neuropelveological physical examination, and presence of the 5 Nantes criteria. Imaging methods, especially ultrasound and magnetic resonance imaging of the pudendal nerve, show great promise for a more accurate and faster diagnosis. These methods can assist in diagnosing issues and excluding other pathologies that may cause symptoms.
