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1.
Neuromodulation ; 27(2): 353-359, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36599767

RESUMO

OBJECTIVES: In this study, we aimed to investigate whether peroneal electrical Transcutaneous Neuromodulation invented for overactive bladder (OAB) treatment elicits activation in brain regions involved in neural regulation of the lower urinary tract. MATERIALS AND METHODS: Among 22 enrolled healthy female volunteers, 13 were eligible for the final analysis. Functional magnetic resonance imaging (fMRI) (Siemens VIDA 3T; Erlangen, Germany) was used to compare the brain region activation elicited by peroneal electrical Transcutaneous Neuromodulation with the activation elicited by sham stimulation. Each subject underwent brain fMRI recording during eight 30-second periods of rest, alternating with 30-second periods of passive feet movement using the sham device, mimicking the motor response to peroneal nerve stimulation. Subsequently, fMRI recording was performed during the analogic "off-on" stimulation paradigm using peroneal electrical transcutaneous neuromodulation. Magnetic resonance imaging data acquired during both paradigms were compared using individual and group statistics. RESULTS: During both peroneal electrical Transcutaneous Neuromodulation and sham feet movements, we observed activation of the primary motor cortex and supplementary motor area, corresponding to the cortical projection of lower limb movement. During peroneal electrical Transcutaneous Neuromodulation, we observed significant activations in the brain stem, cerebellum, cingulate gyrus, putamen, operculum, and anterior insula, which were not observed during the sham feet movement. CONCLUSIONS: Our study provides evidence that peroneal electrical Transcutaneous Neuromodulation elicits activation of brain structures that have been previously implicated in the perception of bladder fullness and that play a role in the ability to cope with urinary urgency. Our data suggest that neuromodulation at the level of supraspinal control of the lower urinary tract may contribute to the treatment effect of peroneal electrical Transcutaneous Neuromodulation in patients with OAB.


Assuntos
Estimulação Elétrica Nervosa Transcutânea , Bexiga Urinária Hiperativa , Humanos , Feminino , Bexiga Urinária Hiperativa/diagnóstico por imagem , Bexiga Urinária Hiperativa/terapia , Estimulação Elétrica Nervosa Transcutânea/métodos , Bexiga Urinária , Encéfalo/fisiologia , Imageamento por Ressonância Magnética/métodos
2.
Cells ; 12(9)2023 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-37174620

RESUMO

The volume reduction of the gray matter structures in patients with Alzheimer's disease is often accompanied by an asymmetric increase in the number of white matter fibers located close to these structures. The present study aims to investigate the white matter structure changes in the motor basal ganglia in Alzheimer's disease patients compared to healthy controls using diffusion tensor imaging. The amounts of tracts, tract length, tract volume, quantitative anisotropy, and general fractional anisotropy were measured in ten patients with Alzheimer's disease and ten healthy controls. A significant decrease in the number of tracts and general fractional anisotropy was found in patients with Alzheimer's disease compared to controls in the right caudate nucleus, while an increase was found in the left and the right putamen. Further, a significant decrease in the structural volume of the left and the right putamen was observed. An increase in the white matter diffusion tensor imaging parameters in patients with Alzheimer's disease was observed only in the putamen bilaterally. The right caudate showed a decrease in both the diffusion tensor imaging parameters and the volume in Alzheimer's disease patients. The right pallidum showed an increase in the diffusion tensor imaging parameters but a decrease in volume in Alzheimer's disease patients.


Assuntos
Doença de Alzheimer , Substância Branca , Humanos , Imagem de Tensor de Difusão/métodos , Doença de Alzheimer/diagnóstico por imagem , Substância Branca/diagnóstico por imagem , Substância Cinzenta/diagnóstico por imagem , Putamen/diagnóstico por imagem
3.
Neurourol Urodyn ; 42(6): 1352-1361, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37144657

RESUMO

OBJECTIVES: To compare brain responses to peroneal electrical transcutaneous neuromodulation (peroneal eTNM®) and transcutaneous tibial nerve stimulation (TTNS), two methods for treating overactive bladder (OAB), using functional magnetic resonance imaging (fMRI). The present study was not designed to compare their clinical efficacy. MATERIALS AND METHODS: This study included 32 healthy adult female volunteers (average age 38.3 years (range 22-73)). Brain MRI using 3 T scanner was performed during three 8-min blocks of alternating sequences. During each 8-min block, the protocol alternated between sham stimulation (30 s) and rest (30 s) for 8 repeats; then peroneal eTNM® stimulation (30 s) and rest (30 s) for 8 repeats; then, TTNS stimulation (30 s) and rest (30 s) for 8 repeats. Statistical analysis was performed at the individual level with a threshold of p = 0.05, family-wise error (FWE)-corrected. The resulting individual statistical maps were analyzed in group statistics using a one-sample t-test, p = 0.05 threshold, false discovery rate (FDR)-corrected. RESULTS: During peroneal eTNM®, TTNS, and sham stimulations, we recorded activation in the brainstem, bilateral posterior insula, bilateral precentral gyrus, bilateral postcentral gyrus, left transverse temporal gyrus, and right supramarginal gyrus. During both peroneal eTNM® and TTNS stimulations, but not sham stimulations, we recorded activation in the left cerebellum, right transverse temporal gyrus, right middle frontal gyrus, and right inferior frontal gyrus. Exclusively during peroneal eTNM® stimulation, we observed activation in the right cerebellum, right thalamus, bilateral basal ganglia, bilateral cingulate gyrus, right anterior insula, right central operculum, bilateral supplementary motor cortex, bilateral superior temporal gyrus, and left inferior frontal gyrus. CONCLUSIONS: Peroneal eTNM®, but not TTNS, induces the activation of brain structures that were previously implicated in neural control of the of bladder filling and play an important role in the ability to cope with urgency. The therapeutic effect of peroneal eTNM® could be exerted, at least in part, at the supraspinal level of neural control.


Assuntos
Estimulação Elétrica Nervosa Transcutânea , Bexiga Urinária Hiperativa , Adulto , Humanos , Feminino , Adulto Jovem , Pessoa de Meia-Idade , Idoso , Bexiga Urinária Hiperativa/diagnóstico por imagem , Bexiga Urinária Hiperativa/terapia , Estimulação Elétrica Nervosa Transcutânea/métodos , Bexiga Urinária , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Imageamento por Ressonância Magnética , Nervo Tibial
4.
Brain Imaging Behav ; 17(1): 18-34, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36396890

RESUMO

Motor disability is a dominant and restricting symptom in multiple sclerosis, yet its neuroimaging correlates are not fully understood. We apply statistical and machine learning techniques on multimodal neuroimaging data to discriminate between multiple sclerosis patients and healthy controls and to predict motor disability scores in the patients. We examine the data of sixty-four multiple sclerosis patients and sixty-five controls, who underwent the MRI examination and the evaluation of motor disability scales. The modalities used comprised regional fractional anisotropy, regional grey matter volumes, and functional connectivity. For analysis, we employ two approaches: high-dimensional support vector machines run on features selected by Fisher Score (aiming for maximal classification accuracy), and low-dimensional logistic regression on the principal components of data (aiming for increased interpretability). We apply analogous regression methods to predict symptom severity. While fractional anisotropy provides the classification accuracy of 96.1% and 89.9% with both approaches respectively, including other modalities did not bring further improvement. Concerning the prediction of motor impairment, the low-dimensional approach performed more reliably. The first grey matter volume component was significantly correlated (R = 0.28-0.46, p < 0.05) with most clinical scales. In summary, we identified the relationship between both white and grey matter changes and motor impairment in multiple sclerosis. Furthermore, we were able to achieve the highest classification accuracy based on quantitative MRI measures of tissue integrity between patients and controls yet reported, while also providing a low-dimensional classification approach with comparable results, paving the way to interpretable machine learning models of brain changes in multiple sclerosis.


Assuntos
Pessoas com Deficiência , Transtornos Motores , Esclerose Múltipla , Humanos , Esclerose Múltipla/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Neuroimagem , Encéfalo/diagnóstico por imagem , Aprendizado de Máquina
5.
Artigo em Inglês | MEDLINE | ID: mdl-34602613

RESUMO

BACKGROUND: The authors present a case study which describes the development of bilateral optic neuropathy as a complication of allogeneic hematopoietic stem cell transplantation (HSCT) in a patient who underwent a transplant for B-cell acute lymphoblastic leukemia (B-ALL). The patient, who was in remission with regard to the underlying hematological disease, developed edema of both optic discs and maculas three months after transplantation. The morphological finding regressed after treatment with corticoids and comprehensive systemic anti-infective therapy. However, the loss of function was not entirely restored. CASE REPORT: One year after the healing, the atrophy of the optic discs persisted, with corresponding findings in vessel density (VD), retinal nerve fibre layer (RNFL) and visual field changes. Electrophysiological examination by pattern electroretinogram (PERG) showed an alteration in retinal ganglion cells in the left eye, but with significant damage to nerve fibres on both sides. Visual evoked potential (VEP) verified bilateral non-inflammatory neurogenic lesions. This finding was also confirmed by functional magnetic resonance imaging (fMRI). Examination by structural magnetic resonance imaging (MRI) showed inflammatory changes in the optic nerve sheaths over time and a consequent marked narrowing of them. CONCLUSION: The authors believe that edema of the optic discs and maculas was caused by a combination of several factors. Firstly, MRI showed inflammatory changes in the optic nerve sheaths, which led to a blockade of axoplasmic transport. Another factor that may have played a part in the outcome was endothelial damage to blood vessels with impaired microcirculation supplying the optic nerve fibres, which contributed to the occurrence of macular edema.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Macula Lutea , Doenças do Nervo Óptico , Humanos , Potenciais Evocados Visuais , Doenças do Nervo Óptico/etiologia , Doenças do Nervo Óptico/patologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Nervo Óptico , Tomografia de Coerência Óptica
6.
Front Aging Neurosci ; 15: 1283660, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38264549

RESUMO

Introduction: Aging negatively influences the structure of the human brain including the white matter. The objective of our study was to identify, using fixel-based morphometry, the age induced changes in the pathways connecting several regions of the central auditory system (inferior colliculus, Heschl's gyrus, planum temporale) and the pathways connecting these structures with parts of the limbic system (anterior insula, hippocampus and amygdala). In addition, we were interested in the extent to which the integrity of these pathways is influenced by hearing loss and tinnitus. Methods: Tractographic data were acquired using a 3 T MRI in 79 volunteers. The participants were categorized into multiple groups in accordance with their age, auditory thresholds and tinnitus status. Fixel-based analysis was utilized to identify alterations in the subsequent three parameters: logarithm of fiber cross-section, fiber density, fiber density and cross-section. Two modes of analysis were used: whole brain analysis and targeted analysis using fixel mask, corresponding to the pathways connecting the aforementioned structures. Results: A significantly negative effect of aging was present for all fixel-based metrics, namely the logarithm of the fiber cross-section, (7 % fixels in whole-brain, 14% fixels in fixel mask), fiber density (5 % fixels in whole-brain, 15% fixels in fixel mask), fiber density and cross section (7 % fixels in whole-brain, 19% fixels in fixel mask). Expressed age-related losses, exceeding 30% fixels, were particularly present in pathways connecting the auditory structures with limbic structures. The effect of hearing loss and/or tinnitus did not reach significance. Conclusions: Our results show that although an age-related reduction of fibers is present in pathways connecting several auditory regions, the connections of these structures with limbic structures are even more reduced. To what extent this fact influences the symptoms of presbycusis, such as decreased speech comprehension, especially in noise conditions, remains to be elucidated.

7.
Front Neurosci ; 16: 921873, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36340777

RESUMO

Presbycusis and tinnitus are the two most common hearing related pathologies. Although both of these conditions presumably originate in the inner ear, there are several reports concerning their central components. Interestingly, the onset of presbycusis coincides with the highest occurrence of tinnitus. The aim of this study was to identify age, hearing loss, and tinnitus related functional changes, within the auditory system and its associated structures. Seventy-eight participants were selected for the study based on their age, hearing, and tinnitus, and they were divided into six groups: young controls (Y-NH-NT), subjects with mild presbycusis (O-NH-NT) or expressed presbycusis (O-HL-NT), young subjects with tinnitus (Y-NH-T), subjects with mild presbycusis and tinnitus (O-NH-T), and subjects with expressed presbycusis and tinnitus (O-HL-T). An MRI functional study was performed with a 3T MRI system, using an event related design (different types of acoustic and visual stimulations and their combinations). The amount of activation of the auditory cortices (ACs) was dependent on the complexity of the stimuli; higher complexity resulted in a larger area of the activated cortex. Auditory stimulation produced a slightly greater activation in the elderly, with a negative effect of hearing loss (lower activation). The congruent audiovisual stimulation led to an increased activity within the default mode network, whereas incongruent stimulation led to increased activation of the visual cortex. The presence of tinnitus increased activation of the AC, specifically in the aged population, with a slight prevalence in the left AC. The occurrence of tinnitus was accompanied by increased activity within the insula and hippocampus bilaterally. Overall, we can conclude that expressed presbycusis leads to a lower activation of the AC, compared to the elderly with normal hearing; aging itself leads to increased activity in the right AC. The complexity of acoustic stimuli plays a major role in the activation of the AC, its support by visual stimulation leads to minimal changes within the AC. Tinnitus causes changes in the activity of the limbic system, as well as in the auditory AC, where it is bound to the left hemisphere.

8.
Quant Imaging Med Surg ; 12(9): 4488-4501, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36060587

RESUMO

Background: Magnetic resonance (MR) tractography of the brachial plexus (BP) is challenging due to different factors such as motion artifacts, pulsation artifacts, signal-to-noise ratio, spatial resolution; eddy currents induced geometric distortions, sequence parameters and choice of used coils. Notably challenging is the separation of the peripheral nerve bundles and skeletal muscles as both structures have similar fractional anisotropy values. We proposed an algorithm for robust visualization and assessment of BP root bundles using the segmentation of the spinal cord (SSC, C4-T1) as seed points for the initial starting area for the fibre tracking algorithm. Methods: Twenty-seven healthy volunteers and four patients with root avulsions underwent magnetic resonance imaging (MRI) examinations on a 3T MR scanner with optimized measurement protocols for diffusion-weighted images and coronal T2 weighted 3D short-term inversion recovery sampling perfection with application optimized contrast using varying flip angle evaluation sequences used for BP fibre reconstruction and MR neurography (MRN). The fibre bundles reconstruction was optimized in terms of eliminating the skeletal muscle fibres contamination using the SSC and the tracking threshold of the normalized quantitative anisotropy (NQA) on reconstruction of the BP. In our study, the NQA parameter has been used for fiber tracking instead of fractional anisotropy (FA). The diffusion data were processed in individual C4-T1 root bundles using the generalized q-sampling imaging (GQI) algorithm. Calculated diffusion parameters were statistically analysed using the two-sample t-test. The MRN was performed in MedINRIA and post-processed using the maximum intensity projection (MIP) method to demonstrate BP root bundles in multiple planes. Results: In control subjects, no significant effect of laterality in diffusion parameters was found (P>0.05) in the BP. In the central part of the BP, a significant difference between control subjects and patients at P=0.02 was found in the NQA values. Other diffusion parameters were not significantly different. Conclusions: Using NQA instead of FA in the proposed algorithm allowed for a better separation of muscle and root nerve bundles. The presented algorithm yields a high quality reconstruction of the BP bundles that may be helpful both in research and clinical practice.

9.
Sci Data ; 9(1): 486, 2022 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-35945231

RESUMO

The human brain represents a complex computational system, the function and structure of which may be measured using various neuroimaging techniques focusing on separate properties of the brain tissue and activity. We capture the organization of white matter fibers acquired by diffusion-weighted imaging using probabilistic diffusion tractography. By segmenting the results of tractography into larger anatomical units, it is possible to draw inferences about the structural relationships between these parts of the system. This pipeline results in a structural connectivity matrix, which contains an estimate of connection strength among all regions. However, raw data processing is complex, computationally intensive, and requires expert quality control, which may be discouraging for researchers with less experience in the field. We thus provide brain structural connectivity matrices in a form ready for modelling and analysis and thus usable by a wide community of scientists. The presented dataset contains brain structural connectivity matrices together with the underlying raw diffusion and structural data, as well as basic demographic data of 88 healthy subjects.


Assuntos
Encéfalo , Processamento de Imagem Assistida por Computador , Substância Branca , Encéfalo/diagnóstico por imagem , Conectoma , Imagem de Difusão por Ressonância Magnética , Imagem de Tensor de Difusão , Humanos , Substância Branca/diagnóstico por imagem
10.
Psychophysiology ; 59(10): e14075, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35460523

RESUMO

Functional connectivity analysis is a common approach to the characterization of brain function. While studies of functional connectivity have predominantly focused on resting-state fMRI, naturalistic paradigms, such as movie watching, are increasingly being used. This ecologically valid, yet relatively unconstrained acquisition state has been shown to improve subject compliance and, potentially, enhance individual differences. However, unlike the reliability of resting-state functional connectivity, the reliability of functional connectivity during naturalistic viewing has not yet been fully established. The current study investigates the intra-session reliability of functional connectivity during naturalistic viewing sessions to extend its understanding. Using fMRI data of 24 subjects measured at rest as well as during six naturalistic viewing conditions, we quantified the split-half reliability of each condition, as well as cross-condition reliabilities. We find that intra-session reliability is relatively high for all conditions. While cross-condition reliabilities are higher for pairings of two naturalistic viewing conditions, split-half reliability is highest for the resting state. Potential sources of variability across the conditions, as well as the strengths and limitations of using intra-session reliability as a measure in naturalistic viewing, are discussed.


Assuntos
Encéfalo , Imageamento por Ressonância Magnética , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Humanos , Individualidade , Filmes Cinematográficos , Reprodutibilidade dos Testes
11.
Mol Clin Oncol ; 15(3): 176, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34276995

RESUMO

The present report presents a rare case in which a patient with pituitary apoplexy (PA) without compression of the optic chiasm experienced diagnosable visual impairment in the ensuing months. Endocrinologically, the condition was a prolactinoma followed by bleeding into the pituitary gland. Due to the unexplained functional changes in the patient, an electrophysiological examination (pattern electroretinogram and pattern visual evoked potentials) was performed, which verified a bilateral non-inflammatory neurogenic lesion. This finding was confirmed by functional magnetic resonance imaging (fMRI) examination. Structural MRI did not reveal chiasm compression in the time sequence or alteration of the optic nerves (the diameter of the optic nerve at different distances from the eye and the diameter of the optic nerve sheath at different distances from the eye). Similarly, neither the retinal nerve fiber layer (RNFL) nor the vessel density was altered. The present report suggests that changes in visual fields may be due to ischemia in the area of the chiasm and optic nerves, similar to PA.

13.
Medicine (Baltimore) ; 100(6): e24646, 2021 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-33578590

RESUMO

ABSTRACT: MR tractography of the lumbosacral plexus (LSP) is challenging due to the difficulty of acquiring high quality data and accurately estimating the neuronal tracts. We proposed an algorithm for an accurate visualization and assessment of the major LSP bundles using the segmentation of the cauda equina as seed points for the initial starting area for the fiber tracking algorithm.Twenty-six healthy volunteers underwent MRI examinations on a 3T MR scanner using the phased array coils with optimized measurement protocols for diffusion-weighted images and coronal T2 weighted 3D short-term inversion recovery sampling perfection with application optimized contrast using varying flip angle evaluation sequences used for LSP fiber reconstruction and MR neurography (MRN).The fiber bundles reconstruction was optimized in terms of eliminating the muscle fibers contamination using the segmentation of cauda equina, the effects of the normalized quantitative anisotropy (NQA) and angular threshold on reconstruction of the LSP. In this study, the NQA parameter has been used for fiber tracking instead of fractional anisotropy (FA) and the regions of interest positioning was precisely adjusted bilaterally and symmetrically in each individual subject.The diffusion data were processed in individual L3-S2 nerve fibers using the generalized Q-sampling imaging algorithm. Data (mean FA, mean diffusivity, axial diffusivity and radial diffusivity, and normalized quantitative anisotropy) were statistically analyzed using the linear mixed-effects model. The MR neurography was performed in MedINRIA and post-processed using the maximum intensity projection method to demonstrate LSP tracts in multiple planes.FA values significantly decreased towards the sacral region (P < .001); by contrast, mean diffusivity, axial diffusivity, radial diffusivity and NQA values significantly increased towards the sacral region (P < .001).Fiber tractography of the LSP was feasible in all examined subjects and closely corresponded with the nerves visible in the maximum intensity projection images of MR neurography. Usage of NQA instead of FA in the proposed algorithm enabled better separation of muscle and nerve fibers.The presented algorithm yields a high quality reconstruction of the LSP bundles that may be helpful both in research and clinical practice.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Imagem de Tensor de Difusão/métodos , Plexo Lombossacral/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Nervos Espinhais/diagnóstico por imagem , Adulto , Algoritmos , Anisotropia , Cauda Equina/diagnóstico por imagem , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/instrumentação , Região Lombossacral/inervação , Masculino , Nervos Espinhais/anatomia & histologia
14.
Eur J Phys Rehabil Med ; 57(6): 889-899, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33565742

RESUMO

BACKGROUND: Changes of white matter integrity in people with multiple sclerosis (MS) were documented following mainly motor/skill acquisitions physical therapy, while following neuroproprioceptive "facilitation, inhibition" (neurofacilitation) only by two pilot studies. Neurofacilitation has potential to induce white matter changes due to the possibility of interfering with the neuronal tactility threshold. However stronger evidence is missing. AIM: This study investigates whether neurofacilitation (three physical therapy types) induce white matter changes and if they relate to clinical improvement. DESIGN: The Three-Arm Parallel-group Exploratory Trial (NCT04355663). SETTING: Each group underwent different kinds of two months ambulatory therapy (Motor Program Activating Therapy, Vojta's reflex locomotion and Functional Electric Stimulation in Posturally Corrected Position). POPULATION: MS people with moderate disability. METHODS: At baseline and after the program, participants underwent magnetic resonance diffusion tensor imaging (DTI) and clinical assessment. Fractional anisotropy maps obtained from DTI were further analyzed using tract-based spatial statistic exploring the mean values in the whole statistic skeleton. Moreover, additional exploratory analysis in 48 regions of white matter was done. RESULTS: Ninety-two people were recruited. DTI data from 61 people were analyzed. The neurofacilitation (irrespective type of therapy) resulted in significant improvement on the Berg Balance Scale (P=0.0089), mainly driven by the Motor Program Activating Therapy. No statistically significant change in the whole statistic skeleton was observed (only a trend for decrement of fractional anisotropy after Vojta's reflex locomotion). Additional exploratory analysis confirmed significant decrement of fractional anisotropy in the right anterior corona radiata. CONCLUSIONS: Neurofacilitation improved balance without much evidence of white matter integrity changes in people with MS. CLINICAL REHABILITATION IMPACT: The study results point to the importance of neuroproprioceptive "facilitation and inhibition" physical therapy in the management of balance in people with multiple sclerosis; and the potential to induce white matter changes due to the possibility of interfering with the neuronal tactility threshold.


Assuntos
Esclerose Múltipla , Substância Branca , Imagem de Tensor de Difusão , Humanos , Modalidades de Fisioterapia , Substância Branca/diagnóstico por imagem
15.
IEEE Trans Med Imaging ; 40(4): 1240-1252, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33434127

RESUMO

We proposed a novel method called HARP-I, which enhances the estimation of motion from tagged Magnetic Resonance Imaging (MRI). The harmonic phase of the images is unwrapped and treated as noisy measurements of reference coordinates on a deformed domain, obtaining motion with high accuracy using Radial Basis Functions interpolations. Results were compared against Shortest Path HARP Refinement (SP-HR) and Sine-wave Modeling (SinMod), two harmonic image-based techniques for motion estimation from tagged images. HARP-I showed a favorable similarity with both methods under noise-free conditions, whereas a more robust performance was found in the presence of noise. Cardiac strain was better estimated using HARP-I at almost any motion level, giving strain maps with less artifacts. Additionally, HARP-I showed better temporal consistency as a new method was developed to fix phase jumps between frames. In conclusion, HARP-I showed to be a robust method for the estimation of motion and strain under ideal and non-ideal conditions.


Assuntos
Algoritmos , Processamento de Imagem Assistida por Computador , Proteínas de Transporte , Citocinas , Imageamento por Ressonância Magnética , Movimento (Física)
16.
Acad Radiol ; 28(8): 1133-1141, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-32620530

RESUMO

RATIONALE AND OBJECTIVES: This study's aims were to depict changes in cartilage quality after surgical intervention using magnetic resonance (MR) examination and in content of glycosaminoglycans chains (GAGs) after two types of surgeries - chondral defect treatment by microfractures and scaffold implantation in combination with microfractures. MATERIALS AND METHODS: Twenty-five patients were studied: 14 with implants, 11 with microfractures. MR examination was made before surgery and 6, 12, and 18 months thereafter. Qualitative changes in cartilage were observed by means of delayed gadolinium enhanced magnetic resonance imaging of cartilage sequence using Gd-DTPA2- and Gd-DOTA. In each examination, GAGs content was determined at three locations: the defect, its surroundings, and a non-load-bearing reference area. RESULTS: Measured indices showed no statistically significant differences in changes within the defect area when comparing the two treatment types at individual time points of 6, 12, and 18 months. In the case of microfracture treatment, more substantial decrease in GAGs concentration occurred at month 6, whereas the greatest decline occurred at month 12 when using an implant. Change in GAGs content and decline in cartilage quality were substantial also in the reference area and close surroundings. CONCLUSIONS: Hyaline cartilage behaves as a unified whole, and change in GAGs content was marked also in locations with no morphological damage. Over the monitored period, no statistically significant difference between treatment types was noted as measured by GAGs content in the defect or its close surroundings. dGEMRIC is suitable for monitoring cartilage quality even if use of Gd-DTPA2- is not possible, because comparable results were achieved using Gd-DOTA.


Assuntos
Cartilagem Articular , Fraturas de Estresse , Cartilagem Articular/diagnóstico por imagem , Cartilagem Articular/cirurgia , Colágeno Tipo I , Humanos , Cartilagem Hialina/diagnóstico por imagem , Articulação do Joelho/diagnóstico por imagem , Articulação do Joelho/cirurgia , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Estudos Prospectivos
17.
Clin Nutr ; 40(4): 1822-1833, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33081982

RESUMO

BACKGROUND & AIMS: Reward circuitry in the brain plays a key role in weight regulation. We tested the effects of a plant-based meal on these brain regions. METHODS: A randomized crossover design was used to test the effects of two energy- and macronutrient-matched meals: a vegan (V-meal) and a conventional meat (M-meal) on brain activity, gastrointestinal hormones, and satiety in participants with type 2 diabetes (T2D; n = 20), overweight/obese participants (O; n = 20), and healthy controls (H; n = 20). Brain perfusion was measured, using arterial spin labeling functional brain imaging; satiety was assessed using a visual analogue scale; and plasma concentrations of gut hormones were determined at 0 and 180 min. Repeated-measures ANOVA was used for statistical analysis. Bonferroni correction for multiple comparisons was applied. The Hedge's g statistic was used to measure the effect size for means of paired difference between the times (180-0 min) and meal types (M-V meal) for each group. RESULTS: Thalamus perfusion was the highest in patients with T2D and the lowest in overweight/obese individuals (p = 0.001). Thalamus perfusion decreased significantly after ingestion of the M-meal in men with T2D (p = 0.04) and overweight/obese men (p = 0.004), and it decreased significantly after ingestion of the V-meal in healthy controls (p < 0.001; Group x Meal x Time: F = 3.4; p = 0.035). The effect size was -0.41 (95% CI, -1.14 to 0.31; p = 0.26) for men with diabetes; -0.72 (95% CI, -1.48 to 0.01; p = 0.05) for overweight/obese men; and 0.82 (95% CI, 0.09 to 1.59; p = 0.03) for healthy men. Postprandial secretion of active GLP-1 increased after the V-meal compared with the M-meal by 42% (95% CI 25-62%; p = 0.003) in men with T2D and by 41% (95% CI 24-61%; p = 0.002) in healthy controls. Changes in thalamus perfusion after ingestion of both test meals correlated with changes in satiety (r = +0.68; p < 0.01), fasting plasma insulin (r = +0.40; p < 0.01), C-peptide (r = +0.48; p < 0.01) and amylin (r = +0.55; p < 0.01), and insulin secretion at 5 mmol/l (r = +0.77; p < 0.05). CONCLUSIONS: The higher postprandial GLP-1 secretion after the V-meal in men with T2D, with concomitant greater satiety and changes in thalamus perfusion, suggest a potential use of plant-based meals in addressing the key pathophysiologic mechanisms of food intake regulation. Trial registration ClinicalTrials.gov number, NCT02474147.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Dieta Vegetariana/métodos , Ingestão de Energia , Nutrientes/metabolismo , Sobrepeso/metabolismo , Tálamo/irrigação sanguínea , Adulto , Idoso , Estudos Cross-Over , Dieta/métodos , Humanos , Masculino , Refeições , Pessoa de Meia-Idade , Obesidade/metabolismo , Tálamo/metabolismo
18.
Eur J Phys Rehabil Med ; 57(3): 356-365, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32935954

RESUMO

BACKGROUND: Imaging methods bring new possibilities for describing the brain plasticity processes that underly the improvement of clinical function after physiotherapy in people with multiple sclerosis (pwMS). Although these processes have been described mainly in connection with task-oriented physiotherapy and aerobic training, they have not been properly verified in neuroproprioceptive "facilitation, inhibition" (facilitation) approaches. AIM: The study determined whether facilitation physiotherapy could enhance brain plasticity, compared two facilitation methods and looked for any relation to clinical improvement in pwMS. DESIGN: The study was designed as parallel group randomized comparison of two kinds of physiotherapeutic interventions referred to healthy controls. SETTING: Thirty-eight outpatients were involved in the study. POPULATION: The study had 80 participants (38 pwMS and 42 healthy controls). METHODS: PwMS were divided into two groups and underwent a two-month physiotherapy program: Vojta reflex locomotion (VRL) or Motor program activating therapy (MPAT), (1 hour, twice a week). Functional magnetic resonance imaging (fMRI) and clinical examination was performed before and after therapy. Healthy controls underwent one fMRI examination. RESULTS: Physiotherapy in pwMS leads to extension of brain activity in specific brain areas (cerebellum, supplementary motor areas and premotor areas) in connection with the improvement of the clinical status of individual patients after therapy (P=0.05). Greater changes (P=0.001) were registered after MPAT than after VRL. The extension of activation was a shift to the examined activation of healthy controls, whose activation was higher in the cerebellum and secondary visual area (P=0.01). CONCLUSIONS: Neuroproprioceptive "facilitation, inhibition" physiotherapy may enhance brain activity and could involve processes connected with the processing of motion activation. CLINICAL REHABILITATION IMPACT: The study showed that facilitation approach can modulate brain activity. This could be useful for developing of effective physiotherapeutic treatment in MS.


Assuntos
Encéfalo/diagnóstico por imagem , Esclerose Múltipla/diagnóstico por imagem , Esclerose Múltipla/terapia , Modalidades de Fisioterapia , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
19.
Front Aging Neurosci ; 12: 553461, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33343328

RESUMO

Age related hearing loss (presbycusis) is a natural process represented by elevated auditory thresholds and decreased speech intelligibility, especially in noisy conditions. Tinnitus is a phantom sound that also potentially leads to cortical changes, with its highest occurrence coinciding with the clinical onset of presbycusis. The aim of our project was to identify age, hearing loss and tinnitus related structural changes, within the auditory system and associated structures. Groups of subjects with presbycusis and tinnitus (22 subjects), with only presbycusis (24 subjects), young tinnitus patients with normal hearing (10 subjects) and young controls (17 subjects), underwent an audiological examination to characterize hearing loss and tinnitus. In addition, MRI (3T MR system, analysis in Freesurfer software) scans were used to identify changes in the cortical and subcortical structures. The following areas of the brain were analyzed: Heschl gyrus (HG), planum temporale (PT), primary visual cortex (V1), gyrus parahippocampus (PH), anterior insula (Ins), amygdala (Amg), and hippocampus (HP). A statistical analysis was performed in R framework using linear mixed-effects models with explanatory variables: age, tinnitus, laterality and hearing. In all of the cortical structures, the gray matter thickness decreased significantly with aging without having an effect on laterality (differences between the left and right hemispheres). The decrease in the gray matter thickness was faster in the HG, PT and Ins in comparison with the PH and V1. Aging did not influence the surface of the cortical areas, however there were differences between the surface size of the reported regions in the left and right hemispheres. Hearing loss caused only a borderline decrease of the cortical surface in the HG. Tinnitus was accompanied by a borderline decrease of the Ins surface and led to an increase in the volume of Amy and HP. In summary, aging is accompanied by a decrease in the cortical gray matter thickness; hearing loss only has a limited effect on the structure of the investigated cortical areas and tinnitus causes structural changes which are predominantly within the limbic system and insula, with the structure of the auditory system only being minimally affected.

20.
Front Behav Neurosci ; 14: 98, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33061893

RESUMO

This study analyzes how people's attitudes to the European refugee crisis (ERC) correspond to selected psychological state and trait measures and impact the neural processing of media images of refugees. From a large pool of respondents, who filled in an online xenophobia questionnaire, we selected two groups (total N = 38) with the same socio-demographic background, but with opposite attitudes toward refugees. We found that a negative attitude toward refugees (high xenophobia - HX) was associated with a significantly higher conscientiousness score and with a higher trait aggression and hostility, but there was no group effect connected with empathy, fear, and anxiety measures. At the neural level we found that brain activity during the presentation of ERC stimuli is affected by xenophobic attitudes-with more xenophobic subjects exhibiting a higher BOLD response in the left fusiform gyrus. However, while the fMRI results demonstrate increased attention and vigilance toward ERC-related stimuli in the HX group, they do not show differentiated patterns of brain activity associated with perception of dehumanized outgroup.

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