Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Front Neurosci ; 16: 822891, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35281497

RESUMO

Gut-brain crosstalk has been demonstrated previously. However, brain metabolic patterns of colorectal cancer and chronic enteritis remain unclear. A better understanding of gut-brain crosstalk from a radiological perspective is necessary. We conducted a retrospective study in which we acquired 18F-fluorodeoxyglucose positron emission tomography in 45 colorectal cancer cases, 45 age- and sex-matched chronic enteritis patients, and 45 age- and sex-matched healthy controls. We calculated a scaled sub-profile pattern based on principal component analysis and metabolic connectivity to explore the brain metabolic model and analyzed correlations between various brain regions and cancer to identify potential neuroimaging markers for non-pharmaceutical therapies. We found a characteristic cerebral metabolic pattern in colorectal cancer patients, which mainly involved visceral sensation and both affective and cognitive psychological processes. The metabolic patterns of patients with colorectal cancer and chronic enteritis were similar but not identical. The metabolic connectivity of the postcentral gyrus and paracentral lobule was found to be significantly different between the controls and patients with colorectal cancer (p < 0.05, false discovery rate correction). The maximal standard uptake value of the cancer focus in colorectal cancer patients was negatively correlated with the dorsolateral superior frontal gyrus (p < 0.05). Patients with colorectal cancer may show abnormal glucose cerebral metabolism characterized by "point-line-surface." This preliminary study revealed the cerebral metabolic characteristics and neurobiological mechanisms of colorectal cancer and chronic enteritis (ChiCTR2000041020; registered December 16, 2020).

2.
Aging (Albany NY) ; 14(2): 923-942, 2022 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-35077393

RESUMO

Using animal models to study the underlying mechanisms of aging will create a critical foundation from which to develop new interventions for aging-related brain disorders. Aging-related reorganization of the brain network has been described for the human brain based on functional, metabolic and structural connectivity. However, alterations in the brain metabolic network of aging rats remain unknown. Here, we submitted young and aged rats to [18F]fluorodeoxyglucose with positron emission tomography (18F-FDG PET) and constructed brain metabolic networks. The topological properties were detected, and the network robustness against random failures and targeted attacks was analyzed for age-group comparison. Compared with young rats, aged rats showed reduced betweenness centrality (BC) in the superior colliculus and a decreased degree (D) in the parietal association cortex. With regard to network robustness, the brain metabolic networks of aged rats were more vulnerable to simulated damage, which showed significantly lower local efficiency and clustering coefficients than those of the young rats against targeted attacks and random failures. The findings support the idea that aged rats have similar aging-related changes in the brain metabolic network to the human brain and can therefore be used as a model for aging studies to provide targets for potential therapies that promote healthy aging.


Assuntos
Fluordesoxiglucose F18 , Tomografia por Emissão de Pósitrons , Envelhecimento , Animais , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Redes e Vias Metabólicas , Tomografia por Emissão de Pósitrons/métodos , Ratos
3.
Pain Physician ; 25(1): E147-E156, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35051163

RESUMO

BACKGROUND: Neuropathic pain following brachial plexus avulsion injury (BPAI) induces plastic changes in multiple brain regions associated with somatosensory function, pain, or cognition at the group level. The alternation of the whole pattern of resting-state brain activity and the feasibility of a brain imaging, information-based diagnosis of pain following BPAI is poorly investigated. OBJECTIVES: To investigate whether brain pattern alternation can  identify neuropathic pain from healthy controls at an individual level and the specific regions that can be used as diagnostic neuroimaging biomarkers. STUDY DESIGN: Controlled animal study. SETTING: The research took place in the school of rehabilitation science of a university and affiliated hospitals. METHODS: A total of 48 female Sprague-Dawley rats weighing 180 g-200 g were randomly assigned to either the BPAI group (n = 24) or normal control group (n = 24). A neuropathic pain rat model following BPAI was established in the BPAI group and a mechanical withdrawal threshold (MWT) test was performed to verify the presence of neuropathic pain. Micro-positron emission tomography with [Fluorine-18]-fluoro-2-deoxy-D-glucose (18F-FDG-PET) was used to obtain the whole brain metabolic activity scans. Multivariate pattern analysis (MVPA) was performed with a linear support vector machine (SVM) analysis both in PRoNTo toolbox (based on regions of interests) and SearchlightSearchlight approach (based on voxels within the region). RESULTS: Compared with baseline status, MWT of the left (intact) forepaw was significantly reduced in the BPAI group (P < 0.001). The accuracy of a whole brain image that correctly discriminated BPAI from normal controls rats was 87.5% with both the PRoNTo toolbox and SearchlightSearchlight method. Pearson's correlation analysis revealed significant positive correlations (P < 0.05) between MWT and the standard taken values of brain regions including the left olfactory nucleus, right entorhinal cortex in the PRoNTo toolbox, and bilateral amygdala, right piriform cortex and right ventral hippocampus in Searchlight method. LIMITATIONS: The alternation of metabolic connectivity among regions and functional connectivity among different networks were not investigated in the present study. CONCLUSIONS: Our study indicated that MVPA based on the PET scans of rats' brains  could successfully identify neuropathic pain from health condition at the individual level and predictive regions could potentially be provided as neuroimaging biomarkers for the neuropathic pain following BPAI.


Assuntos
Plexo Braquial , Neuralgia , Animais , Plexo Braquial/diagnóstico por imagem , Plexo Braquial/lesões , Encéfalo , Feminino , Humanos , Neuralgia/metabolismo , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Ratos , Ratos Sprague-Dawley
4.
Neural Regen Res ; 17(4): 806-811, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34472479

RESUMO

Pain is one of the manifestations of hip disorder and has been proven to lead to the remodeling of somatotopic map plasticity in the cortex. However, most studies are volume-based which may lead to inaccurate anatomical positioning of functional data. The methods that work on the cortical surface may be more sensitive than those using the full brain volume and thus be more suitable for map plasticity study. In this prospective cross-sectional study performed in Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, China, 20 patients with osteonecrosis of the femoral head (12 males and 8 females, aged 56.80 ± 13.60 years) and 20 healthy controls (9 males and 11 females, aged 54.56 ± 10.23 years) were included in this study. Data of resting-state functional magnetic resonance imaging were collected. The results revealed that compared with healthy controls, compared with the healthy controls, patients with osteonecrosis of the femoral head (ONFH) showed significantly increased surface-based regional homogeneity (ReHo) in areas distributed mainly in the left dorsolateral prefrontal cortex, frontal eye field, right frontal eye field, and the premotor cortex and decreased surface-based ReHo in the right primary motor cortex and primary sensory cortex. Regions showing significant differences in surface-based ReHo values between the healthy controls and patients with ONFH were defined as the regions of interests. Seed-based functional connectivity was performed to investigate interregional functional synchronization. When the areas with decreased surface-based ReHo in the frontal eye field and right premotor cortex were used as the regions of interest, compared with the healthy controls, the patients with ONFH displayed increased functional connectivity in the right middle frontal cortex and right inferior parietal cortex and decreased functional connectivity in the right precentral cortex and right middle occipital cortex. Compared with healthy controls, patients with ONFH showed significantly decreased cortical thickness in the para-insular area, posterior insular area, anterior superior temporal area, frontal eye field and supplementary motor cortex and reduced volume of subcortical gray matter nuclei in the right nucleus accumbens. These findings suggest that hip disorder patients showed cortical plasticity changes, mainly in sensorimotor- and pain-related regions. This study was approved by the Medical Ethics Committee of Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine (approval No. 2018-041) on August 1, 2018.

5.
PeerJ ; 9: e11759, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34484979

RESUMO

BACKGROUND: Pain, a major symptom of osteonecrosis of the femoral head (ONFH), is a complex sensory and emotional experience that presents therapeutic challenges. Pain can cause neuroplastic changes at the cortical level, leading to central sensitization and difficulties with curative treatments; however, whether changes in structural and functional plasticity occur in patients with ONFH remains unclear. METHODS: A total of 23 ONFH inpatients who did not undergo surgery (14 males, nine females; aged 55.61 ± 13.79 years) and 20 controls (12 males, eight females; aged 47.25 ± 19.35 years) were enrolled. Functional indices of the amplitude of low-frequency fluctuation (ALFF), regional homogeneity (ReHo), and a structural index of tract-based spatial statistics (TBSS) were calculated for each participant. The probability distribution of fiber direction was determined according to the ALFF results. RESULTS: ONFH patients demonstrated increased ALFF in the bilateral dorsolateral superior frontal gyrus, right medial superior frontal gyrus, right middle frontal gyrus, and right supplementary motor area. In contrast, ONFH patients showed decreased ReHo in the left superior parietal gyrus and right inferior temporal gyrus. There were no significant differences in TBSS or probabilistic tractography. CONCLUSION: These results indicate cerebral pain processing in ONFH patients. It is advantageous to use functional magnetic resonance imaging to better understand pain pathogenesis and identify new therapeutic targets in ONFH patients.

6.
Front Neurol ; 12: 566119, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34276529

RESUMO

Neuropathic pain has been found to be related to profound reorganization in the function and structure of the brain. We previously demonstrated changes in local brain activity and functional/metabolic connectivity among selected brain regions by using neuroimaging methods. The present study further investigated large-scale metabolic brain network changes in 32 Sprague-Dawley rats with right brachial plexus avulsion injury (BPAI). Graph theory was applied in the analysis of 2-deoxy-2-[18F] fluoro-D-glucose (18F-FDG) PET images. Inter-subject metabolic networks were constructed by calculating correlation coefficients. Global and nodal network properties were calculated and comparisons between pre- and post-BPAI (7 days) status were conducted. The global network properties (including global efficiency, local efficiency and small-world index) and nodal betweenness centrality did not significantly change for all selected sparsity thresholds following BPAI (p > 0.05). As for nodal network properties, both nodal degree and nodal efficiency measures significantly increased in the left caudate putamen, left medial prefrontal cortex, and right caudate putamen (p < 0.001). The right entorhinal cortex showed a different nodal degree (p < 0.05) but not nodal efficiency. These four regions were selected for seed-based metabolic connectivity analysis. Strengthened connectivity was found among these seeds and distributed brain regions including sensorimotor area, cognitive area, and limbic system, etc. (p < 0.05). Our results indicated that the brain had the resilience to compensate for BPAI-induced neuropathic pain. However, the importance of bilateral caudate putamen, left medial prefrontal cortex, and right entorhinal cortex in the network was strengthened, as well as most of their connections with distributed brain regions.

7.
J Pain Res ; 14: 693-701, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33732015

RESUMO

INTRODUCTION: Numerous resting-state functional magnetic resonance imaging (fMRI) researches have indicated that large-scale functional and structural remodeling occurs in the whole brain despite an intact sensorimotor network after carpal tunnel syndrome (CTS). Investigators aimed to explore alterations of the global and nodal properties that occur in the whole brain network of patients with CTS based on topographic theory. METHODS: Standard-compliant fMRI data were collected from 27 patients with CTS in bilateral hands and 19 healthy control subjects in this cross-sectional study. The statistics based on brain networks were calculated the differences between the patients and the healthy. Several topological properties were computed, such as the small-worldness, nodal clustering coefficient, characteristic path length, and degree centrality. RESULTS: Compared to those of the healthy controls, the global properties of the CTS group exhibited a decreased characteristic path length. Changes in the local-level properties included a decreased nodal clustering coefficient in 6 separate brain regions and significantly different degree centrality in several brain regions that were related to sensorimotor function and pain. DISCUSSION: The study suggested that CTS reinforces global connections and makes their networks more random. The changed nodal properties were affiliated with basal ganglia-thalamo-cortical circuits and the pain matrix. These results provided new insights for improving our understanding of abnormal topological theory in relation to the functional brain networks of CTS patients. PERSPECTIVE: This article presents that the CTS patients' brain with a higher global efficiency. And the significant alterations in several brain regions which are more related to pain and motor processes. The results provided effective complements to the neural mechanisms underlying CTS.

8.
Br J Neurosurg ; 35(6): 730-735, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32500814

RESUMO

OBJECTIVES: As one of the most objectionable sequelae of facial paralysis, patients with facial synkinesis are more likely to be depressed and have lower quality of life than other facial paralysis patients. However, there is no research on the spatial patterns of intrinsic brain activity and functional connectivity in these patients. The objective of this study was to investigate the spatial patterns and cerebral plasticity of facial synkinesis patients. METHODS: A total of 20 facial synkinesis patients (18 men and 2 women; mean age: 33.35 ± 6.97 years old) and 19 healthy controls (17 men and 2 women; mean age: 33.21 ± 6.75 years old) were enrolled in this study. resting-state functional magnetic resonance imaging (rs-fMRI) data were collected, and the amplitude of low frequency fluctuation (ALFF), regional homogeneity (ReHo), and degree centrality (DC) were calculated for each participant. Two-sample t-tests were performed to compare the ALFF, ReHo, and DC maps between the two groups. RESULTS: Compared with the healthy controls, facial synkinesis patients exhibited decreased ALFF in the fusiform gyrus, lingual gyrus, parahippocampal gyrus, triangular inferior frontal gyrus, precentral gyrus, postcentral gyrus, cingulate gyrus, superior frontal gyrus, precuneus, caudate nucleus and thalamus; decreased ReHo in the cingulate gyrus, superior frontal gyrus, insula, superior temporal gyrus, orbital middle frontal gyrus, caudate nucleus and thalamus; and decreased DC in the frontal lobe, insula, cingulate gyrus, superior temporal gyrus, lenticular putamen, hippocampus and parahippocampal gyrus. We found significant overlap in the superior frontal gyrus across the ALFF, ReHo and DC analyses. CONCLUSIONS: In facial synkinesis patients, the neurological activity in brain areas is reduced and the local synchronization in motion-related brain regions is decreased. The superior frontal gyrus could be a crucial region in the unique spatial patterns of intrinsic brain activity and functional connectivity in these patients.


Assuntos
Qualidade de Vida , Sincinesia , Adulto , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Sincinesia/diagnóstico por imagem
9.
Brain Behav ; 10(9): e01747, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32657022

RESUMO

INTRODUCTION: Numerous treatments suggest that brain plasticity changes after peripheral nerve injury (PNI), and most studies examining functional magnetic resonance imaging focused on abnormal changes in specific brain regions. However, it is the large-scale interaction of neuronal networks instead of isolated brain regions contributed to the functional recovery after PNI. In the present study, we examined the intra- and internetworks alterations between the related functional resting-state networks (RSNs) in a sciatic nerve injury rat model. METHODS: Ninety-six female rats were divided into a control and model group. Unilateral sciatic nerve transection and direct anastomosis were performed in the latter group. We used an independent component analysis (ICA) algorithm to observe the changes in RSNs and assessed functional connectivity between different networks using the functional networks connectivity (FNC) toolbox. RESULTS: Six RSNs related to PNI were identified, including the basal ganglia network (BGN), sensorimotor network (SMN), salience network (SN), interoceptive network (IN), cerebellar network (CN), and default mode network (DMN). The model group showed significant changes in whole-brain FC changes within these resting-state networks (RSNs), but four of these RSNs exhibited a conspicuous decrease. The interalterations performed that significantly decreased FNC existed between the BGN and SMN, BGN and IN, and BGN and DMN (p < .05, corrected). A significant increase in FNC existed between DMN and CN and between CN and SN (p < .05, corrected). CONCLUSION: The results showed the large-scale functional reorganization at the network level after PNI. This evidence reveals new implications to the pathophysiological mechanisms in brain plasticity of PNI.


Assuntos
Mapeamento Encefálico , Traumatismos dos Nervos Periféricos , Animais , Encéfalo/diagnóstico por imagem , Feminino , Imageamento por Ressonância Magnética , Rede Nervosa/diagnóstico por imagem , Plasticidade Neuronal , Traumatismos dos Nervos Periféricos/diagnóstico por imagem , Ratos
10.
Front Neural Circuits ; 14: 35, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32625066

RESUMO

Objective: The present study aimed to investigate the analgesic effect of electroacupuncture (EA) in neuropathic pain due to brachial plexus avulsion injury (BPAI) and related changes in the metabolic brain connectivity. Methods: Neuropathic pain model due to BPAI was established in adult female Sprague-Dawley rats. EA stimulations (2/15 Hz, 30 min/day, 5-day intervention followed by 2-day rest in each session) were applied to the fifth-seventh cervical "Jiaji" acupoints on the noninjured side from 1st to 12th weeks following BPAI (EA group, n = 8). Three control groups included sham EA (nonelectrical acupuncture applied to 3 mm lateral to the real "Jiaji" acupoints), BPAI-only, and normal rats (no particular intervention; eight rats in each group). Thermal withdrawal latency (TWL) of the noninjured forepaw was regularly tested to evaluate the threshold of thermalgesia. Small animal [fluorine-18]-fluoro-2-deoxy-D-glucose (18F-FDG) PET/CT scans of brain were conducted at the end of 4th, 12th, and 16th weeks to explore metabolic alterations of brain. Results: In the EA group, the TWL of the noninjured forepaw significantly decreased following BPAI and then increased following EA stimulation, compared with sham EA (P < 0.001). The metabolic brain connectivity among somatosensory cortex (SC), motor cortex (MC), caudate putamen (Cpu), and dorsolateral thalamus (DLT) in bilateral hemispheres decreased throughout the 16 weeks' observation in the BPAI-only group, compared with the normal rats (P < 0.05). In the EA group, the strength of connectivity among the above regions were found to be increased at the end of 4th week following BPAI modeling, decreased at 12th week, and then increased again at 16th week (P < 0.05). The changes in metabolic connectivity were uncharacteristic and dispersed in the sham EA group. Conclusion: The study revealed long-term and extensive changes of metabolic brain connectivity in EA-treated BPAI-induced neuropathic pain rats. Bilateral sensorimotor and pain-related brain regions were mainly involved in this process. It indicated that modulation of brain metabolic connectivity might be an important mechanism of analgesic effect in EA stimulation for the treatment of neuropathic pain.


Assuntos
Plexo Braquial/lesões , Encéfalo/metabolismo , Eletroacupuntura/métodos , Rede Nervosa/metabolismo , Neuralgia/metabolismo , Neuralgia/terapia , Animais , Encéfalo/diagnóstico por imagem , Feminino , Rede Nervosa/diagnóstico por imagem , Neuralgia/diagnóstico por imagem , Ratos , Ratos Sprague-Dawley
11.
J Pain Res ; 13: 585-595, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32273747

RESUMO

PURPOSE: Brain organisation is involved in the mechanism of neuropathic pain. Acupuncture is a common clinical practise in traditional Chinese medicine for the treatment of chronic pain. This study explored electroacupuncture's effects on brain metabolism following brachial plexus avulsion injury (BPAI)-induced pain. METHODS: A total of 32 female rats were randomised into a normal group, model group, sham electroacupuncture group, and electroacupuncture group. A pain model was included via right BPAI. The electroacupuncture intervention at cervical "Jiaji" points (C5-7) was performed for 11 weeks. The mechanical withdrawal threshold of the non-injured (left) forepaw was measured at the baseline and on days 3, 7, 14, 21, 28, 56, 84, and 112 subsequent to BPAI. Positron emission tomography (PET) was applied to explore metabolic changes on days 28, 84, and 112. RESULTS: After electroacupuncture, the mechanical withdrawal threshold of the left forepaws was significantly elevated and the effect persisted until 4 weeks after the intervention ceased (p<0.05 or p<0.001). In the sensorimotor-related brain regions, standardised uptake values in the bilateral somatosensory and motor cortices were observed in the electroacupuncture group. Metabolism particularly increased in the right somatosensory cortex. Metabolism changes also occurred in the pain-related brain regions and emotion- and cognition-related brain regions. CONCLUSION: The present study demonstrated the beneficial effects of electroacupuncture for relieving BPAI-induced neuropathic pain in rats. Electroacupuncture intervention might inhibit maladaptive plasticity in brain areas governing multidimensional functions, especially in sensorimotor- and cognition-related cortices.

12.
Neurol Sci ; 41(9): 2453-2460, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32206961

RESUMO

BACKGROUND: Structural remodeling is a classic manifestation of disease decompensation. Facial synkinesis is the most troubling sequela of peripheral facial neuritis, and its structural remodeling, especially in white matter (WM), is still poorly understood. Therefore, understanding WM microstructure is important for predicting WM pathology and for early intervention in facial synkinesis patients. METHODS: A total of 20 facial synkinesis patients (18 men and 2 women; mean age, 33.35 ± 6.97 years old) and 19 healthy controls (17 men and 2 women; mean age, 33.21 ± 6.75 years old) were enrolled in this study. rs-fMRI data, diffusion tensor imaging (DTI) data, and Beck's Depression Inventory (BDI) data were collected, and tract-based spatial statistics (TBSS) and voxel-mirrored homotopic connectivity (VMHC) values were used to analyze changes in WM microstructure and interhemispheric coordination. RESULTS: Compared with the healthy controls, facial synkinesis patients exhibited significantly lower regional fractional anisotropy (FA) in the genu of the corpus callosum and the body of the corpus callosum, significantly higher regional FA in the retrolenticular part of the internal capsule, and significantly decreased VMHC values bilaterally in the orbital inferior frontal gyri, the fusiform gyri, the superior temporal gyri, the superior frontal gyri, and the supplementary motor areas. Furthermore, a lower regional FA in the genu of the corpus callosum was correlated with higher BDI scores in facial synkinesis patients. CONCLUSION: Structural remodeling, especially changes in white matter microstructure, may be the central mechanism for severe sequelae of peripheral facial neuritis.


Assuntos
Doenças do Nervo Facial , Substância Branca , Adulto , Anisotropia , Encéfalo , Corpo Caloso , Imagem de Tensor de Difusão , Feminino , Humanos , Masculino , Substância Branca/diagnóstico por imagem
13.
J Clin Neurosci ; 69: 250-256, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31477463

RESUMO

Electroacupuncture (EA) is an adjuvant therapy for peripheral nerve injury (PNI). Both peripheral and central alterations contribute to the rehabilitation process. We employed diffusion tensor imaging (DTI) to investigate the diffusion plasticity of afferent and efferent pathways caused by EA in model of peripheral nerve injury and reparation. Twenty-four rats were divided into three groups: normal group, model group and intervention group. Rats of the model group and the intervention group underwent sciatic nerve transection and anastomosis. EA intervention was performed on the intervention group at ST-36 and GB-30 for three months. Gait assessment and DTI were conducted at days post-operative (DPO) 30, 60 and 90. We selected corticospinal tract, spinothalamic tract and internal capsule as regions of interest and analyzed diffusion metrics including fractional anisotropy (FA), axial diffusivity (AD) and radial diffusivity (RD). FA values and RD values displayed significant differences or obvious tendency while AD values maintained a stable level. RD values displayed better indicative performance than FA in internal capsule. The intervention group presented significant correlation between RD values and Regularity Index (RI) during the intervention period. The effect of EA on peripheral nerve injury repairing rats appeared to be accelerated recovery process of sensory and motor neural pathway. We proposed that RD was a potential in vivo indicator for structural plasticity caused by EA and PNI.


Assuntos
Eletroacupuntura , Cápsula Interna/fisiopatologia , Vias Neurais/fisiopatologia , Plasticidade Neuronal/fisiologia , Traumatismos dos Nervos Periféricos/fisiopatologia , Animais , Imagem de Tensor de Difusão/métodos , Modelos Animais de Doenças , Masculino , Ratos , Ratos Sprague-Dawley , Nervo Isquiático/lesões
14.
Pain Physician ; 22(3): E215-E224, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31151344

RESUMO

BACKGROUND: Approximately 30% to 80% of patients with brachial plexus avulsion (BPA) developed neuropathic pain. It is an intolerable neuropathic pain, which brings heavy burden to family and society. In addition to motor and sensory deficits, neuropathic pain can be another serious sequela that equally influences the patient. The development of a microsurgical technique has promoted the treatment and rehabilitation of brachial plexus injury, but pain relief after BPA is still a difficult problem. OBJECTIVES: The present study aimed to semi-quantify changes in the behavior, spinal cord and cerebral metabolism in a neuropathic pain model following BPA injury in rats. STUDY DESIGN: Controlled animal study. SETTING: Institute of Rehabilitation Medicine, Shanghai, China. METHODS: A total of 15 Sprague-Dawley rats, weighing 200 to 220 g, were randomly divided into 2 groups: experimental group (n = 10) and control group (n = 5). In the experimental group, neuropathic pain induced by BPA was established by directly avulsing the C5, C6, C7, C8, and T1 roots on the right side from the spinal cord. Rats in the control group only received open-close surgery. The autotomic behavior of biting their own digits was recorded and scored at 2 months after the surgery. Small animal positron emission tomography/computed tomography (PET/CT) images after injection of a 2-[18F]-fluoro-2-deoxy-D-glucose (18F-FDG) tracer were acquired to evaluate glucose metabolism in pain-related brain regions before and after the surgery, respectively. Semi-quantitative values of cortical to cerebellum standardized uptake value (SUV) ratios were calculated. Then, the animals were euthanized and the cervical segments of the spinal cord were removed for detection of glial fibrillary acidic protein (GFAP) expression in the astrocytes by immunohistochemical assay. RESULTS: Nine of the 10 rats (90%) in the experimental group showed autotomic behavior at 2 months after the surgery. Slight autotomic behavior was noted only in one of 5 rats (20%) from the control group. The autotomic score in the experimental group was significantly higher than that in the control group (5.4 ± 1.0 vs. 0.2 ± 0.4, P < 0.05). The experimental group showed significantly higher SUV ratio in both the right and left thalamus, compared to the control group (P < 0.05). Immunohistochemical assay demonstrated that GFAP positive astrocytes in the dorsal horn at the injured side significantly increased compared to the control group (P < 0.05). LIMITATIONS: There are differences between small animals and human beings, and the structure and function of the human brain is more complex than in rodents. Therefore, extrapolation of the present conclusion should be cautious. CONCLUSIONS: The present study reported a unique model of neuropathic pain following total BPA in rodents, which was demonstrated by a higher rate and score of autotomic behavior. More astrocytes were found activated in the spinal cord at the corresponding level of C5 and C6 spinal cord. In the small animal PET/CT imaging, significantly higher standardized glucose metabolic activity was found in both the right and left thalamus in the experimental group. The present study semi-quantified the neuropathic pain behavior in rats and explored the plastic changes in the spinal and brain metabolism. KEY WORDS: Brachial plexus avulsion, small animal PET/CT, glucose metabolism, neuropathic pain, astrocyte, 18F-FDG.


Assuntos
Encéfalo/metabolismo , Encéfalo/fisiopatologia , Neuralgia/metabolismo , Neuralgia/fisiopatologia , Medula Espinal/metabolismo , Medula Espinal/fisiopatologia , Animais , Plexo Braquial/lesões , Encéfalo/patologia , China , Modelos Animais de Doenças , Masculino , Neuralgia/patologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Ratos , Ratos Sprague-Dawley , Medula Espinal/patologia
15.
J Neurosurg ; 132(4): 1295-1303, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30835695

RESUMO

OBJECTIVE: Refractory deafferentation pain has been evidenced to be related to central nervous system neuroplasticity. In this study, the authors sought to explore the underlying glucose metabolic changes in the brain after brachial plexus avulsion, particularly metabolic connectivity. METHODS: Rats with unilateral deafferentation following brachial plexus avulsion, a pain model of deafferentation pain, were scanned by small-animal 2-deoxy-[18F]fluoro-d-glucose (18F-FDG) PET/CT to explore the changes of metabolic connectivity among different brain regions. Thermal withdrawal latency (TWL) and mechanical withdrawal threshold (MWT) of the intact forepaw were also measured for evaluating pain sensitization. Brain metabolic connectivity and TWL were compared from baseline to 1 week after brachial plexus avulsion. RESULTS: Alterations of metabolic connectivity occurred not only within the unilateral hemisphere contralateral to the injured forelimb, but also in the other hemisphere and even in the connections between bilateral hemispheres. Metabolic connectivity significantly decreased between sensorimotor-related areas within the left hemisphere (contralateral to the injured forelimb) (p < 0.05), as well as between areas across bilateral hemispheres (p < 0.05). Connectivity between areas within the right hemisphere (ipsilateral to the injured forelimb) significantly increased (p = 0.034). TWL and MWT of the left (intact) forepaw after surgery were significantly lower than those at baseline (p < 0.001). CONCLUSIONS: This study revealed that unilateral brachial plexus avulsion facilitates pain sensitization in the opposite limb. A specific pattern of brain metabolic changes occurred in this procedure. Metabolic connectivity reorganized not only in the sensorimotor area corresponding to the affected forelimb, but also in extensive areas involving the bilateral hemispheres. These findings may broaden our understanding of central nervous system changes, as well as provide new information and a potential intervention target for nosogenesis of deafferentation pain.

16.
Brain Res ; 1712: 132-138, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30738025

RESUMO

The present study aimed to investigate cerebral metabolic changes in a neuropathic pain model following deafferentation. A total of 24 Sprague-Dawley rats were included for modeling of right brachial plexus avulsion (BPA) through the posterior approach. As nerve injury would cause central sensitization and facilitate pain sensitivity in other parts of the body, thermal withdrawal latency (TWL) of the intact forepaw was assessed to investigate the level of pain perception following BPA-induced neuropathic pain. [Fluorine-18]-fluoro-2-deoxy-d-glucose (18F-FDG) positron emission tomography (PET) was applied to the brain before and after brachial plexus avulsion to explore metabolic changes in neuropathic pain following deafferentation. The TWL of the left (intact) forepaw was significantly lower after BPA than that of baseline (p < 0.001). Using TWL as a covariate, standardized uptake values (SUVs) of 18F-FDG significantly increased in the ipsilateral dorsolateral thalamus and contralateral anterodorsal hippocampus after BPA. Conversely, SUVs in multiple brain regions decreased, including the contralateral somatosensory cortex, ipsilateral cingulate cortex, and ipsilateral temporal association cortex. The Pearson correlation analysis showed that the SUVs of the contralateral anterodorsal hippocampus and ipsilateral dorsolateral thalamus were negatively related to the TWL of the intact forepaw, whereas the SUVs in the contralateral somatosensory cortex and ipsilateral cingulate cortex were positively related to it (p < 0.05). These findings indicate that upregulation of metabolism in the anterodorsal hippocampus and dorsolateral thalamus and downregulation metabolism in the contralateral somatosensory cortex and ipsilateral cingulate cortex could be a unique pattern of metabolic changes for neuropathic pain following brachial plexus avulsion.


Assuntos
Plexo Braquial/metabolismo , Encéfalo/metabolismo , Neuralgia/metabolismo , Animais , Modelos Animais de Doenças , Feminino , Fluordesoxiglucose F18/metabolismo , Medição da Dor/métodos , Limiar da Dor/fisiologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/veterinária , Ratos , Ratos Sprague-Dawley , Córtex Somatossensorial/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...