Clinical characteristics and treatment of spinal cord injury in children and adolescents / 中华创伤杂志(英文版)

Pediatric and adult spinal cord injuries (SCI) are distinct entities. Children and adolescents with SCI must suffer from lifelong disabilities, which is a heavy burden on patients, their families and the society. There are differences in Chinese and foreign literature reports on the incidence, injury mechanism and prognosis of SCI in children and adolescents. In addition to traumatic injuries such as car accidents and falls, the proportion of sports injuries is increasing. The most common sports injury is the backbend during dance practice. Compared with adults, children and adolescents are considered to have a greater potential for neurological improvement. The pathogenesis and treatment of pediatric SCI remains unclear. The mainstream view is that the mechanism of nerve damage in pediatric SCI include flexion, hyperextension, longitudinal distraction and ischemia. We also discuss the advantages and disadvantages of drugs such as methylprednisolone in the treatment of pediatric SCI and the indications and timing of surgery. In addition, the complications of pediatric SCI are also worthy of attention. New imaging techniques such as diffusion tensor imaging and diffusion tensor tractography may be used for diagnosis and assessment of prognosis. This article reviews the epidemiology, pathogenesis, imaging, clinical characteristics, treatment and complications of SCI in children and adolescents. Although current treatment cannot completely restore neurological function, patient quality of life can be enhanced. Continued developments and advances in the research of SCI may eventually provide a cure for children and adolescents with this kind of injury.

Reproducible Abnormalities and Diagnostic Generalizability of White Matter in Alzheimer's Disease / 神经科学通报·英文版

Alzheimer's disease (AD) is associated with the impairment of white matter (WM) tracts. The current study aimed to verify the utility of WM as the neuroimaging marker of AD with multisite diffusion tensor imaging datasets [321 patients with AD, 265 patients with mild cognitive impairment (MCI), 279 normal controls (NC)], a unified pipeline, and independent site cross-validation. Automated fiber quantification was used to extract diffusion profiles along tracts. Random-effects meta-analyses showed a reproducible degeneration pattern in which fractional anisotropy significantly decreased in the AD and MCI groups compared with NC. Machine learning models using tract-based features showed good generalizability among independent site cross-validation. The diffusion metrics of the altered regions and the AD probability predicted by the models were highly correlated with cognitive ability in the AD and MCI groups. We highlighted the reproducibility and generalizability of the degeneration pattern of WM tracts in AD.

Efficacy and mechanism of scalp acupuncture for spastic cerebral palsy / 中国针灸

OBJECTIVE@#To observe the clinical efficacy of scalp acupuncture for spastic cerebral palsy (CP), and to explore its possible mechanism based on brain white matter fiber bundles, nerve growth related proteins and inflammatory cytokines.@*METHODS@#A total of 90 children with spastic CP were randomly divided into a scalp acupuncture group and a sham scalp acupuncture group, 45 cases in each group. The children in the two groups were treated with conventional comprehensive rehabilitation treatment. The children in the scalp acupuncture group were treated with scalp acupuncture at the parietal temporal anterior oblique line, parietal temporal posterior oblique line on the affected side, and parietal midline. The children in the sham scalp acupuncture group were treated with scalp acupuncture at 1 cun next to the above point lines. The needles were kept for 30 min, once a day, 5 days a week, for 12 weeks. Before and after treatment, the diffusion tensor imaging (DTI) indexes of magnetic resonance (FA values of corticospinal tract [CST], anterior limb of internal capsule [ICAL], posterior limb of internal capsule [ICPL], genu of internal capsule [ICGL], genu of corpus callosum [GCC], body of corpus callosum [BCC] and splenium of corpus callosum [SCC]), serum levels of nerve growth related proteins (neuron-specific enolase [NSE], glial fibrillary acidic protein [GFAP], myelin basic protein [MBP], ubiquitin carboxy terminal hydrolase-L1 [UCH-L1]) and inflammatory cytokines (interleukin 33 [IL-33], tumor necrosis factor α [TNF-α]), cerebral hemodynamic indexes (mean blood flow velocity [Vm], systolic peak flow velocity [Vs] and resistance index [RI], pulsatility index [PI] of cerebral artery), surface electromyography (SEMG) signal indexes (root mean square [RMS] values of rectus femoris, hamstring muscles, gastrocnemius muscles, tibialis anterior muscles), gross motor function measure-88 (GMFM-88) score, modified Ashworth scale (MAS) score, ability of daily living (ADL) score were observed in the two groups. The clinical effect of the two groups was compared.@*RESULTS@#After treatment, the FA value of each fiber bundle, Vm, Vs, GMFM-88 scores and ADL scores in the two groups were higher than those before treatment (P<0.05), and the above indexes in the scalp acupuncture group were higher than those in the sham scalp acupuncture group (P<0.05). After treatment, the serum levels of NSE, GFAP, MBP, UCH-L1, IL-33, TNF-α as well as RI, PI, MAS scores and RMS values of each muscle were lower than those before treatment (P<0.05), and the above indexes in the scalp acupuncture group were lower than those in the sham scalp acupuncture group (P<0.05). The total effective rate was 95.6% (43/45) in the scalp acupuncture group, which was higher than 82.2% (37/45) in the sham scalp acupuncture group (P<0.05).@*CONCLUSION@#Scalp acupuncture could effectively treat spastic CP, improve the cerebral hemodynamics and gross motor function, reduce muscle tension and spasticity, and improve the ability of daily life. The mechanism may be related to repairing the white matter fiber bundles and regulating the levels of nerve growth related proteins and inflammatory cytokines.

Current contribution of diffusion tensor imaging in the evaluation of diffuse axonal injury / Contribuição atual da imagem por tensor de difusão na avaliação da lesão axonal difusa

ABSTRACT Traumatic brain injury (TBI) is the number one cause of death and morbidity among young adults. Moreover, survivors are frequently left with functional disabilities during the most productive years of their lives. One main aspect of TBI pathology is diffuse axonal injury, which is increasingly recognized due to its presence in 40% to 50% of all cases that require hospital admission. Diffuse axonal injury is defined as widespread axonal damage and is characterized by complete axotomy and secondary reactions due to overall axonopathy. These changes can be seen in neuroimaging studies as hemorrhagic focal areas and diffuse edema. However, the diffuse axonal injury findings are frequently under-recognized in conventional neuroimaging studies. In such scenarios, diffuse tensor imaging (DTI) plays an important role because it provides further information on white matter integrity that is not obtained with standard magnetic resonance imaging sequences. Extensive reviews concerning the physics of DTI and its use in the context of TBI patients have been published, but these issues are still hazy for many allied-health professionals. Herein, we aim to review the current contribution of diverse state-of-the-art DTI analytical methods to the understanding of diffuse axonal injury pathophysiology and prognosis, to serve as a quick reference for those interested in planning new studies and who are involved in the care of TBI victims. For this purpose, a comprehensive search in Pubmed was performed using the following keywords: "traumatic brain injury", "diffuse axonal injury", and "diffusion tensor imaging".

RESUMO O traumatismo cranioencefálico (TCE) é a principal causa de morbimortalidade entre adultos jovens. Aqueles que sobrevivem são frequentemente deixados com sequelas funcionais nos anos mais produtivos de suas vidas. O principal aspecto fisiopatológico do TCE é a lesão axonial difusa (LAD), cada vez mais destacada pois está presente em 40 a 50% dos casos que necessitam de internação hospitalar. LAD é definida como a injúria axonial extensa caracterizada pela axoniotomia completa assim como pelas reações secundárias a axoniopatia, que são demonstradas por métodos de neuroimagem como áreas de edema e micro-hemorragia. Entretanto, os achados da LAD são frequentemente subestimados em estudos de neuroimagem convencional. É neste contexto que imagens por tensor de difusão (DTI) ganharam ênfase, já que permitem obter informações sobre a integridade da substância branca que não eram obtidas por sequências convencionais de ressonância magnética (RM). Existem artigos extensos sobre os fundamentos físicos e as aplicações de DTI em pacientes vítimas de TCE, no entanto, estes assuntos permanecem ainda nebulosos a alguns profissionais da área de saúde. Deste modo, propomos uma revisão didática sobre a contribuição do estado da arte de diferentes métodos analíticos de DTI no entendimento do processo da fisiopatologia e prognóstico da LAD, servindo assim como uma ferramenta acessível para aqueles interessados em planejamento de novos estudos e aqueles envolvidos no tratamento de vítimas de TCE. Uma pesquisa abrangente foi realizada no Pubmed com as seguintes palavras-chave: "traumatismo cranioencefálico", "lesão axonial difusa", "imagem por tensor de difusão".

Avaliação microestrutural do corpo caloso em pacientes com lúpus eritematoso sistêmico: um estudo por imagem de tensor de difusão pela ressonância magnética / Microstructural evaluation of the corpus callosum in patients with systemic lupus erythematosus: a magnetic resonance diffusion tensor imaging study

Resumo: Determinar as alterações microestruturais do corpo caloso (CC) em pacientes com lúpus eritematoso sistêmico (LES) pelas imagens de ressonância magnética, através da técnica de tensor de difusão (DTI) e determinar associações com as manifestações clínicas e laboratoriais e com o tratamento. Material e métodos: O estudo avaliou 116 pacientes com LES (110 mulheres, média de idade 39,4 anos) e 48 controles saudáveis (40 mulheres, média de idade 35,5 anos). Todos os pacientes preenchiam 4 ou mais critérios classificatórios de LES do Colégio Americano de Reumatologia (ACR) e as manifestações neuropsiquiátricas foram analisadas segundo os critérios do ACR para o acometimento neuropsiquiátrico, classificadas em ativas, inativas ou ausentes na data de inclusão do estudo. Foram avaliadas as manifestações clínicas, laboratoriais e atividade de doença (SLEDAI - Systemic Lupus Erythematosus Disease Activity Index) e índice de dano (SLICC- Systemic Lupus International Collaborating Clinics /ACR). Todos os pacientes e controles foram submetidos ao exame de RM de crânio utilizando a técnica de tensor de difusão (DTI) e os valores de anisotropia fracionada (FA), difusividade média (MD), difusividade axial (AD) e radial (RD) foram calculados. O CC foi segmentado em 5 sub-regiões, segundo classificação validada. Resultados: Os pacientes com LES apresentaram valores significativamente menores de FA (0,629±0,0612 vs 0,6781±0,0154; p<0,001) e significativamente maiores de MD (0,0023±0,0036 vs 0,0010±0,0001; p=0,020), AD (0,0018±0,0001 vs 0,0017±0,0002; p=0,040) e RD (0,0008±0,0006 vs 0,0005±0,0001; p=0,024) quando comparados aos controles. Os pacientes com LESNP ativo quando comparado aos LESNP inativo apresentaram valores menores de FA [(0,590±0,072 vs 0,661±0,021); (0,590±0,072 vs 0,646±0,045); (0,590±0,072 vs 0,678±0,015)] e maiores de MD [(0,0044±0,005 vs 0,0010±0,0001); (0,0044±0,005 vs 0,001±0,001); (0,0044±0,005 vs 0,001±0,0001)], AD [(0,0018±0,001 vs 0,0017±0,00009); (0,0018±0,001 vs 0,0017±0,0002)] e RD que os controles (0,0007±0,002 vs 0,0011±0,0006). O SLEDAI apresentou correlação negativa com FA (r=-0,346; p<0,001) e positiva com MD (r=0,239; p=0,010), AD (r=0,223; p=0,016) e RD (r=0,218; p=0,018). O SLICC apresentou correlação negativa com FA (r=-0,314; p= 0,001) e positiva com MD (r=0,275; p=0,002) e AD (r=0,193; p=0,03). Na avaliação parcelada do CC, observamos comprometimento das parcelas anteriores do corpo caloso nos LESNP ativo quando comparado aos controles. Conclusão: Nosso estudo indica que há comprometimento microestrutural em pacientes com LESNP ativo e em pacientes com atividade sistêmica da doença. Não observamos dano microestrutural nos pacientes com LESNP inativo quando comparados aos LES sem MNP e controle, no CC total. Observamos na análise parcelada do CC que as parcelas anteriores foram as que apresentaram alteração microestrutural quando analisadas individualmente. O estudo DTI pela RM pode fornecer elementos para uma análise mais abrangente da microestrutura da substância branca nos pacientes com LES com MNP(AU)

Abstract: The aim of this study was to determine the microstructural changes of the corpus callosum in patients with systemic lupus erythematosus by magnetic resonance imaging using the diffusion tensor technique (DTI) and to determine associations with neuropsychiatric, clinical and laboratory manifestations and treatment. Material and method: The study evaluated 116 patients with SLE (110 women, mean age 40 years) and 48 healthy controls (40 women, mean age 35.5 years). All patients fulfilled 4 or more American College of Rheumatology (ACR) SLE criteria and neuropsychiatric manifestations (NPM) were analyzed based on the ACR diagnostic criteria for neuropsychiatric impairment, classified as active, inactive, or absent on the date of inclusion of the study. Clinical, laboratory and disease manifestations (SLEDAI) and SLICC (Systemic Lupus International Collaborating Clinics / ACR) were evaluated. All patients and controls underwent cranial MRI examination using diffusion tensor technique (DTI) and fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial (RA) values were calculated. The CC was segmented into 5 sub-regions, according to the validated classification. Results: Patients with SLE presented significantly lower values of FA (0.629 ± 0.0612 vs 0.67781 ± 0.0154, p <0.001) and significantly higher MD values (0.0023 ± 0.0036 vs 0.0010 ± 0.0001 , p = 0.020), and AD (0.0018 ± 0.0001 vs. 0.0017 ± 0.0002, p = 0.040) and RD (0.0008 ± 0.0006 vs 0.0005 ± 0.0001, p = 0.024 ) when compared to controls. Patients with active NPSLE when compared to inactive NPSLE had lower values of FA [(0.590 ± 0.072 vs 0.661 ± 0.021); (0.590 ± 0.072 vs. 0.646 ± 0.045); (0.590 ± 0.072 vs. 0.678 ± 0.015)] and higher MD [(0.0044 ± 0.005 vs. 0.0010 ± 0.0001); (0.0044 ± 0.005 vs. 0.001 ± 0.001); (0.0044 ± 0.005 vs 0.001 ± 0.0001)], AD [(0.0018 ± 0.001 vs. 0.0017 ± 0.00009); (0.0018 ± 0.001 vs. 0.0017 ± 0.0002)] and RD than the controls (0.0007 ± 0.002 vs 0.0011 ± 0.0006). The SLEDAI had a negative correlation with FA (r = -0.346, p <0.001) and positive with MD (r = 0.239, p = 0.010), AD (r = 0.223, p = 0.016) and RD 0.018). The SLICC had a negative correlation with FA (r = -0.314, p = 0.001) and positive with MD (r = 0.275, p = 0.002) and AD (r = 0.193, p = 0.03). In the partial evaluation of CC, we observed impairment of the anterior portion of the corpus callosum in active NPSLE when compared to controls. Conclusion: Our study indicates that there is microstructural impairment in patients with active NPSLE and in patients with systemic disease activity. We did not observe microstructural damage in patients with inactive NPSLE when compared to SLE without NPM and control, in the total CC. We observed in the split analysis of CC that the previous plots were those that presented microstructural alteration when analyzed individually. The DTI MRI study may provide elements for a more comprehensive analysis of the microstructure of the white matter in patients with SLE with NPM(AU)

Latent class analysis of attention and white matter correlation in children with attention-deficit/hyperactivity disorder

This study aimed to explore attentional patterns among children with inattentive attention-deficit/hyperactivity disorder (ADHD-I) and children with typical development (TD), using a latent class analysis (LCA). Patterns of brain connectivity were also explored. The sample comprised 29 ADHD-I and 29 TD matched children. An LCA was conducted to reclassify subjects according to their attentional performance, considering cognitive measures of attention and behavioral symptoms, regardless of group of origin. The new clusters were then compared in respect to brain white matter measurements (extracted from diffusion tensor imaging). Participants were rearranged in 2 new latent classes, according to their performance in an attention task and the results of behavioral scales, resulting in groups with more homogeneous attentional profiles. A comparison of the 2 new classes using the white matter measurements revealed increased fractional anisotropy in the left inferior fronto-occipital fasciculus and left inferior longitudinal fasciculus for the class composed by participants with a higher risk of attentional problems. The findings indicated that it was possible to observe variability regarding neuropsychological profile, accompanied by underpinning neurobiological differences, even among individuals with the same disorder subtype - inattentive ADHD. This specific data-driven clustering analysis may help to enhance understanding of the pathophysiology of the disorder's phenotypes.

Diffusion tensor imaging of brain white matter in Huntington gene mutation individuals / Imagem por tensor de difusão em indivíduos com mutação do gene da doença de Huntington

ABSTRACT Objective To evaluate the role of the involvement of white matter tracts in huntingtin gene mutation patients as a potential biomarker of the progression of the disease. Methods We evaluated 34 participants (11 symptomatic huntingtin gene mutation, 12 presymptomatic huntingtin gene mutation, and 11 controls). We performed brain magnetic resonance imaging to assess white matter integrity using diffusion tensor imaging, with measurement of fractional anisotropy. Results We observed a significant decrease of fractional anisotropy in the cortical spinal tracts, corona radiate, corpus callosum, external capsule, thalamic radiations, superior and inferior longitudinal fasciculus, and inferior frontal-occipital fasciculus in the Huntington disease group compared to the control and presymptomatic groups. Reduction of fractional anisotropy is indicative of a degenerative process and axonal loss. There was no statistically significant difference between the presymptomatic and control groups. Conclusion White matter integrity is affected in huntingtin gene mutation symptomatic individuals, but other studies with larger samples are required to assess its usefulness in the progression of the neurodegenerative process.

RESUMO Objetivo Avaliar o envolvimento da substância branca (SB) cerebral em indivíduos com mutação do gene da huntingtina. Métodos Foram avaliados 34 indivíduos: 11 com mutação do gene da huntingtina sintomática, 12 assintomáticos com mutação do gene da huntingtina e 11 indivíduos controles. Realizamos ressonância magnética cerebral para avaliar a integridade da SB usando o tensor de difusão (DTI), com medição da anisotrofia fracionada (FA). Resultados Observamos uma diminuição da FA no trato corticoespinhal, coroa radiada, corpo caloso (joelho, corpo e esplênio), cápsula externa, radiações talâmicas, fascículo longitudinal superior e inferior, e fascículo frontal-occipital inferior no grupo dos indivíduos com mutação sintomática. A redução da FA é indicativa de processo degenerativo e perda axonal. Não houve diferença estatística entre os grupos controle e pré-sintomático. Conclusão Houve comprometimento da integridade da SB em indivíduos com mutação no gene da Huntingtina sintomática, mas outros estudos são necessários para avaliar a sua utilidade na progressão do processo neurodegenerativo.

The fornix: from real to virtual dissection / O fornix: da dissecção real para a virtual

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Assessment of the diagnostic value of diffusion tensor imaging in patients with spinal cord compression: a meta-analysis

We investigated the diagnostic value of the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) of magnetic resonance diffusion tensor imaging (DTI) in patients with spinal cord compression (SCC) using a meta-analysis framework. Multiple scientific literature databases were exhaustively searched to identify articles relevant to this study. Mean values and standardized mean differences (SMDs) were calculated for the ADC and FA in normal and diseased tissues. The STATA version 12.0 software was used for statistical analysis. Of the 41 articles initially retrieved through database searches, 11 case-control studies were eligible for the meta-analysis and contained a combined total of 645 human subjects (394 patients with SCC and 251 healthy controls). All 11 studies reported data on FA, and 9 contained data related to the ADC. The combined SMDs of the ADC and FA showed that the ADC was significantly higher and the FA was lower in patients with SCC than in healthy controls. Subgroup analysis based on the b value showed higher ADCs in patients with SCC than in healthy controls at b values of both ≤500 and >500 s/mm2. In summary, the main findings of this meta-analysis revealed an increased ADC and decreased FA in patients with SCC, indicating that DTI is an important diagnostic imaging tool to assess patients suspected to have SCC.

Somatic and cognitive-affective depressive symptoms among patients with heart disease: differences by sex and age / Sintomas depressivos somáticos e cognitivo-afetivos entre pacientes com doença cardíaca: diferenças por sexo e idade / Síntomas depresivos somáticos y cognitivo-afectivos entre pacientes con enfermedad cardíaca: diferencias por sexo y edad

OBJECTIVE: this study investigated the association of somatic and cognitive-affective symptoms with sex and age, among patients hospitalized with heart disease. METHOD: this study was a secondary analysis of two previous observational studies totaling 531 patients with heart disease, hospitalized from 2005 to 2011 in two public hospitals in Ribeirão Preto, state of São Paulo, Brazil. Somatic and cognitive-affective symptoms were assessed using the subscales of the Beck Depression Inventory - I (BDI-I). RESULTS: of 531 participants, 62.7% were male, with a mean age 57.3 years (SD= 13.0) for males and 56.2 years (SD= 12.1) for females. Analyses of variance showed an effect of sex (p<0.001 for somatic and p=0.005 for cognitive-affective symptoms), but no effect of age. Women presented with higher mean values than men in both BDI-I subscales: 7.1 (4.5) vs. 5.4 (4.3) for somatic, and 8.3 (7.9) vs. 6.7 (7.2) for cognitive-affective symptoms. There were no differences by age for somatic (p=0.84) or cognitive-affective symptoms (p=0.84). CONCLUSION: women hospitalized with heart disease had more somatic and cognitive-affective symptoms than men. We found no association of somatic and cognitive-affective symptoms with age. Future research for these patients could reveal whether these differences according to sex continue throughout the rehabilitation process. .

OBJETIVO: investigar a associação de sintomas somáticos e cognitivo-afetivos ao sexo e à idade de pacientes hospitalizados com doença cardíaca. MÉTODO: este estudo é resultado de uma análise secundária de dois estudos observacionais anteriores, totalizando 531 pacientes com doença cardíaca, internados de 2005 a 2011, em dois hospitais públicos em Ribeirão Preto, estado de São Paulo, Brasil. Os sintomas somáticos e cognitivo-afetivos foram avaliados utilizando-se as subescalas do Inventário de Depressão de Beck - I (IDB-I). RESULTADOS: dos 531 participantes, 62,7% são do sexo masculino, com média de idade de 57,3 anos (DP= 13,0) para os homens e 56,2 anos (DP = 12,1) para as mulheres. A análise da variância mostrou um efeito relacionado ao sexo do paciente (p<0,001 para sintomas somáticos e p=0,005 para os sintomas cognitivo-afetivos), mas nenhum efeito relacionado à idade. As mulheres apresentaram maiores escores do que os homens em ambas subescalas IDB-I: 7,1 (4,5) e 5,4 (4,3) para os sintomas somáticos, e 8,3 (7,9) e 6,7 (7,2) para os sintomas cognitivo-afetivos, respectivamente. Não houve diferenças referentes à idade para sintomas somáticos (p=0,84) ou sintomas cognitivo-afetivos (p=0,84). CONCLUSÃO: as mulheres internadas com doença cardíaca apresentaram mais sintomas somáticos e cognitivo-afetivos do que os homens. Não houve associação dos sintomas somáticos e cognitivo-afetivos com a idade. Pesquisas futuras desses pacientes poderiam revelar se essas diferenças de acordo com o sexo permanecem durante todo o processo de reabilitação. .

OBJETIVO: este estudio investigó la asociación de síntomas somáticos y cognitivo-afectivos con el sexo y la edad en pacientes hospitalizados con enfermedad cardíaca. MÉTODO: este estudio fue un análisis secundario de dos estudios observacionales anteriores, totalizando 531 pacientes con enfermedad cardíaca, internados de 2005 a 2011, en dos hospitales públicos en Ribeirão Preto, estado de São Paulo, Brasil. Los síntomas somáticos y cognitivo-afectivos fueron evaluados utilizándose las subescalas del Inventario Beck de Depresión - I (IBD-I). RESULTADOS: de los 531 participantes, 62,7% era del sexo masculino, con promedio de edad de 57,3 años (DE= 13,0) para los hombres y 56,2 años (DE = 12,1) para el sexo femenino. El análisis de variancia mostró un efecto del sexo (p<0,001 para síntomas somáticos y p=0,005 para los síntomas cognitivo-afectivos), pero ningún efecto de la edad. Las mujeres presentaron valores medios más altos que los hombres en ambas subescalas IBD-I: 7,1 (4,5) vs. 5.4 (4.3) para los síntomas somáticos, y 8,3 (7,9) vs. 6,7 (7,2) para los síntomas cognitivo-afectivos. No fueron encontradas diferencias por edad para síntomas somáticos (p=0,84) o síntomas cognitivo-afectivos (p=0,84). CONCLUSIÓN: las mujeres internadas con enfermedad cardíaca tenían más síntomas somáticos y cognitivo-afectivos que los hombres. No fue encontrada asociación de los síntomas somáticos y cognitivo-afectivos con la edad. Investigaciones futuras de esos pacientes podrían revelar si esas diferencias por sexo continúan durante todo el proceso de rehabilitación. .

Use of low-power laser to assist the healing of traumatic wounds in rats

PURPOSE: To investigate the morphological aspects of the healing of traumatic wounds in rats using low-power laser. METHODS: Twenty four non isogenic, young adult male Wistar rats (Rattus norvegicus) weighing between 200 and 300g was used. The animals were randomly distributed into two groups: Control (GC) and Laser (GL), with 12 animals each. After shaving, anesthesia was performed in the dorsal region and then a surgical procedure using a scapel was carried out to make the traumatic wound. GL received five sessions of laser therapy in consecutive days using the following laser parameters: wavelength 660 nm, power 100 mW, dose 10 J/cm2. The wounds were evaluated through measurement of the area and depth of the wound (MW) and histological analysis (HA). RESULTS: When comparing the GC with the GL in MW there was a difference in area (p<0.001) and depth (p=0.003) measurement of the wounds in GL. The laser group presented more epithelization than GC (p=0.03). The other histological parameters were similar. CONCLUSION: The healing of wounds in rats was improved with the use of the laser. .

Comparison of Regional Gray Matter Atrophy, White Matter Alteration, and Glucose Metabolism as a Predictor of the Conversion to Alzheimer's Disease in Mild Cognitive Impairment

We compared the predictive ability of the various neuroimaging tools and determined the most cost-effective, non-invasive Alzheimer's disease (AD) prediction model in mild cognitive impairment (MCI) individuals. Thirty-two MCI subjects were evaluated at baseline with [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET), MRI, diffusion tensor imaging (DTI), and neuropsychological tests, and then followed up for 2 yr. After a follow up period, 12 MCI subjects converted to AD (MCIc) and 20 did not (MCInc). Of the voxel-based statistical comparisons of baseline neuroimaging data, the MCIc showed reduced cerebral glucose metabolism (CMgl) in the temporo-parietal, posterior cingulate, precuneus, and frontal regions, and gray matter (GM) density in multiple cortical areas including the frontal, temporal and parietal regions compared to the MCInc, whereas regional fractional anisotropy derived from DTI were not significantly different between the two groups. The MCIc also had lower Mini-Mental State Examination (MMSE) score than the MCInc. Through a series of model selection steps, the MMSE combined with CMgl model was selected as a final model (classification accuracy 93.8%). In conclusion, the combination of MMSE with regional CMgl measurement based on FDG-PET is probably the most efficient, non-invasive method to predict AD in MCI individuals after a two-year follow-up period.

Gray and White Matter Degenerations in Subjective Memory Impairment: Comparisons with Normal Controls and Mild Cognitive Impairment

Subjective memory impairment (SMI) is now increasingly recognized as a risk factor of progression to dementia. This study investigated gray and white matter changes in the brains of SMI patients compared with normal controls and mild cognitive impairment (MCI) patients. We recruited 28 normal controls, 28 subjects with SMI, and 29 patients with MCI aged 60 or older. We analyzed gray and white matter changes using a voxel-based morphometry (VBM), hippocampal volumetry and regions of interest in diffusion tensor imaging (DTI). DTI parameters of corpus callosum and cingulum in SMI showed more white matter changes compared with those in normal controls, they were similar to those in MCI except in the hippocampus, which showed more degenerations in MCI. In VBM, SMI showed atrophy in the frontal, temporal, and parietal lobes compared with normal controls although it was not as extensive as that in MCI. Patients with SMI showed gray and white matter degenerations, the changes were distinct in white matter structures. SMI might be the first presenting symptom within the Alzheimer's disease continuum when combined with additional risk factors and neurodegenerative changes.

Effect of Increasing Diffusion Gradient Direction Number on Diffusion Tensor Imaging Fiber Tracking in the Human Brain

OBJECTIVE: To assess the effects of varying the number of diffusion gradient directions (NDGDs) on diffusion tensor fiber tracking (FT) in human brain white matter using tract characteristics. MATERIALS AND METHODS: Twelve normal volunteers underwent diffusion tensor imaging (DTI) scanning with NDGDs of 6, 11, 15, 21, and 31 orientations. Three fiber tract groups, including the splenium of the corpus callosum (CC), the entire CC, and the full brain tract, were reconstructed by deterministic DTI-FT. Tract architecture was first qualitatively evaluated by visual observation. Six quantitative tract characteristics, including the number of fibers (NF), average length (AL), fractional anisotropy (FA), relative anisotropy (RA), mean diffusivity (MD), and volume ratio (VR) were measured for the splenium of the CC at the tract branch level, for the entire CC at tract level, and for the full brain tract at the whole brain level. Visual results and those of NF, AL, FA, RA, MD, and VR were compared among the five different NDGDs. RESULTS: The DTI-FT with NDGD of 11, 15, 21, and 31 orientations gave better tracking results compared with NDGD of 6 after the visual evaluation. NF, FA, RA, MD, and VR values with NDGD of six were significantly greater (smallest p = 0.001 to largest p = 0.042) than those with four other NDGDs (11, 15, 21, or 31 orientations), whereas AL measured with NDGD of six was significantly smaller (smallest p = 0.001 to largest p = 0.041) than with four other NDGDs (11, 15, 21, or 31 orientations). No significant differences were observed in the results among the four NDGD groups of 11, 15, 21, and 31 directions (smallest p = 0.059 to largest p = 1.000). CONCLUSION: The main fiber tracts were detected with NDGD of six orientations; however, the use of larger NDGD (> or = 11 orientations) could provide improved tract characteristics at the expense of longer scanning time.

Aplicación de técnicas avanzadas de neuroimágenes en rehabilitación motora / Application of advanced neuroimaging in motor rehabilitation

Introducción. La resonancia magnética funcional es una técnica no invasiva que permite el mapeo cerebral y la visualización de redes de conectividad. La hemiparesia posterior a un accidente cerebrovascular constituye un buen modelo biológico para estudiar los cambios en la conectividad cerebral. El uso de este modelo se puede expandir si se obtiene información antes y después de la rehabilitación neurológica. Objetivo. Presentar los hallazgos por neuroimágenes funcionales de un paciente con accidente cerebrovascular antes y después del tratamiento de rehabilitación neurológica. Materiales y métodos. Como parte del protocolo de rehabilitación neurológica se tomaron imágenes de resonancia antes y después del tratamiento con un equipo que operaba a 1,5 T. Se obtuvieron imágenes volumétricas potenciadas en T1, imágenes de difusión para tractografía, imágenes de resonancia funcional con el paciente en reposo y haciendo movimientos de pinza con la mano derecha. Resultados. Se obtuvieron mapas funcionales antes y después de la terapia, los cuales se presentan conjuntamente con las imágenes de conectividad estructural obtenidas mediante tractografía. Se observó que los cambios clínicos estaban acompañados de cambios en los patrones de activación obtenidos por resonancia magnética funcional. Conclusión. La versatilidad que ofrece la resonancia magnética permite conocer el estado funcional y estructural del cerebro, generando así nuevas posibilidades de diagnóstico y pronóstico en pacientes que reciben rehabilitación neurológica, con lo que se pueden cuantificar y develar ciertos procesos dinámicos de plasticidad neuronal posteriores a una lesión, que son propios del sistema nervioso central.

Introduction: Functional magnetic resonance imaging is a noninvasive technique that allows mapping and visualizing of brain connectivity networks. The hemiparesis after a stroke is a good biological model to study changes in brain connectivity. This model can be expanded if information is obtained before and after neurorehabilitation therapy. Objective: To present the functional neuroimaging findings in a patient with stroke before and after performing neurorehabilitation therapy. Materials and methods: As part of the neurorehabilitation protocol, resonance imaging was performed before and after treatment with an equipment operating at 1.5 T. Volumetric T1-weighted images, diffusion images for tractography, functional resonance images with the patient at rest and with the patient performing pincer movement with the right hand were obtained. Results: Functional maps before and after therapy were obtained, which are presented together with structural connectivity images obtained by tractography. Clinical changes can be seen accompanied by changes in activation patterns obtained by functional magnetic resonance imaging. Conclusion: The versatility of magnetic resonance imaging allows further knowledge of the structural and functional state of the brain generating new possibilities for diagnosis and prognosis in patients undergoing neurorehabilitation therapy. Neurological rehabilitation processes can be quantified and they can reveal certain postlesional neuroplasticity dynamic processes that the central nervous system possesses.

Thalamocortical Connections between the Mediodorsal Nucleus of the Thalamus and Prefrontal Cortex in the Human Brain: A Diffusion Tensor Tractographic Study

PURPOSE: The elucidation of thalamocortical connections between the mediodorsal nucleus (MD) of thalamus and the prefrontal cortex (PFC) is important in the clinical fields of neurorehabilitation and psychiatry. However, little is known about these connections in human brain. We attempted to identify and investigate the anatomical characteristics of the thalamocortical connection between MD and PFC in human brain using diffusion tensor tractography (DTT). MATERIALS AND METHODS: Thirty-two healthy volunteers were recruited for this study. Diffusion tensor images were scanned using a 1.5-T. A seed region of interest was placed at the MD of the thalamus on coronal images, and target regions of interest were placed on the dorsolateral prefrontal cortex (DLPFC), the ventrolateral prefrontal cortex (VLPFC), and the orbitofrontal cortex (OFC), respectively. The three thalamocortical connections found were reconstructed using Functional Magnetic Resonance Imaging of the Brain (FMRIB) software. RESULTS: The three thalamocortical connections were arranged in subcortical white matter in the following order from upper to lower levels: the DLPFC, the VLPFC, and the OFC. In terms of fractional anisotropy and mean diffusivity values, no significant differences were observed between the DLPFC, VLPFC and OFC (p>0.05). In contrast, the OFC tract volume was higher than those of the DLPFC and the VLPFC (p<0.05). CONCLUSION: Three thalamocortical connections were reconstructed between MD and PFCs in human brain using DTT. We believe that the results of this study would be helpful to clinicians in treating frontal network syndrome and psychiatric diseases.

Segmented corpus callosum diffusivity correlates with the Expanded Disability Status Scale score in the early stages of relapsing-remitting multiple sclerosis

OBJECTIVE: The aim of this study was to characterize the microscopic damage to the corpus callosum in relapsing-remitting multiple sclerosis (RRMS) with diffusion tensor imaging and to investigate the correlation of this damage with disability. The diffusion tensor imaging parameters of fractional anisotropy and mean diffusivity provide information about the integrity of cell membranes, offering two more specific indices, namely the axial and radial diffusivities, which are useful for discriminating axon loss from demyelination. METHOD: Brain magnetic resonance imaging exams of 30 relapsing-remitting multiple sclerosis patients and 30 age- and sex-matched healthy controls were acquired in a 3T scanner. The axial diffusivities, radial diffusivities, fractional anisotropy, and mean diffusivity of five segments of the corpus callosum, correlated to the Expanded Disability Status Scale score, were obtained. RESULTS: All corpus callosum segments showed increased radial diffusivities and mean diffusivity, as well as decreased fractional anisotropy, in the relapsing-remitting multiple sclerosis group. The axial diffusivity was increased in the posterior midbody and splenium. The Expanded Disability Status Scale scores correlated more strongly with axial diffusivities and mean diffusivity, with an isolated correlation with radial diffusivities in the posterior midbody of the corpus callosum. There was no significant correlation with lesion loads. CONCLUSION: Neurological dysfunction in relapsing-remitting multiple sclerosis can be influenced by commissural disconnection, and the diffusion indices of diffusion tensor imaging are potential biomarkers of disability that can be assessed during follow-up. .

Más allá del tensor de difusión: experiencia preliminar en tractografía HARDI-CSD y super-resolución en 1. 5T / Beyond the diffusion tensor model: preliminary experience inHARDI tractography-CSD and super-resolution 1. 5T

Introduction: For more than a decade the diffusion tensor imaging model has been widely used in order to resolve and represent the intracranial white-matter microanatomy. Howeverthere are numerous studies that have successfully demonstrated the limitations associated with DTI in trying to define crossing-fibre regions. Various models have been developed with the intention of overcoming these limitations. This is why our study focuses on the description and preliminary experience in the use of tractography based on high-angular-resolution-diffusion imaging (HARDI) using the constrained spherical deconvolution (CSD) technique. Methods: The data was acquired on a Philips Achieva 1.5T resonator using a diffusion weighted single-shot echoplanar sequence along 32 directions with a b-value of 1000s/mm2. The images were processed using FSL v5.0 and MRtrix v0.2.10 software. Results: We achieved tensor free high-angular-resolution-diffusion tractographic images that better represented the white-matter micro-architecture than those obtained from the tensor model. Additionally, it was possible to generate track-density images (TDI) with a final resolution more than 500 times that of the acquired data.

Introducción: Desde hace más de una década que el modelo de tensor de difusión ha sido ampliamente utilizado con el fin de resolver y representar la microanatomía de la sustancia blanca intra-cerebral. Sin embargo, no son pocos los estudios que han logrado demostrar las grandes desventajas que el modelo presenta al tratar de definir regiones de entrecruzamiento de fibras. Diversos modelos han sido desarrollados para ofrecer una solución consistente, capaz de representar dichas regiones con mayor grado de correlación anatómica. Es por ello que nuestro estudio se enfoca en la descripción y experiencia preliminar en el uso de tractografía basada en imágenes de difusión de alta resolución angular (HARDI) usando el modelo de deconvolución esférica restringida (CSD). Métodos: La adquisición se realizó en un resonador Philips Achieva 1.5T mediante secuencia de difusión single-shot echo-planar de 32 direcciones con un b-value de 1.000s/mm² procesamiento de las imágenes se realizó mediante software FSL v5.0 y MRtrix v0.2.10. Resultados: Se lograron tractografías libres de tensor de difusión de alta resolución angular que representan la micro-arquitectura de la sustancia blanca de mejor manera que con las generadas a partir del modelo de tensor. Adicionalmente, se logró generar imágenes de densidad tractográfica (TDI) con una resolución final de más de 500 veces a la de adquisición.