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1.
J Craniofac Surg ; 30(7): 2280-2284, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31369515

RESUMO

Dural sinuses have critical importance during intracranial approaches. Detailed anatomical knowledge of the dural sinuses is crucial for surgeons to reduce unexpected venous bleeding. The aim of this study was to investigate anatomical relation of sigmoid sinus and tentorium cerebelli according to clinically palpable landmarks and cranial morphometry. The authors evaluated 222 individuals' (94 women, 128 men) 3-dimensional computed tomography angiograms, retrospectively. The authors also studied on 12 mid-sagittal cut dried hemiskulls and 8 formalin fixed cadaver heads hemisected midsagitally. All measurements were completed using Osirix-Lite version 9 software. Craniometrical values were measured to define cranium morphology. Furthermore, level of the sigmoid sinus according to asterion and tentorial angle were evaluated in detail. Our results demonstrated that there were significant differences between parameters and genders, except vertical angle of the tentorium cerebelli. Distance between asterion and sigmoid sinus was statistically different between right and left sides in favor of the left side. This also varied depending on the position of the sigmoid sinus, as well. Only transverse angle between the upper point of external acoustic meatus and asterion demonstrated a significant correlation with age. This study evaluated the detailed 3D anatomy of sigmoid sinus and tentorium cerebelli related with the cranium morphology. Determining to sigmoid sinus anatomy according to clinically palpable landmarks has advantages for setting surgical protocols and reducing to unexpected injuries while surgery to these structures.


Assuntos
Medula Espinal/anatomia & histologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Angiografia , Cadáver , Cefalometria , Cavidades Cranianas/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
2.
Nat Commun ; 10(1): 562, 2019 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-30718484

RESUMO

Sensory axons must traverse a spinal cord glia limitans to connect the brain with the periphery. The fundamental mechanism of how these axons enter the spinal cord is still debatable; both Ramon y Cajal's battering ram hypothesis and a boundary cap model have been proposed. To distinguish between these hypotheses, we visualized the entry of pioneer axons into the dorsal root entry zone (DREZ) with time-lapse imaging in zebrafish. Here, we identify that DRG pioneer axons enter the DREZ before the arrival of neural crest cells at the DREZ. Instead, actin-rich invadopodia in the pioneer axon are necessary and sufficient for DREZ entry. Using photoactivable Rac1, we demonstrate cell-autonomous functioning of invasive structures in pioneer axon spinal entry. Together these data support the model that actin-rich invasion structures dynamically drive pioneer axon entry into the spinal cord, indicating that distinct pioneer and secondary events occur at the DREZ.


Assuntos
Medula Espinal/anatomia & histologia , Raízes Nervosas Espinhais/anatomia & histologia , Peixe-Zebra/anatomia & histologia , Animais , Axônios , Gânglios Espinais/anatomia & histologia , Gânglios Espinais/citologia , Modelos Biológicos , Crista Neural/citologia , Raízes Nervosas Espinhais/citologia
3.
Clin Anat ; 32(5): 618-629, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30807670

RESUMO

A high lumbar puncture (LP) at L2-L3 or above is often necessary to consider on technical grounds, but complications of conus medullaris (CM) damage during high LP are potentially concerning. We hypothesized that a high LP might be safer than previously thought by accounting for movements of the CM upon patient positional changes. We retrospectively reviewed standard normal supine lumbar spine magnetic resonance imaging of 58 patients and used electronic calipers on axial images at the T12-L1, L1-L2, and L2-L3 disc levels to measure the transverse diameter of the CM relative to the size of the dorsal thecal sac space (DTSS) through which a spinal needle could be inserted. On 142 axial images, the means for CM diameters were 8.2, 6.0, and 2.9 mm at the three levels, respectively. We then used known literature mean CM displacement values in the legs flexed and unflexed lateral decubitus position (LDP) to factor in CM shifts to the dependent side. We found that at all three levels, the likely positional shift of the CM would be too small and insufficient to displace the entire CM out of the DTSS. However, if needle placement could be confined to the midsagittal plane, an LP in the unflexed LDP would theoretically be entirely safe at both L1-L2 and L2-L3, and almost so at L2-L3 in the legs flexed LDP. Thus, high LPs at L1-L2 and L2-L3 are in theory likely safer than considered previously, more so in the legs unflexed than in the flexed LDP. Clin. Anat. 32:618-629, 2019. © 2019 Wiley Periodicals, Inc.


Assuntos
Vértebras Lombares/anatomia & histologia , Medula Espinal/anatomia & histologia , Punção Espinal/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Cauda Equina/anatomia & histologia , Cauda Equina/diagnóstico por imagem , Feminino , Humanos , Vértebras Lombares/diagnóstico por imagem , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Medula Espinal/diagnóstico por imagem , Decúbito Dorsal , Adulto Jovem
4.
Ann Anat ; 222: 139-145, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30599238

RESUMO

Severe spinal cord injuries cause permanent neurological deficits and are still considered as inaccessible to efficient therapy. Injured spinal cord axons are unable to spontaneously regenerate. Re-establishing functional activity especially in the lower limbs by reinnervation of the caudal infra-lesional territories might represent an effective therapeutic strategy. Numerous surgical neurotizations have been developed to bridge the spinal cord lesion site and connect the intact supra-lesional portions of the spinal cord to peripheral nerves (spinal nerves, intercostal nerves) and muscles. The major disadvantage of these techniques is the increased hypersensitivity, spasticity and pathologic pain in the spinal cord injured patients, which occur due to the vigorous sprouting of injured afferent sensory fibers after reconstructive surgery. Using micro-surgical instruments and an operation microscope we performed detailed anatomical preparation of the vertebral canal and its content in five human cadavers. Our observations allow us to put forward the possibility to develop a more precise surgical approach, the so called "ventral root bypass" that avoids lesion of the dorsal roots and eliminates sensitivity complications. The proposed kind of neurotization has been neither used, nor put forward. The general opinion is that radix ventralis and radix dorsalis unite to form the spinal nerve inside the dural sac. This assumption is not accurate, because both radices leave the dural sac separately. This neglected anatomical feature allows a reliable intravertebral exposure of the dura-mater ensheathed ventral roots and their damage-preventing end-to-side neurorrhaphy by interpositional nerve grafts.


Assuntos
Paralisia/cirurgia , Traumatismos da Medula Espinal/cirurgia , Raízes Nervosas Espinhais/anatomia & histologia , Raízes Nervosas Espinhais/cirurgia , Cadáver , Dura-Máter/anatomia & histologia , Humanos , Microcirurgia/instrumentação , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/cirurgia , Regeneração Nervosa , Procedimentos Neurocirúrgicos , Nervos Periféricos/anatomia & histologia , Nervos Periféricos/cirurgia , Canal Vertebral/anatomia & histologia , Medula Espinal/anatomia & histologia , Medula Espinal/cirurgia , Coluna Vertebral/anatomia & histologia
5.
IEEE Trans Vis Comput Graph ; 25(9): 2725-2737, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30028709

RESUMO

We present a volume exploration framework, FeatureLego, that uses a novel voxel clustering approach for efficient selection of semantic features. We partition the input volume into a set of compact super-voxels that represent the finest selection granularity. We then perform an exhaustive clustering of these super-voxels using a graph-based clustering method. Unlike the prevalent brute-force parameter sampling approaches, we propose an efficient algorithm to perform this exhaustive clustering. By computing an exhaustive set of clusters, we aim to capture as many boundaries as possible and ensure that the user has sufficient options for efficiently selecting semantically relevant features. Furthermore, we merge all the computed clusters into a single tree of meta-clusters that can be used for hierarchical exploration. We implement an intuitive user-interface to interactively explore volumes using our clustering approach. Finally, we show the effectiveness of our framework on multiple real-world datasets of different modalities.


Assuntos
Algoritmos , Gráficos por Computador , Análise por Conglomerados , Gráficos por Computador/estatística & dados numéricos , Simulação por Computador , Bases de Dados Factuais/estatística & dados numéricos , Humanos , Interpretação de Imagem Assistida por Computador/estatística & dados numéricos , Imagem Tridimensional , Modelos Anatômicos , Semântica , Medula Espinal/anatomia & histologia , Coluna Vertebral/anatomia & histologia , Dente/anatomia & histologia , Interface Usuário-Computador
6.
Acta Radiol ; 60(5): 623-627, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30142995

RESUMO

BACKGROUND: The studies that described the dimensions of the normal fetal thoracic spinal canal and spinal cord on magnetic resonance imaging (MRI) are scarce. PURPOSE: To determine the normal appearance of the fetal spinal canal and spinal cord at T12 across different gestational ages using 3.0-T MRI. MATERIAL AND METHODS: The spines of 43 normal human fetuses, aged 15-40 weeks, were scanned by 3.0-T MRI. All specimens were scanned using a GE 3.0-T MRI scanner. Imaging of the T12 vertebrae was performed in the coronal, sagittal, and axial planes. The anterior-posterior (AP) diameter, width, and cross-sectional area of the spinal canal and spinal cord at T12 were measured. The influence of gestational age on these parameters was investigated with a scatter plot and linear regression analysis using Pearson correlation coefficient. RESULTS: The normal morphology of the fetal vertebra at T12 can be clearly showed by MRI; the spinal canal appeared circular, while the spinal cord was ellipsoid. Linear regression analysis showed a significant positive correlation between the AP diameter, width, and cross-sectional area of the spinal canal at T12 and gestational age. CONCLUSION: Postmortem MRI is a reliable method for understanding the growth dynamics of the spinal canal and spinal cord at T12. Findings from this study would benefit the prenatal diagnosis of congenital malformations by MRI.


Assuntos
Imagem por Ressonância Magnética/métodos , Canal Vertebral/anatomia & histologia , Canal Vertebral/embriologia , Medula Espinal/anatomia & histologia , Medula Espinal/embriologia , Feminino , Humanos , Masculino , Gravidez , Diagnóstico Pré-Natal/métodos , Valores de Referência
7.
J Craniofac Surg ; 30(1): 256-259, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30480625

RESUMO

BACKGROUND: The foramen magnum (FM) is the largest opening and is outlet through which medulla oblongata and spinal cord along with meninges, vertebral arteries, anterior and posterior spinal arteries, tectorial membrane, alar ligaments, and spinal branch of the accessory nerve. Occipital condyle (OC) is an important part of craniovertebral or craniocervical junction located anterolaterally on either side of the FM. The objective of the study was to assess variations of FM and OC in Ethiopian dried adult skulls. METHODS: Observation-based descriptive study design was employed. The study was undertaken in 54 FM and 108 OC of 54 adult Ethiopian skulls. The morphometry of FM and OC were determined using a sliding vernier caliper. RESULTS: The mean values of anteroposterior and transverse diameters of the FM were 35.19 and 30.17 mm, respectively, and the mean area of the FM was 853.36 mm. The shapes of FM were determined as round in 22.2%, oval in 18.5%, egg like in 20.4%, triangular in 3.7%, pentagonal in 11.1%, hexagonal in 7.4%, irregular in 13%, and rectangular in 3.7% of the cases. The mean length of right and left OC was 25.69 and 26.96 mm, respectively, and the mean widths of the right and left OC were 12.76 and 13.04 mm, respectively. CONCLUSION: Our study identified various shapes of FM and diameter. The anteroposterior diameter is greater than the transverse diameter. The morphometric study of OC confirmed the length of left side is significantly greater than the right side.


Assuntos
Forame Magno/anatomia & histologia , Osso Occipital/anatomia & histologia , Base do Crânio/anatomia & histologia , Adulto , Cadáver , Humanos , Masculino , Medula Espinal/anatomia & histologia , Artéria Vertebral/anatomia & histologia
8.
Folia Morphol (Warsz) ; 78(1): 145-152, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30543082

RESUMO

BACKGROUND: In this study, the total volume of the thoracic segments of the spinal cord and volume densities of grey matter and white matter were examined by using stereological methods in adult geese having a weight of 3-4 kg. MATERIALS AND METHODS: Ten geese were used as material without sex discrimi- nation. All animals were perfused with 10% formaldehyde. In addition, after perfusion, the geese were kept in 10% formaldehyde for 1 week. Afterwards, thoracic spine was removed and thoracic part of spinal cord was excised. 5 µm thick sections were taken from these tissue samples by microtome. The cross- sectional series were obtained by sampling from each segment at 250th section. Twelve sections were taken from tissue specimens of every segment. The sections were stained by using haematoxylin-eosin and photographed on a microscope. RESULTS: By using the Cavalieri's Principle, the volume densities (volume fractions) of thoracic segments of spinal cord, volume of white matter, and volume of grey matter in segments were calculated. CONCLUSIONS: In the study, total volume of the thoracic segment, volume of white matter, and the volume of grey matter, and the ratio of these volume values to each other were calculated. The SHTEREOM 1.0 software was used for calculating the volume of section specimens.


Assuntos
Gansos/anatomia & histologia , Medula Espinal/anatomia & histologia , Animais , Feminino , Substância Cinzenta/anatomia & histologia , Imagem Tridimensional/métodos , Masculino , Vértebras Torácicas , Substância Branca/anatomia & histologia
9.
J Ultrasound ; 22(2): 113-119, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30535560

RESUMO

Ultrasound represents the first-line survey for the assessment of spinal cord development abnormalities. In fact, within 6 months of life, the non-ossification of neuronal arcs provides an excellent acoustic window that allows a detailed depiction of the spinal canal, its content and of the surrounding soft tissues. Nevertheless, an accurate ultrasound examination requires a complete knowledge of the anatomy, the condition of normality, the frequent anatomical variants and the main pathologies involved. This review is intended to briefly summarize the US technique, the main clinical indication and the key notions that could help to properly perform this type of ultrasound examination.


Assuntos
Medula Espinal/diagnóstico por imagem , Ultrassonografia , Variação Anatômica , Humanos , Lactente , Recém-Nascido , Medula Espinal/anatomia & histologia , Medula Espinal/patologia , Doenças da Medula Espinal/diagnóstico por imagem , Doenças da Medula Espinal/patologia , Ultrassonografia/métodos
11.
Biomedica ; 38(2): 209-215, 2018 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-30184349

RESUMO

Introduction: Information about the neuroanatomical details of the ascendant transport of the rabies virus through the spinal cord is scarce. Objective: To identify the neuroanatomical route of dissemination of the rabies virus at each of the levels of the spinal cord of mice after being inoculated intramuscularly. Materials and methods: Mice were inoculated with the rabies virus in the hamstrings. After 24 hours post-inoculation, every eight hours, five animals were sacrificed by perfusion with paraformaldehyde. Then, the spinal cord was removed, and transverse cuts were made at the lumbosacral, thoracic, and cervical levels. These were processed by immunohistochemistry for the detection of viral antigens. Results: The first antigens of rabies were observed as aggregated particles in the lumbar spinal cord at 24 hours post-inoculation, within the ventral horn in the same side of the inoculated limb. At 32 hours post inoculation the first motoneurons immunoreactive to the virus became visible. At 40 hours postinoculation the first immunoreactive neurons were revealed in the thoracic level, located on lamina 8 and at 48 hours post-inoculation in the cervical cord, also on lamina 8. At 56 hours post-inoculation the virus had spread throughout the spinal cord, but the animals still did not show signs of the disease. Conclusion: In the mouse model we used, the rabies virus entered the spinal cord through the motoneurons and probably used the descending propriospinal pathway for its retrograde axonal transport to the encephalus.


Assuntos
Vírus da Raiva/fisiologia , Medula Espinal/virologia , Animais , Feminino , Camundongos , Medula Espinal/anatomia & histologia
12.
Prog Neurobiol ; 169: 91-134, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29981393

RESUMO

The substantia gelatinosa Rolandi (SGR) was first described about two centuries ago. In the following decades an enormous amount of information has permitted us to understand - at least in part - its role in the initial processing of pain and itch. Here, I will first provide a comprehensive picture of the histology, physiology, and neurochemistry of the normal SGR. Then, I will analytically discuss the SGR circuits that have been directly demonstrated or deductively envisaged in the course of the intensive research on this area of the spinal cord, with particular emphasis on the pathways connecting the primary afferent fibers and the intrinsic neurons. The perspective existence of neurochemically-defined sets of primary afferent neurons giving rise to these circuits will be also discussed, with the proposition that a cross-talk between different subsets of peptidergic fibers may be the structural and functional substrate of additional gating mechanisms in SGR. Finally, I highlight the role played by slow acting high molecular weight modulators in these gating mechanisms.


Assuntos
Rede Nervosa , Neuroquímica/história , Medula Espinal/anatomia & histologia , Substância Gelatinosa/citologia , Substância Gelatinosa/fisiologia , Animais , História do Século XIX , Humanos , Mamíferos , Rede Nervosa/citologia , Rede Nervosa/metabolismo , Rede Nervosa/fisiologia
13.
Radiographics ; 38(4): 1201-1222, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29995620

RESUMO

The ability to localize the three spinal tracts (corticospinal tract, spinothalamic tract, and dorsal [posterior] columns) involved in incomplete spinal cord syndromes at cross-sectional imaging and knowledge of the classic clinical manifestations of the various syndromes enable optimized imaging evaluation and provide clinicians with information that aids in diagnosis and treatment. The requisite knowledge for localizing these tracts is outlined. The authors review the spinal cord anatomy, blood supply, and course of these tracts and describe the various associated syndromes: specifically, dorsal cord, ventral cord, central cord, Brown-Séquard, conus medullaris, and cauda equina syndromes. In addition, they describe the anatomic basis for the clinical manifestation of each syndrome and the relevant imaging features of the classic causes of these entities. Knowledge of the anatomy and clinical findings of the spinal cord is essential for examining and treating patients with cord abnormalities. ©RSNA, 2018.


Assuntos
Doenças da Medula Espinal/diagnóstico por imagem , Medula Espinal/anormalidades , Diagnóstico Diferencial , Humanos , Medula Espinal/anatomia & histologia , Síndrome
14.
J Neurosci Methods ; 308: 116-128, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30036546

RESUMO

BACKGROUND: Spinal cord (SC) segmentation from magnetic resonance (MR) images can be used to study neurological disorders and facilitates group analysis. Variation of intensity inhomogeneity and small cross section of SC are difficulties that restrict automizing SC segmentation. NEW METHODS: In this paper we present a method for accurate SC segmentation from MR images. The proposed morphological local global intensity fitting model (MLGIF) is based on region based morphological active contour model that utilizes local and global information. The local information is obtained using local morphology fitting and has been embedded into region based active contour to deal with images intensity inhomogeneity and variable contrast levels between SC and the cerebrospinal fluid. The contour evolution has been performed using successive application of a set of morphological operators. RESULTS: The proposed method has been validated on 28 T1-weighted and 29 T2-weighted MR images and simulated MR images with different noise levels. Assessment of the results shows the accuracy of the proposed method for SC segmentation. COMPARISON TO EXISTING METHOD(S): The proposed MLGIF method was comparable with existing SC segmentation methods. Between segmented images and corresponding ground truth images, the mean DICE similarity coefficient, mean conformity coefficient and mean Hausdorff distance were 0.90 (092), 0.8 (0.83) and 0.85 mm (0.70 mm), respectively, for T1(T2)-weighted images. CONCLUSION: The MLGIF model was proposed to achieve a robust method to deal with intensity inhomogeneity and lack of contrast between SC and surrounding tissues. Moreover, accuracy and less sensitivity to initial curve were seen.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Imagem por Ressonância Magnética , Medula Espinal/diagnóstico por imagem , Simulação por Computador , Humanos , Reconhecimento Automatizado de Padrão , Imagens de Fantasmas , Razão Sinal-Ruído , Medula Espinal/anatomia & histologia , Medula Espinal/patologia , Doenças da Medula Espinal/diagnóstico por imagem , Doenças da Medula Espinal/patologia
15.
Clin Anat ; 31(8): 1137-1143, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29770500

RESUMO

Posterior spinal arteries (PSAs) arise from the vertebral (VA) or posterior inferior cerebellar (PICA) artery. We identified variations in their origins and their anastomosis with the first posterior radiculomedullary branches in human spinal cords. Spinal cords from male and female cadavers (n = 30) were injected with colored latex through the vertebral, ascending cervical, costocervical trunk and segmental arteries. Specimens were fixed in formalin and the spinal arteries were dissected under a surgical microscope. PSAs arise from the PICA and from the atlantoaxial (V3) or intracranial (V4) segments of the VA. Their origins can be at V3 between the axis and the transverse processes of the atlas (V3i) or between the processes and the occipital bone (V3s). Half of our specimens exhibited a symmetrical and half an asymmetrical origin of the PSAs. A symmetrical origin from V4 was the most common configuration, identified in 30% of specimens. There was a symmetrical origin from either segment of V3 or PICA in 10%. Asymmetrical configurations were observed from V4/V3 (23.7%), V3/PICA (16.7%), V4/PICA (6.7%) and V3i/V3s (3.3%). PSAs are supplied by the posterior radiculomedullary arteries along the spinal cord. The first of these anastomoses could be located at any level between C4 and T8, though most commonly at C6-C7 or T3-T4. PSAs can originate from either the VA or the PICA in a symmetrical or asymmetrical configuration. Variations in the origin and level of the first posterior radiculomedullary anastomosis could affect surgical approaches, endovascular procedures, and the posterior spinal cord's susceptibility to ischemia. Clin. Anat. 31:1137-1143, 2018. © 2018 Wiley Periodicals, Inc.


Assuntos
Medula Espinal/irrigação sanguínea , Artéria Vertebral/anatomia & histologia , Cadáver , Cerebelo/irrigação sanguínea , Dissecação , Feminino , Humanos , Masculino , Medula Espinal/anatomia & histologia
16.
Am J Med ; 131(11): 1293-1297, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29605415

RESUMO

Myelopathy is a clinical diagnosis based on symptoms and physical examination findings. Laboratories and imaging, particularly with magnetic resonance imaging, can suggest a cause. Compressive myelopathy from degenerative disease of the vertebral column is the most common cause of myelopathy in older adults and should be screened for first in most cases. There are many other causes of myelopathy, including infectious, immune-mediated, nutritional, vascular, and neoplastic etiologies.


Assuntos
Doenças da Medula Espinal/diagnóstico , Doenças da Medula Espinal/patologia , Humanos , Medula Espinal/anatomia & histologia , Medula Espinal/irrigação sanguínea , Doenças da Medula Espinal/diagnóstico por imagem , Doenças da Medula Espinal/terapia
17.
Elife ; 72018 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-29589828

RESUMO

Although, in most animals, brain connectivity varies between individuals, behaviour is often similar across a species. What fundamental structural properties are shared across individual networks that define this behaviour? We describe a probabilistic model of connectivity in the hatchling Xenopus tadpole spinal cord which, when combined with a spiking model, reliably produces rhythmic activity corresponding to swimming. The probabilistic model allows calculation of structural characteristics that reflect common network properties, independent of individual network realisations. We use the structural characteristics to study examples of neuronal dynamics, in the complete network and various sub-networks, and this allows us to explain the basis for key experimental findings, and make predictions for experiments. We also study how structural and functional features differ between detailed anatomical connectomes and those generated by our new, simpler, model (meta-model).


Assuntos
Comportamento Animal , Locomoção , Rede Nervosa/fisiologia , Medula Espinal/anatomia & histologia , Medula Espinal/fisiologia , Potenciais de Ação , Animais , Animais Recém-Nascidos , Modelos Estatísticos , Xenopus
18.
AJNR Am J Neuroradiol ; 39(4): 788-795, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29496723

RESUMO

BACKGROUND AND PURPOSE: SyMRI is a technique developed to perform quantitative MR imaging. Our aim was to analyze its potential use for measuring relaxation times of normal components of the spine and to compare them with values found in the literature using relaxometry and other techniques. MATERIALS AND METHODS: Thirty-two spine MR imaging studies (10 cervical, 5 dorsal, 17 lumbosacral) were included. A modified multiple-dynamic multiple-echo sequence was added and processed to obtain quantitative T1 (millisecond), T2 (millisecond), and proton density (percentage units [pu]) maps for each patient. An ROI was placed on representative areas for CSF, spinal cord, intervertebral discs, and vertebral bodies, to measure their relaxation. RESULTS: Relaxation time means are reported for CSF (T1 = 4273.4 ms; T2 = 1577.6 ms; proton density = 107.5 pu), spinal cord (T1 = 780.2 ms; T2 = 101.6 ms; proton density = 58.7 pu), normal disc (T1 = 1164.9 ms; T2 = 101.9 ms; proton density = 78.9 pu), intermediately hydrated disc (T1 = 723 ms; T2 = 66.8 ms; proton density = 60.8 pu), desiccated disc (T1 = 554.4 ms; T2 = 55.6 ms; proton density = 47.6 ms), and vertebral body (T1 = 515.3 ms; T2 = 100.8 ms; proton density = 91.1 pu). Comparisons among the mean T1, T2, and proton density values showed significant differences between different spinal levels (cervical, dorsal, lumbar, and sacral) for CSF (proton density), spinal cord (T2 and proton density), normal disc (T1, T2, and proton density), and vertebral bodies (T1 and proton density). Significant differences were found among mean T1, T2, and proton density values of normal, intermediately hydrated, and desiccated discs. CONCLUSIONS: Measurements can be easily obtained on SyMRI and correlated with previously published values obtained using conventional relaxometry techniques.


Assuntos
Líquido Cefalorraquidiano , Disco Intervertebral/anatomia & histologia , Imagem por Ressonância Magnética/métodos , Medula Espinal/anatomia & histologia , Coluna Vertebral/anatomia & histologia , Feminino , Humanos , Masculino , Valores de Referência
19.
Biomed Mater ; 13(4): 044105, 2018 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-29359704

RESUMO

Spinal cord injury (SCI) causes immediate damage to the nervous tissue accompanied by loss of motor and sensory function. The limited self-repair competence of injured nervous tissue underscores the need for reparative interventions to recover function after SCI. The vasculature of the spinal cord plays a crucial role in SCI and repair. Ruptured and sheared blood vessels in the injury epicenter and blood vessels with a breached blood-spinal cord barrier (BSCB) in the surrounding tissue cause bleeding and inflammation, which contribute to the overall tissue damage. The insufficient formation of new functional vasculature in and near the injury impedes endogenous tissue repair and limits the prospect of repair approaches. Limiting the loss of blood vessels, stabilizing the BSCB, and promoting the formation of new blood vessels are therapeutic targets for spinal cord repair. Inflammation is an integral part of injury-mediated vascular damage, which has deleterious and reparative consequences. Inflammation and the formation of new blood vessels are intricately interwoven. Biomaterials can be effectively used for promoting and guiding blood vessel formation or modulating the inflammatory response after SCI, thereby governing the extent of damage and the success of reparative interventions. This review deals with the vasculature after SCI, the reciprocal interactions between inflammation and blood vessel formation, and the potential of biomaterials to support revascularization and immunomodulation in damaged spinal cord nervous tissue.


Assuntos
Materiais Biocompatíveis/química , Traumatismos da Medula Espinal/terapia , Animais , Axônios/fisiologia , Vasos Sanguíneos/patologia , Encéfalo/patologia , Adesão Celular , Sistemas de Liberação de Medicamentos , Matriz Extracelular/metabolismo , Humanos , Inflamação , Ligantes , Macrófagos/metabolismo , Teste de Materiais , Microesferas , Neovascularização Fisiológica , Neurônios/fisiologia , Oxigênio , Fenótipo , Medula Espinal/anatomia & histologia , Medula Espinal/patologia , Cicatrização
20.
J Neurotrauma ; 35(3): 403-410, 2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-28922957

RESUMO

Current recommendations support early surgical decompression and blood pressure augmentation after traumatic spinal cord injury (SCI). Elevated intraspinal pressure (ISP), however, has probably been underestimated in the pathophysiology of SCI. Recent studies provide some evidence that ISP measurements and durotomy may be beneficial for individuals suffering from SCI. Compression of the spinal cord against the meninges in SCI patients causes a "compartment-like" syndrome. In such cases, intentional durotomy with augmentative duroplasty to reduce ISP and improve spinal cord perfusion pressure (SCPP) may be indicated. Prior to performing these procedures routinely, profound knowledge of the spinal meninges is essential. Here, we provide an in-depth review of relevant literature along with neuroanatomical illustrations and imaging correlates.


Assuntos
Meninges/anatomia & histologia , Meninges/cirurgia , Traumatismos da Medula Espinal/cirurgia , Medula Espinal/anatomia & histologia , Medula Espinal/cirurgia , Descompressão Cirúrgica/métodos , Humanos , Traumatismos da Medula Espinal/fisiopatologia
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