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1.
Nature ; 572(7767): 62-66, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31341278

RESUMO

Recent work has shown that meningeal lymphatic vessels (mLVs), mainly in the dorsal part of the skull, are involved in the clearance of cerebrospinal fluid (CSF), but the precise route of CSF drainage is still unknown. Here we reveal the importance of mLVs in the basal part of the skull for this process by visualizing their distinct anatomical location and characterizing their specialized morphological features, which facilitate the uptake and drainage of CSF. Unlike dorsal mLVs, basal mLVs have lymphatic valves and capillaries located adjacent to the subarachnoid space in mice. We also show that basal mLVs are hotspots for the clearance of CSF macromolecules and that both mLV integrity and CSF drainage are impaired with ageing. Our findings should increase the understanding of how mLVs contribute to the neuropathophysiological processes that are associated with ageing.


Assuntos
Líquido Cefalorraquidiano/metabolismo , Sistema Glinfático/anatomia & histologia , Sistema Glinfático/fisiologia , Vasos Linfáticos/anatomia & histologia , Vasos Linfáticos/fisiologia , Base do Crânio/anatomia & histologia , Envelhecimento/patologia , Envelhecimento/fisiologia , Animais , Células Endoteliais/citologia , Células Endoteliais/patologia , Feminino , Fatores de Transcrição Forkhead/metabolismo , Sistema Glinfático/citologia , Sistema Glinfático/patologia , Proteínas de Homeodomínio/metabolismo , Vasos Linfáticos/citologia , Vasos Linfáticos/patologia , Linfedema/metabolismo , Linfedema/patologia , Imagem por Ressonância Magnética , Masculino , Camundongos , Espaço Subaracnóideo/anatomia & histologia , Fatores de Tempo , Proteínas Supressoras de Tumor/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/metabolismo
2.
Fluids Barriers CNS ; 16(1): 17, 2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31189484

RESUMO

BACKGROUND: Altered flow of cerebrospinal fluid (CSF) within the subarachnoid space (SAS) is connected to brain, but also optic nerve degenerative diseases. To overcome the lack of suitable in vitro models that faithfully recapitulate the intricate three-dimensional architecture, complex cellular interactions, and fluid dynamics within the SAS, we have developed a perfusion bioreactor-based 3D in vitro model using primary human meningothelial cells (MECs) to generate meningeal tissue constructs. We ultimately employed this model to evaluate the impact of impaired CSF flow as evidenced during optic nerve compartment syndrome on the transcriptomic landscape of MECs. METHODS: Primary human meningothelial cells (phMECs) were seeded and cultured on collagen scaffolds in a perfusion bioreactor to generate engineered meningeal tissue constructs. Engineered constructs were compared to human SAS and assessed for specific cell-cell interaction markers as well as for extracellular matrix proteins found in human meninges. Using the established model, meningeal tissue constructs were exposed to physiological and pathophysiological flow conditions simulating the impaired CSF flow associated with optic nerve compartment syndrome and RNA sequencing was performed. RESULTS: Engineered constructs displayed similar microarchitecture compared to human SAS with regards to pore size, geometry as well as interconnectivity. They stained positively for specific cell-cell interaction markers indicative of a functional meningeal tissue, as well as extracellular matrix proteins found in human meninges. Analysis by RNA sequencing revealed altered expression of genes associated with extracellular matrix remodeling, endo-lysosomal processing, and mitochondrial energy metabolism under pathophysiological flow conditions. CONCLUSIONS: Alterations of these biological processes may not only interfere with critical MEC functions impacting CSF and hence optic nerve homeostasis, but may likely alter SAS structure, thereby further impeding cerebrospinal fluid flow. Future studies based on the established 3D model will lead to new insights into the role of MECs in the pathogenesis of optic nerve but also brain degenerative diseases.


Assuntos
Reatores Biológicos , Meninges/metabolismo , Modelos Biológicos , Espaço Subaracnóideo/metabolismo , Engenharia Tecidual/métodos , Células Cultivadas , Humanos , Meninges/anatomia & histologia , Espaço Subaracnóideo/anatomia & histologia
3.
World Neurosurg ; 129: 190-199, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31136838

RESUMO

The basal subarachnoid cisterns are expansions of the subarachnoid space and transmit cranial nerves and intracranial vessels. Providing neurosurgeons with key concepts, anatomical landmarks, and techniques can result in safer procedures and better patient outcomes. In this review, we discuss the major basal subarachnoid cisterns including their embryology, history, anatomical descriptions, and use during surgical approaches.


Assuntos
Espaço Subaracnóideo/anatomia & histologia , Espaço Subaracnóideo/cirurgia , Humanos
4.
J Biomech Eng ; 140(8)2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-30003260

RESUMO

Cerebrospinal fluid (CSF) dynamics are thought to play a vital role in central nervous system (CNS) physiology. The objective of this study was to investigate the impact of spinal cord (SC) nerve roots (NR) on CSF dynamics. A subject-specific computational fluid dynamics (CFD) model of the complete spinal subarachnoid space (SSS) with and without anatomically realistic NR and nonuniform moving dura wall deformation was constructed. This CFD model allowed detailed investigation of the impact of NR on CSF velocities that is not possible in vivo using magnetic resonance imaging (MRI) or other noninvasive imaging methods. Results showed that NR altered CSF dynamics in terms of velocity field, steady-streaming, and vortical structures. Vortices occurred in the cervical spine around NR during CSF flow reversal. The magnitude of steady-streaming CSF flow increased with NR, in particular within the cervical spine. This increase was located axially upstream and downstream of NR due to the interface of adjacent vortices that formed around NR.


Assuntos
Líquido Cefalorraquidiano/metabolismo , Hidrodinâmica , Modelos Anatômicos , Raízes Nervosas Espinhais/anatomia & histologia , Raízes Nervosas Espinhais/fisiologia , Feminino , Humanos , Imagem por Ressonância Magnética , Modelagem Computacional Específica para o Paciente , Raízes Nervosas Espinhais/diagnóstico por imagem , Espaço Subaracnóideo/anatomia & histologia , Espaço Subaracnóideo/diagnóstico por imagem , Espaço Subaracnóideo/fisiologia , Adulto Jovem
5.
Congenit Anom (Kyoto) ; 58(3): 93-98, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-28976018

RESUMO

Cerebrospinal fluid is thought to be mainly absorbed into arachnoid granules in the subarachnoid space and drained into the sagittal sinus. However, some observations such as late outbreak of arachnoid granules in fetus brain and recent cerebrospinal fluid movements study by magnetic resonance images, conflict with this hypothesis. In this study, we investigated the movement of cerebrospinal fluid in fetuses. Several kinds of fluorescent probes with different molecular weights were injected into the lateral ventricle or subarachnoid space in mouse fetuses at a gestational age of 13 days. The movements of the probes were monitored by live imaging under fluorescent microscope. Following intraventricular injection, the probes dispersed into the 3rd ventricle and aqueduct immediately, but did not move into the 4th ventricle and spinal canal. After injection of low and high molecular weight conjugated probes, both probes dispersed into the brain but only the low molecular weight probe dispersed into the whole body. Following intra-subarachnoid injection, both probes diffused into the spinal canal gradually. Neither probe dispersed into the brain and body. The probe injected into the lateral ventricle moved into the spinal central canal by the fetus head compression, and returned into the aqueduct by its release. We conclude this study as follows: (i) The movement of metabolites in cerebrospinal fluid in the ventricles will be restricted by molecular weight; (ii) Cerebrospinal fluid in the ventricle and in the subarachnoid space move differently; and (iii) Cerebrospinal fluid may not appear to circulate. In the event of high intracranial pressure, the fluid may move into the spinal canal.


Assuntos
Aqueduto do Mesencéfalo/metabolismo , Ventrículos Cerebrais/metabolismo , Corantes Fluorescentes/metabolismo , Medula Espinal/metabolismo , Espaço Subaracnóideo/metabolismo , Seio Sagital Superior/metabolismo , Animais , Transporte Biológico , Aqueduto do Mesencéfalo/anatomia & histologia , Ventrículos Cerebrais/anatomia & histologia , Feminino , Feto , Corantes Fluorescentes/administração & dosagem , Idade Gestacional , Injeções Intraventriculares , Pressão Intracraniana/fisiologia , Camundongos , Camundongos Endogâmicos ICR , Microscopia de Fluorescência , Peso Molecular , Gravidez , Medula Espinal/anatomia & histologia , Espaço Subaracnóideo/anatomia & histologia , Seio Sagital Superior/anatomia & histologia
6.
World Neurosurg ; 111: 279-290, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29269062

RESUMO

INTRODUCTION: Brain is suspended in cerebrospinal fluid (CSF)-filled subarachnoid space by subarachnoid trabeculae (SAT), which are collagen-reinforced columns stretching between the arachnoid and pia maters. Much neuroanatomic research has been focused on the subarachnoid cisterns and arachnoid matter but reported data on the SAT are limited. This study provides a comprehensive review of subarachnoid trabeculae, including their embryology, histology, morphologic variations, and surgical significance. METHODS: A literature search was conducted with no date restrictions in PubMed, Medline, EMBASE, Wiley Online Library, Cochrane, and Research Gate. Terms for the search included but were not limited to subarachnoid trabeculae, subarachnoid trabecular membrane, arachnoid mater, subarachnoid trabeculae embryology, subarachnoid trabeculae histology, and morphology. Articles with a high likelihood of bias, any study published in nonpopular journals (not indexed in PubMed or MEDLINE), and studies with conflicting data were excluded. RESULTS: A total of 1113 articles were retrieved. Of these, 110 articles including 19 book chapters, 58 original articles, 31 review articles, and 2 case reports met our inclusion criteria. CONCLUSIONS: SAT provide mechanical support to neurovascular structures through cell-to-cell interconnections and specific junctions between the pia and arachnoid maters. They vary widely in appearance and configuration among different parts of the brain. The complex network of SAT is inhomogeneous and mainly located in the vicinity of blood vessels. Microsurgical procedures should be performed with great care, and sharp rather than blunt trabecular dissection is recommended because of the close relationship to neurovascular structures. The significance of SAT for cerebrospinal fluid flow and hydrocephalus is to be determined.


Assuntos
Espaço Subaracnóideo/anatomia & histologia , Tecido Conjuntivo , Humanos
7.
Fluids Barriers CNS ; 14(1): 36, 2017 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-29258534

RESUMO

BACKGROUND: The spinal subarachnoid space (SSS) has a complex 3D fluid-filled geometry with multiple levels of anatomic complexity, the most salient features being the spinal cord and dorsal and ventral nerve rootlets. An accurate anthropomorphic representation of these features is needed for development of in vitro and numerical models of cerebrospinal fluid (CSF) dynamics that can be used to inform and optimize CSF-based therapeutics. METHODS: A subject-specific 3D model of the SSS was constructed based on high-resolution anatomic MRI. An expert operator completed manual segmentation of the CSF space with detailed consideration of the anatomy. 31 pairs of semi-idealized dorsal and ventral nerve rootlets (NR) were added to the model based on anatomic reference to the magnetic resonance (MR) imaging and cadaveric measurements in the literature. Key design criteria for each NR pair included the radicular line, descending angle, number of NR, attachment location along the spinal cord and exit through the dura mater. Model simplification and smoothing was performed to produce a final model with minimum vertices while maintaining minimum error between the original segmentation and final design. Final model geometry and hydrodynamics were characterized in terms of axial distribution of Reynolds number, Womersley number, hydraulic diameter, cross-sectional area and perimeter. RESULTS: The final model had a total of 139,901 vertices with a total CSF volume within the SSS of 97.3 cm3. Volume of the dura mater, spinal cord and NR was 123.1, 19.9 and 5.8 cm3. Surface area of these features was 318.52, 112.2 and 232.1 cm2 respectively. Maximum Reynolds number was 174.9 and average Womersley number was 9.6, likely indicating presence of a laminar inertia-dominated oscillatory CSF flow field. CONCLUSIONS: This study details an anatomically realistic anthropomorphic 3D model of the SSS based on high-resolution MR imaging of a healthy human adult female. The model is provided for re-use under the Creative Commons Attribution-ShareAlike 4.0 International license (CC BY-SA 4.0) and can be used as a tool for development of in vitro and numerical models of CSF dynamics for design and optimization of intrathecal therapeutics.


Assuntos
Modelos Anatômicos , Modelos Neurológicos , Medula Espinal/anatomia & histologia , Raízes Nervosas Espinhais/anatomia & histologia , Espaço Subaracnóideo/anatomia & histologia , Adulto , Feminino , Humanos , Imagem Tridimensional , Imagem por Ressonância Magnética , Medula Espinal/diagnóstico por imagem , Raízes Nervosas Espinhais/diagnóstico por imagem , Espaço Subaracnóideo/diagnóstico por imagem , Adulto Jovem
8.
Clin Anat ; 30(6): 742-746, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28514500

RESUMO

The distal dural ring (DDR) is a conserved intracranial anatomic structure marking the boundary point at which the internal carotid artery (ICA) exits the cavernous sinus (CS) and enters the subarachnoid space. Although the CS has been well described in a range of anatomic studies, to our knowledge no prior study has analyzed the histologic relationship between the ICA and DDR. Correspondingly, our objective was to assess the relationship of the DDR to the ICA and determine whether the DDR can be dissected from the ICA and thus divided, or can only be circumferentially trimmed around the artery. The authors examined ten fresh-frozen, adult cadaveric specimens. A standard frontotemporal craniotomy, orbito-optic osteotomy, and extradural anterior clinoidectomy was performed bilaterally. The cavernous ICA, DDR, and supraclinoid ICA were harvested as an en bloc specimen. Specimens formalin-fixed and paraffin-embedded prior to routine histochemical staining with hematoxylin and eosin and Masson trichrome. In all specimens, marked microscopic investment of the DDR throughout the ICA adventitia was noted. Dural collagen fibers extensively permeated the arterial layers superficial to the muscularis propria, with no evidence of a clear separation between the DDR and arterial adventitia. Histologic analysis suggests that the ICA and DDR are highly interrelated, continuous structures, and therefore attempted intraoperative dissection between these structures may carry an elevated risk of injury to the ICA. We correspondingly recommend careful circumferential trimming of the DDR in lieu of direct dissection in cases requiring mobilization of the clinoidal ICA. Clin. Anat. 30:742-746, 2017. © 2017Wiley Periodicals, Inc.


Assuntos
Túnica Adventícia/anatomia & histologia , Artéria Carótida Interna/anatomia & histologia , Cadáver , Seio Cavernoso/anatomia & histologia , Colágeno/ultraestrutura , Histologia , Humanos , Microscopia , Espaço Subaracnóideo/anatomia & histologia
9.
Am J Ophthalmol ; 179: 25-31, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28455115

RESUMO

PURPOSE: Recent studies in patients demonstrated that cerebrospinal fluid does not flow continuously between the intracranial subarachnoid space (SAS) and the space around the optic nerve in the orbit. Its anatomic basis remains elusive. The objective of this study was to use a novel anatomic technology, the epoxy sheet plastination, to reveal the configuration of the fibrous structures within the optic canal and their relationship with the optic nerve, SAS, and ophthalmic artery. DESIGN: A human cadaveric study. METHODS: Nine cadaveric heads (subject age 54-87 years) without optic neuropathy were prepared as sets of transverse, coronal, and sagittal plastinated sections. Three of them were pretreated with hematoxylin staining via the SAS irrigation before sectioning and plastination. The prepared sections were examined under a stereoscope and a confocal microscope. RESULTS: The results showed that (1) the pia and arachnoid maters merged within the optic canal, (2) a dense trabecular mesh network was distributed in the orbital part of the canal, and (3) some optic nerve sheath (ONS) fibers intermingled with the tendinous fibers of the extraocular muscles and attached to the periosteum of the sphenoid bone, rather than entirely continuing with the inner layer of the dura mater. CONCLUSIONS: This study identified and traced the fibrous components within the optic canal and revealed their nature, architecture, and relationship with surroundings and concluded that in the human, free communication of the SAS between the intracranial cavity and ONS was significantly reduced.


Assuntos
Artéria Oftálmica/anatomia & histologia , Nervo Óptico/anatomia & histologia , Órbita/anatomia & histologia , Espaço Subaracnóideo/anatomia & histologia , Idoso , Idoso de 80 Anos ou mais , Cadáver , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osso Esfenoide/anatomia & histologia
10.
J Clin Neurosci ; 26: 79-83, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26675624

RESUMO

Relatively few studies have been performed that analyze the morphology of the choroid plexus of the fourth ventricle. Due to the importance of this tissue as a landmark on imaging and during surgical intervention of the fourth ventricle, the authors performed a cadaveric study to better characterize this important structure. The choroid plexus of the fourth ventricle of 60 formalin fixed adult human brains was examined and measured. The horizontal distance from the midline to the lateral most point of the protruding tip of the horizontal limbs was measured. In the majority of the 60 brain specimens, right and left horizontal limbs of the choroid plexus were seen extending from the midline and protruding out of their respective lateral apertures of the fourth ventricle and into the subarachnoid space. However, on 3.3% of sides, there was absence of an extension into the foramen of Luschka and in one specimen, this lack of extension into the foramen of Luschka was bilateral. On two sides, there was discontinuity between the midline choroid plexus and the tuft of choroid just outside the foramen of Luschka. For specimens in which the choroid plexus did protrude through the foramen of Luschka (96.7%), these tufts were located anterior to the flocculus and inferolateral to the facial/vestibulocochlear nerve complex and posterosuperior to the glossopharyngeal/vagal/accessory complex. A thorough understanding of the normal and variant anatomy of the fourth ventricular choroid plexus is necessary for those who operate in, or interpret imaging of, this region.


Assuntos
Plexo Corióideo/anatomia & histologia , Quarto Ventrículo/anatomia & histologia , Humanos , Espaço Subaracnóideo/anatomia & histologia
11.
J Neurosurg ; 124(2): 389-96, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26230468

RESUMO

OBJECTIVE: The aim of this study was to show that microendoscopic guidance using a double-channel technique could be safely applied during percutaneous cordotomy and provides clear real-time visualization of the spinal cord and surrounding structures during the entire procedure. METHODS: Twenty-four adult patients with intractable cancer pain were treated by microendoscopic-guided percutaneous radiofrequency (RF) cordotomy using the double-channel technique under local anesthesia. A percutaneous lateral puncture was performed initially under fluoroscopy guidance to localize the target. When the subarachnoid space was reached by the guiding cannula, the endoscope was inserted for visualization of the spinal cord and surrounding structures. After target visualization, a second needle was inserted to guide the RF electrode. Cordotomy was performed by a standard RF method. RESULTS: The microendoscopic double-channel approach provided real-time visualization of the target in 91% of the cases. The other 9% of procedures were performed by the single-channel technique. Significant analgesia was achieved in over 90% of the cases. Two patients had transient ataxia that lasted for a few weeks until total recovery. CONCLUSIONS: The use of percutaneous microendoscopic cordotomy with the double-channel technique is useful for specific manipulations of the spinal cord. It provides real-time visualization of the RF probe, thereby adding a degree of safety to the procedure.


Assuntos
Cordotomia/métodos , Endoscopia/métodos , Procedimentos Neurocirúrgicos/métodos , Dor Intratável/cirurgia , Cirurgia Assistida por Computador/métodos , Adulto , Idoso , Cordotomia/efeitos adversos , Feminino , Fluoroscopia , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos , Neoplasias/complicações , Medição da Dor , Dor Intratável/etiologia , Complicações Pós-Operatórias/epidemiologia , Estudos Prospectivos , Ondas de Rádio , Medula Espinal/cirurgia , Tratos Espinotalâmicos/anatomia & histologia , Tratos Espinotalâmicos/cirurgia , Espaço Subaracnóideo/anatomia & histologia , Espaço Subaracnóideo/cirurgia , Resultado do Tratamento
12.
J Hypertens ; 33(9): 1811-7; discussion 1817-8, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26248322

RESUMO

BACKGROUND: Little is known about intracranial pressure (ICP)-cerebral haemodynamic interplay during repetitive apnoea. A recently developed method based on near-infrared transillumination/backscattering sounding (NIR-T/BSS) noninvasively measures changes in pial artery pulsation (cc-TQ) as well as subarachnoid width (sas-TQ) in humans. METHOD: We tested the complex response of the pial artery and subarachnoid width to apnoea using this method. The pial artery and subarachnoid width response to consecutive apnoeas lasting 30, 60 s and maximal breath-hold (91.1 ±â€Š23.1 s) were studied in 20 healthy volunteers. The cc-TQ and sas-TQ were measured using NIR-T/BSS; cerebral blood flow velocity (CBFV), pulsatility index and resistive index were measured using Doppler ultrasound of the left internal carotid artery; heart rate (HR) and beat-to-beat SBP and DBP blood pressure were recorded using a Finometer; end-tidal CO2 (EtCO2) was measured using a medical gas analyser. RESULTS: Apnoea evoked a multiphasic response in blood pressure, pial artery compliance and ICP. First, SBP declined, which was accompanied by an increase in cc-TQ and sas-TQ. Directly after these changes, SBP exceeded baseline values, which was followed by a decline in cc-TQ and the return of sas-TQ to baseline. During these initial changes, CBFV remained stable. Towards the end of the apnoea, BP, cc-TQ and CBFV increased, whereas pulsatility index, resistive index and sas-TQ declined. Changes in sas-TQ were linked to changes in EtCO2, HR and SBP. CONCLUSION: Apnoea is associated with ICP swings, closely reflecting changes in EtCO2, HR and peripheral BP. The baroreflex influences the pial artery response.


Assuntos
Apneia/fisiopatologia , Artérias Cerebrais/fisiologia , Espaço Subaracnóideo/anatomia & histologia , Espaço Subaracnóideo/fisiologia , Adolescente , Adulto , Barorreflexo , Pressão Sanguínea/fisiologia , Artéria Carótida Interna/diagnóstico por imagem , Circulação Cerebrovascular/fisiologia , Feminino , Voluntários Saudáveis , Frequência Cardíaca/fisiologia , Humanos , Pressão Intracraniana/fisiologia , Masculino , Tamanho do Órgão , Ultrassonografia Doppler , Adulto Jovem
13.
Reg Anesth Pain Med ; 40(3): 245-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25899953

RESUMO

BACKGROUND AND OBJECTIVES: Epidural catheters placed for perioperative analgesia in young children confer clinical benefits but are technically challenging to insert. Approximations of the skin to epidural space depth in this population are limited to direct needle measurement and ultrasonography. Magnetic resonance imaging (MRI) is the most comprehensive imaging modality of the spine. This study aims to produce a more clinically useful formula from MRI data to estimate pediatric epidural depth. METHODS: Seventy children with normal lumbar spine MR images were enrolled. After determination of epidural depth, linear regression was used to estimate a weight-based formula. Analysis of variance and bootstrap methods were used to evaluate this formula against 4 commonly cited formulae. The quality of predictions was evaluated using the mean absolute prediction error. RESULTS: The estimated weight-based formula as derived by MRI data is given by: skin to epidural depth (mm) = 9.00 + 0.62 * weight in kilograms. The mean absolute prediction error was 2.56 mm (95% confidence interval [95% CI], 2.12-3.04) for the new formula. Additional derived formulae are skin to dorsal dura depth (mm) = 13.52 + 0.71 * weight in kilograms (mean absolute prediction error, 2.48 mm; 95% CI, 2.00-3.03) and skin to ventral dural depth (mm) = 23.08 + 0.86 * weight in kilograms (mean absolute prediction error, 2.50 mm; 95% CI, 2.04-3.06). CONCLUSIONS: We provide the first predictive formulae, based on MRI data, for pediatric epidural depth estimation.


Assuntos
Anestesia Epidural , Pesos e Medidas Corporais/métodos , Imagem por Ressonância Magnética , Pele/anatomia & histologia , Pré-Escolar , Espaço Epidural/anatomia & histologia , Feminino , Humanos , Lactente , Masculino , Reprodutibilidade dos Testes , Espaço Subaracnóideo/anatomia & histologia
14.
Cir. mayor ambul ; 20(1): 33-40, ene.-mar. 2015. tab
Artigo em Espanhol | IBECS | ID: ibc-154836

RESUMO

En los últimos años hemos asistido a un abandono de la anestesia espinal como técnica habitual en pacientes ambulatorios por el auge de la anestesia general. Esto se debe a los efectos adversos clásicamente asociados a su empleo y al retraso en el alta domiciliaria. Sin embargo, la irrupción en el mercado de los nuevos anestésicos locales de corta duración y la utilización de la anestesia subaracnoidea selectiva en procedimientos ortopédicos ha suscitado un interés creciente por esta técnica anestésica. Con este artículo pretendemos hacer una revisión de la anestesia espinal, de las indicaciones, contraindicaciones y de los efectos adversos asociados a la técnica. Finalmente, proponemos un resumen breve de los nuevos anestésicos locales de acción corta y unas recomendaciones para la cirugía proctológica y del miembro inferior (AU)


Recently, we have witnessed a drop of spinal anesthesia as a routine technique in outpatients by the rise of general anesthesia. This is due to the adverse effects typically associated with its employment and delayed discharge home. However, the introduction of new local anesthetics of short duration and the use of selective spinal anesthesia in orthopedic procedures has led to a growing interest in the anesthetic technique. We intend with this article to make a review of spinal anesthesia, including indications and contraindications and associated technical side effects. Finally, we provide a brief summary of the new short-acting local anesthetics and recommendations for the proctologic and lower limb surgery (AU)


Assuntos
Humanos , Anestesia por Condução/métodos , Raquianestesia/métodos , Procedimentos Cirúrgicos Ambulatórios/métodos , Procedimentos Ortopédicos/métodos , Espaço Subaracnóideo , Espaço Subaracnóideo/anatomia & histologia
15.
Acta Radiol ; 56(12): 1514-8, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25487716

RESUMO

BACKGROUND: Magnetic resonance imaging (MRI) can be helpful in visualizing neurovascular conflict (NVC) of the trigeminal nerve in patients with trigeminal neuralgia (TN), but the relationship between these two events is controversial. PURPOSE: To investigate whether posterior fossa volume is a predisposing factor for NVC in TN. MATERIAL AND METHODS: We conducted a case-control study of clinically diagnosed idiopathic TN of 30 patients aged 30-79 years and 30 age- and sex-matched controls. We compared the volume of the posterior fossa and subarachnoid space using fast-imaging employing steady-state acquisition MRI and the iPlan® programme of BrainLab. RESULTS: The posterior fossa volumes in controls and patients with TN were 168.97 cm(3) and 167.63 cm(3), respectively. A small pontomesencephalic cistern volume was more frequent in TN. However, neither the cisternal nor parenchymal portions of the posterior fossa were different between patients with TN and controls, and no significant volume difference was observed in this study. CONCLUSION: Although the hypothesis that small posterior fossa volume influences TN was feasible, we did not find any volumetric differences (including the cisternal and parenchymal volumes).However, small pontomesencephalic cistern volumes were more frequent in patients with TN.


Assuntos
Encéfalo/anatomia & histologia , Imagem por Ressonância Magnética , Nervo Trigêmeo/patologia , Neuralgia do Trigêmeo/patologia , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Imagem Tridimensional , Masculino , Pessoa de Meia-Idade , Espaço Subaracnóideo/anatomia & histologia
16.
Neurochirurgie ; 61(2-3): 70-6, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-24856313

RESUMO

INTRODUCTION: The pineal region is situated in the posterior part of the incisural space. This region includes the pineal body inside the quadrigeminal arachnoidal cistern. This article reviews the anatomic features of this region, with particular emphasis on those aspects of importance for surgical access to the pineal region. MATERIAL & METHODS: Five cadaver heads fixed in 10% formalin and injected with colored latex were used for anatomic dissection (five other specimens were also prepared and dissected to illustrate the articles on surgical techniques and approaches presented elsewhere in this issue). RESULTS: The pineal body is surrounded by several important structures such as: posterior part of the third ventricle, tectum, the complex of the great cerebral vein of Galen, pulvinar nuclei of the thalamus and splenium of corpus callosum. CONCLUSION: The surgical approach of the pineal body, whatever the route or the technique used (microsurgical, endoscopic or stereotactic), creates a great challenge for the neurosurgeons due to its location in the deep part of the brain and its close relationships with complex surrounded vascular structures.


Assuntos
Veias Cerebrais/anatomia & histologia , Glândula Pineal/anatomia & histologia , Espaço Subaracnóideo/anatomia & histologia , Tálamo/anatomia & histologia , Terceiro Ventrículo/anatomia & histologia , Cadáver , Humanos , Microcirurgia/métodos , Glândula Pineal/irrigação sanguínea , Tálamo/cirurgia , Terceiro Ventrículo/cirurgia
17.
Childs Nerv Syst ; 31(1): 15-28, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25395307

RESUMO

INTRODUCTION: Liliequist's membrane is an arachnoid membrane that forms a barrier within the basilar cisternal complex. This structure is an important landmark in approaches to the sellar and parasellar regions. The importance of this membrane was largely recognized after the advance of neuroendoscopic techniques. Many studies were, thereafter, published reporting different anatomic findings. METHOD: A detailed search for studies reporting anatomic and surgical findings of Liliequist's membrane was performed using "PubMed," and included all the available literature. Manual search for manuscripts was also conducted on references of papers reporting reviews. RESULTS: Liliequist's membrane has received more attention recently. The studies have reported widely variable results, which were systematically organized in this paper to address the controversy. CONCLUSION: Regardless of its clinical and surgical significance, the anatomy of Liliequist's membrane is still a matter of debate.


Assuntos
Aracnoide-Máter/anatomia & histologia , Neurocirurgia , Humanos , PubMed/estatística & dados numéricos , Espaço Subaracnóideo/anatomia & histologia
18.
J Neurosurg ; 121(2): 390-6, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24785320

RESUMO

OBJECT: The aim of this study was to describe the similarity of configuration between the arachnoid complex in the posterior half of the incisural space and the Liliequist membrane. METHODS: Microsurgical dissection and anatomical observation were performed in 20 formalin-fixed adult cadaver heads. The origin, distribution, and configuration of the arachnoid membranes and their relationships with the vascular structures in the posterior half of the incisural space were examined. RESULTS: The posterior perimesencephalic membrane and the cerebellar precentral membrane have a common origin at the tentorial edge and form an arachnoid complex strikingly resembling an inverted Liliequist membrane. Asymmetry between sides is not uncommon. If the cerebellar precentral membrane is hypoplastic on one side or both, the well-developed quadrigeminal membrane plays a prominent part in partitioning the subarachnoid space in the posterior half of the incisural space. CONCLUSIONS: The arachnoid complex in the posterior half of the incisural space can be regarded as an inverted Liliequist membrane. This concept can help neurosurgeons to gain better understanding of the surgical anatomy at the level of the tentorial incisura.


Assuntos
Aracnoide-Máter/anatomia & histologia , Aracnoide-Máter/irrigação sanguínea , Cadáver , Cerebelo/anatomia & histologia , Artérias Cerebrais/anatomia & histologia , Veias Cerebrais/anatomia & histologia , Humanos , Membranas/anatomia & histologia , Mesencéfalo/anatomia & histologia , Espaço Subaracnóideo/anatomia & histologia
19.
Folia Morphol (Warsz) ; 72(2): 142-6, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23740502

RESUMO

BACKGROUND: The subarachnoid space (SAS) and ventricular width (VW) in normal infants and children were studied with ultrasonography to provide the objective measurement and define a normal range for these measurements. The additional aim was to determine the stable ratio as a SAS/VW. MATERIALS AND METHODS: A total of 100 healthy subjects, including 48 males and 52 females, were studied. The cases were divided into 3 age groups: 0-6 months(n = 65), 7-12 months (n = 24) and > 13 months (n = 11). Transfontanel ultrasonography was performed in all the cases. SAS, VW and the SAS/VW ratios were calculated. The study was approved by the ethical committee. All parents were informed about the sonographic examination and their approvals were taken. RESULTS: SAS was calculated as 3.1 (0.5-6) mm and VW was calculated as 3.6(1.3-5) mm. SAS/VW ratio was 0.9 ± 0.3. There was no statistically significant difference among SAS, VW and SAS/VW ratios in 3-97 percentile group (p > 0.05). CONCLUSIONS: Ultrasonography can be used as a practicable and reproducible modality in the measurement of SAS and VW in healthy children. It is a non-invasive method and allows for serial follow-up. SAS/VW ratio can be used as an index in healthy children.


Assuntos
Ventrículos Cerebrais/diagnóstico por imagem , Espaço Subaracnóideo/diagnóstico por imagem , Ventrículos Cerebrais/anatomia & histologia , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Valores de Referência , Espaço Subaracnóideo/anatomia & histologia , Ultrassonografia
20.
J Glaucoma ; 22 Suppl 5: S8-10, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23733131

RESUMO

The function of cerebrospinal fluid (CSF) is to protect the brain and optic nerve from mechanical damage, provide nutrition for axons/neurons, and remove of toxic metabilites. CSF is produced mainly by the choroid plexus epithelium and ependymal cells of the ventricles and flows into interconnecting chambers; namely, the cisterns and the subarachnoid spaces. Based on studies of CSF circulation and direction of flow using radioisotopes and other tracers injected into the CSF, it is thought that there is a bulk circulation of fluid from the sites of production in the third, fourth, and lateral ventricles to the arachnoid villi and probably to the lymphatic capillaries in the cranial dura mater. The mechanism by which CSF is propelled is incompletely understood, but probably is influenced by the release of newly produced CSF, ventricular pulsations, and the pulse pressure of the vascular choroid plexus. This mechanism would account for the steady CSF pressure. In addition to the steady CSF pressure, overlapping pressure spikes occur during trunk inclination, coughing and other valsalva.


Assuntos
Líquido Cefalorraquidiano/fisiologia , Nervo Óptico/anatomia & histologia , Espaço Subaracnóideo/anatomia & histologia , Humanos
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