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1.
World Neurosurg ; 131: e255-e264, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31351205

RESUMEN

BACKGROUND: Resection of intraventricular lesions remains a challenge for modern neurosurgery. Endoscopy has provided great advantages in ventricular surgery, even if limited in terms of operability, due to the restricted working channel and impossibility for bimanual surgical manipulation. Tubular approaches have been considered as an option, enabling the use of microsurgical techniques, minimizing violation of brain tissue. The aim of our study was to describe and critically evaluate the use of portal surgery to access lateral ventricles in terms of surgical exposure and operability. METHODS: A microanatomic laboratory cadaver study was conducted with a stepwise description of the surgical technique. The operability score was applied for quantitative analysis of surgical operability, and an illustrative case is reported. RESULTS: Through the anterior approach, the neuroport provides maximal operability at the foramen of Monro and the posterior aspect of the frontal horn, while through the posterior approach maximal operability is achieved in the paratrigonal area. Endoscopic assistance does not affect operability but provides adjunctive exposure in blind spots, as the roof of the frontal horn, the most anterior aspect of the temporal and occipital horn. CONCLUSIONS: Ventricular tubular systems provide adequate visualization, with minimal brain retraction, improving operability as compared with endoscopy. Endoscopic assistance critically widens surgical exposure in blind spots without providing concomitant significant advantage in terms of surgical operability.


Asunto(s)
Corteza Cerebral/cirugía , Ventrículos Laterales/cirugía , Microcirugia/métodos , Neuroendoscopía/métodos , Cadáver , Corteza Cerebral/anatomía & histología , Humanos , Ventrículos Laterales/anatomía & histología
2.
PLoS One ; 14(4): e0207967, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30939173

RESUMEN

OBJECTIVE: In a three-wave 6 yrs longitudinal study we investigated if the expansion of lateral ventricle (LV) volumes (regarded as a proxy for brain tissue loss) predicts third wave performance on a test of response inhibition (RI). PARTICIPANTS AND METHODS: Trajectories of left and right lateral ventricle volumes across the three waves were quantified using the longitudinal stream in Freesurfer. All participants (N = 74;48 females;mean age 66.0 yrs at the third wave) performed the Color-Word Interference Test (CWIT). Response time on the third condition of CWIT, divided into fast, medium and slow, was used as outcome measure in a machine learning framework. Initially, we performed a linear mixed-effect (LME) analysis to describe subject-specific trajectories of the left and right LV volumes (LVV). These features were input to a multinomial logistic regression classification procedure, predicting individual belongings to one of the three RI classes. To obtain results that might generalize, we evaluated the significance of a k-fold cross-validated f1-score with a permutation test, providing a p-value that approximates the probability that the score would be obtained by chance. We also calculated a corresponding confusion matrix. RESULTS: The LME-model showed an annual ∼ 3.0% LVV increase. Evaluation of a cross-validated score using 500 permutations gave an f1-score of 0.462 that was above chance level (p = 0.014). 56% of the fast performers were successfully classified. All these were females, and typically older than 65 yrs at inclusion. For the true slow performers, those being correctly classified had higher LVVs than those being misclassified, and their ages at inclusion were also higher. CONCLUSION: Major contributions were: (i) a longitudinal design, (ii) advanced brain imaging and segmentation procedures with longitudinal data analysis, and (iii) a data driven machine learning approach including cross-validation and permutation testing to predict behaviour, solely from the individual's brain "signatures" (LVV trajectories).


Asunto(s)
Envejecimiento , Ventrículos Laterales/fisiología , Anciano , Femenino , Humanos , Ventrículos Laterales/anatomía & histología , Estudios Longitudinales , Aprendizaje Automático , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Neuroimagen , Tamaño de los Órganos
3.
Nature ; 567(7746): 113-117, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30787442

RESUMEN

The expansion of brain size is accompanied by a relative enlargement of the subventricular zone during development. Epithelial-like neural stem cells divide in the ventricular zone at the ventricles of the embryonic brain, self-renew and generate basal progenitors1 that delaminate and settle in the subventricular zone in enlarged brain regions2. The length of time that cells stay in the subventricular zone is essential for controlling further amplification and fate determination. Here we show that the interphase centrosome protein AKNA has a key role in this process. AKNA localizes at the subdistal appendages of the mother centriole in specific subtypes of neural stem cells, and in almost all basal progenitors. This protein is necessary and sufficient to organize centrosomal microtubules, and promote their nucleation and growth. These features of AKNA are important for mediating the delamination process in the formation of the subventricular zone. Moreover, AKNA regulates the exit from the subventricular zone, which reveals the pivotal role of centrosomal microtubule organization in enabling cells to both enter and remain in the subventricular zone. The epithelial-to-mesenchymal transition is also regulated by AKNA in other epithelial cells, demonstrating its general importance for the control of cell delamination.


Asunto(s)
Centrosoma/metabolismo , Proteínas de Unión al ADN/metabolismo , Ventrículos Laterales/citología , Ventrículos Laterales/embriología , Microtúbulos/metabolismo , Neurogénesis , Proteínas Nucleares/metabolismo , Factores de Transcripción/metabolismo , Animales , Movimiento Celular , Células Cultivadas , Células Epiteliales/metabolismo , Transición Epitelial-Mesenquimal , Humanos , Uniones Intercelulares/metabolismo , Interfase , Ventrículos Laterales/anatomía & histología , Glándulas Mamarias Animales/citología , Ratones , Tamaño de los Órganos , Organoides/citología
4.
Nat Commun ; 9(1): 3945, 2018 09 26.
Artículo en Inglés | MEDLINE | ID: mdl-30258056

RESUMEN

The volume of the lateral ventricles (LV) increases with age and their abnormal enlargement is a key feature of several neurological and psychiatric diseases. Although lateral ventricular volume is heritable, a comprehensive investigation of its genetic determinants is lacking. In this meta-analysis of genome-wide association studies of 23,533 healthy middle-aged to elderly individuals from 26 population-based cohorts, we identify 7 genetic loci associated with LV volume. These loci map to chromosomes 3q28, 7p22.3, 10p12.31, 11q23.1, 12q23.3, 16q24.2, and 22q13.1 and implicate pathways related to tau pathology, S1P signaling, and cytoskeleton organization. We also report a significant genetic overlap between the thalamus and LV volumes (ρgenetic = -0.59, p-value = 3.14 × 10-6), suggesting that these brain structures may share a common biology. These genetic associations of LV volume provide insights into brain morphology.


Asunto(s)
Genoma Humano , Ventrículos Laterales/anatomía & histología , Anciano , Estudio de Asociación del Genoma Completo , Humanos , Persona de Mediana Edad , Tamaño de los Órganos/genética
5.
Bratisl Lek Listy ; 119(5): 265-271, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29749238

RESUMEN

Different types of ependymal areas were studied and labelled in the human brain lateral ventricle. Periventricular structures were included in coining the names of the ependymal areas because they represent a basic and stable part of brain nerve structures suitable for the sake of clarity of localization of the ependyma. The labelling of individual ependymal areas was composed from letters: "Lv" (lateral ventricle); "E" (ependymal area) and letters for abbreviations of the closest periventricular structure, e.g. the septum pellucidum is "sp". The labelling for ependymal area over the septum pellucidum is thus "LvE-sp". The studied types of ependymal areas were arranged in so­called ependymal tables for cornu anterius, pars centralis, cornu inferius and cornu posterius of the human lateral ventricle. Labelling of individual ependymal areas allows for better localization and characterisation of these areas in future studies carried out by various methods (e.g. morphological, biological, molecular) and will prevent from using misnomers with different types of ependymal areas in norm as well as in pathology (Tab. 5, Fig. 6, Ref. 22). Text in PDF www.elis.sk.


Asunto(s)
Epéndimo , Ventrículos Laterales , Epéndimo/anatomía & histología , Humanos , Ventrículos Laterales/anatomía & histología
6.
J Neurosurg ; 128(5): 1492-1502, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-28777024

RESUMEN

OBJECTIVE The best approach to deep-seated lateral and third ventricle lesions is a function of lesion characteristics, location, and relationship to the ventricles. The authors sought to examine and compare angles of attack and surgical freedom of anterior ipsilateral and contralateral interhemispheric transcallosal approaches to the frontal horn of the lateral ventricle using human cadaveric head dissections. Illustrative clinical experiences with a contralateral interhemispheric transcallosal approach and an anterior interhemispheric transcallosal transchoroidal approach are also related. METHODS Five formalin-fixed human cadaveric heads (10 sides) were examined microsurgically. CT and MRI scans obtained before dissection were uploaded and fused into the navigation system. The authors performed contralateral and ipsilateral transcallosal approaches to the lateral ventricle. Using the navigation system, they measured areas of exposure, surgical freedom, angles of attack, and angle of view to the surgical surface. Two clinical cases are described. RESULTS The exposed areas of the ipsilateral (mean [± SD] 313.8 ± 85.0 mm2) and contralateral (344 ± 87.73 mm2) interhemispheric approaches were not significantly different (p = 0.12). Surgical freedom and vertical angles of attack were significantly larger for the contralateral approach to the most midsuperior reachable point (p = 0.02 and p = 0.01, respectively) and to the posterosuperior (p = 0.02 and p = 0.04) and central (p = 0.04 and p = 0.02) regions of the lateral wall of the lateral ventricle. Surgical freedom and vertical angles of attack to central and anterior points on the floor of the lateral ventricle did not differ significantly with approach. The angle to the surface of the caudate head region was less steep for the contralateral (135.6° ± 15.6°) than for the ipsilateral (152.0° ± 13.6°) approach (p = 0.02). CONCLUSIONS The anterior contralateral interhemispheric transcallosal approach provided a more expansive exposure to the lower two-thirds of the lateral ventricle and striothalamocapsular region. In normal-sized ventricles, the foramen of Monro and the choroidal fissure were better visualized through the lateral ventricle ipsilateral to the craniotomy than through the contralateral approach.


Asunto(s)
Ventrículos Laterales/anatomía & histología , Ventrículos Laterales/cirugía , Procedimientos Neuroquirúrgicos/métodos , Anciano de 80 o más Años , Neoplasias del Ventrículo Cerebral/diagnóstico por imagen , Neoplasias del Ventrículo Cerebral/patología , Neoplasias del Ventrículo Cerebral/cirugía , Humanos , Ventrículos Laterales/diagnóstico por imagen , Ventrículos Laterales/patología , Masculino , Persona de Mediana Edad
7.
J Vis Exp ; (128)2017 10 22.
Artículo en Inglés | MEDLINE | ID: mdl-29155719

RESUMEN

Anatomy students are typically provided with two-dimensional (2D) sections and images when studying cerebral ventricular anatomy and students find this challenging. Because the ventricles are negative spaces located deep within the brain, the only way to understand their anatomy is by appreciating their boundaries formed by related structures. Looking at a 2D representation of these spaces, in any of the cardinal planes, will not enable visualisation of all of the structures that form the boundaries of the ventricles. Thus, using 2D sections alone requires students to compute their own mental image of the 3D ventricular spaces. The aim of this study was to develop a reproducible method for dissecting the human brain to create an educational resource to enhance student understanding of the intricate relationships between the ventricles and periventricular structures. To achieve this, we created a video resource that features a step-by-step guide using a fiber dissection method to reveal the lateral and third ventricles together with the closely related limbic system and basal ganglia structures. One of the advantages of this method is that it enables delineation of the white matter tracts that are difficult to distinguish using other dissection techniques. This video is accompanied by a written protocol that provides a systematic description of the process to aid in the reproduction of the brain dissection. This package offers a valuable anatomy teaching resource for educators and students alike. By following these instructions educators can create teaching resources and students can be guided to produce their own brain dissection as a hands-on practical activity. We recommend that this video guide be incorporated into neuroanatomy teaching to enhance student understanding of the morphology and clinical relevance of the ventricles.


Asunto(s)
Encéfalo/anatomía & histología , Ventrículos Cerebrales/anatomía & histología , Ventrículos Laterales/anatomía & histología , Disección , Humanos
8.
J Neurosurg ; 126(3): 945-971, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27257832

RESUMEN

OBJECTIVE The relationship of the white matter tracts to the lateral ventricles is important when planning surgical approaches to the ventricles and in understanding the symptoms of hydrocephalus. The authors' aim was to explore the relationship of the white matter tracts of the cerebrum to the lateral ventricles using fiber dissection technique and MR tractography and to discuss these findings in relation to approaches to ventricular lesions. METHODS Forty adult human formalin-fixed cadaveric hemispheres (20 brains) and 3 whole heads were examined using fiber dissection technique. The dissections were performed from lateral to medial, medial to lateral, superior to inferior, and inferior to superior. MR tractography showing the lateral ventricles aided in the understanding of the 3D relationships of the white matter tracts with the lateral ventricles. RESULTS The relationship between the lateral ventricles and the superior longitudinal I, II, and III, arcuate, vertical occipital, middle longitudinal, inferior longitudinal, inferior frontooccipital, uncinate, sledge runner, and lingular amygdaloidal fasciculi; and the anterior commissure fibers, optic radiations, internal capsule, corona radiata, thalamic radiations, cingulum, corpus callosum, fornix, caudate nucleus, thalamus, stria terminalis, and stria medullaris thalami were defined anatomically and radiologically. These fibers and structures have a consistent relationship to the lateral ventricles. CONCLUSIONS Knowledge of the relationship of the white matter tracts of the cerebrum to the lateral ventricles should aid in planning more accurate surgery for lesions within the lateral ventricles.


Asunto(s)
Cerebro/anatomía & histología , Hidrocefalia/patología , Hidrocefalia/cirugía , Ventrículos Laterales/anatomía & histología , Ventrículos Laterales/cirugía , Sustancia Blanca/anatomía & histología , Cerebro/diagnóstico por imagen , Cerebro/patología , Cerebro/cirugía , Imagen de Difusión por Resonancia Magnética , Disección , Humanos , Hidrocefalia/diagnóstico por imagen , Imagen Tridimensional , Ventrículos Laterales/diagnóstico por imagen , Ventrículos Laterales/patología , Vías Nerviosas/anatomía & histología , Vías Nerviosas/diagnóstico por imagen , Vías Nerviosas/patología , Vías Nerviosas/cirugía , Sustancia Blanca/diagnóstico por imagen , Sustancia Blanca/patología , Sustancia Blanca/cirugía
9.
Oncotarget ; 7(36): 58203-58217, 2016 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-27533460

RESUMEN

Bmi1 was originally identified as a gene that contributes to the development of mouse lymphoma by inhibiting MYC-induced apoptosis through repression of Ink4a and Arf. It codes for the Polycomb group protein BMI-1 and acts primarily as a transcriptional repressor via chromatin modifications. Although it binds to a large number of genomic regions, the direct BMI-1 target genes described so far do not explain the full spectrum of BMI-1-mediated effects. Here we identify the putative tumor suppressor gene EphA7 as a novel direct BMI-1 target in neural cells and lymphocytes. EphA7 silencing has been reported in several different human tumor types including lymphomas, and our data suggest BMI1 overexpression as a novel mechanism leading to EphA7 inactivation via H3K27 trimethylation and DNA methylation.


Asunto(s)
Regulación de la Expresión Génica , Genes Supresores de Tumor , Complejo Represivo Polycomb 1/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Receptor EphA7/genética , Animales , Linfocitos B , Técnicas de Cultivo de Célula/métodos , Núcleo Celular/metabolismo , Proliferación Celular/fisiología , Células Cultivadas , Cerebelo/anatomía & histología , Cerebelo/metabolismo , Metilación de ADN/fisiología , Regulación hacia Abajo , Histonas/metabolismo , Inmunohistoquímica , Antígeno Ki-67/metabolismo , Ventrículos Laterales/anatomía & histología , Ventrículos Laterales/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Análisis por Micromatrices , Células-Madre Neurales , Complejo Represivo Polycomb 1/genética , Proteínas Proto-Oncogénicas/genética , Receptor EphA7/metabolismo , Bazo/citología , Transducción Genética , Regulación hacia Arriba
10.
J Craniofac Surg ; 27(7): e716-e718, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26147031

RESUMEN

Endoscopic surgery has been applied in the treatment of lateral cerebral ventricular lesions for years, but few morphometric studies in vivo have been reported with medical imaging. In the current study, the authors aimed to investigate the related morphometric data of endoscopic transoccipital approach to lateral ventricle with the magnetic resonance images of lateral ventricle from healthy adults anonymously. Seven parameters on the axial plane and 3 on the left occipital horn of sagittal plane of T1-weighted image were measured and the results were as follows: The distance from incision to the cranium posterior intersection with midsagittal line (D1) was 29.69 ±â€Š3.09 mm.The distance from incision to the superior border of transverse sinus (D2) was 29.40 ±â€Š4.76 mm; the length between incision and the entry trajectory intersection K of posterior wall of lateral ventricle (D3) was 43.25 ±â€Š4.20 mm; the distance between the midpoint of largest width of occipital horn and the intersection K (D4) was 9.39 ±â€Š2.75 mm; the bilateral occipital horn and left frontal horn (W1, W2, W3) were, respectively: 10.29 ±â€Š2.27, 9.74 ±â€Š2.51, and 7.91 ±â€Š1.19 mm. The angulations between entry trajectory and the projections of longitudinal axis of posterior lateral ventricle body that goes through the midpoint of largest breadths of left occipital horn on the axial and sagittal planes and the longitudinal axis of temporal horn (A1, A2, A3) were separately as follows: (38.10 ±â€Š4.50)°, (30.30 ±â€Š4.47)°, and (31.08 ±â€Š4.54)°. The resultant anatomical data of the distances and angles validate the previous surgical experience and, moreover, facilitate neurosurgery to the lateral ventricle through the endoscopic transoccipital approach.


Asunto(s)
Ventrículos Laterales/anatomía & histología , Ventrículos Laterales/diagnóstico por imagen , Imagen por Resonancia Magnética , Neuroendoscopía , Adolescente , Adulto , Femenino , Voluntarios Sanos , Humanos , Ventrículos Laterales/cirugía , Masculino , Lóbulo Occipital/anatomía & histología , Lóbulo Occipital/diagnóstico por imagen , Lóbulo Temporal/anatomía & histología , Lóbulo Temporal/diagnóstico por imagen , Adulto Joven
11.
J Neurosurg ; 124(2): 450-62, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26361277

RESUMEN

OBJECTIVE: The cerebral isthmus is the white matter area located between the periinsular sulcus and the lateral ventricle. Studies demonstrating the fiber tract and topographic anatomy of this entity are lacking in current neurosurgical literature. Hence, the authors' primary aim was to describe the microsurgical white matter anatomy of the cerebral isthmus by using the fiber dissection technique, and they discuss its functional significance. In addition, they sought to investigate its possible surgical utility in approaching lesions located in or adjacent to the lateral ventricle. METHODS: This study was divided into 2 parts and included 30 formalin-fixed cerebral hemispheres, 5 of which were injected with colored silicone. In the first part, 15 uncolored specimens underwent the Klinger's procedure and were dissected in a lateromedial direction at the level of the superior, inferior, and anterior isthmuses, and 10 were used for coronal and axial cuts. In the second part, the injected specimens were used to investigate the surgical significance of the superior isthmus in accessing the frontal horn of the lateral ventricle. RESULTS: The microsurgical anatomy of the anterior, superior, and inferior cerebral isthmuses was carefully studied and recorded both in terms of topographic and fiber tract anatomy. In addition, the potential role of the proximal part of the superior isthmus as an alternative safe surgical corridor to the anterior part of the lateral ventricle was investigated. CONCLUSIONS: Using the fiber dissection technique along with coronal and axial cuts in cadaveric brain specimens remains a cornerstone in the acquisition of thorough anatomical knowledge of narrow white matter areas such as the cerebral isthmus. The surgical significance of the superior isthmus in approaching the frontal horn of the lateral ventricle is stressed, but further studies must be carried out to elucidate its role in ventricular surgery.


Asunto(s)
Fibras Nerviosas Mielínicas , Vías Nerviosas/anatomía & histología , Procedimientos Neuroquirúrgicos/métodos , Sustancia Blanca/anatomía & histología , Sustancia Blanca/cirugía , Cadáver , Humanos , Ventrículos Laterales/anatomía & histología , Microcirugia , Fibras Nerviosas , Vías Nerviosas/cirugía , Tractos Piramidales/anatomía & histología , Fijación del Tejido
12.
Radiol Phys Technol ; 9(1): 69-76, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26404397

RESUMEN

The volume of the temporal horn of the lateral ventricle (THLV) on brain computed tomography (CT) images is important for neurologic diagnosis. Our purpose in this study was to develop a z-score-based semi-quantitative analysis for estimation of the THLV volume by using voxel-based morphometry. The THLV volume was estimated by use of a z-score mapping method that consisted of four main steps: anatomic standardization, construction of a normal reference database, calculation of the z score, and calculation of the mean z score in a volume of interest (VOI). A mean z score of the CT value obtained from a VOI around the THLV was used as an index for the THLV volume. CT scans from 50 subjects were evaluated. For evaluation of the accuracy of this method for estimating the THLV volume, the THLV volume was determined manually by neuroradiologists (serving as the reference volume). A mean z score was calculated from the VOI for each THLV of the 50 subjects by use of the proposed method. The accuracy of this method was evaluated by use of the relationship between the mean z score and the reference volume. The quadratic polynomial regression equation demonstrated a statistically significant correlation between the mean z score and the reference volume of the THLV (R (2) = 0.94; P < 0.0001). In 92 of 100 THLVs (92 %), the 95 % prediction interval of the regional mean z score captured the reference volume of the THLV. The z-score-based semi-quantitative analysis has the potential quantitatively to estimate the THLV volume on CT images.


Asunto(s)
Ventriculografía Cerebral , Ventrículos Laterales/anatomía & histología , Ventrículos Laterales/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Tamaño de los Órganos
13.
Anat Histol Embryol ; 45(5): 373-85, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26394884

RESUMEN

The spatial anatomy of the white matter tracts is a subject of growing interest not only for researchers but also for clinicians. Imagistic methods have some limitations so that they should be confronted with dissection studies. The aim of this paper was to provide a three-dimensional view of the major white matter tracts in equine, feline and canine brains by use of the fibre dissection technique. Twenty cerebral hemispheres (six equine, four feline and 10 canine brains) were prepared according to the Klingler method. Stepwise mediolateral and lateromedial blunt dissections were performed using wooden sticks and spatulas. The lateromedial dissection was followed by the opening of the lateral ventricle. The use of the same multi-stage procedures resulted in a comparable exposure of the major association, projection and commissural fibres and their spatial relation with the lateral ventricle. To conclude, the proposed techniques are reproducible in equine, feline and canine brains and they can be successfully used for teaching, training or research in the field of neurobiology.


Asunto(s)
Gatos , Disección/veterinaria , Perros , Caballos/anatomía & histología , Ventrículos Laterales/anatomía & histología , Sustancia Blanca/anatomía & histología , Animales
14.
Morfologiia ; 147(3): 17-21, 2015.
Artículo en Ruso | MEDLINE | ID: mdl-26390541

RESUMEN

The aim of this study was to examine the structural organization of processes of ependymocytes lining the lateral ventricles of the rat brain using vimentin immunocytochemistry and confocal laser microscopy. The study was performed on adult male rats (n = 3). It was found that most typical ependymocytes had basal processes, while 1/3 of these cells had none. Some vimentin-immunopositive tanycyte-like cells with long processes appoaching blood vessels, were found inside the ependymal lining In some typical ependymocytes, cytroskeleton wa s formed by intermediate filaments of mixed type containing both vimentin and glial fibrillary acidic protein.


Asunto(s)
Epéndimo/anatomía & histología , Proteína Ácida Fibrilar de la Glía/fisiología , Ventrículos Laterales/anatomía & histología , Morfogénesis , Animales , Astrocitos/citología , Epéndimo/citología , Inmunohistoquímica , Ventrículos Laterales/fisiología , Masculino , Microscopía Confocal , Neuroglía/citología , Ratas
15.
J Vis Exp ; (99): e52328, 2015 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-26068121

RESUMEN

The ventricular system carries and circulates cerebral spinal fluid (CSF) and facilitates clearance of solutes and toxins from the brain. The functional units of the ventricles are ciliated epithelial cells termed ependymal cells, which line the ventricles and through ciliary action are capable of generating laminar flow of CSF at the ventricle surface. This monolayer of ependymal cells also provides barrier and filtration functions that promote exchange between brain interstitial fluids (ISF) and circulating CSF. Biochemical changes in the brain are thereby reflected in the composition of the CSF and destruction of the ependyma can disrupt the delicate balance of CSF and ISF exchange. In humans there is a strong correlation between lateral ventricle expansion and aging. Age-associated ventriculomegaly can occur even in the absence of dementia or obstruction of CSF flow. The exact cause and progression of ventriculomegaly is often unknown; however, enlarged ventricles can show regional and, often, extensive loss of ependymal cell coverage with ventricle surface astrogliosis and associated periventricular edema replacing the functional ependymal cell monolayer. Using MRI scans together with postmortem human brain tissue, we describe how to prepare, image and compile 3D renderings of lateral ventricle volumes, calculate lateral ventricle volumes, and characterize periventricular tissue through immunohistochemical analysis of en face lateral ventricle wall tissue preparations. Corresponding analyses of mouse brain tissue are also presented supporting the use of mouse models as a means to evaluate changes to the lateral ventricles and periventricular tissue found in human aging and disease. Together, these protocols allow investigations into the cause and effect of ventriculomegaly and highlight techniques to study ventricular system health and its important barrier and filtration functions within the brain.


Asunto(s)
Ventrículos Laterales/anatomía & histología , Factores de Edad , Animales , Modelos Animales de Enfermedad , Epéndimo/anatomía & histología , Epéndimo/citología , Epéndimo/patología , Células Epiteliales/citología , Células Epiteliales/patología , Gliosis/patología , Humanos , Hidrocefalia/patología , Imagen Tridimensional/métodos , Ventrículos Laterales/citología , Ventrículos Laterales/patología , Imagen por Resonancia Magnética , Ratones , Modelos Anatómicos , Neuroglía/citología , Neuroglía/patología
16.
World Neurosurg ; 84(5): 1333-9, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26100167

RESUMEN

BACKGROUND: Educational simulators provide a means for students and experts to learn and refine surgical skills. Educators can leverage the strengths of medical simulators to effectively teach complex and high-risk surgical procedures, such as placement of an external ventricular drain. OBJECTIVE: Our objective was to develop a cost-effective, patient-derived medical simulacrum for cerebral lateral ventriculostomy. METHODS: A cost-effective, patient-derived medical simulacrum was developed for placement of an external lateral ventriculostomy. Elastomeric and gel casting techniques were used to achieve realistic brain geometry and material properties. 3D printing technology was leveraged to develop accurate cranial properties and dimensions. An economical, gravity-driven pump was developed to provide normal and abnormal ventricular pressures. A small pilot study was performed to gauge simulation efficacy using a technology acceptance model. RESULTS: An accurate geometric representation of the brain was developed with independent lateral cerebral ventricular chambers. A gravity-driven pump pressurized the ventricular cavities to physiologic values. A qualitative study illustrated that the simulation has potential as an educational tool to train medical professionals in the ventriculostomy procedure. CONCLUSION: The ventricular simulacrum can improve learning in a medical education environment. Rapid prototyping and multi-material casting techniques can produce patient-derived models for cost-effective and realistic surgical training scenarios.


Asunto(s)
Ventrículos Cerebrales/anatomía & histología , Modelos Anatómicos , Impresión Tridimensional , Ventriculostomía/métodos , Actitud del Personal de Salud , Humanos , Hidrogeles , Ventrículos Laterales/anatomía & histología , Imagen por Resonancia Magnética , Neurocirugia/educación , Proyectos Piloto , Estudiantes de Medicina , Tomografía Computarizada por Rayos X
17.
Magn Reson Med Sci ; 14(4): 251-5, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25833274

RESUMEN

PURPOSE: Signal intensity (SI) and image contrast on postmortem magnetic resonance (MR) imaging are different from those of imaging of living bodies. We sought to suppress the SI of cerebrospinal fluid (CSF) sufficiently for fluid-attenuated inversion recovery (FLAIR) sequence in postmortem MR (PMMR) imaging by optimizing inversion time (TI). MATERIALS AND METHODS: We subject 28 deceased patients to PMMR imaging 3 to 113 hours after confirmation of death (mean, 27.4 hrs.). PMMR imaging was performed at 1.5 tesla, and T1 values of CSF were measured with maps of relaxation time. Rectal temperatures (RT) measured immediately after PMMR imaging ranged from 6 to 32°C (mean, 15.4°C). We analyzed the relationship between T1 and RT statistically using Pearson's correlation coefficient. We obtained FLAIR images from one cadaver using both a TI routinely used for living bodies and an optimized TI calculated from the RT. RESULTS: T1 values of CSF ranged from 2159 to 4063 ms (mean 2962.4), and there was a significantly positive correlation between T1 and RT (r = 0.96, P < 0.0001). The regression expression for the relationship was T1 = 74.4 * RT + 1813 for a magnetic field strength of 1.5T. The SI of CSF was effectively suppressed with the optimized TI (0.693 * T1), namely, TI = 0.693 * (77.4 * RT + 1813). CONCLUSION: Use of the TI calculated from the linear regression of the T1 and RT optimizes the FLAIR sequence of PMMR imaging.


Asunto(s)
Temperatura Corporal/fisiología , Líquido Cefalorraquídeo , Aumento de la Imagen/métodos , Imagen por Resonancia Magnética/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anatomía Transversal/métodos , Autopsia , Cadáver , Niño , Preescolar , Femenino , Humanos , Imagen Tridimensional/métodos , Lactante , Ventrículos Laterales/anatomía & histología , Masculino , Persona de Mediana Edad , Técnicas de Imagen Sincronizada Respiratorias/métodos , Factores de Tiempo , Adulto Joven
18.
Dev Neurosci ; 37(2): 115-30, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25678047

RESUMEN

Stimulation of postnatal neurogenesis in the subventricular zone (SVZ) and robust migration of neuroblasts to the lesion site in response to traumatic brain injury (TBI) is well established in rodent species; however, it is not yet known whether postnatal neurogenesis plays a role in repair after TBI in gyrencephalic species. Here we describe the anatomy of the SVZ in the piglet for the first time and initiate an investigation into the effect of TBI on the SVZ architecture and the number of neuroblasts in the white matter. Among all ages of immaturity examined the SVZ contained a dense mesh network of neurogenic precursor cells (doublecortin+) positioned directly adjacent to the ependymal cells (ventricular SVZ, Vsvz) and neuroblasts organized into chains that were distinct from the Vsvz (abventricular SVZ, Asvz). Though the architecture of the SVZ was similar among ages, the areas of Vsvz and Asvz neuroblast chains declined with age. At postnatal day (PND) 14 the white matter tracts have a tremendous number of individual neuroblasts. In our scaled cortical impact model, lesion size increased with age. Similarly, the response of the SVZ to injury was also age dependent. The younger age groups that sustained the proportionately smallest lesions had the largest SVZ areas, which further increased in response to injury. In piglets that were injured at 4 months of age and had the largest lesions, the SVZ did not increase in response to injury. Similar to humans, swine have abundant gyri and gyral white matter, providing a unique platform to study neuroblasts potentially migrating from the SVZ to the lesioned cortex along these white matter tracts. In piglets injured at PND 7, TBI did not increase the total number of neuroblasts in the white matter compared to uninjured piglets, but redistribution occurred with a greater number of neuroblasts in the white matter of the hemisphere ipsilateral to the injury compared to the contralateral hemisphere. At 7 days after injury, less than 1% of neuroblasts in the white matter were born in the 2 days following injury. These data show that the SVZ in the piglet shares many anatomical similarities with the SVZ in the human infant, and that TBI had only modest effects on the SVZ and the number of neuroblasts in the white matter. Piglets at an equivalent developmental stage to human infants were equipped with the largest SVZ and a tremendous number of neuroblasts in the white matter, which may be sufficient in lesion repair without the dramatic stimulation of neurogenic machinery. It has yet to be determined whether neurogenesis and migrating neuroblasts play a role in repair after TBI and/or whether an alteration of normal migration during active postnatal population of brain regions is beneficial in species with gyrencephalic brains.


Asunto(s)
Lesiones Encefálicas/patología , Movimiento Celular/fisiología , Corteza Cerebral/citología , Ventrículos Laterales/anatomía & histología , Ventrículos Laterales/citología , Células-Madre Neurales/citología , Neurogénesis/fisiología , Sustancia Blanca/citología , Factores de Edad , Animales , Modelos Animales de Enfermedad , Femenino , Masculino , Porcinos
19.
Pediatr Neurosurg ; 50(1): 12-7, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25613691

RESUMEN

Ventricle sizes are important for the early diagnosis of hydrocephalus or for follow-up after ventriculostomy. Diameters of ventricles may change, especially in childhood. This study aims to provide normative data about ventricle diameters. Among 14,854 cranial MRI performed between 2011 and 2013, 2,755 images of Turkish children aged 0-18 years were obtained. After exclusions, 517 images were left. Four radiologists were trained by a pediatric radiologist. Twenty images were assessed by all radiologists for a pilot study to see that there was no interobserver variation. There were 10-22 children in each age group. The maximum width of the third ventricle was 5.54 ± 1.29 mm in males in age group 1 and 4.98 ± 1.08 mm in females in age group 2. The Evans' index was <0.3 and consistent with the literature. The third ventricle/basilar artery width ratio was found to be >1 and <2 in all age groups and both gender groups. Our study showed the ventricle size data of children in various age groups from newborn to adolescent. The ventricle volume/cerebral parenchyma ratio seems to decrease with age. We think that these data can be applied in clinical practice, especially for the early diagnosis of hydrocephalus.


Asunto(s)
Cuarto Ventrículo/anatomía & histología , Ventrículos Laterales/anatomía & histología , Tercer Ventrículo/anatomía & histología , Adolescente , Factores de Edad , Ventrículos Cerebrales/anatomía & histología , Ventrículos Cerebrales/crecimiento & desarrollo , Niño , Preescolar , Femenino , Cuarto Ventrículo/crecimiento & desarrollo , Humanos , Hidrocefalia/diagnóstico , Lactante , Recién Nacido , Ventrículos Laterales/crecimiento & desarrollo , Imagen por Resonancia Magnética/métodos , Masculino , Tamaño de los Órganos , Tercer Ventrículo/crecimiento & desarrollo
20.
J Neurol Surg A Cent Eur Neurosurg ; 76(4): 261-7, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25594819

RESUMEN

OBJECTIVE: Accessing large lesions located in the atrium of the lateral ventricle without causing a neurologic deficit can be challenging. The aim of this study was to evaluate a modification of the posterior transcortical approach that may create sufficient exposure to the atrium of the lateral ventricle with less injury to the brain cortex and fibers using a technique that combines a microscope with an endoscope. MATERIAL AND METHODS: Craniotomy procedures performed using the posterior transcortical keyhole approach were simulated on 10 adult cadaveric heads (20 hemispheres). The anatomical structures in the lateral ventricle were observed through the microscope and endoscope. Three distance measurements on the intraparietal sulcus were recorded. RESULTS: The anatomical structures related to the atrium of the lateral ventricle, including the calcar avis, corpus callosum bulb, caudate nucleus, pulvinar, and glomus, were clearly observed under the microscope. Via the endoscope, a wider visualization of anatomical structures could be obtained. The distance from the intersection of the intraparietal sulcus and postcentral sulcus to the cerebral longitudinal fissure was 35.36 ± 1.06 mm, the depth of the intraparietal sulcus was 19.16 ± 1.03 mm, and the distance from the bottom of the intraparietal sulcus to the lateral ventricle was 21.31 ± 1.32 mm. CONCLUSIONS: The microsurgical posterior transcortical keyhole approach could provide an ideal exposure to the atrium and the posterior part of the body of the lateral ventricle. The endoscopic posterior transcortical keyhole approach demonstrated a wider viewing range compared with the microscope. An endoscopic-controlled or -assisted surgery may reduce damage to normal brain tissue, facilitate total resection of the lesion, and improve the surgical outcome.


Asunto(s)
Revascularización Cerebral/métodos , Endoscopía/métodos , Ventrículos Laterales/cirugía , Neuroendoscopía/métodos , Cadáver , Neoplasias del Ventrículo Cerebral/patología , Neoplasias del Ventrículo Cerebral/cirugía , Craneotomía , Femenino , Humanos , Ventrículos Laterales/anatomía & histología , Imagen por Resonancia Magnética , Meningioma/patología , Meningioma/cirugía , Persona de Mediana Edad
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