Semisitting position for cerebello-pontine angle surgery: Analysis of complications and how to avoid it.

OBJECTIVE: To analyze the primary complications related to semisitting position in patients undergoing cerebelo-pontine angle surgery. METHODS: Retrospective data analysis from patients undergoing elective tumoral cerebelo-pontine angle surgery in a semisitting position. The incidence, severity, occurrence moment, treatment, duration, and outcomes of venous air embolism (VAE), pneumocephalus, postural hypotension, and other complications were recorded. Neurointensive care unit (NICU), length of stay (LOS), hospital LOS, and modified Rankin scale scores were calculated six months after surgery. RESULTS: Fifty patients were operated on. Eleven (22%) presented VAE (mean duration 8±4.5min): five (10%) during tumor resection, and four (8%) during dural opening. Ten (20%) were resolved by covering the surgical bed, air bubbles aspiration, jugular compression, and one (2%) tilted to a steep Trendelenburg position. One (2%) had intraoperative hemodynamic instability. The only variable associated with VAE was meningioma at histopathology OR=4.58, p=0.001. NICU was higher in patients with VAE (5.5±1.06 vs. 1.9±0.20 days, p=0.01). There were no differences in the Rankin scale. All patients presented postoperative pneumocephalus with a good level of consciousness, except one (2%) who required evacuation. Seven patients (14%) showed postural hypotension, three (6%) after positioning, and one (2%) after developing a VAE; all were reversed with usual vasoactive drugs. No other position-related complications or mortality were registered in this series. CONCLUSIONS: The semisitting position is a safe option with the knowledge, prevention, detection, and early solution of all the possible complications. The development of VAE rarely implies hemodynamic instability or greater disability after surgery. Postoperative pneumocephalus is very common and rarely requires evacuation. Excellent cooperation between anesthesia, nursing, neurophysiology, and neurosurgery teams is essential to manage complications.

Study of Cerebellar Tissue Following Induction of Aging in Mice By Di-Galactose / Estudio del Tejido Cerebeloso tras la Inducción del Envejecimiento en Ratones por D-Galactosa

SUMMARY: The cerebellum is a crucial area of the hindbrain that plays an essential role in balancing, excitement control, and subtle and accurate functions. Studies have shown that long-term use of D-galactose in mice, as with the symptoms of aging, causes morphological and functional disorders in the brain. This study was performed to evaluate the changes in the cerebellum cortex tissue and the measurement of reactive oxygen species (ROS) in the cerebellum following the induction of aging in mice by D-galactose. Accordingly, subjects were randomly assigned into two groups: Normal saline group and Aging group (D-galactose). To create an aging model, D- galactose, and saline solution (sodium chloride 0.9 %) were used. After completing the preparation and passage of the tissue, the cerebellum specimens were cut in 5 microns thickness and then stained with hematoxylin-eosin stain and finally examined under a Nikon microscope. Quantitative variables were analyzed by SPSS software using T-test. In the observations of cerebellum tissue samples, in the aged induced group by D-galactose, the most changes were observed in the Neuron purkinjense (Purkinje cells) layer. In the observations of the cerebellum tissue samples of aging group induced by D-galactose, the most changes were observed in the Neuron purkinjense, and the arrangement and placement of these cells were disorientated. The nucleus positioning was not central, and the Neuron purkinjense induced by aging were seen in different morphological forms. Necrosis, Chromatolysis, and Pyknosis were found. Based on the results, D-galactose (induction of aging) causes pathological changes in the cerebellar cortex, especially in the Neuron purkinjense layer.

El cerebelo es un área crucial del rombencéfalo que desempeña un papel esencial en el equilibrio, el control de la excitación y las funciones sutiles y precisas. Los estudios han demostrado que el uso a largo plazo de D-galactosa en ratones, al igual que con los síntomas del envejecimiento, provoca trastornos morfológicos y funcionales en el cerebro. Este estudio se realizó para evaluar los cambios en el tejido de la corteza del cerebelo y la medición de especies reactivas de oxígeno (ROS) en el cerebelo luego de la inducción del envejecimiento en ratones por D-galactosa. En consecuencia, los sujetos fueron asignados aleatoriamente a dos grupos: grupo de solución salina normal y grupo de envejecimiento (D-galactosa). Para crear un modelo de envejecimiento, se utilizaron D-galactosa y solución salina (cloruro de sodio al 0,9 %). Después de completar la preparación y el paso del tejido, las muestras de cerebelo se cortaron en un grosor de 5 µm y luego se tiñeron con tinción de hematoxilina-eosina y finalmente se examinaron bajo un microscopio Nikon. Las variables cuantitativas se analizaron mediante el software SPSS utilizando la prueba T. En las observaciones de muestras de tejido de cerebelo, en el grupo envejecido inducido por D-galactosa, la mayoría de los cambios se observaron en la capa de neuronas purkinjenses (células de Purkinje). En las observaciones de las muestras de tejido del cerebelo del grupo de envejecimiento inducidas por D-galactosa, la mayoría de los cambios se observaron en las neuronas purkinjenses, y la disposición y ubicación de estas células estaban desorientadas. El posicionamiento del núcleo no era central y las neuronas purkinjenses inducidas por el envejecimiento se observaban en diferentes formas morfológicas. Se encontró necrosis, cromatólisis y picnosis. Según los resultados, la D-galactosa (inducción del envejecimiento) provoca cambios patológicos en la corteza cerebelosa, especialmente en la capa de neuronas purkinjenses.

Comparative histological analysis of cerebellum of representative species of elasmobranchii

SUMMARY: In elasmobranch fishes, variations in gross structural organization of cerebellum has been extensively explored. The basic histological features of cerebellum although conserved in the group but the comparative account on subtle cellular variations is largely underestimated. The present study aims to explore the histological and cellular variations in different layers of cerebellar cortex of the representative elasmobranchs' species belonging to different habitat. Our findings showed that the histological architecture of cerebellar granular layer between the examined species varies noticeably. By and large increase cellular density were observed in all the layers of cerebellum in the representative species of shark compared to ray. The findings were then compared and discussed with reference to their habitat and behavior.

En los peces elasmobranquios, las variaciones en la organización estructural general del cerebelo se han explorado ampliamente. Las características histológicas básicas del cerebelo, aunque se conservan en el grupo, pero la descripción comparativa de las variaciones celulares sutiles es limitada. El presente estudio tiene como objetivo explorar las variaciones histológicas y celulares en diferentes capas de la corteza cerebelosa de las especies representativas de elasmobranquios pertenecientes a diferentes hábitats. Nuestros hallazgos mostraron que la arquitectura histológica de la capa granular del cerebelo entre las especies examinadas varía notablemente. Se observó un gran aumento de la densidad celular en todas las capas del cerebelo en las especies representativas de tiburón en comparación con la raya. Luego, los hallazgos se compararon y discutieron con referencia a su hábitat y comportamiento.

Aristoteles and the anatomy of the nervous system (Nota Histórica) / Aristoteles e a anatomia do sistema nervoso (Historical Note)

Aristoteles was probably the first anatomist in the modern sense of this term. He wrote on human anatomy relying on the external aspects, and the lacking data on internal structures were generalized through the study of lower animals. The different body regions were described according to a precise topography, and his contribution to the development of anatomy was extensive, as he correctly described many organs and introduced new terms to indicate anatomical structures. Regarding the nervous system, he identified the brain and the two hemispheres, the cerebellum, and the spinal cord. The brain coverings, the meninges, were identified, a tougher external, and a delicate internal, and the related blood vessels. He described the bony casing, the skull and part of its bones and sutures, as well as the vertebral column formed by distinct holed vertebrae. The sensory organs were also defined, but he overlooked the presence of nerves, confusing such structures with vessels, tendons, ducts, among other similar structures. Additionally, he explained the functions of the brain, to which he attributed an important role, despite his cardiocentric standpoint. More than twenty and three centuries have elapsed since Aristoteles began his biological investigation, and his work was and continues to be admired, despite the inaccuracies that were pointed out by later authors. Evidently, knowledge on anatomy of the nervous system before Aristoteles was very scant, thus, it must be recognized that the pioneer anatomical studies he performed may be seen as fundamental, leaving a solid ground for future research on anatomy.

Aristóteles foi provavelmente o primeiro anatomista no sentido moderno deste termo. Escreveu sobre anatomia humana baseado nos aspectos externos, e os dados em falta sobre as estruturas internas eram generalizados através do estudo de animais inferiores. As diversas regiões do corpo foram descritas de acordo a uma topografia precisa e sua contribuição para o desenvolvimento da anatomia foi extensa, considerando que ele descreveu corretamente muitos órgãos e introduziu novos termos para indicar estruturas anatômicas. Considerando o sistema nervoso, identificou o cérebro e os dois hemisférios, o cerebelo e a medula. As coberturas cerebrais, as meninges, foram identificadas, uma externa resistente, e uma delicada interna, e os vasos sanguíneos relacionados. Descreveu o invólucro ósseo, o crânio e parte de seus ossos e suturas, assim como a coluna vertebral formada por vértebras perfuradas distintas. Os órgãos sensoriais também foram descritos, mas a presença de nervos foi ignorada, confundindo tais estruturas com vasos, tendões, dutos, entre outras estruturas similares. Adicionalmente, descreveu funções do cérebro, ao qual atribuiu um papel importante, apesar do seu ponto de vista cardiocêntrico. Mais de vinte e três séculos decorreram desde que Aristóteles começou suas investigações biológicas, e sua obra foi e continua sendo admirada, apesar das imperfeições apontadas por autores que se seguiram. Evidentemente, o conhecimento da anatomia do sistema nervoso antes de Aristóteles era muito escasso, assim, deve ser reconhecido que os estudos anatômicos pioneiros que ele realizou podem ser vistos como fundamentais, deixando solo firme para pesquisas futuras sobre anatomia.

Exploring clinical outcomes in patients with idiopathic/inherited isolated generalized dystonia and stimulation of the subthalamic region / Explorando os desfechos clínicos em pacientes com distonia idiopática/hereditária generalizada isolada submetidos a estimulação da região subtalâmica

Abstract Background Deep Brain Stimulation (DBS) is an established treatment option for refractory dystonia, but the improvement among the patients is variable. Objective To describe the outcomes of DBS of the subthalamic region (STN) in dystonic patients and to determine whether the volume of tissue activated (VTA) inside the STN or the structural connectivity between the area stimulated and different regions of the brain are associated with dystonia improvement. Methods The response to DBS was measured by the Burke-Fahn-Marsden Dystonia Rating Scale (BFM) before and 7 months after surgery in patients with generalized isolated dystonia of inherited/idiopathic etiology. The sum of the two overlapping STN volumes from both hemispheres was correlated with the change in BFM scores to assess whether the area stimulated inside the STN affects the clinical outcome. Structural connectivity estimates between the VTA (of each patient) and different brain regions were computed using a normative connectome taken from healthy subjects. Results Five patients were included. The baseline BFM motor and disability subscores were 78.30 ± 13.55 (62.00-98.00) and 20.60 ± 7.80 (13.00-32.00), respectively. Patients improved dystonic symptoms, though differently. No relationships were found between the VTA inside the STN and the BFM improvement after surgery (p = 0.463). However, the connectivity between the VTA and the cerebellum structurally correlated with dystonia improvement (p = 0.003). Conclusions These data suggest that the volume of the stimulated STN does not explain the variance in outcomes in dystonia. Still, the connectivity pattern between the region stimulated and the cerebellum is linked to outcomes of patients.

Resumo Antecedentes A estimulação cerebral profunda (ECP) é um tratamento estabelecido para distonias refratárias. Porém, a melhora dos pacientes é variável. Objetivo O objetivo do estudo foi descrever os desfechos da ECP da região do núcleo subtalâmico (NST) e determinar se o volume de tecido ativado (VTA) dentro do NST ou se a conectividade estrutural entre a área estimulada e diferentes regiões cerebrais estão associadas a melhora da distonia. Métodos A resposta da ECP em pacientes com distonia generalizada isolada de etiologia hereditária/idiopática foi mensurada pela escala de Burke-Fahr-Marsden Dystonia Rating Scale (BFM) antes e 7 meses após a cirurgia. A soma dos volumes do NST nos dois hemisférios foi correlacionada com a melhora nos escores do BFM para avaliar se a área estimulada dentro do NST afeta o desfecho clínico. A conectividade estrutural estimada entre o VTA de cada paciente e as diferentes regiões cerebrais foram computadas usando um conectoma normativo retirado de indivíduos saudáveis. Resultados Cinco pacientes com idade de 40,00 ± 7,30 anos foram incluídos. O BFM motor e de incapacidade basal eram de 78,30 ± 13,55 (62,00-98,00) e 20,60 ± 7,80 (13,00-32,00), respectivamente. Os pacientes melhoraram com a cirurgia, mas com variabilidade. Não houve relação entre o VTA dentro do NST e a melhora do BFM após a cirurgia (p = 0.463). Entretanto, a conectividade estrutural entre o VTA e o cerebelo correlacionaram com a melhora da distonia (p = 0.003). Conclusão Os dados sugerem que o VTA dentro do NST não explica a variabilidade do desfecho clínico na distonia. Porém, o padrão de conectividade entre a região estimulada e o cerebelo foi relacionada com o desfecho dos pacientes.

Utilidad de la medición del diámetro transversal del cerebelo fetal para la predicción de la edad gestacional

Objetivo: Establecer la utilidad de la medición del diámetro transversal del cerebelo fetal para la predicción de la edad gestacional. Diseño : Estudio de cohortes, prospectivo y longitudinal. Institución. Hospital Central "Dr. Urquinaona", Maracaibo, Venezuela. Participantes : Mujeres con embarazos simples de bajo riesgo, entre las 14 y las 40 semanas de gestación. Métodos : Se midieron los valores de diámetro biparietal, circunferencia abdominal, longitud del fémur y diámetro transverso del cerebelo fetal durante la duración del embarazo. Principales medidas de resultado. Predicción de la edad gestacional por medición de diámetro transverso del cerebelo. Resultados : Fueron seleccionados los datos de 215 embarazadas. Se realizaron un total de 3,858 evaluaciones totales, siendo el menor número de evaluaciones 131 a las 18 semanas y el mayor número 157 a las 28 semanas. El diámetro transversal del cerebelo presentó correlaciones fuertes, positivas y significativas con la edad gestacional por fecha de última menstruación y las mediciones ecográficas (p < 0,001). El modelo de edad gestacional predicha por el diámetro transverso del cerebelo alcanzó un valor del coeficiente de determinación de 0,908. La correlación entre la edad gestacional por fecha de última menstruación y la predicha por el modelo alcanzó un valor de r = 0,953 (p < 0,001). Conclusión : La medición del diámetro transversal del cerebelo es un parámetro útil para predecir la edad gestacional en embarazadas sanas.

Objective : To establish the usefulness of fetal cerebellar transverse diameter measurement for the prediction of gestational age. Design : Prospective, longitudinal, cohort study. Institution: Hospital Central "Dr. Urquinaona", Maracaibo, Venezuela. Participants : Women with low-risk singleton pregnancies, between 14 and 40 weeks of gestation. Methods : Biparietal diameter, abdominal circumference, femur length, and transverse diameter of the fetal cerebellum were measured during the duration of pregnancy. Main outcome measures: Prediction of gestational age by measurement of the transverse diameter of the cerebellum. Results : Data from 215 pregnant women were selected. A total of 3,858 total evaluations were performed, with the lowest number of evaluations 131 at 18 weeks and the highest number 157 at 28 weeks. The transverse diameter of the cerebellum presented strong, positive, and significant correlations with gestational age by date of last menstrual period and ultrasound measurements (p < 0.001). The model of gestational age predicted by the transverse diameter of the cerebellum reached a value of the coefficient of determination of 0.908. The correlation between gestational age by date of last menstrual period and that predicted by the model reached a value of r = 0.953 (p < 0.001). Conclusion : Measurement of the transverse diameter of the cerebellum is a useful parameter for predicting gestational age in healthy pregnant women.

Capacidade de deglutição e gravidade do risco de aspiração laringotraqueal no Acidente Vascular Encefálico atípico em via cerebelar: relato de caso / Swallowing capacity and gravity of the laryngotracheal aspiration risk in atypical cerebellar stroke: case report

RESUMO Esse relato de caso teve o objetivo de avaliar a capacidade de deglutição e a gravidade do risco de aspiração laringotraqueal de uma paciente, 52 anos, com Acidente Vascular Encefálico (AVE) atípico, com comprometimento na via cerebelar. Para mensurar a capacidade de deglutição e do risco de aspiração foram utilizados a avaliação de rotina na clínica de fonoaudiologia e dois testes clínicos validados: o Massey Bedside Swallowing Screen (MBSS) e o Gugging Swallowing Screen (GUSS). Após a avaliação com os testes clínicos, foi observado que a paciente apresentou capacidade de deglutição diminuída, desempenho caracterizado como patológico e de risco, com 100% de alteração no teste de deglutição de água pelo MBSS, presença de engasgo, tosse, alteração na qualidade vocal e escape anterior de alimento. Já na avaliação do risco de aspiração com o GUSS, a paciente apresentou disfagia moderada e com risco de aspiração laringotraqueal. A disfagia pode estar presente em casos de AVE com lesão anatômica comprometendo o cerebelo e suas vias, o que sugere a importância de avaliação específica da deglutição nesses casos. Os testes GUSS e o MBSS podem ser utilizados para avaliação de casos atípicos de AVE em fase ambulatorial, com objetivos de avaliar o risco de aspiração e a capacidade de deglutição.

ABSTRACT This case report aimed to evaluate the swallowing capacity and the severity of the risk of laryngotracheal aspiration of a 52-year-old female patient with atypical and rare stroke, with major injury in the cerebellar pathway. In order to measure swallowing capacity and risk of aspiration a routine clinical assessment used in the speech therapy clinic was performed and two valid clinical tests were used: Massey Bedside Swallowing Screen (MBSS) and Gugging Swallowing Screen (GUSS). After evaluation with the clinical tests, it was observed that the patient had reduced swallowing capacity, performance characterized as pathological, 100% dysfunction in the water swallowing test (MBSS), presence of choking, coughing, change in vocal quality and anterior escape. In the assessment of risk of aspiration with the GUSS, the patient presented moderate dysphagia and risk of laryngotracheal aspiration.This case report demonstrated that moderate dysphagia is found in a stroke patient with lesions that affect the cerebellum. Standardized and validated clinical tests such as GUSS and MBSS should also be used to assess the risk of dysphagia after stroke at ambulatory care.

Infarto cerebeloso bilateral agudo en territorio de la arteria cerebelosa posterior inferior: reporte de caso / Acute bilateral cerebellar infarction in territory of the posterior inferior cerebellar artery: a case report

Antecedentes: Los infartos cerebelosos suponen una entidad rara con una incidencia baja del total de ictus isquémicos. El territorio más prevalente de los infartos cerebelosos son los de la arteria cerebelosa posterior inferior (PICA). Cuando los infartos se limitan al cerebelo, los pacientes típicamente experimentan síntomas no específicos, esto hace considerar otros diagnósticos de forma errónea. Descripción del caso clínico: paciente femenina de 54 años, con antecedente de hipertensión arterial, quien presentaba cefalea insidiosa y progresiva acompañado de vértigo, alteración en la marcha y deterioro progresivo del estado de conciencia. Se realizó imagen de Resonancia Magnética Cerebral (IRM), la cual reveló zonas hiper intensas bilaterales en región cerebelosa que delimitaban territorio vascular de la arteria cerebelosa posterior inferior además dilatación moderada del sistema ventricular. Fue intervenida quirúrgicamente, realizándose craniectomía suboccipital descompresiva; posterior a la cirugía presentó mejoría clínica. Conclusiones: El ictus isquémico cerebeloso bilateral es una forma infrecuente de ictus y su presentación clínica es muy diversa. El desarrollo de las neuroimágenes, juegan un papel importante para ayudar a los médicos a seleccionar el tratamiento adecuado. Alrededor de la mitad de los pacientes con infartos cerebelosos que presentan deterioro neurológico progresivo y son tratados con craniectomía suboccipital descompresiva tienen buenos resultados. El pilar fundamental de este caso fue el hacer un diagnóstico temprano de esta entidad, ya que permitió prevenir las posibles complicaciones graves asociadas al infarto cerebeloso, las cuales ocurren durante la primera semana del ictus y, por lo tanto, asegurar un pronóstico favorable para el paciente...(AU)

3-Step didactic white matter dissection of human cerebellum: Micro-neuroanatomical training.

OBJECTIVES: A thorough understanding of cerebellum anatomy is essential in 4th ventricle approaches (more frequent in pediatric neurosurgery), avoiding relevant complications such as cerebellar mutism. The aim of the present work is to show the feasibility of a didactic dissection of human cerebellum focusing on cerebellar peduncles and dentate nucleus (DN), which are structures at high risk during these surgical procedures. MATERIAL AND METHODS: The cerebellum was dissected according to the Klingler method for white matter, using standard and specific microsurgery tools. Surgical microscope magnification (×6-×40) provided by a D.F. Vasconcellos M900 was required. A Canon EOS T7 18-55 mm digital camera was used and Adobe Lightroom Classic CC and Keynote were selected as photo enhancing software. Special methods such as LED light endoscopic transillumination were used for photographical reasons. RESULTS: DN dissection was successfully achieved and the relations between these nucleus and the cerebellar peduncles, inferior vermis and medullary velums were described. Through this three steps dissection guide (1. tentorial surface; 2. suboccipital surface; 3. 4th ventricle structures), the most relevant anatomical structures were shown and its implications in different 4th ventricle approaches were characterised. CONCLUSION: 3 D perspective provided by real specimen anatomical dissection is critical for learning neuroanatomy. LED transillumination was shown as a useful technique for the 4th ventricle structures photographic documentation which improves spatial recognition. This benefit can be applied for the study of the relations between the medullary velums and the rhomboid fossa foramina, which are permeable to light. The proposed three-steps dissection guide helps to a better understanding of human cerebellum and to gain self-confidence, allowing safer practice for neurosurgeons in all stages of their career.

Modulatory effect of continuous theta burst stimulation in patients with essential tremor.

INTRODUCTION: We aimed to study the cortical and intracortical functions in patients of ET using transcranial magnetic stimulation (TMS) and to evaluate the effect of continuous theta burst stimulation (cTBS) on the tremor characteristics. METHODS: Ten ET and 20 healthy controls were included in the study. All the participants were evaluated with TMS with recording of resting motor threshold (RMT), central motor conduction time, contralateral silent period (cSP), short interval intracortical inhibition (SICI) and intracortical facilitation (ICF). Subsequently only ET patients underwent cTBS of the motor cortex (M1) followed by repeat TMS. RESULTS: The mean age of the patients (46.5 ± 17.2 years) was comparable to healthy controls (55.4 ± 9.2 years; p = 0.16). There was a non-significant increase in RMT in ET patients (44 ± 12.5%) when compared to healthy controls (40.9 ± 6.9%; p = 0.48). There was a significant reduction of cSP in the ET group (102.03 ± 15.26 msec) compared to healthy controls (116.1 ± 15.2, p = 0.03). In addition, a significant reduction in ICF was observed in ET patients (0.9 ± 0.7) compared to healthy controls (1.8 ± 0.8, p = 0.01). Following cTBS there was a significant reduction in the tremor scores [FTMRS (Pre-cTBS: 29.3 ± 18.7, Post-cTBS: 25.3 ± 16.8; p < 0.001) and TETRAS (pre-cTBS: 34.4 ± 16.2, post-cTBS: 29.8 ± 12.1; p = 0.01)] and improvement (increase) of the duration of cSP (pre-cTBS: 102.03 ± 15.3 msec., post-cTBS: 119.4 ± 12.03 msec; p = 0.05). CONCLUSIONS: Patients with ET have GABAergic and glutaminergic dysfunction as demonstrated by reduced cSP and ICF. However, only the cSP improved following cTBS of M1 region, with a corresponding improvement of tremor severity suggesting the effect of cTBS on the cerebello-thalamo-cortical network.

The evaluation of cerebellum gross morphometric measurements in subjects having migraine, ataxia, dementia and vertigo / Evaluación de las medidas morfométricas macroscópicas del cerebelo en sujetos con migraña, ataxia, demencia, vértigo

SUMMARY: This paper was aimed to determine the morphometric measurements of cerebellum using MRI in subjects having migraine, ataxia, dementia and vertigo. Three hundred twenty six (326 subjects; 80 migraine subjects; 85 vertigo subjects; 83 dementia subjects; 78 ataxia subjects) subjects ranging from 20 up to 85 years were included in this study. Cerebellum morphometric measurements were taken from subjects having brain MRI in the Radiology Department. The means and standard deviations of the measurements were: Sagittal section cerebellum superior inferior length, 56.21±5.16 mm; sagittal section cerebellum anteroposterior length, 86.36 ±5.36 mm; axial section cerebellum antereoposterior length, 66.53±5.41 mm; axial section bi-cerebellar length, 100.48±5.14 mm; coronal section cerebellum supero-inferior length,53.60±3.84 mm; coronal section bi-cerebellar length, 99.77±6.24 mm in subjects with migraine, whereas the corresponding values were 62.33±8.66 mm; 93.31±9.89 mm; 60.26±7.98 mm; 99.89±6.41 mm; 54.35±4.64 mm; 85.58±14.74 mm in subjects with vertigo, respectively. The same values were found as 58.82±8.34 mm; 86.74±13.22 mm; 58.93±8.89 mm; 97.93±6.07 mm; 50.66±4.92 mm; 84.96±14.93 mm in patients having dementia, respectively, while the same measurements were as 60.83±8.59 mm; 92.18±9.12 mm; 57.76±7.85 mm; 97.71±5.82 mm; 52.48±4.85 mm; 81.49±14.38 mm in ataxia patients, respectively. Also, ages were divided into seven groups as decades. There were found significant difference in all parameters according to sex and ages (p<0.05). The cerebellum morphometry provides important and useful knowledge in terms of comparison of abnormalities clinicians and data will be valuable for the determination of pathologies for clinical disciplines.

RESUMEN: Este trabajo tuvo como objetivo determinar las medidas morfométricas del cerebelo mediante resonancia magnética en sujetos con migraña, ataxia, demencia y vértigo. Trescientos veintiseis sujetos (80 con migraña; 85 con vértigo; 83 con demencia y 78 con ataxia) entre los 20 y los 85 años de edad se incluyeron en este estudio. Se tomaron medidas morfométricas del cerebelo de sujetos sometidos a resonancia magnética en el Departamento de Radiología. Las medias y desviaciones estándar de las medidas fueron: sección sagital longitud superoinferior del cerebelo, 56,21±5,16 mm; sección sagital longitud anteroposterior del cerebelo, 86,36 ±5,36 mm; sección axial longitud anteroposterior del cerebelo, 66,53±5,41 mm; sección axial longitud bicerebelosa, 100,48±5,14 mm; sección coronal longitud superoinferior del cerebelo, 53,60±3,84 mm; longitud bicerebelosa de la sección coronal, 99,77±6,24 mm en sujetos con migraña, mientras que los valores correspondientes fueron 62,33±8,66 mm; 93,31±9,89mm; 60,26±7,98 mm; 99,89±6,41 mm; 54,35±4,64 mm; 85,58±14,74 mm en sujetos con vértigo, respectivamente. Se encontraron los mismos valores para pacientes con demencia 58,82±8,34 mm; 86,74±13,22 mm; 58,93±8,89 mm; 97,93±6,07 mm; 50,66±4,92 mm; 84,96±14,93 mm , respectivamente, mientras que las mismas medidas fueron de 60,83±8,59 mm; 92,18±9,12 mm; 57,76±7,85 mm; 97,71±5,82 mm; 52,48±4,85 mm; 81,49±14,38 mm en pacientes con ataxia, respectivamente. Las edades se dividieron en siete grupos, cada uno en década. Se encontraron diferencias significativas en todos los parámetros según sexo y edad (p<0,05). La morfometría del cerebelo proporciona un conocimiento importante y útil en términos de comparación de anormalidades clínicas y los datos serán valiosos para la determinación de patologías para las disciplinas clínicas.

Individual variation of tentorial notch morphometry in a series of neurocritical patients / Variación individual de la morfometría de la hendidura tentorial en una serie de pacientes neurocríticos

Background: Cadaveric studies on humans have shown anatomical variabilities in the morphometric characteristics of the tentorial notch. These anatomical variations could influence the worsening of neurocritical patients. Objectives: 1) To investigate the morphometric characteristics of the tentorial notch in neurocritical patients using computed tomography (CT); 2) To investigate the correlation between tentorial notch measurements by CT and by magnetic resonance imaging (MRI); and 3) To analyze the individual variability of the tentorial notch anatomy seen in neurocritical patients. Methods: Prospective series of neurocritical patients was examined. An imaging protocol for measurements was designed for CT and MRI. The level of the agreement of the measurements from CT and MR images was established. According to the measurements found, patients were divided into different types of tentorial notch. Results: We studied 34 neurocritical patients by CT and MRI. Measurements of the tentorial notch via CT and MRI showed significant agreement: concordance correlation coefficient of 0.96 for notch length and 0.85 for maximum width of tentorial notch. Classification of tentorial notch measurements according to the criteria established by Adler and Milhorat, we found the following: 15 patients (58%) corresponded to a "short" subtype; 7 (21%) to "small"; 3 (9%) to "narrow"; 2 (6%) to "wide"; 2 (6%) to "large"; 1 (3%) to "long"; and 4 (12%) to "typical". Conclusions: The anatomical variability of the tentorial notch could be detected in vivo by means of CT scan and MRI. Good agreement between the measurements made using these two imaging methods was found.

Antecedentes: Estudios cadavéricos en humanos han mostrado variabilidad anatómica en las características morfométricas de la hendidura tentorial (HT). Estas variaciones anatómicas podrían influir en el neurodeterioro agudo de los pacientes neurocríticos. Objetivos: 1) Investigar las características morfométricas de la HT en pacientes neurocríticos mediante tomografía computarizada (TC); 2) Investigar la correlación de las mediciones de la HT realizadas por TC y resonancia magnética (RM); 3) Analizar la variabilidad individual de la anatomía de la HT observada en pacientes neurocríticos. Métodos: Se examinó una serie prospectiva de pacientes neurocríticos. Se diseñó un protocolo de imágenes para mediciones por TC y RM. Se estableció la concordancia de las mediciones realizadas mediante TC y RM. Según las mediciones encontradas, los pacientes se dividieron en diferentes tipos de HT. Resultados: Estudiamos 34 pacientes neurocríticos por TC y RM. Las mediciones de la HT por TC y RM mostraron una concordancia significativa: coeficiente de correlación de concordancia de 0,96 para la longitud de la HT y 0,85 para el ancho máximo de la HT. Clasificando las medidas de la HT de acuerdo con los criterios establecidos por Adler y Milhorat, encontramos: 15 pacientes (58%) correspondieron al subtipo "corto", 7 (21%) al "pequeño", 3 (9%) al "estrecho" ", 2 (6%) a "ancho ", 2 (6%) al "grande ", 1 (3%) al "largo" y 4 (12%) al "típico". Conclusiones: Se pudo detectar variabilidad anatómica de la HT in vivo, mediante TC y RM. Se encontró una buena concordancia en las medidas obtenidas con ambos métodos imagenológicos.

El cerebelo y sus afecciones en los niños / The cerebellum and its conditions in children

Introducción: Cuando se piensa en estudiar el cerebelo es posible que lo primero que viene a la mente sean las siguientes preguntas: ¿cuáles son sus enfermedades?, ¿cómo se expresan clínicamente? y quizás, ¿cómo es su estructura y cuáles las funciones de este órgano? Objetivo: Examinar las principales características anatómicas y funcionales del cerebelo y relacionarlas con su expresión clínica cuando enferma, así como comentar sobre su abanico de etiologías en el niño. Métodos: Las fuentes de búsquedas fueron las bases de datos computarizadas: PubMed, Ebsco y SciELO. Se utilizaron las palabras clave: cerebelo, ataxia, erores congénicos del metabolismo y ataxias, ataxias episódicas, enfermedades progresivas del sistema nervioso y ataxias; en idioma español e inglés. Resultados: El cerebelo recepciona múltiples informaciones y las envía a diversas estructuras cerebrales por medio de las cuales modula la excitabilidad de estas estructuras y sus sistemas descendentes. Este órgano organiza, dirige, coordina múltiples funciones que se traducen en fuerza, tiempo y secuencia. El cerebelo enfermo impide que la persona ejecute sus funciones y movimientos de forma uniforme y coordinada; puede resultar afectado por un amplio abanico de posibilidades etiológicas, genéticas o adquiridas y enfermarse todo o parte de él. Consideraciones finales: El cerebelo cumple importantes funciones dentro del sistema nervioso, tiene una expresividad muy típica cuando está enfermo. El uso adecuado de las nuevas técnicas de estudios por imágenes y genéticas, entre otras, permiten al pediatra clínico estar en mejores condiciones para el diagnóstico de sus afecciones y tratamiento oportuno(AU)

Introduction: When we think about studying the cerebellum, the first thing that comes to mind may be the following questions: Which are its diseases? How they are clinically expressed? , and perhaps: What is its structure and what functions do this organ has? Objective: Examine the main anatomical and functional characteristics of the cerebellum and relate them to its clinical expression when it becomes ill, as well as comment on its range of etiologies in the child. Methods: Search sources were computerized databases like: PubMed, Ebsco, and SciELO. Keywords used were: cerebellum, ataxia, metabolism congenital errors and ataxias, episodic ataxias, progressive diseases of the nervous system and ataxias; in Spanish and English. Results: The cerebellum receives information and sends it to various brain structures through which it modulates the excitability of these structures and their downstream systems. This organ organizes, directs, and coordinates multiple functions that translate into strength, time and sequence. An ill cerebellum prevents the person from performing their functions and movements in a uniform and coordinated way; it can be affected by a wide range of etiological, genetic or acquired possibilities and make all or part of it ill. Final considerations: The cerebellum performs important functions within the nervous system; it has a very typical expressiveness when it is ill. Proper use of new imaging and genetic study techniques, among others, allows the clinical pediatricians to be better able to diagnose its conditions and timely treatment(AU)

3-Step didactic white matter dissection of human cerebellum: Micro-neuroanatomical training. / Disección didáctica de fibra blanca en cerebelo humano en tres pasos: entrenamiento microneuroanatómico.

OBJECTIVES: A thorough understanding of cerebellum anatomy is essential in 4th ventricle approaches (more frequent in pediatric neurosurgery), avoiding relevant complications such as cerebellar mutism. The aim of the present work is to show the feasibility of a didactic dissection of human cerebellum focusing on cerebellar peduncles and dentate nucleus (DN), which are structures at high risk during these surgical procedures. MATERIAL AND METHODS: The cerebellum was dissected according to the Klingler method for white matter, using standard and specific microsurgery tools. Surgical microscope magnification (x6-x40) provided by a D.F. Vasconcellos M900 was required. A Canon EOS T7 18-55 mm digital camera was used and Adobe Lightroom Classic CC and Keynote were selected as photo enhancing software. Special methods such as LED light endoscopic transillumination were used for photographical reasons. RESULTS: DN dissection was successfully achieved and the relations between these nucleus and the cerebellar peduncles, inferior vermis and medullary velums were described. Through this three steps dissection guide (1. tentorial surface; 2. suboccipital surface; 3. 4th ventricle structures), the most relevant anatomical structures were shown and its implications in different 4th ventricle approaches were characterised. CONCLUSION: 3 D perspective provided by real specimen anatomical dissection is critical for learning neuroanatomy. LED transillumination was shown as a useful technique for the 4th ventricle structures photographic documentation which improves spatial recognition. This benefit can be applied for the study of the relations between the medullary velums and the rhomboid fossa foramina, which are permeable to light. The proposed three-steps dissection guide helps to a better understanding of human cerebellum and to gain self-confidence, allowing safer practice for neurosurgeons in all stages of their career.

Effects of prenatal tobacco smoke on cerebellum histomorphological changes at critical developmental stages in CD-1 mice / Efectos del humo de tabaco en los cambios histomorfológicos del cerebelo en las etapas críticas del desarrollo prenatal en ratones CD-1

SUMMARY: In this study the consequences of prenatal exposure to tobacco smokes on the histo-morphological changes of cerebellum was assessed by comparing the smoker mice to the nonsmoker mice. A total of 30 pregnant cd-1 mice were divided into three groups of 10 mice each and with two replicates per group (5 mice each). Following acclimation for five days, the mice were placed in a special modified smoking machine for 2 hours per day over a two- and three-week period for group two and group three, respectively. Group one was considered as a control group. Mice in the control group were exposed simultaneously to fresh air from the room, while those in the treatment groups were exposed to tobacco smoke from six commercial filter cigarettes, containing 0.8 mg of nicotine, 10 mg of tar, and 10 mg of carbon monoxide, for three 1-hour exposure periods every day for three weeks. The mice in the control group were exposed to room air for three 1-hour periods every day for the same period of three weeks. The results from this study showed a correlation between maternal smoking and histological changes in Neuron purkinjense (Purkinje cells) of the cerebellum. They also showed that prenatal smoking period may have caused more damage in the histology and structure of Neuron purkinjense in some juvenile mice. An increased incidence of morphology damage of the cerebellum's Neuron purkinjense' structures was also observed in fetuses with prolonged exposure to tobacco smoking. Exposure of in utero maternal smoking may interfere with brain biological development parameters, giving rise to structural abnormalities of the cerebellum. This study concluded that tobacco smoke exposure to pregnant mice may affect neurodevelopment which may induce behavioural changes as a result of reduced cerebellar size and function.

RESUMEN: Se evaluaron los efectos producidos por la exposición prenatal al humo de tabaco en ratones expuestos y no expuestos y los cambios histomorfológicos observados en el cerebelo en ambos grupos. Un total de 30 ratones cd-1 preñados se dividieron en tres grupos de 10 ratones cada uno y con dos réplicas por grupo (5 ratones cada uno). Después de la aclimatación durante cinco días, los ratones se colocaron en una máquina de fumar modificada, especial durante 2 horas al día, durante un período de dos y tres semanas para el grupo dos y el grupo tres, respectivamente. El grupo uno se consideró como grupo control. Los ratones del grupo de control fueron expuestos simultáneamente al aire limpio de la habitación, mientras que los grupos de tratamiento fueron expuestos al humo de tabaco de seis cigarrillos comerciales, que contenían 0,8 mg de nicotina, 10 mg de alquitrán y 10 mg de monóxido de carbono. durante tres períodos de 1 hora diariamente, durante tres semanas. Los ratones del grupo de control se expusieron al aire ambiente durante tres períodos de 1 hora todos los días durante el mismo período de tres semanas. Los resultados de este estudio mostraron una correlación entre el tabaquismo materno y los cambios histológicos en las neuronas purkinjenses (células de Purkinje). Se observó además que el período de tabaquismo prenatal puede haber causado mayor daño en la histología y estructura de las neuronas purkinjenses en algunos ratones jóvenes. También se observó una mayor incidencia de daño morfológico de las estructuras de las neuronas purkinjenses del cerebelo en fetos con exposición prolongada al tabaquismo. La exposición al tabaquismo materno en el útero puede interferir con los parámetros de desarrollo biológico del cerebro, dando lugar a anomalías estructurales del cerebelo. Este estudio concluyó que la exposición al humo del tabaco en ratones preñados puede afectar el desarrollo neurológico, lo que puede inducir cambios de comportamiento como resultado de la reducción del tamaño y la función del cerebelo.

Glioblastoma de células gigantes: informe de un caso / Giant cell glioblastoma: case report

Antecedentes: El Glioblastoma (GB) o astrocitoma grado IV, es un tumor agresivo que se origina de células gliales, con alto grado de malignidad, prevalencia menor al 1% en fosa posterior e incidencia menor al 0.5% de todos los GB. Actualmente se describen alrededor de 75 casos a nivel mundial. Descripción del caso clínico: Femenina, 24 años, referida a emergencia de Neurocirugía del Hospital Escuela Universitario, presentó cefalea holocraneana intensa, vómitos, náuseas, visión borrosa, vértigo y anorexia. Al examen neurológico mostró discreta adiadococinesia derecha y signos de papiledema. La tomografía axial computarizada cerebral evidenció lesión heterogénea en vermis extendido a hemisferio cerebeloso derecho, por lo que se realizó craniectomía suboccipital, abordaje transcerebelar, con citorreducción tumoral, encontrando masa vascularizada con componente quístico. Estudio anatomopatológico evidenció glioblastoma multiforme variante de células gigantes, confirmado con tinción de inmunohistoquímica (PFGA, CD34+ y vimentina). Paciente con buena evolución clínica postquirúrgica, egresada sin déficit neurológico. 16 meses después, presentó síndrome de recidiva tumoral y complicaciones, por lo que se reintervino en 4 ocasiones, posterior a recibir 30 dosis de radioterapia y 12 ciclos de quimioterapia, se reingresó con deterioro neurológico progresivo, signos meníngeos y síndrome de Parinaud, escala de Karnofsky (30 puntos), realizándose derivación ventrículo-peritoneal por compresión del IV ventrículo e hidrocefalia obstructiva secundaria, luego desarrolló neumonía intrahospitalaria, falleciendo a las dos semanas. Conclusiones: Es importante identificar la variante biológica del glioblastoma de forma temprana, para determinar pronóstico y acciones terapéuticas que influirán en la calidad de vida, así como la supervivencia...(AU)

Supra and infratentorial massive strokes in previously healthy young patients with SARS-CoV-2. The role of neurosurgery.

The coronavirus disease 2019 (COVID-19) has amazed by its distinct forms of presentation and severity. COVID-19 patients can develop large-scale ischemic strokes in previously healthy patients without risk factors, especially in patients who develop an acute respiratory distress syndrome (SARS-CoV-2). We hypothesize that ischemic events are usually the result of the combined process of a pro-inflammatory and pro-coagulant state plus vascular endothelial dysfunction probably potentiated by hypoxia, hemodynamic instability, and immobilization, as reported in other cases. To the best of our knowledge, we report the first case of partial obstruction of a vertebral artery in a patient with COVID-19. Decompressive surgery remains a life-saving maneuver in these patients (as in other non-COVID-19 strokes) and requires further investigation.

Neuroanatomy of two species of genus Myliobatis (Chondrichthyes: Myliobatoidea) / Neuroanatomía de dos especies del género Myliobatis (Chondrichthyes: Myliobatoidea)

Several studies on the elasmobranchs neuroanatomy have shown that their brain is more complex than previously thought, and had significant intra and interspecific variations. The objective of this work was conducting a comparative encephalic neuroanatomy study of two species of genus Myliobatis. In total, 16 organisms of genera Myliobatis californica and Myliobatis longirostris, collected in the coasts of Kino Bay, Sonora, Mexico, were used. In Myliobatis, the brain has a long telencephalon and the posterior central nucleus is poorly developed. Their cerebellum is asymmetric, has several sulci, most of which are transversally oriented, with four lobes (anterior, medium and two posterior), a condition which has not been reported for any other species. It was observed that, despite the morphology of M. californica and M. longirostris is similar, there are some significant differences. Both species have moderate foliation, but M. californica has more sulci. In the diencephalon of M. californica, it was observed that the lobes of the infundibulum are oval-shaped and separated, while in M. longirostris, such lobes are rounded and near the medium line. It has to be highlighted that Myliobatis belongs to the most derived batoid group; nevertheless, its brain is considerably less complex, as compared to what has been reported for the most derived milyobatoids species.

Diversos estudios sobre la neuroanatomía de los elasmobranquios han demostrado que el cerebro es más complejo de lo que se pensaba y presenta considerables variaciones tanto intra como interespecíficas. El objetivo de este trabajo fue realizar un estudio de neuroanatomía comparada del encéfalo de dos especies del género Myliobatis. Se utilizaron un total de 16 organismos de Myliobatis californica y Myliobatis longirostris, los cuales fueron colectados en las costas de Bahía Kino, Son., México. El cerebro de Myliobatis tiene un telencéfalo largo, el núcleo central posterior está poco desarrollado; el cerebelo es asimétrico, presenta surcos que en su mayoría están orientados transversalmente, con cuatro lóbulos (anterior, medio y dos posteriores), condición que no ha sido reportada para otra especie. Se observó que, aunque M. californica y M. longirostris presentan una morfología similar existen ciertas diferencias. En ambas especies presentan una foliación moderada; sin embargo, en M. californica se observan más surcos. En el diencéfalo de M. californica se observa que los lóbulos del infundíbulo son ovalados y están separados, mientras que en M. longirostris son redondeados y se encuentran próximos a la línea media. Es importante señalar que, pese a que Myliobatis pertenece al grupo de batoideos más derivado, su cerebro es considerablemente menos complejo de lo que se ha reportado para las especies de miliobatoideos más derivadas.

Severe Cerebellar Degeneration and Chiari I Malformation - Speculative pathophysiology based on a systematic review

SUMMARY BACKGROUND Symptomatic Chiari Type I Malformation (CM) is treated with posterior fossa decompression with or without duroplasty. We have noticed some cases with concomitant severe cerebellar ataxia due to cerebellar atrophy. The aim of this study is to review the literature of CM associated with severe cerebellar atrophy and discuss its potential physiopathology. METHODS A systematic literature review in the Pubmed Database was performed using the following key-terms: "cerebellar atrophy Chiari", and "cerebellar degeneration Chiari". Articles reporting the presence of cerebellar degeneration/atrophy associated with CM were included. RESULTS We found only six studies directly discussing the association of cerebellar atrophy with CM, with a total of seven cases. We added one case of our own practice for additional discussion. Only speculative causes were described to justify cerebellar atrophy. The potential causes of cerebellar atrophy were diffuse cerebellar ischemia from chronic compression of small vessels (the most mentioned speculative cause), chronic raised intracranial pressure due to CSF block, chronic venous hypertension, and association with platybasia with ventral compression of the brainstem resulting in injury of the inferior olivary nuclei leading to mutual trophic effects in the cerebellum. Additionally, it is not impossible to rule out a degenerative cause for cerebellar atrophy without a causative reason. CONCLUSIONS Severe cerebellar atrophy is found in some patients with CM. Although chronic ischemia due to compression is the most presumed cause, other etiologies were proposed. The real reasons for cerebellar degeneration are not known. Further studies are necessary.

RESUMO OBJETIVO A Malformação de Chiari (MC) tipo I sintomática é tratada através da descompressão da fossa posterior com ou sem duroplastia. Observamos alguns casos com ataxia cerebelar grave concomitante devido à atrofia cerebelar. O objetivo deste estudo é revisar a literatura sobre MC associada à atrofia cerebelar grave e discutir sua possível fisiopatologia. METODOLOGIA Conduzimos uma revisão sistemática da literatura no banco de dados Pubmed utilizando as seguintes palavras-chave: "cerebellar atrophy Chiari", e "cerebellar degeneration Chiari". Artigos sobre a presença de degeneração/atrofia cerebelar associada à MC foram incluídos. RESULTADOS Encontramos apenas seis estudos que discutiam diretamente a associação entre atrofia cerebelar e MC, com um total de sete casos. Nós adicionamos um caso da nossa própria prática para ampliar a discussão. Apenas causas especulativas foram descritas para justificar a atrofia cerebelar, entre elas: isquemia cerebelar difusa devido à compressão crônica de pequenos vasos (a causa especulativa mais citada), pressão intracraniana elevada crônica devido ao bloqueio de LCR, hipertensão venosa crônica e associação com platibasia com compressão ventral do tronco cerebral, resultando em lesão do núcleo olivar inferior e levando a efeitos tróficos mútuos no cerebelo. Além disso, não é possível descartar uma causa degenerativa para atrofia cerebelar sem motivos claros. CONCLUSÃO A atrofia cerebelar grave é encontrada em alguns pacientes com MC. A isquemia crônica causada por compressão é a causa mais apontada como suspeita, porém outras etiologias foram propostas. As reais causas da degeneração cerebelar não são conhecidas. Mais estudos são necessários.

Analysis of the pattern of functional activation of the cerebellum and its topographical correlation. / Análisis del patrón de activación funcional del cerebelo y su correlación topográfica.

OBJECTIVES: To describe the normal patterns of cerebellar activation in specific cerebral functions (motor, language, memory) and their topographical correlations in the cerebellar cortex on functional magnetic resonance imaging. MATERIALS AND METHODS: We evaluated 25 healthy subjects (8 women and 17 men; 23 right-handed and 2 left-handed; age range, 16-64 years), who did language, memory, and motor tasks while undergoing 1.5T functional magnetic resonance imaging. RESULTS: We assessed functional activity of the cerebellum associated with motor, language, and memory components, describing their relations with topographical regions of the cerebellum and their functional relations with areas in the cerebral cortex. CONCLUSIONS: Knowledge of the normal patterns of morphological characteristics and functional behavior in the cerebellum as well as their relations with the brain is important for radiologists and clinicians evaluating the cerebellum and possible pathological conditions that affect it.