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)

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.

Ventromedial Thalamus-Projecting DCN Neurons Modulate Associative Sensorimotor Responses in Mice / 神经科学通报·英文版

The deep cerebellar nuclei (DCN) integrate various inputs to the cerebellum and form the final cerebellar outputs critical for associative sensorimotor learning. However, the functional relevance of distinct neuronal subpopulations within the DCN remains poorly understood. Here, we examined a subpopulation of mouse DCN neurons whose axons specifically project to the ventromedial (Vm) thalamus (DCNVm neurons), and found that these neurons represent a specific subset of DCN units whose activity varies with trace eyeblink conditioning (tEBC), a classical associative sensorimotor learning task. Upon conditioning, the activity of DCNVm neurons signaled the performance of conditioned eyeblink responses (CRs). Optogenetic activation and inhibition of the DCNVm neurons in well-trained mice amplified and diminished the CRs, respectively. Chemogenetic manipulation of the DCNVm neurons had no effects on non-associative motor coordination. Furthermore, optogenetic activation of the DCNVm neurons caused rapid elevated firing activity in the cingulate cortex, a brain area critical for bridging the time gap between sensory stimuli and motor execution during tEBC. Together, our data highlights DCNVm neurons' function and delineates their kinematic parameters that modulate the strength of associative sensorimotor responses.

Noradrenaline modulates the spontaneous firing activities of Purkinje cells via α2-adrenergic receptor in mouse cerebellar cortex / 生理学报

Cerebellar Purkinje cells (PCs) exhibit two types of discharge activities: simple spike (SS) and complex spike (CS). Previous studies found that noradrenaline (NA) can inhibit CS and bidirectionally regulate SS, but the enhancement of NA on SS is overwhelmed by the strong inhibition of excitatory molecular layer interneurons. However, the mechanism underlying the effect of NA on SS discharge frequency is not clear. Therefore, in the present study, we examined the mechanism underlying the increasing effect of NA on SS firing of PC in mouse cerebellar cortex in vivo and in cerebellar slice by cell-attached and whole-cell recording technique and pharmacological methods. GABAA receptor was blocked by 100 µmol/L picrotoxin in the whole process. In vivo results showed that NA significantly reduced the number of spikelets of spontaneous CS and enhanced the discharge frequency of SS, but did not affect the discharge frequency of CS. In vitro experiments showed that NA reduced the number of CS spikelets and after hyperpolarization potential (AHP) induced by electrical stimulation, and increased the discharge frequency of SS. NA also reduced the amplitude of excitatory postsynaptic current (EPSC) of parallel fiber (PF)-PC and significantly increased the paired-pulse ratio (PPR). Application of yohimbine, an antagonist of α2-adrenergic receptor (AR), completely eliminated the enhancing effect of NA on SS. The α2-AR agonist, UK14304, also increased the frequency of SS. The β-AR blocker, propranolol, did not affect the effects of NA on PC. These results suggest that in the absence of GABAA receptors, NA could attenuate the synaptic transmission of climbing fiber (CF)-PC via activating α2-AR, inhibit CS activity and reduce AHP, thus enhancing the SS discharge frequency of PC. This result suggests that NA neurons of locus coeruleus can finely regulate PC signal output by regulating CF-PC synaptic transmission.

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)

Lhermitte-Duclos disease: A case report and literature review / 中南大学学报(医学版)

Lhermitte-Duclos disease (LDD) is a type of rare brain tumor located in posterior fossa. A patient with LDD located in the left cerebellum and vermis was admitted by the Department of Neurosurgery, Xiangya Hospital, Central South University. MRI scan showed slightly heterogeneous enhancement at the region close to vermis. The patient underwent partial resection on August 11, 2016 without postoperative chemoradiotherapy. The progress free survival was 11 months and the overall survival was 17 months. What the case reveals is that the partial resection is not beneficial to these patients with LDD as the residual lesion probably recurs in a short term after operation. The pathogenesis, diagnosis and treatment of LDD are explored and summarized in combination with relevant literature.

Three-Dimensional Heterogeneity of Cerebellar Interposed Nucleus-Recipient Zones in the Thalamic Nuclei / 神经科学通报·英文版

The cerebellum is conceptualized as a processor of complex movements and is also endowed with roles in cognitive and emotional behaviors. Although the axons of deep cerebellar nuclei are known to project to primary thalamic nuclei, macroscopic investigation of the characteristics of these projections, such as the spatial distribution of recipient zones, is lacking. Here, we studied the output of the cerebellar interposed nucleus (IpN) to the ventrolateral (VL) and centrolateral (CL) thalamic nuclei using electrophysiological recording in vivo and trans-synaptic viral tracing. We found that IpN stimulation induced mono-synaptic evoked potentials (EPs) in the VL but not the CL region. Furthermore, both the EPs induced by the IpN and the innervation of IpN projections displayed substantial heterogeneity across the VL region in three-dimensional space. These findings indicate that the recipient zones of IpN inputs vary between and within thalamic nuclei and may differentially control thalamo-cortical networks.

Magnetic resonance spectroscopy features of the thalamus and the cerebellum and their association with clinical features in children with autism spectrum disorder: a prospective study / 中国当代儿科杂志

OBJECTIVES@#To study the changes in biochemical metabolites in the thalamus and the cerebellum and their association with clinical features in children with autism spectrum disorder (ASD).@*METHODS@#In this prospective study, magnetic resonance spectroscopy (MRS) with point-resolved spatial selection was used to analyze the thalamus and the cerebellum at both sides in 50 children with ASD aged 2-6 years. Creatine (Cr) was as the internal standard to measure the relative values of N-acetylaspartate (NAA)/Cr, choline (Cho)/Cr, myoinositol (MI)/Cr, and glutamine and glutamate complex (Glx)/Cr, and the differences in metabolites and their association with clinical symptoms were compared.@*RESULTS@#In the children with ASD, NAA/Cr in the left thalamus was positively correlated with the scores of hearing-language and hand-eye coordination in the Griffiths Development Scales-Chinese (@*CONCLUSIONS@#There are metabolic disorders in the cerebellum and the thalamus in children with ASD, and there is a correlation between the changes of metabolites in the left cerebellum and the left thalamus. Some metabolic indexes are related to the clinical symptoms of ASD. MRS may reveal the pathological basis of ASD and provide a basis for diagnosis and prognosis assessment of ASD as a noninvasive and quantitative detection method.

Phenotype and genotype analysis of a pedigree affected with Joubert syndrome due to variant of TMEM237 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the pathogenesis of two siblings (including a fetus) from a pedigree affected with Joubert syndrome.@*METHODS@#Peripheral blood samples of the proband and his parents as well as amniotic fluid and abortion tissues of the fetus were collected. Part of the samples were used for the extraction of DNA, and whole exome sequencing (WES) was carried out to screen potential variants in the proband and his parents. Suspected variants were subjected to bioinformatics analysis with consideration of the clinical phenotype, and were verified by Sanger sequencing of the proband, fetus and their parents.The remainders were used for the extraction of RNA, and the mechanism of splicing variant was validated by reverse transcription-PCR (RT-PCR).@*RESULTS@#WES showed that both patients have carried c.175C>T (p.R59X) and c.553+1G>A compound heterozygous variants of the TMEM237 gene. Among these, c.175C>T was a nonsense mutation inherited from the asymptomatic mother, while c.553+1G>A was an alternative splicing mutation inherited from the asymptomatic father. RT-PCR showed that this variant has resulted in aberrant splicing by exon skipping.@*CONCLUSION@#The compound heterozygous variants of the TMEM237 gene probably underlay the etiology of Joubert syndrome in this pedigree. Above finding has enriched the phenotype and variant spectrum of the TMEM237 gene, and facilitated genetic counseling and prenatal diagnosis for the family.

Clinical and genetic analysis of a child with mental retardation and microcephaly with pontine and cerebellar hypoplasia / 中华医学遗传学杂志

OBJECTIVE@#To analyze the clinical phenotype and pathogenic variant in a child diagnosed with mental retardation and microcephaly with pontine and cerebellar hypoplasia (MICPCH).@*METHODS@#Clinical phenotype of the child was reviewed. Whole exome sequencing was carried out for the child. Candidate variant was verified by Sanger sequencing of the family member.@*RESULTS@#The proband manifested dyskinesia, development delay, cerebellar hypoplasia and bilateral hearing impairment. WES results revealed that the proband has carried a pathogenic c.1641_1644delACAA (p.Thr548Trpfs*69) variant of the CASK gene, which was verified by Sanger sequencing to be a de novo variant.@*CONCLUSION@#The c.1641_1644delACAA (p.Thr548Trpfs*69) variant of the CASK gene probably underlay the MICPCH in the proband. Above finding has provided a basis for genetic counseling. WES should be considered for the diagnosis of neurological dysplasia.

Phenotypic analysis and variant identification of a fetus with Joubert syndrome 17 / 中华医学遗传学杂志

OBJECTIVE@#To analyze the phenotype and genetic variant of a fetus with dysplasia of cerebellar vermis.@*METHODS@#Gestational status and family history of the gravida was taken in combination with the imaging results of the fetus. Following elected abortion, fetal tissue and peripheral blood samples of the couple were collected for the extraction of genome DNA. Whole exome sequencing was carried out to screen potential variant associated with the phenotype of the proband. Specific PCR primers were designed to verify the results by Sanger sequencing.@*RESULTS@#Prenatal ultrasound revealed that the fetal vermis cerebellum was poorly developed, which was similar to the previous pregnancy. Whole exome sequencing revealed that the fetus has carried compound heterozygous variants of the CPLANE1 gene, namely c.7978C>T and c.7169delT, which were respectively inherited from the husband and wife.@*CONCLUSION@#The c.7978C>T and c.7169delT compound heterozygous variants of the CPLANE1 gene probably underlay the dysplasia of cerebellar vermis in the fetus, which has provided a basis for genetic counseling and prenatal diagnosis.

Fentanyl attenuates air-puff stimulus-evoked field potential response in the cerebellar molecular layer via inhibiting interneuron activity in mice / 生理学报

Fentanyl as a synthetic opioid works by binding to the mu-opioid receptor (MOR) in brain areas to generate analgesia, sedation and reward related behaviors. As we know, cerebellum is not only involved in sensory perception, motor coordination, motor learning and precise control of autonomous movement, but also important for the mood regulation, cognition, learning and memory. Previous studies have shown that functional MORs are widely distributed in the cerebellum, and the role of MOR activation in cerebellum has not been reported. The aim of the present study was to investigate the effects of fentanyl on air-puff stimulus-evoked field potential response in the cerebellar molecular layer using in vivo electrophysiology in mice. The results showed that perfusion of 5 μmol/L fentanyl on the cerebellar surface significantly inhibited the amplitude, half width and area under the curve (AUC) of sensory stimulation-evoked inhibitory response P1 in the molecular layer. The half-inhibitory concentration (IC

Transaxonal degenerations of cerebellar connections: the value of anatomical knowledge / Degenerações transaxonais das conexões cerebelares: o valor do conhecimento anatômico

ABSTRACT Transaxonal degenerations result from neuronal death or the interruption of synaptic connections among neuronal structures. These degenerations are not common but may be recognized by conventional magnetic resonance imaging. Objective: The learning objectives of this review include recognition of the imaging characteristics of transaxonal degenerations involving cerebellar connections, the identification of potential encephalic lesions that can lead to these degenerations and correlation of the clinical manifestations with imaging findings that reflect this involvement. Methods: In this report, we review the neuroanatomical knowledge that provides a basis for identifying potential lesions that can result in these degenerations involving cerebellar structures. Results: Hypertrophic olivary degeneration results from an injury that interrupts any of the components of the Guillain-Mollaret triangle. In this work, we describe cases of lesions in the dentate nucleus and central tegmental tract. The crossed cerebellar diaschisis presents specific imaging findings and clinical correlations associated with its acute and chronic phases. The Wallerian degeneration of the middle cerebellar peduncle is illustrated by fiber injury of the pontine cerebellar tracts. A T2-hyperintensity in the dentate nucleus due to a thalamic acute lesion (in ventral lateral nuclei) is also described. Each condition described here is documented by MRI images and is accompanied by teaching points and an anatomical review of the pathways involved. Conclusion: Neurologists and radiologists need to become familiar with the diagnosis of these conditions since their presentations are peculiar and often subtle, and can easily be misdiagnosed as ischemic events, degenerative disease, demyelinating disease or even tumors.

RESUMO Degenerações transaxonais resultam da morte neuronal ou da interrupção de conexões sinápticas entre estruturas neurais. Essas degenerações não são comuns, mas podem ser reconhecidas por imagens de ressonância magnética convencional. Objetivo: Os objetivos de aprendizado desta revisão incluem o reconhecimento das características de imagem de degenerações transaxonais envolvendo conexões cerebelares, a identificação de possíveis lesões encefálicas que podem levar a essas degenerações e a correlação das manifestações clínicas com os achados de imagem que refletem esse envolvimento. Métodos: Neste artigo, revisamos conhecimentos neuroanatômicos que fornecem a base para identificar possíveis lesões que podem resultar nessas degenerações envolvendo estruturas cerebelares. Resultados: A degeneração olivar hipertrófica resulta de uma lesão que interrompe algum dos componentes do triângulo de Guillain-Mollaret. Neste trabalho, descrevemos casos de lesões no núcleo denteado e no trato tegmentar central. A diásquise cerebelar cruzada apresenta achados de imagem específicos e correlações clínicas associadas às suas fases aguda e crônica. A degeneração walleriana dos pedúnculos cerebelares médios é ilustrada pela lesão dos tratos pontino-cerebelares. Uma hiperintensidade em T2 do núcleo denteado devido a uma lesão talâmica aguda (no núcleo ventrolateral) também é descrita. Cada condição aqui descrita é documentada por imagens de ressonância magnética e é acompanhada por pontos didáticos e uma revisão anatômica das vias envolvidas. Conclusão: Neurologistas e radiologistas precisam estar familiarizados com o diagnóstico dessas condições, uma vez que suas apresentações são peculiares e frequentemente sutis, e podem ser facilmente equivocadamente diagnosticadas como lesões isquêmicas, doenças degenerativas, desmielinizantes, ou mesmo tumorais.

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.

Lesión multinodular y vacuolar de fosa posterior. Presentación de caso en Colombia / Multinodular and Vacuolating Posterior Fossa Lesions of Unknown Significance. Case Report in Colombia

Existen múltiples lesiones quísticas que se pueden encontrar en el encéfalo y en la fosa posterior. Entre estas, una nueva entidad denominada MV PLUS (por su sigla en inglés de multinodular and vacuolating posterior fossa lesions of unknown significance) tiene características imagenológicas similares al tumor multinodular vacuolante, pero como lo indican su sigla en inglés, está localizado en la fosa posterior. Estos tumores se definen como un conjunto de lesiones subcorticales nodulares pequeñas, de alta señal en secuencias con informaciónT2-FLAIR, con o sin realce al administrar medio de contraste. Pueden diferenciarse de otras entidades quísticas porque son lesiones agrupadas, sin cambios inflamatorios reactivos, presentes en una corteza de apariencia normal y sin evolución en el seguimiento. Esto último hace que se consideren lesiones benignas, no agresivas. Se presenta el caso de un paciente de 21 años de edad, a quien de manera incidental se le encontró en la región central del vermis una lesión de aspecto multiquístico, sin cambios durante el seguimiento en los últimos 3 años, con diagnóstico probable de MV PLUS.

There are multiple types of cystic lesions that can be found in the brain and in the posterior fossa. Among these, a new entity called MV PLUS (Multinodular and Vacuolating Posterior Fossa Lesions of Unknown Significance) has similar imaging characteristics to the vacuolating multinodular tumor, but as indicated by its acronym in English, it is located in the posterior fossa. These tumors are defined as a group of small, high intensity nodular subcortical images in the T2-FLAIR, with or without post-contrast enhancement. They can be differentiated from other cystic entities, because they are clustered lesions, without reactive inflammatory changes, in a cortex of normal appearance and without changes at follow-up. The latter, causes them to be considered benign, non-aggressive lesions. We present the case of a 21-year-old patient, who presented an incidentally found lesion in the central region of the vermis. MRI showed a multicystic-looking mass, that had no changes at follow-up in the last 3 years and without obvious differential diagnosis, suggestive of MV PLUS.

Genetic testing and prenatal diagnosis for two families affected with Joubert syndrome / 中华医学遗传学杂志

OBJECTIVE@#To identify pathogenic variants in two families with patients suspected for Joubert syndrome(UBST) by cerebellar vermis hypoplasia.@*METHODS@#Clinical data and peripheral venous blood and skin tissue samples were collected for the extraction of genomic DNA. Potential variants were screened by using targeted capture and next generation sequencing. Suspected variants were validated by PCR and Sanger sequencing. The frequency of the variants in the population was calculated. Pathogenicity of the variants was predicted by following the guidelines of the American College of Medical Genetics and Genomics (ACMG). Prenatal diagnosis was provided to these families upon subsequent pregnancy.@*RESULTS@#The proband of family 1 was found to harbor homozygous c.2072delT (p.F691S*fs19) frameshift variant of the AHI1 gene, which may cause premature termination of translation of the Abelson helper integration site 1 after the 691st amino acid. The proband of family 2 was found to harbor compound heterozygous variants of the CPLANE1 gene, namely c.7243dupA (p.T2415Nfs*7) and c.8001delG (p.K2667Nfs*31), which can respectively lead to premature termination of translation of ciliogenesis and planar polarity effector 1 after the 2145th and 2667th amino acids. All of the three variants were previously unreported, and were predicted to be pathogenic by bioinformatic analysis.@*CONCLUSION@#The AHI1 c.2072delT and CPLANE1 c.7243dupA and c.8001delG variants probably underlay JBTS3 in family 1 and JBTS17 in family 2, respectively. Based on above results, prenatal diagnosis may be offered to the affected families upon their subsequent pregnancies.

A bionic cerebellar motion control model and its application in arm control / 生物医学工程学杂志

How to realize the control of limb movement and apply it to intelligent robot systems at the level of cerebellar cortical neurons is a hot topic in the fields of artificial intelligence and rehabilitation medicine. At present, the cerebellar model usually used is only for the purpose of controlling the effect, borrowing from the functional mode of the cerebellum, but it ignores the structural characteristics of the cerebellum. In fact, in addition to being used for controlling purposes, the cerebellar model should also have the interpretability of the control process and be able to analyze the consequences of cerebellar lesions. Therefore, it is necessary to establish a bionic cerebellar model which could better express the characteristics of the cerebellum. In this paper, the process that the cerebellum processes external input information and then generates control instructions at the neuron level was explored. By functionally segmenting the cerebellum into homogeneous structures, a novel bionic cerebellar motion control model incorporating all major cell types and connections was established. Simulation experiments and force feedback device control experiments show that the bionic cerebellar motion control model can achieve better control effect than the currently widely used cerebellar model articulation controller, which verifies the effectiveness of the bionic cerebellar motion control model. It has laid the foundation for real brain-like artificial intelligence control.

A Cortical Substrate for Square-Wave Jerks in Progressive Supranuclear Palsy