Common and uncommon neuroimaging manifestations of ataxia: an illustrated guide for the trainee radiologist. Part 2 - neoplastic, congenital, degenerative, and hereditary diseases / Manifestações de neuroimagem comuns e incomuns na ataxia: um guia ilustrado para radiologistas em treinamento. Parte 2 - doenças neoplásicas, congênitas, degenerativas e hereditárias

Abstract Ataxia is defined as a lack of coordination of voluntary movement, caused by a variety of factors. Ataxia can be classified by the age at onset and type (chronic or acute). The causative lesions involve the cerebellum and cerebellar connections. The correct, appropriate use of neuroimaging, particularly magnetic resonance imaging, can make the diagnosis relatively straightforward and facilitate implementation of the appropriate clinical management. The purpose of this pictorial essay is to describe the imaging findings of ataxia, based on cases obtained from the archives of a tertiary care hospital, with a review of the most important findings. We also discuss and review the imaging aspects of neoplastic diseases, malformations, degenerative diseases, and hereditary diseases related to ataxia.

Resumo Ataxia é definida como uma síndrome de falta de coordenação dos músculos de movimentação voluntária. Vários fatores podem causar ataxias, as quais podem ser classificadas de acordo com a idade, tipo de evolução (crônica ou aguda), cujas lesões envolvem o cerebelo e as conexões cerebelares. Com o uso correto e apropriado da neuroimagem, particularmente da ressonância magnética, o diagnóstico pode ser relativamente direito e o manejo clínico pode ser implementado de maneira correta. O objetivo deste artigo é descrever os achados de imagem na síndrome atáxica a partir de casos recuperados do arquivo digital de um hospital terciário, com a revisão dos principais achados de imagem. Neste ensaio revisamos e discutimos os aspectos de imagem de doenças neoplásicas, malformações, doenças degenerativas e doenças hereditárias relacionadas à ataxia.

Common and uncommon neuroimaging manifestations of ataxia: an illustrated guide for the trainee radiologist. Part 1 - acquired diseases / Manifestações de neuroimagem comuns e incomuns na ataxia: um guia ilustrado para radiologistas em treinamento. Parte 1 - doenças adquiridas

Abstract Ataxia is defined as a lack of coordination of voluntary movement, caused by a variety of factors. Ataxia can be classified by the age at onset and type (chronic or acute). The causative lesions involve the cerebellum and cerebellar connections. The correct, appropriate use of neuroimaging, particularly magnetic resonance imaging, can make the diagnosis relatively accurate and facilitate implementation of the appropriate clinical management. The purpose of this pictorial essay is to describe the imaging findings of ataxia, based on cases obtained from the archives of a tertiary care hospital, with a review of the most important findings. We also review and discuss the imaging aspects of infectious, toxic, vascular, and inflammatory diseases.

Resumo Ataxia é definida como uma síndrome de falta de coordenação dos músculos de movimentação voluntária. Vários fatores podem causar ataxias, os quais podem ser classificados de acordo com a idade, tipo de evolução (crônica ou aguda), cujas lesões envolvem o cerebelo e as conexões cerebelares. Com o uso correto e apropriado da neuroimagem, particularmente da ressonância magnética, o diagnóstico pode ser relativamente preciso e o manejo clínico pode ser implementado de maneira correta. O objetivo deste artigo é descrever os achados de imagem na síndrome atáxica com base em casos recuperados do arquivo digital de um hospital terciário, com a revisão dos principais achados de imagem. Neste ensaio revisamos e discutimos os aspectos imagem de doenças infecciosas, tóxicas, vasculares e inflamatórias.

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.

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.

Neuronal Activity in the Cerebellum During the Sleep-Wakefulness Transition in Mice / 神经科学通报·英文版

Cerebellar malfunction can lead to sleep disturbance such as excessive daytime sleepiness, suggesting that the cerebellum may be involved in regulating sleep and/or wakefulness. However, understanding the features of cerebellar regulation in sleep and wakefulness states requires a detailed characterization of neuronal activity within this area. By performing multiple-unit recordings in mice, we showed that Purkinje cells (PCs) in the cerebellar cortex exhibited increased firing activity prior to the transition from sleep to wakefulness. Notably, the increased PC activity resulted from the inputs of low-frequency non-PC units in the cerebellar cortex. Moreover, the increased PC activity was accompanied by decreased activity in neurons of the deep cerebellar nuclei at the non-rapid eye-movement sleep-wakefulness transition. Our results provide in vivo electrophysiological evidence that the cerebellum has the potential to actively regulate the sleep-wakefulness transition.

DTI study of neonatal hyperbilirubinemia brain injury based on cerebellar dentate nucleus / 中国医师杂志

Objective Magnetic resonance diffusion tensor imaging ( DTI) technique was used to investigate the changes of DTI parameters in nerve fiber bundles of children with hyperbilirubinemia. Meth-ods A retrospective analysis of DTI imaging data of 43 children with hyperbilirubinemia and 24 normal controls in our hospital using the German Siemens 3. 0t Trio superconducting magnetic resonance imaging in-strument from December 2016 to March 2018. Children with hyperbilirubinemia were divided into two groups, total serum bilirubin mildly elevated group (34 cases) and total serum bilirubin moderate to severe elevation group (9 cases). The right and left cerebellar dentate nuclei were selected as the regions of inter-est. Relevant parameters were measured, and the parameters of each group were analyzed and compared. Results Compared with the normal control group,the fractional anisotropy ( FA) of the total serum biliru-bin mildly elevated group was decreased ( P=0. 022 ) and the volume ratio ( VR ) of that was increased (P=0. 036). Compared with the normal control group, the FA of the total serum bilirubin moderate to se-vere elevation group was decreased (P=0. 002) and the VR of that was increased (P=0. 047). Compared with the total serum bilirubin mildly elevated group,the FA of the total serum bilirubin moderate to severe elevation group was decreased (P=0. 035). In addition, in the cerebellar dentate nucleus, there was a lin-ear negative correlation (r= -0. 201, P=0. 029) between the FA values and the total bilirubin level, while linear positive correlation (r=0. 245, P=0. 045) between the VR value and the total bilirubin level. Conclusions There are changes in FA and VR values of the cerebellar dentate nucleus in children with hy-perbilirubinemia,which of them are linearly related to bilirubin levels. It can early indicate the destruction or dysplasia of nerve fiber bundles in children.

Curcumin prevents the structural changes induced in the rats' deep cerebellar nuclei by sodium metabisulfite, a preservative agent

OBJECTIVE@#To evaluate the the possible neurotoxic effects of sulfite and the protective potential of curcumin on the deep cerebellar nuclei using stereological methods.@*METHODS@#The rats were randomly divided into five experimental groups (n=6): Group I: distilled water, Group II: Olive oil, Group III: Curcumin (100 mg/kg/day), Group IV: Sodium metabisulfite (25 mg/kg/day), and Group V: Sodium metabisulfite+curcumin. At the end of 56 d, the right cerebellar hemispheres were removed and assigned to stereological studies. The total volume and total neuron number of deep cerebellar nuclei were assessed using Cavalieri and optical disector methods, respectively.@*RESULTS@#The data showed ∼20% and ∼16% decrease was respectively observed in the total volume and the total neuron number of the deep cerebellar nuclei of the sulfite-treated rats in comparison to the distilled water group (P<0.04). However, no significant change was observed in the total volume and neuronal number of the deep cerebellar nuclei in sulfite+curcumin-treated rats and curcumin played a protective role against sulfite. Curcumin or its vehicle (olive oil) did not induce any significant changes.@*CONCLUSIONS@#Curcumin, the main part of the turmeric, could prevent the structural changes induced in the deep cerebellar nuclei by sodium metabisulfite, a preservative agent, in rats.

Curcumin prevents the structural changes induced in the rats' deep cerebellar nuclei by sodium metabisulfite, a preservative agent

Objective: To evaluate the the possible neurotoxic effects of sulfite and the protective potential of curcumin on the deep cerebellar nuclei using stereological methods. Methods: The rats were randomly divided into five experimental groups (n=6): Group I: distilled water, Group II: Olive oil, Group III: Curcumin (100 mg/kg/day), Group IV: Sodium metabisulfite (25 mg/kg/day), and Group V: Sodium metabisulfite+curcumin. At the end of 56 d, the right cerebellar hemispheres were removed and assigned to stereological studies. The total volume and total neuron number of deep cerebellar nuclei were assessed using Cavalieri and optical disector methods, respectively. Results: The data showed ~20% and ~16% decrease was respectively observed in the total volume and the total neuron number of the deep cerebellar nuclei of the sulfite-treated rats in comparison to the distilled water group (P<0.04). However, no significant change was observed in the total volume and neuronal number of the deep cerebellar nuclei in sulfite+curcumin-treated rats and curcumin played a protective role against sulfite. Curcumin or its vehicle (olive oil) did not induce any significant changes. Conclusions: Curcumin, the main part of the turmeric, could prevent the structural changes induced in the deep cerebellar nuclei by sodium metabisulfite, a preservative agent, in rats.

Case of Atypical Wernicke's Encephalopathy in a GB Cancer Patient / 대한내과학회지

Wernicke's encephalopathy (WE) is an acute neuropsychiatric syndrome resulting from thiamine deficiency. Traditionally, diagnosis of WE rests on a clinical symptom triad consisting of ocular signs, altered consciousness, and ataxia. However, the complete triad is only present in a fraction of cases, which means that WE tends to be under-diagnosed, especially in nonalcoholic patients. Brain MRI of WE patients usually shows symmetrical signal intensity alterations in the thalami, mammillary bodies, and periaqueductal area, because of cytotoxic edema in the same region. These typical findings are useful diagnostic leads in WE patients with atypical symptoms. However, atypical findings can occasionally be seen in the vermis of cerebellum and cerebellar nuclei. Notably, alterations of signal intensity in the cerebellar dentate nuclei, which is a typical finding of metronidazole-induced encephalopathy (MIE), need to be distinguished according to medication history and response to thiamine.

A family with earlier onset spinocerebellar ataxia 6 in China / 中华神经科杂志

Objective To investigate the real type of the first earlier onset spinocerebellar ataxia family in China. Methods Two family members were subjected to autopsy, whose genetypings were confirmed by polymerase chain reaction (PCR) and direct sequencing technique. Golgi staining, immunohistochemistry and electron microscopy methods were used to detect the neurodegeneration in central nervous system of 2 patients. Results The light microscopic and electron microscopic showed synaptic degeneration of Purkinje cell in the cerebellar cortex, which was accompanied by deterioration of Purkinje cell, and both inferior olivary complex, dentate nucleus and anterior central gyrus. Conclusions There is severer neurodegeneration in the central nervous system of earlier onset spiuocerebellar ataxia 6 patient, especially in cerebellar cortex, inferior olivary complex and dentate nucleus, and the neurodegeneration may depend on disease duration.

DIRECT SPINAL PROJECTIONS FROM THE CEREBELLAR NUCLEI IN THE RABBIT / 解剖学报

The direct spinal projections from the cerebellar nuclei in the rabbit were retro gradely traced by unilateral injection of WGA-HRP into different levels of the spinal cord, including the cervical, thoracic and lumbar segments. The labeled neurons in the cerebellar nuclei were constantly seen in those animals, in which the upper cervical segments (C_(2-4)) were injected. No labeled neurons could be found in the cerebellar nuclei following injection into the lower cervical cord (C_(6-8)) or more caudal segments. All labeled neurons were located in the caudal parts of the fastigial and the interposed nuclei on the side contralateral to the injection. The results show that there are crossed projections from the cerebellar nuclei directly to the upper cervical cord. This study provide certain morphological evidences for further investigation of some aspects of cerebellar functions on motor coordination.

FIBER PROJECTIONS FROM THE NucLEI OF THE TRIGEMINAL NERVE TO THE CEREBELLAR NUCLEI OF THE RAT / 解剖学报

The trigemino-cerebellar projections of the rats were studied by introducing HRP microelectrophoretically in to various deep icerebellar nuclei (dentate nucleus, ND; interpositus nucleus, anterior part, NIA; interpositus nucleus, posterior part, NIP; fastigial nucleus, NF). The results indicate that all nuclei of the trigeminal nerve give their projections to bilateral (mostly ipsilateral) deep cerebellar nuclei. Most of them come from the interpolar and oral subnuclei of the spinal nucleus of the trigeminal nerve. The caudal subnucleus of the spinal nucleus of the trigeminal nerve and the principal sensory nucleus of the trigeminal nerve (VP) take the second place. Least of all come from the mesencephalic nucleus (ME) and the motor nucleus (MO) of the trigeminal nerve. In addition, cells in the region ventrolateral to the motor nucleus (VMO) and in the root of the trigeminal nerve (VR) also project to deep cerebellar nuclei. Fibers coming from ME terminate mostly in NF and NIA. Fibers from the spinal nucleus of the trigeminal nerve and VP terminate more in NIP and ND. Fibers from MO terminate in NF, NIA and ND. Fibers from VMO and VR have the same termination as those from the sensory nuclear complex of the trigeminal nerve.