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Lhermitte-Duclos disease (LDD) is a rare, slow-growing neoplasm that develops in the brain's posterior fossa. It can appear as a single lesion or as part of Cowden's syndrome.We report the case of a 51-year-old female with a history of diabetes, hypertension, and a previously treated neuroendocrine tumor, who presented to the hospital after experiencing a generalized tonic-clonic seizure. Except for a tongue laceration, the neurological examination was unremarkable. Brain magnetic resonance imaging (MRI) showed a T2 left cerebellar hemisphere pseudomass lesion with iso-hyperintense signals suggestive of Lhermitte-Duclos disease. This case describes a unique presentation of LDD and its various radiological manifestations, emphasizing the importance of neuroimaging in its diagnosis. Additionally, it contributes to the expanding literature on the varied manifestations of LDD.

Simple Summary: Neuronavigation and microscope-based augmented reality are widely used in neurosurgery to support intraoperative orientation, preserve neurological function, and maximize the extent of resection. However, in the sitting position, navigation may not be accurate enough to fully exploit its potential due to brain deformations caused by gravity and brain shift. To ensure accurate navigation and augmented reality support, it is necessary to verify and update navigation regularly. Intraoperative ultrasound is an easy-to-use tool that can be used to verify accuracy and to generate real-time image data to update navigation without significantly interrupting the surgical workflow. This can be achieved by outlining the lesion within the data set or by rigidly co-registering preoperative and intraoperative data to update and enable navigation and augmented reality support. In this study, image-based co-registration improved the navigation accuracy, making intraoperative ultrasound useful for enabling navigation and augmented reality support during posterior fossa surgery in the sitting position. Despite its broad use in cranial and spinal surgery, navigation support and microscope-based augmented reality (AR) have not yet found their way into posterior fossa surgery in the sitting position. While this position offers surgical benefits, navigation accuracy and thereof the use of navigation itself seems limited. Intraoperative ultrasound (iUS) can be applied at any time during surgery, delivering real-time images that can be used for accuracy verification and navigation updates. Within this study, its applicability in the sitting position was assessed. Data from 15 patients with lesions within the posterior fossa who underwent magnetic resonance imaging (MRI)-based navigation-supported surgery in the sitting position were retrospectively analyzed using the standard reference array and new rigid image-based MRI-iUS co-registration. The navigation accuracy was evaluated based on the spatial overlap of the outlined lesions and the distance between the corresponding landmarks in both data sets, respectively. Image-based co-registration significantly improved (p < 0.001) the spatial overlap of the outlined lesion (0.42 ± 0.30 vs. 0.65 ± 0.23) and significantly reduced (p < 0.001) the distance between the corresponding landmarks (8.69 ± 6.23 mm vs. 3.19 ± 2.73 mm), allowing for the sufficient use of navigation and AR support. Navigated iUS can therefore serve as an easy-to-use tool to enable navigation support for posterior fossa surgery in the sitting position. [ABSTRACT FROM AUTHOR]

Posterior fossa tumors are the most common pediatric brain tumors, and present unique challenges in terms of their location and surgical management. The posterior fossa comprehends complex anatomy and represents the smallest and deepest of the three cranial base fossae. An in-depth understanding of posterior fossa anatomy is crucial when it comes to the surgical resection of pediatric brain tumors. Mastering the knowledge of posterior fossa anatomy helps the neurosurgeon in achieving a maximal and safe volumetric resection, that impacts in both overall and progression free survival. With the advancements in microsurgery, the telovelar approach has emerged as the workhorse technique for the resection of posterior fossa tumors in pediatric patients. This approach involves meticulously dissecting of the natural clefts present in the cerebellomedullary fissure, making a comprehensive understanding of the underlying anatomy key for its success. [ABSTRACT FROM AUTHOR]

Despite its broad use in cranial and spinal surgery, navigation support and microscope-based augmented reality (AR) have not yet found their way into posterior fossa surgery in the sitting position. While this position offers surgical benefits, navigation accuracy and thereof the use of navigation itself seems limited. Intraoperative ultrasound (iUS) can be applied at any time during surgery, delivering real-time images that can be used for accuracy verification and navigation updates. Within this study, its applicability in the sitting position was assessed. Data from 15 patients with lesions within the posterior fossa who underwent magnetic resonance imaging (MRI)-based navigation-supported surgery in the sitting position were retrospectively analyzed using the standard reference array and new rigid image-based MRI-iUS co-registration. The navigation accuracy was evaluated based on the spatial overlap of the outlined lesions and the distance between the corresponding landmarks in both data sets, respectively. Image-based co-registration significantly improved (p < 0.001) the spatial overlap of the outlined lesion (0.42 ± 0.30 vs. 0.65 ± 0.23) and significantly reduced (p < 0.001) the distance between the corresponding landmarks (8.69 ± 6.23 mm vs. 3.19 ± 2.73 mm), allowing for the sufficient use of navigation and AR support. Navigated iUS can therefore serve as an easy-to-use tool to enable navigation support for posterior fossa surgery in the sitting position.

Glioblastomas multiformes (GBMs), are the most common primary malignant tumors of the Central Nervous System. Frequently located in supratentorial topography, infratentorial location is rare, around 0-3.4% of primary GBMs. The diagnosis of these tumors is uncommon in adults, few cases have been reported, being even more infrequent in elderly patients. The most typical clinical presentation is a rapidly growing posterior fossa lesion, increased intracranial pressure, and cerebellar signs associated with the mass and perilesional edema. Clinical presentation, computed tomography (CT), and magnetic resonance imaging (MRI) provide useful information about the possible diagnosis but are not definitive. We describe a clinical case, 76 years old female with a clinical history of hypertension, depressive syndrome, and dyslipidemia. Started progressively with ataxy, imbalance, and vertigo. Brain CT shows an intra-axial, infiltrative lesion in the superior and middle vermis. MRI presents a heterogeneous lesion in the superior and median vermian region of the cerebellum with ring enhancement and central necrotic area. Was performed a middle suboccipital approach, corticectomy in the superior vermis. The intraoperative histological study reveal a high-grade malignancy astrocytoma, which was released through a subtotal resection. The histological result was a high-grade astrocytoma, grade IV in WHO classification. Four weeks after the surgery the patient started treatment with chemotherapy and radiotherapy. The main point of this case is the atypical location of the tumor. These lesions are rare in this location but they will do considering the differential diagnosis of posterior fossa tumors. However, the most frequent lesions with high percentages of incidence are metastatic lesions. [ABSTRACT FROM AUTHOR]

Epithelioid glioblastoma (eGB) is an uncommon morphological variant of isocitrate dehydrogenase wild-type GB that commonly presents as a cerebral mass in young adults and children. Here, we report the case of a 22-year-old man who presented with a cerebellar tumor. With the provisional diagnosis of pilocytic astrocytoma and adult medulloblastoma, he underwent suboccipital craniotomy with gross total excision of the tumor. On histopathological examination, he was diagnosed with eGB. Cerebellar presentation of eGB is a rare event that has not been previously described in the literature. The present case also highlights the need for differentiating eGB from its morphological mimics by carefully interpreting histopathological and immunohistochemical examination findings.

Lhermitte-Duclos disease (LDD), or cerebellar dysplastic gangliocytoma, is a rare type of cerebellar tumor, from unknown origin. Patients can be asymptomatic for several years, but there are usually imprecise neurological signs for long periods.

Hodgkin Lymphoma (HL) is a systemic disease with involvement of the cervical, supraclavicular, and mediastinal lymph nodes. It is commonly diagnosed in patients within the second and third decades of their lives. Diagnosis is usually made based on the distinct morphological and immunohistochemical characteristics, with the tissue biopsy being the cornerstone of workup. Extranodal presentation of HL is unusual and seldom encountered. Primary HL of the central nervous system (CNS) is exceedingly rare. We herein report a case of a 38yearold male patient who was diagnosed with primary CNSHL. The patient was treated with complete surgical resection followed by radiotherapy and chemotherapy. The patient was diseasefree for 7 years postoperatively without any clinical evidence of relapse. We also discussed a possible role of CNS regulatory Tcells (Tregs) in developmental primary CNSHL.

Granulosa cell tumors (GCTs) accounts 70% of all sex cord stromal tumors, of which adult types constitutes 95%. In rare cases, Primary extraovarian GCTs can occur and is supposed to arise from mesenchymal tissue along the embryonic genital ridge. One such rare case was encountered in a 71 year-old-widow-female who was admitted with the complain of dizziness and walking instability for 10 days. MR enhancement revealed the right cerebellar hemisphere with abnormal mass about 39*42*38 mm. The patient underwent complete removal of tumor by right occipital paramedian approach. IHC results were positive for Calretinin, CD99, Vimentin, PgR, Ki67 while negative for EMA, CKpan. As, she had history of hysterectomy 45yrs ago for “Myoma of Uterus” with no pathological evidence of GCTs, the tumor was diagnosed as AGCT. This case is presented as an unusual case and is the first case to be reported in cerebellum.

Atypical teratoid/rhabdoid tumor (AT/RT) is a rare tumor that is most frequently encountered in the pediatric patient population. AT/RT accounts for approximately 1%−2% of all pediatric central nervous system tumors and roughly 10%−20% of tumors in patients younger than 3 years of age. While AT/RT has been encountered in the adult population, the vast majority of the cases reported occur in the supratentorial space. In the existing literature, only 3 adult cases that arise from the cerebellum have ever been reported. A 38-year-old female presented with 6 months of worsening nausea, emesis, vertigo, diplopia, and coordination difficulty. Magnetic resonance imaging revealed a T1 avidly contrast-enhancing mass, composed of both cystic and solid areas, extending from the cerebellum into the fourth ventricle. Following a gross total resection, surgical pathology was consistent with AT/RT, with tumor cell loss of integrase interactor-1 (INI-1) observed via immunohistochemical staining. This case represents just the fourth ever reported case of AT/RT arising from the cerebellum in an adult and the oldest reported age to date of a cerebellar AT/RT occurring in a female. Due to the paucity of reported adult AT/RT cases, little is known about adults with AT/RT. Further reports will function to improve the general understanding of AT/RT in the adult population. [ABSTRACT FROM AUTHOR]

Within the past decade, circular RNAs have largely emerged as novel regulators of human biology, including brain function and cancer development. On the other hand, the Hedgehog pathway has established roles in regulating biological processes, including tumorigenesis. Here, the circular RNA transcriptome, in the context of Hedgehog signaling activation of medulloblastoma Daoy and human embryonic palatal mesenchyme HEPM cells, was determined. In total, 29 out of the 30 selected circular RNAs were validated by Sanger sequencing, with some regulated to a limited extent by Hedgehog signaling. Interestingly, back-spliced junctions, the marker of exonic RNA circles, were also identified at a low frequency within poly (A) mRNAs, reflecting exon repetition events. Thirteen circular RNAs had reduced expression in human medulloblastoma tumors in comparison to normal cerebellum. For seven out of these thirteen RNA circles, the linear mRNAs originating from the same genes did not exhibit a reduced expression. Depletion and/or overexpression of these seven circular RNAs minimally affected medulloblastoma cell proliferation. These findings highlight that differential expression of a gene product may not necessarily elicit an obvious phenotypic impact. Consequently, further analysis is required to determine the possible subtle contributions to the development of this cerebellar tumor.

Supplemental Digital Content is Available in the Text. Background and Purpose: Benign paroxysmal positional vertigo (BPPV) is the most common cause of positional vertigo. The term "benign" is consistent with a peripheral vestibular disorder that does not carry the potentially sinister sequelae of a central nervous system (CNS) cause. However, in 12% to 20% of cases, positional vertigo may be attributed to CNS pathology, including tumors of the cerebellum. Case Description: Here, we present a series of 3 cases in which positional vertigo and nystagmus were the only presenting features in 2 cases of cerebellar tumor and 1 case of obstructive hydrocephalus. Intervention: All patients underwent surgical intervention for removal of posterior fossa tumors or posterior fossa decompression for obstructive hydrocephalus. Following surgery, all 3 patients underwent a period of vestibular rehabilitation for postoperative motion sensitivity and balance impairment. Outcomes: Despite the continuing presence of central positioning nystagmus, all 3 patients recovered well, putatively with the aid of vestibular rehabilitation. Discussion: The presence of central positioning nystagmus may be the sole presenting feature of serious neurological conditions such as posterior fossa tumor. It is recommended that a diagnosis of BPPV can only be made if Dix-Hallpike or supine roll maneuver elicits nystagmus that is consistent with BPPV. Any features of the nystagmus, which are not consistent with BPPV, should raise suspicion of central pathology, and warrant further investigation. Video Abstract available for more insights from the authors (see Video Abstract, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A265). [ABSTRACT FROM AUTHOR]

After cerebellar tumors resection, patients show motor skill learning impairments but also cognitive deficits. However, their exact origins remain controversial. Using a rat model of cerebellar injury, we assessed the involvement of two structures often damaged during resection (vermis and interpositus nuclei) on habits development. During extended training of an instrumental task, rats develop response routines that are no longer voluntary or goal-directed but habit-based, evidenced by their insensitivity to changes in the value of the reward. Here we showed that, in contrast to sham or vermis lesioned rats, discrete lesions to interpositus nuclei prevented rats from developing habits with overtraining, without motor difficulties, nor alteration of the instrumental task acquisition. Our results suggest that the role of the cerebellum can be extended from motor skill learning to cognitive routines learning. Similar habit impairment could possibly account for some of the long-term outcome difficulties observed in cerebellar-damaged patients.

Relatamos dois casos de mutismo observados após ressecção de tumores do cerebelo em duas crianças do sexo feminino, tratando-se, no primeiro caso de meduloblastoma, e no segundo, de astrocitoma juvenil. Em ambas havia lesão pré-operatória de nervos bulbares. A fisiopatogenia do mutismo envolve fatores anatômicos, vasculares e emocionais. As características essenciais do mutismo cerebelar são discutidas com base em revisão da literatura.We present two cases of mutism observed after resection of tumors of the cerebellum, in two children of the feminine sex, being in the first case of medulloblastoma and in the second of juvenile astrocytoma. In both patients there was pre-operative lesion of low cranial nerves. The pathophysiology of the mutism involves anatomical, vascular and emotional factors, being its essential characteristics discussed with base in revision of the literature.

Lipomas intracranianos são raros, geralmente sendo achado de autópsia. Situam-se na linha média, mais frequentemente de localização central. Podem ocorrer desde a infância até a vida adulta. Muitos dos "lipomas", na verdade são associados a lesões hamartomatosas ou, mesmo, a neoplasias como os meduloblastomas do cerebelo. Relatamos e discutimos um caso de lipoma de cerebelo, achado de autópsia de um recém-nascido prematuro.Intracranial lipomas are rare. Usually they are incidental findings at autopsy. They occur in all the age groups and are often associated with hamartomatous lesions or neoplasms as cerebellum medulloblastomas. More frequently they are central and located at the midline. We report and discuss a case of lipoma of the cerebellum, an incidental finding at autopsy of a premature newborn.

Introduction: The purpose of our study was to test the accuracy and applicability of decision rules utilizing apparent diffusion coefficient (ADC) ratios on accurate preoperative diagnosis of common pediatric cerebellar tumors across two institutions. Methods: In this HIPAA-compliant, IRB-approved study, performed at two institutions, 140 pediatric cerebellar tumors were included. Two separate reviewers placed regions of interest on the solid components of 140 tumors (98 at site A and 42 at site B) and normal brain on the ADC maps. The third reviewer who was blinded to the histopathological diagnoses made the same measurements on 140 patients to validate the data. Tumor to normal brain ADC ratios were calculated. Receiver operator curve (ROC) analysis was performed to generate thresholds to discriminate tumors. Utility of decision rules based on these thresholds was tested. Results: While ADC values of medulloblastomas were different between the sites, there was no difference among the ADC ratios of medulloblastomas, pilocytic astrocytomas, ependymomas, and atypical teratoid rhabdoid tumors between the sites. ADC ratio of ≥1.8 correctly discriminated pilocytic astrocytomas from ependymomas with a sensitivity of 0.83 and a specificity of 0.78. ADC ratio of <1.2 correctly discriminated ependymomas from embryonal tumors with a sensitivity of 0.87 and a specificity of 0.83. The proposed decision rules correctly discriminated 120 of the 140 tumors (85.71 %). Age ≥2 years criterion correctly sorted medulloblastomas in 84.48 % of patients and age <2 years correctly distinguished atypical teratoid rhabdoid tumors in 90.00 % of patients with embryonal tumors. Conclusions: Decision rules based on ADC ratios are applicable across two institutions in the accurate preoperative diagnosis of common pediatric cerebellar tumors. [ABSTRACT FROM AUTHOR]

Abstract: Intracranial hemangioblastomas are benign vascular tumors. The peak age of incidence is between 20 to 50years. Hemangioblastomas rarely occur in patients over the age of 65. To our knowledge there is no review of the prevalence and clinical features in an elderly population. We reviewed our 12year experience with intracranial hemangioblastomas, and characterized the clinical features of hemangioblastomas in patients over the age of 65. We present a 72-year-old man with a cerebellar mass initially thought to be a metastasis as an illustrative case. We reviewed our pathology database and identified all patients with a histopathologically confirmed diagnosis of hemangioblastoma over the last 12years in a large tertiary adult hospital; all patients were over the age of 18. Of all cases of hemangioblastoma in the last 12years, six of 77 (7.7%) occurred in patients over the age of 65. All were cerebellar in location, and none were associated with von-Hippel Lindau disease. Hemangioblastomas are uncommon, but not rare, in patients over the age of 65, and should be included in the differential diagnosis of patients presenting with gait ataxia and a cerebellar lesion in this age group. [Copyright &y& Elsevier]

Background: Pilomyxoid astrocytoma (PMA) was recently classified as a variant of pilocytic astrocytoma (PA) with significantly more aggressive clinical features than those of PA. Like PAs, PMAs frequently arise in the chiasmatic/hypothalamic regions. The cerebellum is also a common site of occurrence for PAs but not for PMAs. Case description: We present the case of a 31-month-old boy with cerebellar PMA that showed rapid regrowth during the 3 months following the first subtotal resection. Gross total resection was achieved in the second surgery, followed by radiation to the tumor bed. Results: During follow-up over the next 12 years, there has been no evidence of recurrence on magnetic resonance imaging. Conclusions: Although the prognosis of cerebellar PMAs remains unknown because of the paucity of cases, the relevant literature reports a more favorable outcome for cerebellar PMAs than for PMAs occurring at other locations. The results of this case study and a review of the relevant literature advocate radical resection, sometimes involving multiple surgeries, for cerebellar PMAs because gross total or near total resection is more feasible in the cerebellum than in other locations. [ABSTRACT FROM AUTHOR]

Background: The aim of this case-control study was to investigate the severity of the cerebellar cognitive affective syndrome (CCAS) in patients treated for pediatric posterior fossa tumors (PFT) and evaluate its diagnostic validity and predictive value for long-term effects., Methods: Using neuropsychological test data from 56 patients with PFT (average age: 14 years), the severity of deficits in the CCAS core areas (executive functions, verbal functions, visuospatial abilities and emotions/behaviour) was examined. Neuropsychological and academic long-term outcomes of patients with CCAS were compared to two control groups of PFT patients (treated with either surgery or surgery followed by radio-/chemotherapy) without the syndrome. Risk factors associated with various deficits were considered., Results: All but one PFT patient suffered from slight to severe impairments in at least one CCAS domain, while complete CCAS occurred in 35.7%. Seven years after tumor diagnosis CCAS patients performed worse in information processing, logical reasoning, verbal functions, visuospatial skills, and executive functioning and required more special educational support compared to the control groups. CCAS patients performed equally poor as patients treated with chemo-/radiotherapy in tasks measuring information processing speed. Risk factors were significantly associated with deficits in information processing speed but not CCAS emergence., Conclusions: Deficits in the core CCAS domains are commonly found in PFT patients, but varying in severity, which suggests the syndrome to be continuous rather than dichotomous. However, the validity of CCAS diagnosis was low and unspecific. The exclusion of relevant functions typically impaired in PFT patients (eg, information processing) resulted in difficulties being overlooked., (© The Author(s) 2022. Published by Oxford University Press, the Society for Neuro-Oncology and the European Association of Neuro-Oncology.)

This report describes a patient who developed agitation, disorientation, visual hallucinations, inappropriate verbal outbursts, and impaired memory following resection of a choroid plexus papilloma. No medical, neurologic, or metabolic disorders unrelated to the surgery were identified. Five weeks following surgery, treatment with aripiprazole, a partial dopamine agonist, was started to address the delirious state. Improvements in agitation, orientation, memory, and executive functions, as well as a decrease in emotional lability, began within twenty-four hours and continued over the remainder of the inpatient hospitalization. Five months after initial resection, aripiprazole was discontinued without worsening of cognitive or emotional functions. Persistent difficulties with working memory, planning, judgment, and visuospatial skills were noted on neuropsychological examination six months following tumor removal. This case illustrated the therapeutic benefit of aripiprazole for treatment of mental status changes associated with resection of a posterior fossa tumor. [ABSTRACT FROM AUTHOR]

Rationale and Objectives: The aim of this study was to identify clinically useful tumor/normal brain apparent diffusion coefficient (ADC) ratios for distinguishing common pediatric cerebellar tumors. Materials and Methods: Review of medical records revealed 79 patients with cerebellar tumors who underwent preoperative magnetic resonance imaging, including diffusion-weighted imaging sequences, and surgery. There were 31 pilocytic astrocytomas, 27 medulloblastomas, 14 ependymomas, and seven atypical teratoid/rhabdoid tumors. ADC values were measured by placing regions of interest on the solid tumor and normal brain parenchyma by two reviewers. Tumor/normal brain ADC ratios were calculated. Results: Mean ADC values of the pilocytic astrocytomas were greater than those of ependymomas, whose mean ADC values were greater than those of medulloblastomas and atypical teratoid/rhabdoid tumors. Using a tumor/normal brain ADC ratio threshold of 1.70 to distinguish pilocytic astrocytomas from ependymomas, sensitivity of 92% and specificity of 79% were achieved. A tumor/normal brain ADC ratio threshold of 1.20 enabled the sorting of ependymomas from medulloblastomas with sensitivity of 93% and specificity of 88%. Conclusions: Tumor/normal brain ADC ratios allow the distinguishing of common pediatric cerebellar tumors. [Copyright &y& Elsevier]

An 18-year-old girl presented with a history of visual disturbance without headache, nausea, or vomiting in May 2010. In July 2010, the patient visited our hospital because of visual disturbance. Head magnetic resonance images revealed hydrocephalus caused by a ring-enhancing mass lesion located in the vermis. Total tumor removal was performed. Histological findings revealed that honeycomb cells resembling oligodendrocytes accounted for most parts of the tumor. Rosenthal fibers and hyaline droplets were seen in a small portion. The tumor cells were immunoreactive for GFAP and Olig2, but none of the tumor cells were immunoreactive for Symaptophysin, EMA, or IDH 1. according to these findings, the tumor was diagnosed as pilocytic astrocytoma with an abundant oligodendroglioma-like component. Pilocytic astrocytoma is known to be associated with an oligodendroglioma-like component; however, the differential diagnosis for oligodendroglioma may be difficult when an oligodendroglioma-like component occupies most of the tumor. [ABSTRACT FROM AUTHOR]

Intraparenchymal schwannomas are rare and most of the reported cases are in supratentorial region with frontal lobe being most common. Infratentorial location is very rare. We report a posterior fossa midline large cystic schwannoma with mural nodule mimicking as pilocytic astrocytoma. The pathogenesis and neuroradiological findings of intraparenchymal schwannomas are discussed with review of the related literature. [ABSTRACT FROM AUTHOR]

Purpose: I read the article 'An Inside View of Autism' written by a 44-year-old autistic woman who had a successful international career designing livestock equipment. In this article, she wrote about her life, disease, and experiences as an autistic individual. She stated that 'It is interesting that my speech resembled the stressed speech in young children who have had tumors removed from the cerebellum'. Methods: In this article, we intend to review and extensively document both postoperative cerebellar mutism and autistic spectrum disorder. Results: We reviewed the clinical and neurological findings, etio-pathogenesis, neuroanatomy, mechanisms of development, and similarities between the etio-pathogenesis of both diseases. Conclusions: Cerebellar lesions can produce mutism and dysarthria, symptoms sometimes seen in autistic spectrum disorder. In mammals, cerebellar lesions disturb motivated behavior and reduce social interactions, functions that are disturbed in autistic spectrum disorder and cerebellar mutism. The cerebellum and two regions within the frontal lobes are active in certain language tasks. Language is abnormal in autistic spectrum disorder and cerebellar mutism. [ABSTRACT FROM AUTHOR]

Castleman's disease (CD) is a rare nonneoplastic lymphoproliferative disorder of unknown etiology. It is characterized by enlarged hyperplastic lymph nodes, usually presenting as a localized mass. Although an intracranial location is very uncommon, it should be considered in the differential diagnosis of a chordoid meningioma. We describe a pediatric case of CD with a cerebellar chordoid meningioma and intestinal lymphangiectasia. [ABSTRACT FROM AUTHOR]

Children and young adolescents with chronic surgical cerebellar lesions show persistent balance control problems during standing when lesions affect the deep cerebellar fastigial and adjacent interposed nuclei. The purpose of this study is to confirm that the same lesion sites are also associated with permanent signs of trunkal ataxia during sitting. A second aim is to demonstrate that examining the postural control of patients while sitting or standing on a foam cushion may constitute a simple clinical exam yielding results commensurate to a more involved dynamic posturography exam. Balance control was assessed in 16 patients after surgery of a benign cerebellar tumor in chronic state and healthy age- and gender-matched control subjects. Using an ultrasound-based kinematic recording system, trunkal and shoulder sway was measured during sitting and standing in different conditions. High-resolution MRI scans were acquired in the cerebellar patients. Voxel-wise statistical lesion symptom mapping was performed to compare lesioned areas between affected and unaffected patients in a given condition using χ tests. During sitting, 56% of cerebellar patients exhibited trunkal sway outside the range of healthy controls, and 87.5% of cerebellar patients revealed abnormal sway patterns during standing. Abnormalities were most pronounced when visual information was absent, and somatosensory information became unreliable and/or when the base of support along the medio-lateral axis was minimized during tandem stance. Lesion symptom mapping revealed that pathological values in the behavior data were more likely in patients with surgical lesions involving the fastigial nuclei (NF) and adjacent interposed nuclei (NI). In patients with surgery <1-year lesions of the inferior cerebellar vermis also had an impact on balance function. Our results corroborate previous evidence that the extent of permanent damage to the deep cerebellar nuclei greatly impacts on the recovery on balance function. [ABSTRACT FROM AUTHOR]

Dysplastic cerebellar gangliocytoma or Lhermitte-Duclos disease (LDD) especially in children are extremely rare. In this report we add one further case to this rare entity. A three year old boy with a history of cerebellar and brain stem compression signs was presented in unconscious condition. Computerized tomography (CT) scan revealed a well defined lesion mixed with area of calcification in the right cerebellum and severe obstructive hydrocephalus. Ventricular shunting was performed followed by gross total tumor removal three days after shunting. In the follow up period, the patient showed almost total resolution of all neurological deficits. MRI has been an imaging tool to preoperatively diagnose this disease; otherwise it would be uncertain preoperative diagnosis. However, in this report we would like to emphasize that not all uncertain diagnosis of LDD leads to palliative treatment. Well demarcated lesion may account for the safe surgical resection of this disease. [ABSTRACT FROM AUTHOR]

Transient mutism as a consequence of posterior fossa surgery is a well-known phenomenon. However, it has rarely been reported after focal nonsurgically induced cerebellar damage. We describe a 7-year-old child affected by a tumor arising from the quadrigeminal plate who developed transient cerebellar mutism after a spontaneous bleeding which extended to the upper cerebellar vermis. The recovery from mutism started about a week after the bleeding. At the time of the surgical treatment, 8 weeks after the spontaneous intratumoral bleeding, she was only dysarthric. To our knowledge, this is the first pediatric case of presurgical cerebellar mutism due to a hemorrhage of a neoplastic lesion. Moreover, the focality of bleeding allows the confirmation of the role played by the upper vermis in speech control as well as exclusion of surgically induced lesions commonly suggested as possible cause of the cerebellar mutism. [ABSTRACT FROM AUTHOR]

Simple Summary: Here the expression profile of circular RNAs in Hedgehog signaling-dependent cell lines and medulloblastoma cells was interrogated. Using stringent criteria, a reduced expression of seven circular RNAs in Hedgehog-dependent medulloblastoma versus cerebellum was clearly established. Depletion and/or overexpression of these deregulated RNA circles in two medulloblastoma cell lines revealed minimal effects in cellular proliferation based on two independent assays. These findings highlight the complexity of gene expression outcomes and the possibility that gene products may not necessarily have an obvious phenotypic impact on the cellular context where they are present. It is not inconceivable that a substantial number of differentially expressed circular RNAs may represent "passenger molecules" with little impact on a cell, reflecting the stochasticity of the gene expression and splicing processes. Within the past decade, circular RNAs have largely emerged as novel regulators of human biology, including brain function and cancer development. On the other hand, the Hedgehog pathway has established roles in regulating biological processes, including tumorigenesis. Here, the circular RNA transcriptome, in the context of Hedgehog signaling activation of medulloblastoma Daoy and human embryonic palatal mesenchyme HEPM cells, was determined. In total, 29 out of the 30 selected circular RNAs were validated by Sanger sequencing, with some regulated to a limited extent by Hedgehog signaling. Interestingly, back-spliced junctions, the marker of exonic RNA circles, were also identified at a low frequency within poly (A) mRNAs, reflecting exon repetition events. Thirteen circular RNAs had reduced expression in human medulloblastoma tumors in comparison to normal cerebellum. For seven out of these thirteen RNA circles, the linear mRNAs originating from the same genes did not exhibit a reduced expression. Depletion and/or overexpression of these seven circular RNAs minimally affected medulloblastoma cell proliferation. These findings highlight that differential expression of a gene product may not necessarily elicit an obvious phenotypic impact. Consequently, further analysis is required to determine the possible subtle contributions to the development of this cerebellar tumor. [ABSTRACT FROM AUTHOR]