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BioRxiv : the Preprint Server For... Aug 2023Glial cells are essential for proper nervous system development and function. To understand glial development and function, we comprehensively annotated glial cells in a...
Glial cells are essential for proper nervous system development and function. To understand glial development and function, we comprehensively annotated glial cells in a single-cell mRNA-sequencing (scRNAseq) atlas of the developing visual system. This allowed us to study their developmental trajectories, from larval to adult stages, and to understand how specific types of glia diversify during development. For example, neuropil glia that are initially transcriptionally similar in larvae, split into ensheathing and astrocyte-like glia during pupal stages. Other glial types, such as chiasm glia change gradually during development without splitting into two cell types. The analysis of scRNA-seq allowed us to discover that the transcriptome of glial cell bodies can be distinguished from that of their broken processes. The processes contain distinct enriched mRNAs that were validated in vivo. Therefore, we have identified most glial types in the developing optic lobe and devised a computational approach to identify mRNA species that are localized to cell bodies or cellular processes.
PubMed: 37609218
DOI: 10.1101/2023.08.06.552169 -
Frontiers in Neurology 2023Pituitary adenomas are benign tumors of the anterior pituitary gland for which surgery or pharmacological treatment is the primary treatment. When initial treatment...
Pituitary adenomas are benign tumors of the anterior pituitary gland for which surgery or pharmacological treatment is the primary treatment. When initial treatment fails, radiation therapy should be considered. There are several case reports demonstrating radiation-induced vascular injury. We report an adult patient who presented with headache and diplopia for 6 months and a sellar tumor with optic chiasm compression. The patient received transnasal surgery, and the tumor was partially removed, which demonstrated adenoma. Stereotactic radiosurgery (SRS) was arranged. However, owing to progressive tumor growth, the patient received further transnasal surgery and stereotactic radiosurgery (SRS). After 14 years, the patient reported the sudden onset of headache and diplopia, and a ruptured fusiform aneurysm from the left internal carotid artery with pituitary apoplexy was diagnosed. The patient received transarterial embolization of the aneurysm. There were no complications after embolization, and this patient was ambulatory on discharge with blindness in the left eye and cranial nerve palsies. Aneurysm formation may be a complication of SRS, and it may occur after several years. Further research is needed to investigate the pathogenesis of radiosurgery and the development of cerebral aneurysms.
PubMed: 37602248
DOI: 10.3389/fneur.2023.1219372 -
Cell Reports Aug 2023The balance of contralateral and ipsilateral retinogeniculate projections is critical for binocular vision, but the transcriptional programs regulating this process...
The balance of contralateral and ipsilateral retinogeniculate projections is critical for binocular vision, but the transcriptional programs regulating this process remain ill defined. Here we show that the Pou class homeobox protein POU3F1 is expressed in nascent mouse contralateral retinal ganglion cells (cRGCs) but not ipsilateral RGCs (iRGCs). Upon Pou3f1 inactivation, the proportion of cRGCs is reduced in favor of iRGCs, leading to abnormal projection ratios at the optic chiasm. Conversely, misexpression of Pou3f1 in progenitors increases the production of cRGCs. Using CUT&RUN and RNA sequencing in gain- and loss-of-function assays, we demonstrate that POU3F1 regulates expression of several key members of the cRGC gene regulatory network. Finally, we report that POU3F1 is sufficient to induce RGC-like cell production, even in late-stage retinal progenitors of Atoh7 knockout mice. This work uncovers POU3F1 as a regulator of the cRGC transcriptional program, opening possibilities for optic nerve regenerative therapies.
PubMed: 37590135
DOI: 10.1016/j.celrep.2023.112985 -
Journal of Neurosurgery. Case Lessons Aug 2023A glomus vagale tumor is an infrequent paraganglioma primarily characterized by auditory symptoms, cranial nerve involvement, or autonomic symptoms. However, visual...
BACKGROUND
A glomus vagale tumor is an infrequent paraganglioma primarily characterized by auditory symptoms, cranial nerve involvement, or autonomic symptoms. However, visual involvement is not commonly observed, and to date, no cases have been reported in the literature.
OBSERVATIONS
The case involves a 62-year-old female patient with a history of right carotid body tumor resection. She presented to the emergency department with a sudden decrease in visual acuity and bitemporal hemianopsia, accompanied by a left parietal headache. Initial brain magnetic resonance imaging (MRI) revealed a pituitary macroadenoma, which was completely resected. However, postoperatively, the patient developed left amaurosis. Subsequent brain MRI showed the presence of hemostatic material mixed with blood in the sellar region, causing displacement of the optic chiasm. A repeat intervention was performed, identifying bleeding from both cavernous sinuses. Head and neck angiography demonstrated a right glomus vagale tumor with abundant blood drainage into the right cavernous sinus. Embolization of the glomus vagale tumor was performed, resulting in no further bleeding and improvement of symptoms.
LESSONS
The aim of this case report is to describe a rare occurrence of bilateral visual disturbances caused by bleeding in both cavernous sinuses due to venous hypertension caused by a right glomus vagale tumor.
PubMed: 37581586
DOI: 10.3171/CASE23145 -
Geometric evaluations of CT and MRI based deep learning segmentation for brain OARs in radiotherapy.Physics in Medicine and Biology Aug 2023Deep-learning auto-contouring (DL-AC) promises standardisation of organ-at-risk (OAR) contouring, enhancing quality and improving efficiency in radiotherapy. No...
Deep-learning auto-contouring (DL-AC) promises standardisation of organ-at-risk (OAR) contouring, enhancing quality and improving efficiency in radiotherapy. No commercial models exist for OAR contouring based on brain magnetic resonance imaging (MRI). We trained and evaluated computed tomography (CT) and MRI OAR autosegmentation models in RayStation. To ascertain clinical usability, we investigated the geometric impact of contour editing before training on model quality.Retrospective glioma cases were randomly selected for training (= 32, 47) and validation (= 9, 10) for MRI and CT, respectively. Clinical contours were edited using international consensus (gold standard) based on MRI and CT. MRI models were trained (i) using the original clinical contours based on planning CT and rigidly registered T1-weighted gadolinium-enhanced MRI (MRIu), (ii) as (i), further edited based on CT anatomy, to meet international consensus guidelines (MRIeCT), and (iii) as (i), further edited based on MRI anatomy (MRIeMRI). CT models were trained using: (iv) original clinical contours (CTu) and (v) clinical contours edited based on CT anatomy (CTeCT). Auto-contours were geometrically compared to gold standard validation contours (CTeCT or MRIeMRI) using Dice Similarity Coefficient, sensitivity, and mean distance to agreement. Models' performances were compared using paired Student's t-testing.The edited autosegmentation models successfully generated more segmentations than the unedited models. Paired t-testing showed editing pituitary, orbits, optic nerves, lenses, and optic chiasm on MRI before training significantly improved at least one geometry metric. MRI-based DL-AC performed worse than CT-based in delineating the lacrimal gland, whereas the CT-based performed worse in delineating the optic chiasm. No significant differences were found between the CTeCT and CTu except for optic chiasm.T1w-MRI DL-AC could segment all brain OARs except the lacrimal glands, which cannot be easily visualized on T1w-MRI. Editing contours on MRI before model training improved geometric performance. MRI DL-AC in RT may improve consistency, quality and efficiency but requires careful editing of training contours.
Topics: Humans; Deep Learning; Head and Neck Neoplasms; Retrospective Studies; Radiotherapy Planning, Computer-Assisted; Organs at Risk; Brain; Tomography, X-Ray Computed; Magnetic Resonance Imaging; Image Processing, Computer-Assisted
PubMed: 37579753
DOI: 10.1088/1361-6560/acf023 -
Radiation Oncology (London, England) Aug 2023Children with brain tumors are at high risk of neurocognitive decline after radiotherapy (RT). However, there is a lack of studies on how RT doses to organs at risk...
BACKGROUND
Children with brain tumors are at high risk of neurocognitive decline after radiotherapy (RT). However, there is a lack of studies on how RT doses to organs at risk (OARs) impacts neurocognition. The aim of this study was to examine dose-risk relationships for mean RT dose to different brain structures important for neurocognitive networks. We explored previously established OARs and potentially new OARs.
METHODS
A sample of 44 pediatric brain tumor survivors who had received proton and/or photon RT were included. Correlations between mean RT doses to OARs and IQ were analyzed. Previously established OARs were cochleae, optic chiasm, optic nerve, pituitary gland, hypothalamus, hippocampus and pons. Potential new OARs for RT-induced neurocognitive decline were cerebellum, vermis and thalamus.
RESULTS
Mean RT dose to different OARs correlated with several IQ subtests. Higher mean RT dose to cochleae, optic nerve, cerebellum, vermis and pons was correlated with lower performance on particularly full-scale IQ (FIQ), Perceptual Reasoning (PRI), Working Memory (WMI) and Processing Speed Index (PSI). Higher mean RT dose to hippocampus correlated with lower performance on processing speed and working memory. For those receiving whole brain RT (WBRT), higher mean RT dose to the pituitary gland correlated with lower performance on working memory.
CONCLUSION
A high dose-risk correlation was found between IQ subtests and mean RT dose in established and potential new OARs. Thus, in the lack of validated dose constraints for vulnerable brain structures, a parsimonious approach in RT planning should be considered to preserve neurocognitive networks.
Topics: Child; Humans; Organs at Risk; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Brain; Brain Neoplasms; Radiotherapy, Intensity-Modulated
PubMed: 37568180
DOI: 10.1186/s13014-023-02324-2 -
Journal of Medical Cases Jul 2023Wolfram syndrome (WS) is a rare neurodegenerative and genetic disorder, also known by the synonym DIDMOAD, which stands for diabetes insipidus (DI), childhood-onset...
Wolfram syndrome (WS) is a rare neurodegenerative and genetic disorder, also known by the synonym DIDMOAD, which stands for diabetes insipidus (DI), childhood-onset diabetes mellitus (DM), optic atrophy (OA), and deafness (D). We present a case of a 25-year-old diabetic patient, using insulin for 15 years, who had increasing polyuria and polydipsia, along with progressive hearing and vision loss. Laboratory tests revealed elevated hemoglobin A1c (HbA1c) and blood sugar levels. Optic nerve, optic chiasm, pons, and brain stem atrophy was seen on magnetic resonance imaging (MRI) of brain. After workup, a diagnosis of DI was made. Once the diagnosis was reached, treatment with subcutaneous insulin and nasal desmopressin improved patient's symptoms. In juvenile diabetic patients presenting with new onset or worsening polyuria and polydipsia, the possibility of WS should be considered. Early diagnosis and initiation of appropriate management leads to improved outcomes and the quality of life.
PubMed: 37560547
DOI: 10.14740/jmc4128 -
Frontiers in Neuroscience 2023The clinical-radiological and biological overlap of the spectrum of pediatric demyelinating disorders makes the diagnostic process of a child with an acquired...
The clinical-radiological and biological overlap of the spectrum of pediatric demyelinating disorders makes the diagnostic process of a child with an acquired demyelinating syndrome truly challenging. We present a 9-year-old girl with subacute symptoms of severe decrease in bilateral visual acuity and gait ataxia. An urgent MRI showed inflammatory-demyelinating lesions affecting the periaqueductal gray matter, the cerebellar hemispheres, the area postrema as well as both optic nerves and chiasm. Likewise, multisegmental involvement of the cervical and dorsal spinal cord was found, with short and peripheral lesions. Anti myelin oligodendrocyte glycoprotein (MOG) antibodies (Abs) were positive in cerebrospinal fluid (CSF) and weakly in serum. Oligoclonal bands (OB) were positive in CSF. Based on all this, the diagnosis of MOG antibody disease (MOGAD) with a neuromyelitis optica spectrum disorder (NMOSD)-like picture was made. Given the good clinical and radiological recovery after the acute phase treatment, and that anti MOG Abs became negative, it was decided to keep the patient without specific treatment. However, during follow-up, while the patient was asymptomatic, a control brain MRI showed the appearance of new lesions with morphology and topography suggestive of multiple sclerosis (MS). This, added to the presence of OB, made the diagnosis of pediatric-onset MS (POMS) likely. Immunosuppressive treatment was restarted with a good response since then. Unlike adult-onset MS, children with POMS may usually not have entirely typical clinical and radiological features at presentation. In many cases, the time factor and close clinical and radiological monitoring could be critical to make an accurate diagnosis.
PubMed: 37547139
DOI: 10.3389/fnins.2023.1205065