Optical Coherence Tomography Identifies Visual Pathway Involvement Earlier than Visual Function Tests in Children with MRI-Verified Optic Pathway Gliomas

This study investigates whether optical coherence tomography (OCT) could add useful information in the examination of children with optic pathway glioma (OPG) at high risk of developing vision loss. For this purpose, the relationship between ganglion cell-inner plexiform layer (GC-IPL) thickness and visual function, evaluated with tests of visual acuity (VA) and visual field (VF), as well as tumor site according to magnetic resonance imaging (MRI), were examined in a geographically defined group of children with OPG. Methods: Children aged <18 years with OPG underwent ophthalmic examination including VA, VF (Zeiss HFA perimetry) and OCT imaging (Zeiss Cirrus HD-OCT). Results: Out of 51 patients included, 45 provided 77 eyes with MRI-verified OPG, and 19 patients provided 25 eyes without OPG. Significant correlations were found between GC-IPL, VF and VA (p < 0.001). The GC-IPL pattern loss corresponded in 95% to VF defects and in 92% to MRI findings. Conclusions: Our study indicates that GC-IPL measures could serve as an early marker of vision-threatening changes related to OPG and as a valuable link between MRI and visual function tests. Thinning of GC-IPL and differences in topography between eyes are strong indicators of and predictive of vision loss related to OPG.

Tumor load rather than contrast enhancement is associated with the visual function of children and adolescents with optic pathway glioma – a retrospective Magnetic Resonance Imaging study

Introduction Optic pathway gliomas are often asymptomatic tumors occurring in children with neurofibromatosis type 1 (NF1 + OPG) or sporadically (spOPG). Treatment is usually prompted by visual loss and/or tumor progression on MRI. The aim of this study was to investigate the relationship between visual acuity (VA), tumor growth, and contrast enhancement to provide more distinct indications for the administration of gadolinium-based contrast agents. Methods Tumor load was retrospectively measured and enhancement semi-quantitatively scored on 298 MRIs of 35 patients (63% NF1 + OPG). Spearman rank correlation between tumor load and enhancement was calculated and a linear mixed model used to examine the influence of tumor load and enhancement on corresponding VA tests (LogMAR). Results The optic nerve width in NF1 + OPGs was strongly associated with VA (regression coefficient 0.75; confidence interval 0.61—0.88), but weakly with enhancement (0.06; −0.04—0.15). In spOPGs, tumor volume and optic nerve width were more relevant (0.31; −0.19—0.81 and 0.39; 0.05—0.73) than enhancement (0.09; −0.09—0.27). Conclusions Tumor load measures may be more relevant for the surveillance of optic pathway gliomas than enhancement, given that VA is the relevant outcome parameter. Regular contrast administration should therefore be questioned in these patients.

The diagnostic accuracy and prognostic value of OCT for the evaluation of the visual function in children with a brain tumour: A systematic review

Purpose To systematically review the evidence on the diagnostic accuracy and prognostic value of retinal optical coherence tomography (OCT) to detect visual acuity (VA) or visual field (VF) loss in children with a brain tumour. Methods PubMed, Embase and Cochrane Library databases were searched from inception to February 2021. We included studies evaluating retinal OCT and standard visual function parameters (VA and or VF) in children with a brain tumour. Two authors independently extracted data from each included study. They also assessed the methodological quality of the studies using the QUADAS-2 or QUIPS tool. The diagnostic accuracy of OCT was evaluated with receiver operating characteristic analysis, sensitivity, specificity, positive predictive value and negative predictive value. The prognostic value of OCT was evaluated with predictive measures (odds ratio). Results We included five diagnostic studies, with a total of 186 patients, all diagnosed with optic pathway glioma. No prognostic studies were eligible for inclusion. Included studies evaluated either retinal nerve fiber layer (RNFL) thickness or ganglion cell layer—inner plexiform layer (GCL-IPL) thickness. There was considerable heterogeneity between OCT devices, OCT protocols, visual function parameters and threshold values. Sensitivity and specificity for RNFL thickness measurement ranged from 60.0% to 100.0% and 76.6% to 100%, respectively. For GCL-IPL thickness measurement, area under the curve ranged from 0.91 to 0.98 for different diameters. Conclusion The literature regarding the diagnostic accuracy and prognostic value of OCT parameters in children with a brain tumour is scarce. Due to heterogeneity and a considerable risk of bias of included studies, we cannot draw solid conclusions regarding the accuracy of retinal OCT. Future research should investigate the potential of OCT as diagnostic and prognostic tool for the evaluation of the visual function and detection of visual impairment in children with any type of brain tumour.

Spontaneous Regression of Tumor in an Optic Pathway Glioma Patient With Diencephalic Syndrome: Case Report and Literature Review

Background: Diencephalic syndrome (DS) can cause failure to thrive in pediatrics, which is mostly found in optic pathway gliomas (OPGs) patients. OPGs patients with DS always show a poor outcome. Case presentation: We present the case of an OPG patient with DS who got a spontaneous regression without any treatment. A 6-month-old girl presented with failure to thrive for two months and visual dysfunction with bilateral horizontal nystagmus. MRI demonstrated a 42mm*37mm*36mm enhanced and lobulated lesion located in the sellar region with a clear boundary with surrounding tissues. OPG and DS was diagnosed according to her radiological examination and manifestation. Conservative follow-up was given. There was a spontaneous decrease in tumor size during follow-up. Symptom improves and the patient continues to have a good quality of life despite a moderate dysfunction of her left eye.Conclusions: Conservative observation can be used as a treatment for some OPG patients, body weight may be a marker of the growth of tumor in OPG patients with DS.

BT-4 The treatment history of long-term survivors of Optic Pathway Glioma in Kobe Children’s Hospital

Optic pathway glioma(OPG) is almost recognized in childhood and about 0.01–0.02% of whole brain tumor in Japan. Because of the rare tumor, there are few reports about results of its treatment. In 2021, Guideline of Optic pathway/hypothalamic glioma is indicated from The japan Society for Neuro-Oncology. We retrospectively study 9 cases history of OPG who have treated for more than 5 years from January 2005 to March 2021 in Kobe Children’s Hospital. Cases are 4 boys and 5 girls. Average age at diagnosis is 3.8 years old and average follow up term is 11 years 10 months. They are 4 Pilocytic astrocytoma, 3 Pilomyxoid astrocytoma, and 1 Fibrillary astrocytoma. Al l cases have survived. There are only 2 cases who could be controlled with single series of surgical treatment and chemotherapy. Most cases need several times of resection and chemotherapy and uncontrollable 5 cases required radiological treatment. 2 cases are still under treatment for over 10 years. For OPG, partial resection to control hydrocephalus is recommended and several trial of chemotherapy must be carried out. There exist a few cases who need continuous treatment for long term. The other side, a few cases are uncontrollable those need radiotherapy to manage tumor volume. Because the history of OPG would be long term, we should adjust the treatment plan to environment of patients.

Asthma reduces glioma formation by T cell decorin-mediated inhibition of microglia

To elucidate the mechanisms underlying the reduced incidence of brain tumors in children with Neurofibromatosis type 1 (NF1) and asthma, we leverage Nf1 optic pathway glioma (Nf1OPG) mice, human and mouse RNAseq data, and two different experimental asthma models. Following ovalbumin or house dust mite asthma induction at 4–6 weeks of age (WOA), Nf1OPG mouse optic nerve volumes and proliferation are decreased at 12 and 24 WOA, indicating no tumor development. This inhibition is accompanied by reduced expression of the microglia-produced optic glioma mitogen, Ccl5. Human and murine T cell transcriptome analyses reveal that inhibition of microglia Ccl5 production results from increased T cell expression of decorin, which blocks Ccl4-mediated microglia Ccl5 expression through reduced microglia NFκB signaling. Decorin or NFκB inhibitor treatment of Nf1OPG mice at 4–6 WOA inhibits tumor formation at 12 WOA, thus establishing a potential mechanistic etiology for the attenuated glioma incidence observed in children with asthma.

Optic pathway glioma and the sex association in neurofibromatosis type 1: a single-center study

Background Low-grade optic pathway glioma (OPG) develops in 15–20% of children with neurofibromatosis type 1 (NF1). OPGs are symptomatic in 30–50% and one-third of these require treatment. A few studies have suggested female sex as a risk factor for visual impairment associated with NF1-OPG. This descriptive study investigated the correlation between NF1-OPG growth, sex and visual impairment. Method We based our cross-sectional study on a systematic, retrospective data collection in a NF1 cohort of children and adolescents below 21 years of age followed at Center for Rare Diseases, Aarhus University Hospital, Denmark. For each patient with OPG a medical chart review was performed including demographics, ophthalmological examinations and magnetic resonance imaging (MRI) of OPG. Results Of 176 patients with NF1 (85 females, 91 males), we identified 21 patients with OPG (11.9%) with a preponderance of females, p = 0.184. Eight females (62%) and one male (13%) had visual impairment at the last ophthalmological evaluation. Five out of 21 children with OPG (24%) underwent diagnostic MRI because of clinical findings at the ophthalmological screening. Nine children (43%) had symptoms suggestive of OPG and seven (33%) experienced no OPG-related symptoms before the diagnostic MRI. Of eight children diagnosed with OPG ≤ two years of age, one had visual impairment. Of 13 children diagnosed > two years of age, eight had visual impairment; in each group, four of the children were treated with chemotherapy. The study suggested no correlation between NF1-OPG growth and sex. Conclusion Our data suggest sex as a risk factor for visual impairment, while an OPG diagnose ≤ two years of age was a protective factor for visual impairment. Females with NF1-OPG had a higher prevalence of visual impairment outcome compared to males. Interestingly, our data also suggest a better response to treatment in children with OPG diagnosed ≤ two years of age compared to older children. The findings in our study suggest sex as a potential prognostic factor for visual impairment.

Neuroimaging Features of Optic Nerve Hemangioblastoma Identified by Conventional and Advanced Magnetic Resonance Techniques: A Case Report and Literature Review

Optic nerve hemangioblastoma is a very rare benign tumor with only 39 reported cases by now. It appears to be hyperintense on T2-weighted images with a significant enhancement on contrast scans, which are similar to glioma and meningioma. Due to the lack of specificity in MRI manifestations, optic nerve hemangioblastoma is often misdiagnosed. To provide new insights into differential diagnosis of optic nerve hemangioblastoma, we report for the first time an optic nerve hemangioblastoma case employing advanced magnetic resonance techniques including diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) maps, and magnetic resonance angiography (MRA). In addition, we have collected all reported optic nerve hemangioblastoma cases and reviewed their neuroimaging findings by MRI and angiography. Our results show that solid-type tumor is the dominant form of optic nerve hemangioblastoma and extensive edema is widely observed. These findings are surprisingly contrary to manifestations of cerebellar hemangioblastoma. Besides the structural features, quantitative indexes including ADC and relative cerebral blood volume (rCBV) ratio, which are significantly elevated in cerebellar hemangioblastoma, may also shed a light on the preoperative diagnosis of hemangioblastoma of optic nerve. Finally, we discuss the critical neuroimaging features in the differential diagnosis between optic nerve hemangioblastoma from optic pathway glioma and optic nerve sheath meningioma.