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Current Opinion in Ophthalmology Sep 2019Optic pathway gliomas are low-grade neoplasms that affect the precortical visual pathway of children and adolescents. They can affect the optic nerve, optic chiasm,... (Review)
Review
PURPOSE OF REVIEW
Optic pathway gliomas are low-grade neoplasms that affect the precortical visual pathway of children and adolescents. They can affect the optic nerve, optic chiasm, optic tracts and radiations and can either be sporadic or associated with neurofibromatosis type one. Gliomas isolated to the optic nerve (ONG) represent a subgroup of optic pathway gliomas, and their treatment remains controversial. New developments in ONG treatment have emerged in recent years, and it is necessary for clinicians to have a current understanding of available therapies.
RECENT FINDINGS
The current review of the literature covers the background of and recent developments in ONG treatment, with a focus on standard chemotherapy, new molecularly targeted therapies, radiation therapy and surgical resection and debulking.
SUMMARY
Although standard chemotherapy remains the mainstay of ONG treatment, newer molecularly targeted therapies such as mitogen-activated protein kinase kinase inhibitors and bevacizumab represent a promising new treatment modality, and clinical studies are ongoing.
Topics: Adolescent; Antineoplastic Agents; Child; Female; Humans; Male; Molecular Targeted Therapy; Ophthalmologic Surgical Procedures; Optic Chiasm; Optic Nerve Glioma; Optic Nerve Neoplasms; Optic Tract; Radiotherapy
PubMed: 31246635
DOI: 10.1097/ICU.0000000000000587 -
Frontiers in Medicine 2022Optic tract lesions (OTL) are often difficult to diagnose. We suggest an algorithm to simplify the often-challenging diagnosis of OTL. Clinical and imaging data were...
Optic tract lesions (OTL) are often difficult to diagnose. We suggest an algorithm to simplify the often-challenging diagnosis of OTL. Clinical and imaging data were retrospectively collected from the electronic files of 6 patients diagnosed with OTL at a tertiary medical center in 2016-2020. The series included 4 children and 2 adults with an OTL caused by a glioma ( = 5) or motor vehicle accident ( = 1). Magnetic resonance imaging (MRI) revealed a suprasellar glioma involving the chiasm and tract alone (n = 1) and the ipsilateral optic nerve (n = 2) and only optic tract (3). Perimetry showed incongruent homonymous hemianopia in 3 patients. In two patients, perimetry could only be performed in one eye, and demonstrated hemianopia. In one patient perimetry was unreliable. Fundus examination revealed bow-tie atrophy in all patients. On optical coherence tomography (OCT) of the peripapillary retinal nerve fiber layer (RNFL) horizontal thinning was observed in the contralateral eye ( = 6). By presenting the information in a predefined order-visual field damage, OCT RNFL thickness, and MRI-the diagnosis could be easily reached even in children, and when other structures like the chiasm were involved. Fundus photographs easily detect bow tie atrophy in children. Systematic presentation of the data in a predefined order can ease the diagnostic process of OTLs.
PubMed: 36388882
DOI: 10.3389/fmed.2022.1029829 -
Operative Neurosurgery (Hagerstown, Md.) Jul 2022In surgeries involving resection of the amygdala, despite clear relations established with the medial, lateral, anterior, posterior, and inferior segments, the upper...
BACKGROUND
In surgeries involving resection of the amygdala, despite clear relations established with the medial, lateral, anterior, posterior, and inferior segments, the upper limit remains controversial. The optic tract (OT) has been anatomically considered as a good landmark immediately inferior to the striatopallidal region. This anatomic structure has barely been explored by microsurgical study, generating uncertainty about the exact relationship with the surrounding structures.
OBJECTIVE
To describe the OT in its entire length through microsurgical study, showing its superior, inferior, medial, and lateral relationships and highlighting its value as a landmark in superior amygdala resection.
METHODS
Microsurgical anatomic dissection of the OT, from its origin in the chiasm to the lateral geniculate nucleus was performed in 8 alcohol-fixed human hemispheres, showing its different segments and relations. Photographs were taken from different angles to facilitate surgical orientation.
RESULTS
We performed a dissection of the OT, showing its position relative to caudate and hippocampal formations. We exposed the structures related to the OT superiorly (striatopallidal region and superior caudate fasciculus), inferiorly (head of the hippocampus, amygdala, anterior choroidal artery, perforating artery branch of the anterior choroidal artery, terminal stria, and basal vein), medially (internal capsule and midbrain), and laterally (temporal stem [uncinate and inferior fronto-occipital fascicle], anterior perforated substance, and superior caudate fasciculus).
CONCLUSION
To date, there is a paucity of articles describing the anatomy of the OT from a neurosurgery perspective. In this study, we describe the microsurgical anatomic path of the OT, as a reliable upper limit landmark for amygdala resection.
Topics: Amygdala; Cerebral Arteries; Cerebral Veins; Humans; Optic Tract; White Matter
PubMed: 35486869
DOI: 10.1227/ons.0000000000000208 -
Stroke Nov 2021Damage to the adult primary visual cortex (V1) causes vision loss in the contralateral visual hemifield, initiating a process of trans-synaptic retrograde degeneration....
BACKGROUND AND PURPOSE
Damage to the adult primary visual cortex (V1) causes vision loss in the contralateral visual hemifield, initiating a process of trans-synaptic retrograde degeneration. The present study examined functional implications of this process, asking if degeneration impacted the amount of visual recovery attainable from visual restoration training in chronic patients, and if restoration training impacted optic tract (OT) shrinkage.
METHODS
Magnetic resonance imaging was used to measure OT volumes bilaterally in 36 patients with unilateral occipital stroke. From OT volumes, we computed laterality indices (LI), estimating the stroke-induced OT shrinkage in each case. A subset of these chronic patients (n=14, 13±6 months poststroke) underwent an average of nearly 1 year of daily visual restoration training, which repeatedly stimulated vision in their blind field. The amount of visual field recovery was quantified using Humphrey perimetry, and post training magnetic resonance imaging was used to assess the impact of training on OT shrinkage.
RESULTS
OT LI was correlated with time since stroke: it was close to 0 (no measurable OT shrinkage) in subacute participants (<6 months poststroke) while chronic participants (>6 months poststroke) exhibited LI >0, but with significant variability. Visual training did not systematically alter LI, but chronic patients with baseline LI≈0 (no OT shrinkage) exhibited greater visual field recovery than those with LI>0.
CONCLUSIONS
Unilateral OT shrinkage becomes detectable with magnetic resonance imaging by ≈7 months poststroke, albeit with significant interindividual variability. Although visual restoration training did not alter the amount of degeneration already sustained, OT shrinkage appeared to serve as a biomarker of the potential for training-induced visual recovery in chronic cortically blind patients.
Topics: Adult; Aged; Blindness, Cortical; Female; Functional Laterality; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Optic Tract; Primary Visual Cortex; Recovery of Function; Stroke; Stroke Rehabilitation
PubMed: 34266305
DOI: 10.1161/STROKEAHA.121.034738 -
Japanese Journal of Clinical Oncology Apr 2023the advent of BRAF inhibitors for preoperative treatment of craniopharyngioma has necessitated the identification of BRAFV600E status. Hence, we investigated predictors...
OBJECTIVE
the advent of BRAF inhibitors for preoperative treatment of craniopharyngioma has necessitated the identification of BRAFV600E status. Hence, we investigated predictors of BRAFV600E mutation in craniopharyngiomas.
METHODS
this retrospective study utilized data from 30 patients who were newly diagnosed with craniopharyngioma between 2011 and 2021. Magnetic resonance imaging (MRI) and computed tomography were performed within 1 week prior to surgery. Genetic analysis for BRAF mutation was performed using the Oncomine next-generation sequencing panel or Sanger sequencing. The relationship between BRAF mutation and demographic data, endocrinological function and tumour characteristics on imaging was assessed.
RESULTS
tumour tissue carried the BRAFV600E mutation in nine patients. There was no significant difference in age, sex, or presence of hormonal dysfunction amongst patients with and without the BRAFV600E mutation in the tumour. Most tumours with the BRAFV600E mutation were histologically categorized as papillary craniopharyngioma (P = 0.0005), and were solid (P = 0.0002) and supra-diaphragmatic (P = 0.0033) on MRI. BRAFV600E tumours were more frequently associated with optic tract edema than wild-type tumour s (55.6 vs. 0%, P = 0.0009) and all tumour s with optic tract edema carried the BRAFV600E mutation. Optic tract edema was not associated with tumour volume, cysts, or preoperative pituitary function.
CONCLUSIONS
in craniopharyngiomas, the presence of optic tract edema can predict the presence of BRAFV600E mutation with a positive predictive value of 100%. The finding should be verified in larger prospective cohorts and multivariate regression analysis.
Topics: Humans; Craniopharyngioma; Pituitary Neoplasms; Optic Tract; Proto-Oncogene Proteins B-raf; Retrospective Studies; Prospective Studies; Mutation
PubMed: 36702745
DOI: 10.1093/jjco/hyad003 -
Frontiers in Aging Neuroscience 2022To investigate the association between degeneration of retinal structure and shrinkage of the optic tract in patients after thalamic stroke.
OBJECTIVES
To investigate the association between degeneration of retinal structure and shrinkage of the optic tract in patients after thalamic stroke.
MATERIALS AND METHODS
Patients with unilateral thalamic stroke were included. Structural magnetic resonance imaging (MRI) and optical coherence tomography (OCT) were performed to obtain parameters of optic tract shrinkage (lateral index) and retina structural thickness (retinal nerve fiber layer, RNFL; peripapillary retinal nerve fiber layer, pRNFL; ganglion cell-inner plexiform layer, GCIP), respectively. Visual acuity (VA) examination under illumination was conducted using Snellen charts and then converted to the logarithm of the minimum angle of resolution (LogMAR). We investigated the association between LI and OCT parameters and their relationships with VA.
RESULTS
A total of 33 patients and 23 age-sex matched stroke-free healthy controls were enrolled. Patients with thalamic stroke showed altered LI compared with control participants ( = 0.011) and a significantly increased value of LI in the subgroup of disease duration more than 6 months ( = 0.004). In these patients, LI were significantly associated with pRNFL thickness (β = 0.349, 95% confidence interval [CI]: 0.134-0.564, = 0.002) after adjusting for confounders (age, sex, hypertension, diabetes, dyslipidemia, and lesion volume). LI and pRNFL were both significantly associated with VA in all patients (LI: β = -0.275, 95% CI: -0.539 to -0.011, = 0.041; pRNFL: β = -0.023, 95% CI: -0.046 to -0.001, = 0.040) and in subgroup of disease duration more than 6 months (LI: β = -0.290, 95% CI: -0.469 to -0.111, = 0.002; pRNFL: β = -0.041, 95% CI: -0.065 to -0.017, = 0.003).
CONCLUSION
Shrinkage of the optic tract can be detected in patients with thalamic stroke, especially after 6 months of stroke onset. In these patients, the extent of optic tract atrophy is associated with pRNFL thickness, and they are both related to visual acuity changes.
PubMed: 35966790
DOI: 10.3389/fnagi.2022.942438 -
Journal of AAPOS : the Official... Aug 2015We report a case of isolated unilateral optic tract hypoplasia, described only twice previously. Bilateral optic disk hypoplasia was seen ophthalmoscopically and visual...
We report a case of isolated unilateral optic tract hypoplasia, described only twice previously. Bilateral optic disk hypoplasia was seen ophthalmoscopically and visual field studies showed an incongruous right homonymous hemianopia. Magnetic resonance imaging showed bilateral hypoplasia of both optic nerves and the left optic tract. Spectral domain optical coherence tomography mapping correlated well with the visual field studies.
Topics: Child, Preschool; Eye Abnormalities; Hemianopsia; Humans; Magnetic Resonance Imaging; Male; Ophthalmoscopy; Optic Disk; Optic Nerve; Optic Tract; Tomography, Optical Coherence; Visual Acuity; Visual Fields
PubMed: 26228965
DOI: 10.1016/j.jaapos.2015.03.018 -
The Canadian Journal of Neurological... Mar 2023
Topics: Humans; Metronidazole; Optic Tract; Optic Nerve Diseases; Optic Nerve; Neuroimaging
PubMed: 35190000
DOI: 10.1017/cjn.2022.21