RESUMEN
OBJECTIVE: Sporadic optic chiasmatic-hypothalamic gliomas (OCHGs), though histologically low-grade tumors, manifest as aggressive neoplasms radiologically, leading to difficulty in diagnosis. Molecular alterations of the BRAF gene are detectable in a majority of sporadic OCHGs. The purpose of our study was to elucidate the characteristic imaging features of sporadic OCHGs and to investigate whether imaging phenotypes could potentially correlate with specific BRAF gene alterations associated with these tumors. METHODS: We retrospectively reviewed baseline magnetic resonance (MR) images and medical records of 26 patients with histopathologically proven sporadic OCHGs. MR imaging (MRI) features were systematically evaluated. Statistical analysis was performed to determine whether there was a significant association between imaging findings and BRAF molecular alterations. RESULTS: Twenty-two cases (84.6%) presented with solid-cystic masses, while four (15.4%) presented with purely solid lesions. In all 26 cases, the solid component revealed central necrosis; there was minimal necrosis in 11 cases (42.3%), moderate in 8 (30.7%), and marked in 7 (26.9%). The presence of multiple cysts (>4) and minimal necrosis showed a significant association with BRAFV600E mutation (P < 0.005). Marked necrosis in the solid component significantly correlated with BRAF wild genotype (P < 0.001). The presence of a single peripheral cyst significantly correlated with BRAF fusion (P = 0.04). CONCLUSION: Sporadic OCHGs have a distinctive appearance on imaging. The solid-cystic composition coupled with varying degrees of central necrosis are clues to the radiological diagnosis of this entity and can facilitate early recognition in clinical practice. Imaging could potentially serve as a non-invasive predictor of the BRAF alteration status, thereby serving as a prognostic marker and guiding personalized management.
Asunto(s)
Imagen por Resonancia Magnética , Proteínas Proto-Oncogénicas B-raf , Humanos , Proteínas Proto-Oncogénicas B-raf/genética , Femenino , Masculino , Estudios Retrospectivos , Adulto , Neoplasias Hipotalámicas/genética , Neoplasias Hipotalámicas/diagnóstico por imagen , Neoplasias Hipotalámicas/patología , Mutación , Glioma/genética , Glioma/diagnóstico por imagen , Glioma/patología , Adolescente , Niño , Persona de Mediana Edad , Quiasma Óptico/diagnóstico por imagen , Quiasma Óptico/patología , Adulto Joven , Preescolar , Glioma del Nervio Óptico/genética , Glioma del Nervio Óptico/diagnóstico por imagen , Glioma del Nervio Óptico/patologíaRESUMEN
Neuro-ophthalmic evaluation is a crucial component of the diagnostic and prognostic assessment of pituitary disease and compressive chiasmopathy, and can inform the timing of vision-restoring tumour resection surgery. The most common disease affecting the pituitary with neuro-ophthalmic implications are pituitary adenomas. Neuro-ophthalmic manifestations include decreased vision, abnormal colour vision and impaired visual field or diplopia. The recognition of these syndromes is critical to achieve early diagnosis and treatment and to improve prognosis. The pattern of vision loss in chiasmal compression is determined by the anatomical relationship between the pituitary lesion and optic chiasm, and potential visual field defects include bitemporal deficits, junctional scotomas, monocular cecocentral defects, and incongruous homonymous hemianopias. Rarer neuro-ophthalmic manifestations of pituitary disease include ophthalmoplegia, nystagmus, and obstructive hydrocephalus. There is growing evidence that demonstrates the strong diagnostic utility of optical coherence tomography (OCT) parameters in detecting the presence of compressive chiasmopathy, as well as the prognostic ability to predict the rate and degree of visual recovery following decompression surgery. Long-term neuro-ophthalmic monitoring is critical for detecting delayed vision loss following resection surgery, which may represent tumour recurrence or secondary complications.
Asunto(s)
Quiasma Óptico , Humanos , Quiasma Óptico/patología , Enfermedades de la Hipófisis/diagnóstico , Enfermedades de la Hipófisis/terapia , Tomografía de Coherencia Óptica , Trastornos de la Visión/diagnóstico , Trastornos de la Visión/etiología , Trastornos de la Visión/fisiopatología , Neoplasias Hipofisarias/diagnóstico , Neoplasias Hipofisarias/terapia , Neoplasias Hipofisarias/complicaciones , Campos Visuales/fisiologíaRESUMEN
BACKGROUND AND PURPOSE: Morning glory disc anomaly (MGDA) is a congenital malformation characterized by a funnel-shaped optic disc excavation with radiating vessels and a central glial tuft. Imaging is essential to evaluate associated cephalocele and steno-occlusive vasculopathy. The goal of this study was to assess optic nerve, chiasmatic, and sphenoid bone morphology in MGDA. MATERIALS AND METHODS: This retrospective study examined all subjects with funduscopically confirmed MGDA diagnosed and imaged with brain MR imaging between 2008 and 2023. RESULTS: Thirty-two children met inclusion criteria. Ocular involvement was unilateral in 29 subjects and bilateral in 3. Segmental optic nerve enlargement ipsilateral to the MGDA was seen in 21 subjects, with 3 also demonstrating a segmental reduction in the size of the ipsilateral optic nerve. Segmental reduction in the size of the ipsilateral optic nerve was present in 3 additional subjects, one with bilateral MGDA. The optic chiasm appeared asymmetrically thickened in 21 subjects, often with deformity. The optic nerves appeared normal in signal intensity in all subjects, with faint peripheral chiasmatic enhancement in 4 of 20 patients who received contrast. Optic nerve findings were stable in 15 subjects with multiple examinations. A persistent craniopharyngeal canal was identified in 17 subjects with sphenoid cephalocele in 1 and mild inferior pituitary gland displacement in 4. Tubular or nodular nasopharyngeal lesions were seen in 10 subjects. One subject had an off-midline sphenoid bone cleft, midbrain deformity, and abnormal thickening of and enhancement around the left oculomotor nerve; the oculomotor nerve finding was present in 1 additional patient. CONCLUSIONS: MGDA often manifests with ipsilateral optic nerve thickening, leading to a potential misdiagnosis as optic glioma. MGDA is also commonly associated with a persistent craniopharyngeal canal with variable pituitary gland and infundibular deformity, cephalocele, and tubular or nodular nasopharyngeal lesions.
Asunto(s)
Imagen por Resonancia Magnética , Disco Óptico , Humanos , Femenino , Masculino , Estudios Retrospectivos , Niño , Imagen por Resonancia Magnética/métodos , Disco Óptico/diagnóstico por imagen , Disco Óptico/anomalías , Disco Óptico/patología , Preescolar , Adolescente , Lactante , Fenotipo , Hueso Esfenoides/diagnóstico por imagen , Hueso Esfenoides/anomalías , Hueso Esfenoides/patología , Quiasma Óptico/diagnóstico por imagen , Quiasma Óptico/anomalías , Quiasma Óptico/patología , Anomalías del Ojo/diagnóstico por imagen , Anomalías del Ojo/patologíaRESUMEN
A 27-year-old woman with a known suprasellar dermoid cyst and stable idiopathic intracranial hypertension (IIH) presented with new monocular vision change and new-onset headaches. Formal visual field testing accurately identified progressive chiasmal compression due to her suprasellar dermoid cyst before radiographic change was appreciable on magnetic resonance imaging. Accurate interpretation of her visual field findings avoided the common pitfall of attributing new visual symptoms to her IIH diagnosis. This case highlights the value of recognizing visual field changes that localize to the chiasm even in patients with history of other ophthalmologic conditions.
Asunto(s)
Quiste Dermoide , Escotoma , Humanos , Femenino , Adulto , Quiste Dermoide/diagnóstico por imagen , Quiste Dermoide/complicaciones , Quiste Dermoide/cirugía , Escotoma/etiología , Escotoma/diagnóstico por imagen , Imagen por Resonancia Magnética , Quiasma Óptico/diagnóstico por imagen , Quiasma Óptico/patología , Seudotumor Cerebral/diagnóstico por imagen , Seudotumor Cerebral/complicacionesRESUMEN
OBJECTIVE: Tumors located in the retrochiasmatic region with extension to the third ventricle might be difficult to access when the pituitary-chiasmatic corridor is narrow. Similarly, tumor extension into the interpeduncular and retrosellar space poses a major surgical challenge. Pituitary transposition techniques have been developed to gain additional access. However, when preoperative pituitary function is already impaired or the risk of postoperative panhypopituitarism (PH) is considered to be particularly high, removal of the pituitary gland (PG) might be the preferred option to increase the working corridor. The aim of this study was to describe the relevant surgical anatomy, operative steps, and clinical experience with the endoscopic endonasal pituitary sacrifice (EEPS) and transsellar approach. METHODS: This study comprised anatomical dissections to highlight the relevant surgical steps and a retrospective case series reporting clinical characteristics, indications, and outcomes of patients who underwent EEPS. The surgical technique is as follows: both lateral opticocarotid recesses are exposed laterally, the limbus sphenoidale superiorly, and the sellar floor inferiorly. After opening the dura, the PG is detached circumferentially and mobilized off the medial walls of the cavernous sinuses. The descending branches of the superior hypophyseal artery are coagulated, and the stalk is transected. After removal of the PG, drilling of the dorsum sellae and bilateral posterior clinoidectomies are performed to gain access to the hypothalamic region, interpeduncular, and prepontine cisterns. RESULTS: From 2018 to 2023, 11 patients underwent EEPS. The cohort comprised mostly tuberoinfundibular craniopharyngiomas (n = 8, 73%). Seven (64%) patients had partial or complete anterior PG dysfunction preoperatively, while 4 (36%) had preoperative diabetes insipidus. Because of the specific tumor configuration, the chance of preserving endocrine function was estimated to be very low in patients with intact function. The main reasons for pituitary sacrifice were impaired visibility and surgical accessibility to the retrochiasmatic and retrosellar spaces. Gross-total tumor resection was achieved in 10 (91%) patients and near-total resection in 1 (9%) patient. Two (18%) patients experienced a postoperative CSF leak, requiring surgical revision. CONCLUSIONS: When preoperative pituitary function is already impaired or the risk for postoperative PH is considered particularly high, the EEPS and transsellar approach appears to be a feasible surgical option to improve visibility and accessibility to the retrochiasmatic hypothalamic and retrosellar spaces, thus increasing tumor resectability.
Asunto(s)
Hipófisis , Neoplasias Hipofisarias , Humanos , Neoplasias Hipofisarias/cirugía , Neoplasias Hipofisarias/patología , Masculino , Femenino , Persona de Mediana Edad , Adulto , Estudios Retrospectivos , Hipófisis/cirugía , Hipófisis/patología , Hipófisis/anatomía & histología , Anciano , Neuroendoscopía/métodos , Procedimientos Neuroquirúrgicos/métodos , Quiasma Óptico/cirugía , Quiasma Óptico/patología , Adulto Joven , Craneofaringioma/cirugía , Craneofaringioma/patología , Silla Turca/cirugía , Silla Turca/patología , Cirugía Endoscópica por Orificios Naturales/métodos , Resultado del Tratamiento , Adenoma/cirugía , Adenoma/patologíaRESUMEN
BACKGROUND: Optic neuritis (ON) is a common feature of inflammatory demyelinating diseases (IDDs) such as multiple sclerosis (MS), aquaporin 4-antibody neuromyelitis optica spectrum disorder (AQP4 + NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). However, the involvement of the optic chiasm (OC) in IDD has not been fully investigated. AIMS: To examine OC differences in non-acute IDD patients with (ON+) and without ON (ON-) using magnetisation transfer ratio (MTR), to compare differences between MS, AQP4 + NMOSD and MOGAD and understand their associations with other neuro-ophthalmological markers. METHODS: Twenty-eight relapsing-remitting multiple sclerosis (RRMS), 24 AQP4 + NMOSD, 28 MOGAD patients and 32 healthy controls (HCs) underwent clinical evaluation, MRI and optical coherence tomography (OCT) scan. Multivariable linear regression models were applied. RESULTS: ON + IDD patients showed lower OC MTR than HCs (28.87 ± 4.58 vs 31.65 ± 4.93; p = 0.004). When compared with HCs, lower OC MTR was found in ON + AQP4 + NMOSD (28.55 ± 4.18 vs 31.65 ± 4.93; p = 0.020) and MOGAD (28.73 ± 4.99 vs 31.65 ± 4.93; p = 0.007) and in ON- AQP4 + NMOSD (28.37 ± 7.27 vs 31.65 ± 4.93; p = 0.035). ON+ RRMS had lower MTR than ON- RRMS (28.87 ± 4.58 vs 30.99 ± 4.76; p = 0.038). Lower OC MTR was associated with higher number of ON (regression coefficient (RC) = -1.15, 95% confidence interval (CI) = -1.819 to -0.490, p = 0.001), worse visual acuity (RC = -0.026, 95% CI = -0.041 to -0.011, p = 0.001) and lower peripapillary retinal nerve fibre layer (pRNFL) thickness (RC = 1.129, 95% CI = 0.199 to 2.059, p = 0.018) when considering the whole IDD group. CONCLUSION: OC microstructural damage indicates prior ON in IDD and is linked to reduced vision and thinner pRNFL.
Asunto(s)
Acuaporina 4 , Autoanticuerpos , Esclerosis Múltiple Recurrente-Remitente , Glicoproteína Mielina-Oligodendrócito , Neuromielitis Óptica , Quiasma Óptico , Tomografía de Coherencia Óptica , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Acuaporina 4/inmunología , Autoanticuerpos/sangre , Imagen por Resonancia Magnética , Esclerosis Múltiple Recurrente-Remitente/diagnóstico por imagen , Esclerosis Múltiple Recurrente-Remitente/inmunología , Esclerosis Múltiple Recurrente-Remitente/patología , Glicoproteína Mielina-Oligodendrócito/inmunología , Neuromielitis Óptica/inmunología , Neuromielitis Óptica/diagnóstico por imagen , Neuromielitis Óptica/patología , Quiasma Óptico/patología , Quiasma Óptico/diagnóstico por imagen , Neuritis Óptica/inmunología , Neuritis Óptica/diagnóstico por imagen , Neuritis Óptica/patología , Adulto JovenRESUMEN
BACKGROUND: Differential diagnosis of hypothalamic-optic chiasmatic gliomas (HOCGs) and craniopharyngiomas on magnetic resonance imaging (MRI) can be quite challenging. PURPOSE: To compare the MRI features of HOCGs and cranipharyngiomas. MATERIAL AND METHODS: Patients diagnosed with HOCG or craniopharyngioma in histopathological evaluation between 2012 and 2022 and who underwent preoperative contrast-enhanced brain MRI were included. Various MRI features were retrospectively evaluated for each lesion: T2-weighted imaging and fluid attenuation inversion recovery hyperintensity, calcification, cystic change, T1-weighted (T1W) imaging hyperintensity of the cystic component, hemorrhage, involvement of sellar, suprasellar or other adjacent structures, lobulated appearance, presence of hydrocephalus, and contrast enhancement pattern. Apparent diffusion coefficient (ADC) values were also evaluated and compared. RESULTS: Among 38 patients included, 13 (34%) had HOCG and 25 (66%) had craniopharyngioma. Craniopharyngiomas had a significantly higher rate of cystic changes, calcification, and T1W imaging hyperintensity of the cystic component than HOCGs (P <0.05). Of HOCGs, 92% had chiasm involvement, 23% had optic nerve involvement, and 31% had brain stem involvement. On the other hand, chiasm involvement was observed in 8% of craniopharyngiomas, but none had optic nerve and/or brain stem involvement (P <0.05). While 62% (8/13) of HOCGs had diffuse homogeneous enhancement, 80% (20/25) of craniopharyngiomas had a diffuse heterogeneous enhancement pattern. Mean ADC values were significantly higher in craniopharyngiomas compared to HOCGs (2.1 vs. 1.6 ×10-3mm2/s, P <0.05). CONCLUSION: Although some neuroimaging findings may overlap, features such as presence of cyst and calcification, brain stem and optic pathway involvement, different enhancement patterns, and ADC values may be helpful in the differential diagnosis of HOCGs and craniopharyngiomas.
Asunto(s)
Craneofaringioma , Glioma , Imagen por Resonancia Magnética , Quiasma Óptico , Neoplasias Hipofisarias , Humanos , Craneofaringioma/diagnóstico por imagen , Masculino , Femenino , Imagen por Resonancia Magnética/métodos , Adulto , Persona de Mediana Edad , Neoplasias Hipofisarias/diagnóstico por imagen , Neoplasias Hipofisarias/patología , Estudios Retrospectivos , Diagnóstico Diferencial , Adolescente , Glioma/diagnóstico por imagen , Glioma/patología , Quiasma Óptico/diagnóstico por imagen , Quiasma Óptico/patología , Adulto Joven , Niño , Anciano , Neoplasias Hipotalámicas/diagnóstico por imagen , Preescolar , Medios de ContrasteRESUMEN
We aimed to investigate the changes in cupping in chiasmal lesion optic neuropathy (chON) compared to baseline optic disc and glaucoma. We used a novel study design to enroll patients who had fundus photographs incidentally taken during routine health check-ups prior to the onset of optic neuropathy. In 31 eyes (21 patients) with chON and 33 eyes (30 patients) with glaucoma, we investigated the change in cup-to-disc (C/D) area from the baseline to overt cupping using flicker analysis. Compared to the baseline, 23 eyes (74.2%) had increased cup size and 3 (9.7%) had vascular configuration changes in the chONgroup; in contrast, all glaucoma eyes exhibited changes in cup size and vascular configuration. The increase in C/D area ratio was significantly smaller in chON (0.04 ± 0.04) compared to glaucoma (0.10 ± 0.04, P < 0.001); the minimum residual neuroretinal rim width showed a more pronounced difference (29.7 ± 8.2% vs 7.1 ± 3.9%, P < 0.001). The changes distributed predominantly towards the nasal direction in chON, contrasting the changes to the arcuate fibers in glaucoma. In conclusion, our results provide the first longitudinal evidence of true pathological cupping in chONcompared to photographically disease-free baseline. The marked difference in the residual minimum rim width reaffirms the importance of rim obliteration in the differential diagnosis between the two diseases.
Asunto(s)
Glaucoma , Disco Óptico , Enfermedades del Nervio Óptico , Humanos , Disco Óptico/patología , Glaucoma/patología , Enfermedades del Nervio Óptico/patología , Quiasma Óptico/patología , Fondo de Ojo , Presión IntraocularRESUMEN
PURPOSE: To describe the pattern of MRI changes in the pregeniculate visual pathway in Leber hereditary optic neuropathy (LHON). METHOD: This retrospective observational study enrolled 60 patients with LHON between January 2015 and December 2021. The abnormal MRI features seen in the pregeniculate visual pathway were investigated, and then correlated with the causative mitochondrial DNA (mtDNA) mutation, the distribution of the MRI lesions and the duration of vision loss. RESULT: The cohort included 48 (80%) males and 53 (88%) had bilateral vision loss. The median age of onset was 17.0 years (range 4.0-58.0). 28 (47%) patients had the m.11778G>A mutation. 34 (57%) patients had T2 hyperintensity (HS) in the pregeniculate visual pathway and 13 (22%) patients with chiasmal enlargement. 20 patients (71%) carrying the m.11778G>A mutation had T2 HS, significantly more than the 14 patients (44%) with T2 HS in the other LHON mutation groups (p=0.039). Furthermore, significantly more patients in the m.11778G>A group (16 patients (57%)) had T2 HS in optic chiasm (OCh)/optic tract (OTr) than the other LHON mutation groups (7 patients (22%), p=0.005). Optic chiasmal enlargement was more common in patients with vision loss duration <3 months compared with those ≥3 months (p=0.028). CONCLUSION: T2 HS in the pregeniculate visual pathway is a frequent finding in LHON. Signal changes in the OCh/OTr and chiasmal enlargement, in particular within the first 3 months of visual loss, were more commonly seen in patients carrying the m.11778G>A mtDNA mutation, which may be of diagnostic significance.
Asunto(s)
ADN Mitocondrial , Imagen por Resonancia Magnética , Atrofia Óptica Hereditaria de Leber , Quiasma Óptico , Vías Visuales , Humanos , Atrofia Óptica Hereditaria de Leber/genética , Atrofia Óptica Hereditaria de Leber/fisiopatología , Atrofia Óptica Hereditaria de Leber/diagnóstico , Masculino , Quiasma Óptico/patología , Quiasma Óptico/diagnóstico por imagen , Estudios Retrospectivos , Femenino , Adulto , Vías Visuales/patología , Vías Visuales/diagnóstico por imagen , Vías Visuales/fisiopatología , Persona de Mediana Edad , Adolescente , Adulto Joven , Niño , ADN Mitocondrial/genética , Preescolar , Agudeza Visual/fisiología , Neuroimagen , MutaciónRESUMEN
Craniopharyngiomas are histologically benign tumors that originate from squamous rests along the pituitary stalk. They make up approximately 1.2% to 4.6% of all intracranial tumors and do not show significant differences in occurrence based on sex. Adamantinomatous craniopharyngiomas have 2 peaks of incidence, commonly observed in patients from ages 5 to 15 years and again from 45 to 60 years. In contrast, papillary craniopharyngiomas mainly affect adults in their fifth and sixth decades of life.1 The "malignancy" of craniopharyngiomas is attributed to their location and the challenges associated with achieving complete removal because they can manifest in the sellar, parachiasmatic, and intraventricular regions or a combination of these.2,3 Various approaches have been used to resect these tumors.4,5 Radical resection offers the most promising option for disease control, potential cure, and the ability to transform the disease from lethal to survivable in children, allowing for a functional adult life.2,3 Meticulous evaluation is crucial to determine the appropriate approach and side, with particular emphasis on closely examining the relationship between the tumor and optic pathways (nerve, chiasm, tract), which are frequently involved. This assessment should also include the tumor's relationship with other crucial structures, such as the hypothalamus and adjacent arteries, to ensure that the strategy is adjusted accordingly to further minimize the risk of postoperative morbidity. Video 1 demonstrates a left-sided pterional transsylvian approach to remove a parachiasmatic craniopharyngioma involving the left optic chiasm and tract.
Asunto(s)
Craneofaringioma , Neoplasias Hipofisarias , Adulto , Niño , Humanos , Craneofaringioma/diagnóstico por imagen , Craneofaringioma/cirugía , Craneofaringioma/patología , Neoplasias Hipofisarias/diagnóstico por imagen , Neoplasias Hipofisarias/cirugía , Neoplasias Hipofisarias/patología , Hipófisis/patología , Hipotálamo/patología , Quiasma Óptico/diagnóstico por imagen , Quiasma Óptico/cirugía , Quiasma Óptico/patologíaRESUMEN
OBJECTIVE: For unilateral Dodge Class â optic pathway glioma (OPG-uDCâ ) without neurofibromatosis type 1, unilateral isolated optic nerve gliomas before the optic chiasm have been confirmed to possibly cause visual deterioration and poor prognosis. For this type of highly selective localized tumor, we explored surgery as the only treatment method. This article retrospectively analyzed and summarized the clinical data of this case series, with the aim of exploring the main technical details and clinical prognosis. METHODS: Included were patients with OPG-uDCâ without neurofibromatosis type 1 and experiencing vision loss on the affected side. The fronto-orbital approach was used, which was mainly divided into 3 parts: intraorbital, optic canal, and intracranial. All patients underwent prechiasmatic resection without any adjuvant treatments. The follow-up period was 3 months after surgery, and magnetic resonance imaging and contralateral visual acuity were reviewed annually after surgery. RESULTS: All OPG-uDCâ cases were completely removed without any adjuvant treatments, and there was no recurrence during the follow-up period. Pathological results showed that, except for 1 adult patient with pilomyxoid astrocytoma (World Health Organization grade â ¡), the others all had pilocytic astrocytoma (World Health Organization grade â ). Five patients experienced transient ptosis, and all recovered 3 months after surgery. CONCLUSIONS: For OPG-uDCâ without neurofibromatosis type 1, radical prechiasmatic resection of the tumor is possible, without the need for postoperative radiotherapy and chemotherapy.
Asunto(s)
Astrocitoma , Neurofibromatosis 1 , Glioma del Nervio Óptico , Adulto , Humanos , Glioma del Nervio Óptico/complicaciones , Glioma del Nervio Óptico/diagnóstico por imagen , Glioma del Nervio Óptico/cirugía , Neurofibromatosis 1/complicaciones , Neurofibromatosis 1/diagnóstico por imagen , Neurofibromatosis 1/cirugía , Estudios Retrospectivos , Quiasma Óptico/diagnóstico por imagen , Quiasma Óptico/cirugía , Quiasma Óptico/patología , Pronóstico , Astrocitoma/patología , Imagen por Resonancia MagnéticaRESUMEN
Purpose: Albinism is a congenital disorder affecting pigmentation levels, structure, and function of the visual system. The identification of anatomical changes typical for people with albinism (PWA), such as optic chiasm malformations, could become an important component of diagnostics. Here, we tested an application of convolutional neural networks (CNNs) for this purpose. Methods: We established and evaluated a CNN, referred to as CHIASM-Net, for the detection of chiasmal malformations from anatomic magnetic resonance (MR) images of the brain. CHIASM-Net, composed of encoding and classification modules, was developed using MR images of controls (n = 1708) and PWA (n = 32). Evaluation involved 8-fold cross validation involving accuracy, precision, recall, and F1-score metrics and was performed on a subset of controls and PWA samples excluded from the training. In addition to quantitative metrics, we used Explainable AI (XAI) methods that granted insights into factors driving the predictions of CHIASM-Net. Results: The results for the scenario indicated an accuracy of 85 ± 14%, precision of 90 ± 14% and recall of 81 ± 18%. XAI methods revealed that the predictions of CHIASM-Net are driven by optic-chiasm white matter and by the optic tracts. Conclusions: CHIASM-Net was demonstrated to use relevant regions of the optic chiasm for albinism detection from magnetic resonance imaging (MRI) brain anatomies. This indicates the strong potential of CNN-based approaches for visual pathway analysis and ultimately diagnostics.
Asunto(s)
Albinismo , Quiasma Óptico , Humanos , Quiasma Óptico/diagnóstico por imagen , Quiasma Óptico/patología , Inteligencia Artificial , Vías Visuales/patología , Albinismo/patología , Imagen por Resonancia MagnéticaRESUMEN
OBJECTIVES: To investigate the characteristics and objective assessment method of visual field defects caused by optic chiasm and its posterior visual pathway injury. METHODS: Typical cases of visual field defects caused by injuries to the optic chiasm, optic tracts, optic radiations, and visual cortex were selected. Visual field examinations, visual evoked potential (VEP) and multifocal visual evolved potential (mfVEP) measurements, craniocerebral CT/MRI, and retinal optical coherence tomography (OCT) were performed, respectively, and the aforementioned visual electrophysiological and neuroimaging indicators were analyzed comprehensively. RESULTS: The electrophysiological manifestations of visual field defects caused by optic chiasm injuries were bitemporal hemianopsia mfVEP abnormalities. The visual field defects caused by optic tract, optic radiation, and visual cortex injuries were all manifested homonymous hemianopsia mfVEP abnormalities contralateral to the lesion. Mild relative afferent pupil disorder (RAPD) and characteristic optic nerve atrophy were observed in hemianopsia patients with optic tract injuries, but not in patients with optic radiation or visual cortex injuries. Neuroimaging could provide morphological evidence of damages to the optic chiasm and its posterior visual pathway. CONCLUSIONS: Visual field defects caused by optic chiasm, optic tract, optic radiation, and visual cortex injuries have their respective characteristics. The combined application of mfVEP and static visual field measurements, in combination with neuroimaging, can maximize the assessment of the location and degree of visual pathway damage, providing an effective scheme for the identification of such injuries.
Asunto(s)
Lesiones Traumáticas del Encéfalo , Traumatismos del Nervio Óptico , Humanos , Quiasma Óptico/diagnóstico por imagen , Quiasma Óptico/patología , Vías Visuales/diagnóstico por imagen , Vías Visuales/patología , Campos Visuales , Potenciales Evocados Visuales , Técnica del ADN Polimorfo Amplificado Aleatorio , Hemianopsia/etiología , Hemianopsia/complicaciones , Trastornos de la Visión/diagnóstico , Trastornos de la Visión/etiología , Trastornos de la Visión/patología , Traumatismos del Nervio Óptico/diagnóstico por imagen , Lesiones Traumáticas del Encéfalo/diagnóstico , Lesiones Traumáticas del Encéfalo/diagnóstico por imagenRESUMEN
The authors review the phenomenon of third ventricular dilation causing chiasmal compression and vision loss, emphasize the need for further study given continued poor outcomes, and, in a patient case, illustrate the value of obtaining magnetic resonance imaging and nerve and macular optical coherence tomography in a patient with an unclear mechanism of vision loss. [J Pediatr Ophthalmol Strabismus. 2023;60(5):e49-e54.].
Asunto(s)
Hidrocefalia , Tercer Ventrículo , Humanos , Campos Visuales , Quiasma Óptico/diagnóstico por imagen , Quiasma Óptico/patología , Trastornos de la Visión , Hidrocefalia/complicaciones , Hidrocefalia/diagnóstico , Hidrocefalia/patología , Tomografía de Coherencia Óptica/métodosRESUMEN
Introduction: Diabetic neuropathy and diabetic eye disease are well known complications of type 1 diabetes. We hypothesized that chronic hyperglycemia also damages the optic tract, which can be measured using routine magnetic resonance imaging. Our aim was to compare morphological differences in the optic tract between individuals with type 1 diabetes and healthy control subjects. Associations between optic tract atrophy and metabolic measures, cerebrovascular and microvascular diabetic complications were further studied among individuals with type 1 diabetes. Methods: We included 188 subjects with type 1 diabetes and 30 healthy controls, all recruited as part of the Finnish Diabetic Nephropathy Study. All participants underwent a clinical examination, biochemical work-up, and brain magnetic resonance imaging (MRI). Two different raters manually measured the optic tract. Results: The coronal area of the optic chiasm was smaller among those with type 1 diabetes compared to non-diabetic controls (median area 24.7 [21.0-28.5] vs 30.0 [26.7-33.3] mm2, p<0.001). In participants with type 1 diabetes, a smaller chiasmatic area was associated with duration of diabetes, glycated hemoglobin, and body mass index. Diabetic eye disease, kidney disease, neuropathy and the presence of cerebral microbleeds (CMBs) in brain MRI were associated with smaller chiasmatic size (p<0.05 for all). Conclusion: Individuals with type 1 diabetes had smaller optic chiasms than healthy controls, suggesting that diabetic neurodegenerative changes extend to the optic nerve tract. This hypothesis was further supported by the association of smaller chiasm with chronic hyperglycemia, duration of diabetes, diabetic microvascular complications, as well as and CMBs in individuals with type 1 diabetes.
Asunto(s)
Complicaciones de la Diabetes , Diabetes Mellitus Tipo 1 , Hiperglucemia , Humanos , Quiasma Óptico/patología , Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 1/patología , Complicaciones de la Diabetes/patología , Enfermedad Crónica , Atrofia , Hiperglucemia/patologíaRESUMEN
AIM: To demonstrated demyelination and remyelination of the optic nerve histologically by electron microscopy in an experimental model similar to the compression of pituitary adenomas on the optic chiasm. MATERIAL AND METHODS: The rats were fixed to a stereotaxic device under deep anesthesia, and a balloon catheter was placed under the optic chiasm through a burr hole which was in front of the bregma in accordance with the brain atlas of rats. The animals were divided into five groups (n=8): control, mild compression demyelination, severe compression demyelination, mild compression remyelination, severe compression remyelination. The fine structures of the tissues obtained were evaluated using electron microscopy. RESULTS: We found a significant difference in the severity of degeneration when comparing group 1 with group 5 (p < 0.001); there was no degeneration in group 1 rats and severe degeneration in all of the group 5 rats. Oligodendrocytes were found in all rats in group 1 and none of the rats in no group 2. The nuclei were preserved in the group 1 rats but damaged in all of the group 5 rats. There were no lymphocytes or erythrocytes in group 1 and all positives in group 5. CONCLUSION: This technique, which induced degeneration without causing damage to the optic nerve with toxic or chemical agents, revealed Wallerian degeneration similar to tumoral compression. After compression relief, the optic nerve remyelination process can be better understood, particularly for sellar lesions. In our opinion, this model may guide future experiments to identify protocols to induce and accelerate remyelination.
Asunto(s)
Enfermedades Desmielinizantes , Remielinización , Ratas , Animales , Quiasma Óptico/patología , Nervio Óptico/patología , Enfermedades Desmielinizantes/inducido químicamente , Enfermedades Desmielinizantes/patología , Modelos TeóricosRESUMEN
OBJECTIVE: Low-field portable MRI (pMRI) is a recent technological advancement with potential for broad applications. Compared with conventional MRI, pMRI is less resource-intensive with regard to operational costs and scan time. The application of pMRI in neurosurgical oncology has not been previously described. The goal of this study was to demonstrate the efficacy of pMRI in assessing optic nerve decompression after endoscopic endonasal surgery for sellar and suprasellar pathologies. METHODS: Patients who underwent endoscopic endonasal surgery for sellar and suprasellar lesions at a single institution and for whom pMRI and routine MRI were performed postoperatively were retrospectively reviewed to compare the two imaging systems. To assess the relative resolution of pMRI compared with MRI, the distance from the optic chiasm to the top of the third ventricle was measured, and the measurements were compared between paired equivalent slices on T2-weighted coronal images. The inter- and intrarater correlations were analyzed. RESULTS: Twelve patients were included in this study (10 with pituitary adenomas and 2 with craniopharyngiomas) with varying degrees of optic chiasm compression on preoperative imaging. Measurements were averaged across raters before calculating agreement between pMRI and MRI, which demonstrated significant interrater reliability (intraclass correlation coefficient [ICC] = 0.78, p < 0.01). Agreement between raters within the pMRI measurements was also significantly reliable (ICC = 0.93, p < 0.01). Finally, a linear mixed-effects model was specified to demonstrate that MRI measurement could be predicted using the pMRI measurement with the patient and rater set as random effects (pMRI ß coefficient = 0.80, p < 0.01). CONCLUSIONS: The results of this study suggest that resolution of pMRI is comparable to that of conventional MRI in assessing the optic chiasm position in relation to the third ventricle. Portable MRI sufficiently demonstrates decompression of the optic chiasm after endoscopic endonasal surgery. It can be an alternative strategy in cases in which cost, scan-time considerations, or lack of intraoperative MRI availability may preclude the ability to assess adequate optic nerve decompression after endoscopic endonasal surgery for sellar and suprasellar lesions.
Asunto(s)
Quiasma Óptico , Neoplasias Hipofisarias , Humanos , Quiasma Óptico/diagnóstico por imagen , Quiasma Óptico/cirugía , Quiasma Óptico/patología , Estudios Retrospectivos , Reproducibilidad de los Resultados , Neoplasias Hipofisarias/diagnóstico por imagen , Neoplasias Hipofisarias/cirugía , Neoplasias Hipofisarias/patología , Imagen por Resonancia Magnética , DescompresiónRESUMEN
The optic chiasm is a critical component of the visual pathway, and lesions in the pituitary and sellar regions can cause irreversible damage to a patient's visual function, resulting in a significant decrease in their quality of life. As a result, neuro-ophthalmology evaluation is a crucial part of the multidisciplinary treatment of pituitary diseases. However, due to the significant variation in the anatomical structure of the optic chiasm and the sellar region, as well as the complexity of the injury mechanism, chiasm injury can result in diverse manifestations and severity levels, which can make it difficult to correlate with anatomical parameters. In recent years, research has increasingly focused on the early recognition of optic chiasm compression, the prediction of visual function after intervention, and the long-term neurodegenerative effects, while optical coherence tomography (OCT), electrophysiological examinations, and functional magnetic resonance imaging are currently the most commonly used methods for evaluating sellar region lesions. However, the role of these methods, represented by OCT, in clinical diagnosis and treatment, still lacks high-level clinical evidence support, and the evaluation and prediction of optic chiasm function remain key areas for further study. In addition to compression lesions, lesions such as inflammation, infiltration, and demyelination in the sellar region, caused by systemic multi-system diseases, can also lead to visual function damage and require recognition in clinical practice.
Asunto(s)
Quiasma Óptico , Neoplasias Hipofisarias , Humanos , Quiasma Óptico/patología , Calidad de Vida , Neoplasias Hipofisarias/patología , Vías Visuales/patología , Visión Ocular , Imagen por Resonancia Magnética/métodosRESUMEN
We describe gross and histopathological features of multiple ocular and neuro-ophthalmic abnormalities in a fox squirrel (Sciurus niger). Ophthalmic findings included severe bilateral microphthalmos, with the right eye more affected than the left. Histopathology confirmed severe microphthalmia, aphakia, disorganized retinal tissue and small optic nerves, as well as agenesis of the optic chiasm and optic tract. This combination of neuro-ophthalmic abnormalities has not been previously described in wild animals.