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Pituitary incidental adenomas
Published in Nadia Barghouthi, Jessica Perini, Endocrine Diseases in Pregnancy and the Postpartum Period, 2021
ImagingThe best imaging modality is MRI with pituitary protocol. In pregnancy, this is usually performed without gadolinium.MRI can demonstrate the presence of impingement on or abutment of the optic chiasm.MRI may show mass effect on surrounding areas of the brain that could cause harm for the patient (e.g. occlusion of vessels).
Low-grade Glioma Presenting in the Optic Pathways and Hypothalamus
Published in David A. Walker, Giorgio Perilongo, Roger E. Taylor, Ian F. Pollack, Brain and Spinal Tumors of Childhood, 2020
Peter M.K. de Blank, Ian Simmons, Astrid Sehested, Michael J. Fisher
Although surgical resection is a critical component in the treatment of most low-grade gliomas, complete resection of OPHG is rarely possible without significant morbidity. Biopsy of the optic pathway can lead to new or further visual deficits, as well as other morbidities, including endocrinopathies and neurovascular complications.104 Early recommendations for surgical resection arose from concerns that optic nerve gliomas may progress to invade the chiasm and threaten vision in both eyes.105 However, more recent studies demonstrate that surgical resection does not eliminate the risk of tumor progression, and tumor cells may be found in apparently normal tissue distant from tumor.106 Therefore, surgery to prevent tumor extension into the chiasm is not recommended.107
Central nervous system
Published in A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha, Clark’s Procedures in Diagnostic Imaging: A System-Based Approach, 2020
A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha
T2-weighted imaging of the brain is performed to provide an overview of the brain anatomy and pathology and particularly of the structures of the visual pathway. On T2-weighted imaging the outer margin of the globe and the lens are low signal intensity contrasted with the high signal intensity of the aqueous and vitreous humour. The extraocular muscles and the optic nerve are isointense with brain white matter and well demonstrated in contrast to the high signal retro-orbital fat. T2-weighted imaging of the brain identifies conditions such as multiple sclerosis that may cause optic neuritis. Abnormalities posterior to the optic chiasm may be identified on brain imaging and are indicated by binocular visual disturbances.
Hypophysitis identified on initial presentation of systemic lupus erythematosus: a case report and review of the literature
Published in Scandinavian Journal of Rheumatology, 2021
R Yoshihara, H Tsuchiya, S Tsuzuki, H Harada, H Shoda, K Fujio
Magnetic resonance imaging (MRI) of the brain showed an enlargement of the pituitary stalk and high signal intensity involving the entire pituitary gland and adjacent optic chiasm on T2-weighted sequences. These are considered typical findings for hypophysitis (Figure 1). Functional evaluation of the pituitary proved that the patient retained the ability to secrete thyroid stimulating hormone, luteinizing hormone, follicle-stimulating hormone, adrenocorticotropic hormone, and growth hormone. Her visual fields were not compromised on ophthalmological examination. Lumbar puncture revealed a normal opening pressure of 120 mmH2O (normal range 80–180 mmH2O), with an elevated cerebrospinal fluid protein level of 113 mg/dL (normal range 10–40 mg/dL) and an immunoglobulin G (IgG) index of 1.41 (normal range, 0.34–0.85) without leucocytosis. Computed tomography of the torso confirmed remarkable bilateral pleural effusions and ascites; the nature of the pleural fluid was exudative without signs of infection. Scintigraphy using technetium-99m-diethylenetriamine pentaacetic acid human serum albumin (99mTc-HSA-D) was performed to assess for protein leakage from the intestinal tract. The test demonstrated diffuse radioisotope distribution in the stomach, small bowel, and peritoneum.
Atypical junctional scotoma secondary to optic chiasm atrophy: a case report
Published in Clinical and Experimental Optometry, 2019
A variety of pathologies can affect the integrity of the optic chiasm based on its anatomy. The chiasm is comprised of 2.4 million nerves converging from the two optic nerves and traverse posteriorly to the optic tracts.2015 Temporal retinal fibres remain ipsilateral and pass through the lateral sides of the optic chiasm on their way to the ipsilateral lateral geniculate nucleus.2015 Nasal retinal fibres decussate in the central area of the optic chiasm on their way to the contralateral lateral geniculate nucleus by way of the optic tracts.2015 Approximately 53-per cent of retinal fibres cross in the chiasm while 47-per cent remain ipsilateral.2016 Nasal macular fibres are known to cross more posteriorly in the optic chiasm.2016 Inferior retinal fibres (representing the superior visual field) remain inferior through the chiasm, while the superior retinal fibres (representing the inferior visual field) remain superior through the chiasm.2016 Further, a newer study has found that the nasal retinal fibres cross more posteriorly in the superior parts of the chiasm and more anteriorly in the inferior parts.2015 Given the level of sophistication of optic chiasm anatomy, lesions here can produce a variety of visual field defects and/or vision loss depending on the size and location of the lesion in the chiasm, as described in this case of a junctional scotoma secondary to optic chiasm atrophy.2011
Factors Associated with Occurrence of Radiation-induced Optic Neuropathy at “Safe” Radiation Dosage
Published in Seminars in Ophthalmology, 2018
Pavle Doroslovački, Madhura A. Tamhankar, Grant T. Liu, Kenneth S. Shindler, Gui-Shuang Ying, Michelle Alonso-Basanta
This study was conducted with the approval of the institutional review board and in accordance with all applicable institutional research policies and procedures, as well as all applicable federal and state laws and regulations. The first portion of the study consisted of a retrospective case series of patients with RION seen at our institution. We reviewed the medical records of patients with RION seen by neuro-ophthalmologists (GTL, MT, KSS) at our institution. RION cases were obtained from the personal databases of these providers. Data, including patient age, diagnosis, tumor location, radiation modality, prescribed radiation dose, fractionation, latency of RION development, treatments, presenting visual acuity, and visual acuity at the end of available follow-up, were collected from the patient charts. Where available, the maximum dose to the anterior visual pathways (Dmax) was noted. The anterior visual pathways were defined as the eyes, optic nerves, and optic chiasm for the purposes of this study. Data on the presence or absence of vasculopathic risk factors such as diabetes mellitus, hypertension, hyperlipidemia, and history of smoking were also collected from the charts.