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Infiltrative Optic Neuropathies
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Aniruddha Agarwal, Sabia Handa, Vishali Gupta
Magnetic resonance imaging (MRI) of the optic nerve head and brain is the investigation of choice and it shows characteristic fusiform enlargement of the optic nerve. Lesions are usually isointense to hypointense on T1-weighted MRI and hyperintense on T2-weighted MRI. The two characteristic radiologic features seen with optic nerve gliomas are kinking and double intensity tubular thickening of the optic nerve. Involvement of the chiasm results in a “dumbbell tumor.” This finding is highly characteristic of optic nerve glioma.15,16 There is increased T2 signal surrounding the nerve due to perineural arachnoid gliomatosis.17
Tumors of the Nervous System
Published in Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw, Hankey's Clinical Neurology, 2020
Sphenoid ridge: Fibrous dysplasia.Skull or dural metastasis.Optic nerve glioma.Skull sarcoma.
Neuro-ophthalmology
Published in Mostafa Khalil, Omar Kouli, The Duke Elder Exam of Ophthalmology, 2019
Ophthalmic Optic nerve glioma.Bilateral Lisch nodules (iris hamartomas).Plexiform neurofibromas: ‘Bag of worms’ sensation in the eyelidsChoroidal naevi: Patients with this have a higher risk of choroidal melanoma
Optic Nerve Tortuosity in Neurofibromatosis Type 1: A Rare Case Report
Published in Neuro-Ophthalmology, 2021
Dilek Top Karti, Omer Karti, Ali Murat Koç, Neşe Çelebisoy
Optic nerve tortuosity is a rare asymptomatic radiological manifestation of a non-malignant optic nerve abnormality that is visible on MRI. Dilatation of the subarachnoid space surrounding the anterior portion of the optic nerve has been defined by Armstrong et al. as the most reliable feature of optic nerve tortuosity, with high sensitivity and specificity.6 Besides being detected in healthy individuals as an incidental radiological finding, the abnormality may also accompany some disorders, such as idiopathic intracranial hypertension and NF1.6,7 The incidence and clinical significance of optic nerve tortuosity in NF1 is unknown. It is also controversial whether optic nerve tortuosity is a precursor of a developing optic nerve glioma. Some studies have reported the relationship between optic glioma and optic nerve tortuosity and suggested that the risk of developing optic glioma may increase in NF1 cases with optic nerve tortuosity at baseline.6,8 Ji et al.9 reported that children with NF1 had higher average optic nerve tortuosity than a similar population without NF1. This abnormal morphological appearance of the optic nerve in NF1 cases has been detected irrespective of clinical symptoms or glioma.
Cerebral granulomatous condition mimicking optic pathway glioma
Published in British Journal of Neurosurgery, 2018
Navneet Singh, Martin Palin, Konstantina Karabatsou
Parenchymal mass lesions may be dark on T2-weighted images. Central necrosis is uncommon. Leptomeningeal thickening and enhancement, around the base of the brain, is the most typical manifestation, seen in 40% of the cases.2 Cranial nerves are affected in up to 50% of the patients3 showing enhancement and thickening. There is poor correlation between imaging findings and clinical symptoms. The commonest clinically affected cranial nerve is the facial though the optic nerve is the most common to appear abnormal on MRI.4 It may be affected at the chiasm or intraorbitally and changes may be bilateral or unilateral.1 The differential diagnosis of isolated optic nerve involvement includes optic neuritis and optic nerve glioma. The diagnosis is commonly made by a combination of exclusion of other conditions, imaging and tissue biopsy.
Multicentric Glioblastoma Multiforme Mimicking Optic Neuritis
Published in Neuro-Ophthalmology, 2018
Francesco Pellegrini, Andrew G. Lee, Cristina Cercato
In adults with multicentric glioblastoma multiforme (GBM), the frontal lobes are most often involved, followed by the temporal lobes.12 Less than 20% of GBMs are multifocal or multicentric. Whereas benign optic nerve glioma is the most common optic nerve tumour (especially in children), malignant optic glioma of the adult (MOGA) is rare and was first defined by Hoyt et al. in 1973.13 MOGA is a high-grade glioma typically presenting as an anaplastic astrocytoma (grade III) or glioblastoma (grade IV). Mean age at diagnosis is 54 years. At onset, up to 70% of cases present with unilateral decreased vision, 41% had optic disc oedema, and interestingly pain is present in 20% of cases. These findings can mimic optic neuritis. The visual loss from MOGA inexorably progresses, and the mean interval from initial symptoms to total blindness is 3.3 ± 2.8 months.14 The neuroimaging appearance of MOGA is not specific for neoplasm, but the optic nerve may be thickened and may show enhancement with heterogeneous and cystic areas.15 The prognosis for patients with MOGA is poor with the median survival of approximately 12 months.16 At presentation, MOGA may mimic either optic neuritis or ischaemic optic neuropathy, but the history, clinical examination, and paraclinical testing can help differentiate these entities from one another.16 Clinically speaking, MOGA may produce one of two clinical pictures.17,18 If the tumour is posterior (intracranial optic nerve or chiasm), there is rapidly progressive visual loss associated with optic disc atrophy. However, the optic nerve may initially appear normal and may be initially mistaken for retrobulbar ON particularly when there is associated pain. When the tumour initially affects the proximal portion of the intraorbital optic nerve, there is acute/subacute loss of vision associated with optic disc swelling.