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PubMed2003

Optic pathway tumors in children.

Tumors of the optic pathways are sub-divided in this review into those that arise in one or both optic nerves anterior to the chiasm (optic nerve tumors); those that arise within the chiasm and do not extend significantly into the hypothalamus (optic chiasmatic tumors) and the large exophytic tumors that involve both the optic chiasm and the hypothalamus to a lesser or greater degree (optic chiasmatic/hypothalamic tumors). The management of optic chiasmatic gliomas is controversial, partly related to failure to separate out chiasmatic tumors from the chiasmatic/hypothalamic tumors. The optic nerve tumors are reviewed briefly, since they rarely extend intracranially. Chiasmatic tumors tend to be associated with NF1 and to behave almost like hamartomas. Close observation is usually the most appropriate management. On the other hand, chiasmatic/hypothalamic tumors grow like typical neoplasms. The tumors are almost uniformly low grade astrocytomas, but growth rates may berapid, especially in infants. Modern management has trended away from radical surgical resection, which has significant morbidity, to chemotherapy as the first line of treatment. In this review, the clinical presentation and management of different types of optic pathway tumors are discussed.

Child↗

PubMed2001

Damage to intracranial optic pathways in fatal closed head injury in man.

Head injury is a leading cause of visual impairment. This is partly due to direct trauma to the eye and optic nerve but much of the damage involves the intracranial optic pathways. We have studied the frequency, distribution and nature of the intracranial lesions of the optic pathways at autopsy in 45 cases of severe closed head injury, and examined the correlation between these post-mortem lesions and the ante-mortem clinical findings. Twenty-four of the patients had been involved in road traffic accidents. The ages ranged from 9 to 88 years (mean 46.4), the Glasgow Coma Score (GCS) on admission ranged from 3 to 15 (mean 5), and the survival time after injury from 2.5 h to15 days (mean 3.3 days). Skull fractures were present in 75.6% of the cases. Histological assessment included the use of immunohistochemistry for beta-amyloid precursor protein (beta-APP) and the microglial marker CD68. Axonal injury of varying severity was demonstrable in all cases, and in 39 (87%) the optic chiasm, tracts or radiations were involved, usually in more than one region. The severity of axonal injury was mild in 11 (24%), moderate in 9 (20%) and severe in 19 (42%) cases. The optic radiation at the level of the trigone of the lateral ventricle was particularly frequently and severely affected. The least affected parts of the intracranial optic pathways were the optic chiasm and the posterior segment of the optic nerve. The severity of injury to the optic pathways did not always reflect severity of axonal injury elsewhere in the brain and correlated poorly with the type of trauma (high- or low-velocity), presence of skull fractures or evidence of raised intracranial pressure (ICP). Of the 39 patients who survived more than 6 h, histological evidence of ischaemic injury to the primary optic cortex was present in 26 (67%) and was severe in 12. We conclude that the visual pathways are affected in a high proportion of patients with fatal closed head injury, nerve fibres in the optic radiations being particularly vulnerable. The findings suggest that damage to the posterior parts of the optic pathways may be under-diagnosed among patients with head injury.

Adolescent↗

PubMed2003

Optic pathways tuberculoma mimicking glioma: case report.

BACKGROUND: Optochiasmatic tuberculomas are very rare lesions. They can occur with concomitant tuberculous meningitis, and pulmonary tuberculosis or as the only manifestation of the disease. The authors present a case of optic pathways tuberculoma with radiologic appearance simulating an optic pathways glioma. CASE DESCRIPTION: We report a case of a 20-year-old man with mental retardation due to anoxic encephalopathy who developed a sudden bilateral amaurosis. He also presented with diabetes insipidus, panhypopituitarism, right proptosis, and chemosis. Computed tomography (CT) and magnetic resonance imaging (MRI) showed an enhancing lesion in the optochiasmatic region extending to both optic nerves, with a mass in the right orbit, mimicking an optic pathways glioma. There was no other evidence of systemic involvement of the tuberculosis. The lesion was explored through a right pterional transylvian approach with opening of the optic canal and orbital roof, and a biopsy and an internal decompression were performed. Histopathological studies demonstrated a granulomatous lesion with central caseous necrosis with acid-fast bacilli. The patient improved after treatment with tuberculostatic drugs, but vision recovery could not be achieved. CONCLUSIONS: Visual compromise in tuberculosis is associated with hydrocephalus, optical neuritis or tuberculomas involving the optic pathways. Reviewing the literature on tuberculomas of the optochiasmatic area, we could not find any other case with such extensive involvement of the optic pathways that was radiologically suggestive of an infiltrating glioma. Histopathological studies remain crucial in the diagnosis of intrinsic expansive processes of the optochiasmatic region.

Adult↗

PubMed1981

Axonal transport of phospholipids in rabbit optic pathway.

The uptake of different labeled precursors, their incorporation into lipids, and transport along the rabbit optic pathway [ipsilateral retina and optic nerve (ON), and contralateral optic tract (OT), lateral geniculate body (LGB), and superior colliculus (SC)] were investigated. Albino rabbits were used. The following radioactive precursors ,either combined or separately, dissolved in 50 microliter of saline containing 15% BSA, were injected into vitreous body: [2-3H]glycerol (50 microCi), [1-14C]palmitate (15 microCi), and [1-14C]linoleate (7.5 microCi). Animals were killed at different time intervals from 1 hr up to 24 days. The radioactivity of total lipids and of different phospholipid classes from total tissue was measured. One hour after administration of precursors, the radioactivity into the retina was high and the incorporation of [3H]glycerol and [14C]palmitate increased until 12 hr and 24 hr, respectively. The incorporation of [14C]linoleate reached a maximum on the second day. The phospholipids of LGB and SC were intensively labeled after 4-8 hr, and their radioactivity increased up to the 10th day after injection, independent of the precursor employed. The results obtained indicate that the labeled hydrophilic and hydrophobic precursors used were actively incorporated into the retina, The phospholipids were later transported at a rapid rate along the optic pathway.

Animals↗

PubMed1991

Optic pathway tumors.

Overall, the majority of patients with optic pathway tumors will have stable disease regardless if they are radiated or receive chemotherapy. This is a very indolent tumor system and, for the most part, not a threat to life. Because of this, issues regarding appropriate therapeutic approaches have yet to be resolved. Most agree that in patients with progressive visual loss and tumor limited to the orbit, surgery can be associated with a cure. The downside is the loss of vision associated with surgical extirpation. Radiation rather than surgery has been the mainstay of treatment for intracranial tumors of the optic pathway. To eliminate side effects associated with radiotherapy in the young child, chemotherapy may be the more considered choice. However, on escape of control, i.e., conversion of stable disease to progressive disease, radiotherapy should be considered.

Child↗

PubMed1998

Curved reconstruction along the anterior optic pathway.

Curved reconstruction of a three-dimensional data set along the anterior optic pathway improves visibility of the optic nerves and chiasm and facilitates comparison between the two nerves. Curved reconstruction reveals three patterns in patients with masses of the anterior optic pathway. Retrobulbar buckling of the optic nerve into a "periscope" configuration is observed in some patients.

Child↗

PubMed1994

Follow-up of optic pathway gliomas in children with neurofibromatosis type 1.

Optic pathway gliomas (OPG) are found in about 15% of patients with neurofibromatosis Type 1 (NF-1). The natural history of OPG is not yet well documented. Treatment in cases with growing tumors is still controversial. Twenty-one patients with NF-1 and OPG, diagnosed over a 20-year period, and followed neuroradiologically and ophthalmologically for at least two years, were reevaluated. The diagnosis of OPG was made at a mean age of 7.1 years (range 0-14.5 years); six children were asymptomatic, 15 were symptomatic. The mean follow-up was 9.0 years (2.0-18.5 (years). In eight initially operated or biopsied patients (three optic nerve and five chiasmal gliomas) tumor regrowth was found in one patient without progression on subsequent follow-up. Improvement of visual acuity occurred in one child after operation of a large suprasellar tumor and deterioration in one patient after biopsy of a chiasmal glioma. The neuroradiological follow-up of the 13 not-operated and not-radiated patients (four optic nerve and nine chiasmal gliomas) was stable in 10, progressive in three, resulting in visual loss in one patient. In 11 children (52%) a second tumor outside the optic pathway was found at a mean age of 4.0 years after the diagnosis of an OPG. Until now they are mostly asymptomatic. Second site tumors were operated in two children because of rapid tumor growth, one child died of a brainstem tumor. OPG are a frequent complication in children with NF-1, appearing within the first decade.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1993

Carboplatin treatment of progressive optic pathway gliomas to delay radiotherapy.

Six patients with optic pathway gliomas who were previously managed with surgery and/or chemotherapy were treated with carboplatin (560 mg/sq m) after radiographic evidence of disease progression. The median age at diagnosis was 2 years (range 4 months to 7 years), and the interval between diagnosis and carboplatin therapy ranged between 7 months and 6.5 years (median 1.8 years). Treatment was given at 4-week intervals and continued until unacceptable toxicity supervened, the disease progressed, or the disease was stable for 12 months. All patients demonstrated disease stability at the outset of the third cycle and continued to do so at the time of this writing. Two patients are 16 and 32 months from initial carboplatin therapy and have been off treatment for 5 and 14 months, respectively; two patients are still receiving therapy at 7 and 11 months after their initial treatment. During the study, two patients developed hypersensitivity to the drug, requiring its discontinuation. Toxicity was minimal, consisting mainly of thrombocytopenia, requiring a one-dose reduction in four of the six treated patients. No platelet transfusions were needed. These results suggest that carboplatin can arrest growth of progressive optic pathway gliomas in children and can allow delay of radiotherapy. A larger trial will be required to define the optimal use of carboplatin in the treatment of low-grade gliomas in children.

Astrocytoma↗

PubMed2001

[Optic pathway gliomas in patients with neurofibromatosis type 1: clinical-neuroradiological integrated approach].

PURPOSE: To evaluate a patient population affected by Neurofibromatosis type 1 (NF1) with special reference to optic pathway gliomas. MATERIAL AND METHODS: A total of 419 NF1 patients (222 men, 197 women) were retrospectively evaluated to show incidence, biological behaviour, neuroradiological and clinical presentation of optic pathway gliomas. Central Nervous System MR and ophthalmologic evaluations were reviewed. RESULTS: Thirty-two patients out of 419 (7.6%) showed the presence of optic pathway gliomas. Of these, 28 (87.2%) patients showed tumoral involvement of the optic chiasma. The right intracranial optic nerve was involved in 15 patients (46.8%), the left intracranial optic nerve in 18 (56.2%), the right extracranial optic nerve in 11 (34.3%), the left extracranial optic nerve in 10 (31.2%) and the right and left optic tracts in 6 (18.7%) patients. Geniculate body and optic radiation were not involved by tumour diffusion. Visual acuity testing was positive in 26/32 (81.2%), the fundus oculi in 11/32 (34.3%) patients and the visual field evaluation in 12/32 (37.5%) patients. CONCLUSIONS: In this study we showed an high correlation between optic pathway tumours and ophthalmologic abnormalities confirming the usefulness of an integrated clinical-neuroradiological approach in patients affected by NF1. We also described the biological behaviour of these tumours in our NF1 patient population.

Adolescent↗

PubMed2001

Visual loss in children with neurofibromatosis type 1 and optic pathway gliomas: relation to tumor location by magnetic resonance imaging.

PURPOSE: To examine the potential for visual acuity loss, and its relation to extent and location of optic pathway gliomas in a cohort of children with neurofibromatosis type 1 studied with magnetic resonance imaging. METHODS: We reviewed the neuro-ophthalmologic records and brain/orbital magnetic resonance imaging scans for 43 consecutive pediatric patients with neurofibromatosis type 1 and optic pathway gliomas who were followed at the Children's Hospital of Philadelphia. The presence of visual loss, defined as abnormal visual acuity for age in one or both eyes, was determined. Optic pathway gliomas were classified by tumor extent and location according to involvement of the optic nerves, chiasm, and postchiasmal structures by magnetic resonance imaging. RESULTS: Involvement of the optic tracts and other postchiasmal structures at tumor diagnosis was associated with a significantly higher probability of visual acuity loss (P =.048, chi-square test). Visual loss was noted in 20 of 43 patients (47%) at a median age of 4 years; however, three patients developed visual acuity loss for the first time during adolescence. CONCLUSIONS: In pediatric patients with neurofibromatosis type 1 and optic pathway gliomas, the likelihood of visual loss is dependent on the extent and location of the tumor by magnetic resonance imaging and is particularly associated with involvement of postchiasmal structures. Furthermore, older age during childhood (adolescence) does not preclude the occurrence of visual loss. Close follow-up beyond the early childhood years, particularly for those with postchiasmal tumor, is recommended.

Adolescent↗

PubMed2000

Three subpopulations of fast axonally transported retinal ganglion cell proteins are differentially trafficked in the rat optic pathway.

Post-Golgi trafficking of the major fast axonally transported (FT) proteins was investigated in the rat optic pathway. Following intra-ocular injection of 35S-methionine, radiolabeled FT proteins in the optic tract (OT) and superior colliculus (SC) were analyzed by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and fluorography. Twenty FT proteins, including a known plasma membrane protein (SNAP-25) and synaptic vesicle protein (synaptobrevin-2), displayed consistent 2D-PAGE migration behavior and were chosen for densitometric quantitative analysis. Results showed that at least three subpopulations of the 20 FT proteins could be differentiated based on their trafficking behavior to axons (OT) vs. terminals (SC). To assess whether Golgi-independent processes (e.g., delayed somal release and/or retrograde transport) could account for the differential compartmentation behavior between the three FT classes, we assessed whether radiolabeled FT proteins became redistributed in the optic pathway following a nerve transection blockade. The results showed that radiolabelled FT proteins did not show a quantitative change in their axon vs. terminal compartmentation in response to disconnection from cell bodies or targets. Thus, the three classes of fast axonally transported proteins were likely trafficked to distinct destinations in the optic pathway by Golgi sorting mechanisms.

Animals↗

PubMed2002

Heavily T2 weighted MR images of anterior optic pathways in patients with sellar and parasellar tumours - prediction of surgical anatomy.

OBJECTIVE: Location of anterior optic pathways in sellar and parasellar tumours was preoperatively evaluated, by use of heavily T2 weighted MR images. METHODS: Heavily T2 and conventional T1 weighted images were studied in 20 patients with sellar and parasellar tumours who underwent craniotomy. Pathology revealed pituitary adenoma in 5 patients, craniopharyngioma in 8 and parasellar meningioma in 7. Maximum sizes ranged from 15 mm to 58 mm. Sequence parameters of TR/TE for heavily T2 weighted and T1 weighted images were 5800/220 msec and 600/20 msec, respectively, and slice thickness was 3 mm for both. RESULTS: The anterior optic pathway was detected in 95% on heavily T2 weighted images and 50% on T1 weighted images. All preoperative heavily T2 weighted images were compatible with operative findings. The optic chiasms were most commonly supero-posterior in pituitary adenomas, anterior (prefixed) in craniopharyngiomas and posterior in meningiomas. The optic nerves were commonly located superior or lateral to the tumours. However, parasellar meningiomas, off the midline, revealed the optic nerves in various locations, depending on the tumour origin. In such tumours, heavily T2 weighted images provided surgical information on the width of the working space through prechiasmal and/or optico-carotid spaces in the pterional approach. Spatial relation of the tumours to the lamina terminalis, anterior commissure and anterior communicating artery complex was clearly shown in craniopharyngioma patients, who underwent the anterior interhemispheric approach. CONCLUSION: Heavily T2 weighted MR images are useful in determining the location of optic pathways and surgical approach and in individual prediction of the anatomy for even large sellar and parasellar tumours.

Adenoma↗

PubMed1991

Relationship of retinotopic ordering of axons in the optic pathway to the formation of visual maps in central targets.

We examined in rats the relationship between the ordering of retinal axons in the optic pathway and the formation of a retinotopically organized projection to their primary target, the contralateral superior colliculus (SC). We have previously found that axons labeled by focal injections of 1,1'-dioctadecyl 3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) made in temporal or nasal retina of perinatal rats commonly mistarget along the medial-lateral and rostral-caudal axes of the SC. By postnatal day (P) 11-12, the retinocollicular projection attains an adult-like topography. Incorrectly targeted axons or axon segments are removed; axons that persist terminate in the topographically appropriate part of the SC (Simon and O'Leary: Dev Biol 137:125, 1990). In the present study, we made similar DiI injections, covering less than 2% of the retinal area, in peripheral temporal, nasal, superior, or inferior retina, in rats of two age groups, embryonic day (E) 21 to P (postnatal day) 2 and P11-P17. Whole mounts of retina, optic nerve and tract, and SC, and cross sections of the optic nerve, were examined. In E21-P2 rats, retinal axons labeled from each retinal site are diffusely distributed in the SC, and poorly ordered in the optic pathway. In retina, labeled axons travel in fascicles directly from the injection site to the optic disc, but neighbor relationships begin to degrade as fascicles split and mix. Retinotopic order is virtually lost in the optic nerve; axons labeled from each injection site disperse throughout its cross-sectional area, but the labeled axons tend to be concentrated toward a specific half of the nerve depending upon their retinal origin. This slight tendency toward retinotopic order increases in the optic tract, but axons are still poorly ordered as they leave the tract and enter the SC. Targeting errors along the medial-lateral axis of the SC, but apparently not along its rostral-caudal axis, are related to the positioning of axons across the width of the optic tract. In P11-P17 rats, axons labeled from each injection site arborize only in a small, topographically correct part of the SC. However, the distributions of labeled retinal axons observed in whole mounts of the retina and optic pathway have a degree of disorder similar to those in E21-P2 rats. Further, the scatter of labeled axons in optic nerve cross sections is comparable in both age groups. Therefore, the emergence of topographic order in the retinocollicular projection is not accompanied by an emergence of a retinotopic ordering of axons in the optic nerve.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMedDate not supplied

Optic pathway glioma: correlation of imaging findings with the presence of neurofibromatosis.

BACKGROUND AND PURPOSE: Despite the benign histology of optic pathway glioma (OPG) (low-grade astrocytoma), its biological behavior is unpredictable, and it is unclear whether specific morphologic or anatomic patterns may be predictive of prognosis. It is also unclear whether OPG associated with neurofibromatosis (NF) is a distinct entity from non-NF-OPG. Our purpose was to describe the MR imaging features of OPG, compare the findings between patients with and those without NF, and identify prognostic imaging signs. METHODS: MR examinations of 91 patients with OPG (47 with NF and 44 without) were reviewed at presentation and during follow-up. The images were evaluated for size and extension of tumor, and imaging parameters. Statistical bivariate analysis was used to compare the patients with and those without NF, and Pearson correlation was used to evaluate the correlation between the different imaging parameters and prognosis. Kappa values were calculated to determine intraobserver and interobserver variability. RESULTS: The most common site of involvement in the NF group was the orbital nerve (66%), followed by the chiasm (62%). In the non-NF group, the chiasm was the most common site of involvement (91%); the orbital nerves were involved in only 32%. Extension beyond the optic pathway at diagnosis was uncommon in the NF group (2%) but frequent in the non-NF group (68%). In the NF group, the tumor was smaller and the original shape of the optic pathways was preserved (91% vs. 27% in the non-NF group). The presence of cystic components was significantly more common in the non-NF patients (66% vs. 9% in the NF group). During follow-up, half the NF patients remained stable, in contrast to 5% of the non-NF group. No statistical correlation was found between imaging features and biological behavior of the tumor. CONCLUSION: NF-OPG is a separate entity from non-NF-OPG, with different imaging features and prognosis, thereby warranting a specific diagnostic, clinical, and therapeutic approach.

Adolescent↗

PubMed1991

Leptomeningeal dissemination of optic pathway gliomas in three children.

We treated three children with optic pathway gliomas who had progressive disease associated with metastatic spread to the leptomeninges. One patient had radiographic resolution of leptomeningeal disease after treatment with intravenous carmustine and oral mercaptopurine but died of progressive pulmonary fibrosis. The second patient was treated with intravenous thiotepa, and the leptomeningeal disease remained stable. The third patient was treated with intravenous vincristine sulfate, cyclophosphamide, cisplatin, and etoposide and had a significant size reduction of the leptomeningeal lesion. Although leptomeningeal dissemination is a seemingly rare event, it is important that all children with optic pathway gliomas be considered for this possibility, particularly after the onset of new, atypical neurologic symptoms.

Antineoplastic Agents↗

PubMed2000

When do children with optic pathway tumours need treatment? An oncological perspective in 106 patients treated in a single centre.

UNLABELLED: Progression patterns of optic pathway tumours (OPT) need to be precisely defined for treatment planning. In patients with neurofibromatosis type 1 (NF1), this disease is usually indolent and the available literature rarely reports progression after the age of 6 years. In patients without NF1, the disease course seems to be less favourable. We reviewed the clinical and radiological files of 106 children referred to our institution for the treatment of a symptomatic OPT since 1980. NF1 was present in 51 of them. Progression patterns in children with NF1 differed markedly from those in the other patients. A total of 83 children had tumour extension beyond the chiasm (Dodge type III). Children with NF1 had progressive tumours later during follow-up (47% after the age of 6 years), had more often proptosis and infiltrating tumours but less frequently nystagmus or increased intracranial pressure. 32 children were not treated at diagnosis because they had only mild symptoms related to the OPT. In these patients, progression occurred more often in children without than with NF1 (12/12 versus 12/20 respectively, P = 0.04). A high number of patients needed treatment for progression or severe symptoms after 6 years of age. Of the patients, 33% needed treatment for progression or severe symptoms after 6 years of age. CONCLUSION: Progression patterns of optic pathway tumours in children with neurofibromatosis type 1 differ markedly from those in other patients. This study emphasises the need for prolonged follow-up of children with optic pathway tumours, especially in neurofibromatosis type 1.

Adolescent↗

PubMed2001

MRI and clinical differences between optic pathway tumours in children with and without neurofibromatosis.

The purpose of this study was to evaluate the value of MRI in studying optic pathway tumours associated with neurofibromatosis, and to look for potentially helpful criteria for the management of such lesions. This retrospective study included 14 children with neurofibromatosis type 1 (NF-1) as well as a lesion of the optic pathway. Clinical data and MRI findings were analysed with regard to location, structure and course of the tumours, and were compared with 13 optic pathway tumours in patients without NF-1. The median age of onset was 4.1 years. 11 patients with NF-1 were asymptomatic. In the NF-1 group, the optic nerves were involved in 10 cases without a cystic component at the time of diagnosis. In the non-NF-1 group, the tumour was located in the chiasma in 11 cases; 12 cases had a cystic component. 10 of the NF-1 group had no tumour progression over an average follow-up of 3.2 years without treatment. These findings suggest that optic astrocytomas in association with NF-1 are distinct lesions from isolated optic gliomas. In NF-1, most such tumours show only slight progression, and may correspond to perineural gliomatosis rather than a true pilocytic astrocytoma. Among NF-1 patients, initial MRI provides no prognostic criteria in children who subsequently show tumour progression. Nevertheless, MRI can be useful in establishing the diagnosis of NF-1 and can serve as a baseline study.

Age of Onset↗

PubMed2006

Normal patterns of déjà experience in a healthy, blind male: challenging optical pathway delay theory.

We report the case of a 25-year-old healthy, blind male, MT, who experiences normal patterns of déjà vu. The optical pathway delay theory of déjà vu formation assumes that neuronal input from the optical pathways is necessary for the formation of the experience. Surprisingly, although the sensation of déjà vu is known to be experienced by blind individuals, we believe this to be the first reported application of this knowledge to the understanding of the phenomenon. Visual input is not present in MT, yet the experiences he describes are consistent with reports in the literature of déjà vu occurrence in sighted people. The fact that blind people can experience déjà vu challenges the optical pathway delay theory, and alternative causes are briefly discussed.

Adult↗