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Tal Shahar, Akiva Korn, Gal Barkay, Tali Biron, Amir Hadanny, Tomer Gazit, Erez Nossek, Margaret Ekstein, Anat Kesler, and Zvi Ram

navigation and electrophysiological studies are being used in an effort to avoid intraoperative white matter tract injury. Cortical and subcortical mapping has become the standard method to assess motor and language functions during resection of intraaxial tumors. However, the value of intraoperative mapping of the visual pathways during resection of tumors adjacent to the OR is unclear. In addition, the conclusions of recently published reports of the credibility and usefulness of visual pathway mapping are conflicting. 2 Several reports have suggested that cortical

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Bruce E. Pollock, L. Dade Lunsford, Douglas Kondziolka, David J. Bissonette, and John C. Flickinger

radiosurgical procedure average 80%. 4, 8, 17, 22, 28 Patients remain at risk for hemorrhage during a 1- to 3-year latency interval until their AVM has been completely obliterated. In this study we have evaluated the outcomes after stereotactic radiosurgery in 34 patients with AVMs in the postgeniculate visual pathways. The goal of radiosurgery was twofold: to achieve AVM obliteration and to preserve vision. Clinical Material and Methods Between August 1987 and January 1992, 313 patients with angiographically identified AVMs underwent radiosurgery at our center with a

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Greg Bowden, Hideyuki Kano, Ellen Caparosa, Daniel Tonetti, Ajay Niranjan, Edward A. Monaco III, John Flickinger, Yoshio Arai, and L. Dade Lunsford

study, we sought to evaluate the outcomes of Gamma Knife radiosurgery on postgeniculate visual pathway AVMs with a focus on visual field deficits. Methods Study Design We conducted a single-institution retrospective analysis approved by the University of Pittsburgh Institutional Review Board. We evaluated outcomes for AVMs residing within the postgeniculate visual pathway and treated with Gamma Knife radiosurgery between 1987 and 2009. The AVMs occurred along the anatomically normal course of the optic radiation, which extends from the lateral geniculate

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Ylva Lilja, Oscar Gustafsson, Maria Ljungberg, Göran Starck, Bertil Lindblom, Thomas Skoglund, Henrik Bergquist, Karl-Erik Jakobsson, and Daniel Nilsson

P ituitary adenomas account for 12%–15% of symptomatic intracranial neoplasms. 35 Although their prevalence in the general population is high—15% according to autopsy studies and 23% according to radiological studies 11 —only a minority cause symptoms and require treatment. The most common and earliest symptom is visual impairment, caused by tumor growth that leads to compression of the anterior visual pathways, specifically the optic chiasm. Despite ample experience of treatment by tumor resection, which leads to visual recovery in the majority of cases, 17

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Guillaume Gras-Combe, Sylvie Moritz-Gasser, Guillaume Herbet, and Hugues Duffau

I n brain tumor surgery, real-time identification of functional networks (for example, sensorimotor or language structures) by direct electrical stimulation has been extensively demonstrated as improving both functional and oncological outcomes. 15 , 34 Indeed, the neurosurgeon's goal is now not only to optimize the extent of resection but also to preserve the quality of life, to optimize the “onco-functional” balance. 10 To date, however, visual pathways have received little attention. The challenge with respect to surgery within the posterior part of

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Takahiro Ota, Kensuke Kawai, Kyousuke Kamada, Taichi Kin, and Nobuhito Saito

I ntraoperative neurophysiological monitoring is now indispensable in many neurosurgical situations. Monitoring of VEPs during surgical manipulation along the visual pathway was commenced in the late 1970s almost concurrently with monitoring of somatosensory evoked potentials and auditory brainstem responses. 1 , 2 , 8 , 13 , 15 , 23 , 26 , 30 While those earlier reports suggested the possible usefulness of VEP in detecting impending injury and preventing functional deterioration, some authors have pointed out the difficulty of obtaining stable recordings

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Hiroyuki Kenai, Masanori Yamashita, Takaharu Nakamura, Tomoshige Asano, Michifumi Sainoh, and Hirofumi Nagatomi

Prescription Isodose (%) Prescription Isodose (Gy) Conformity Index Percentage of Coverage Shot No. and Collimator Visual Pathway Vol (mm 3 ) Vol & % (mm 3 %) Ipsilat Visual Pathway Receiving Max Dose Ipsilat Visual Pathway Case Tumor Total 18 14 8 4 Rt Lt Side 10 Gy 12 Gy 14 Gy 1 10.0 50.0 14.5 0.935 98.6 22 0 2 14 6 743.5 722.3 lt 180.6 (25) 115.6 (16) 57.8 (8) 14.8 2 20.2 50.0 14.0 0.895 97.3 28 1 8 14 5 987.5 995.3 rt 325.9 (33) 128.4 (13

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Klaus A. Leber, Jutta Berglöff, and Gerhard Pendl

T he proximity of skull base tumors to critical structures such as the anterior visual pathways and the cranial nerves of the cavernous sinus requires that special care be taken to achieve an optimum curative radiation dose to the tumor while avoiding excessive exposure of these structures. Knowledge of the radiation dose—response characteristics of these structures is therefore essential to make rational dose planning decisions. However, the tolerance dose in radiosurgery for such delicate nerve structures is still controversial. For example, in a

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John W. Rutland, Francesco Padormo, Cindi K. Yim, Amy Yao, Annie Arrighi-Allisan, Kuang-Han Huang, Hung-Mo Lin, James Chelnis, Bradley N. Delman, Raj K. Shrivastava, and Priti Balchandani

cortical thickness of the primary visual cortices to identify any association with macroadenomas. While reduced thickness of the cortical ribbon has been observed in conditions that affect vision, such as glaucoma, 6 , 14 changes in cortical thickness have not been reported in patients with macroadenomas. These anatomical measurements may supplement microstructural findings in the visual pathways and help better characterize secondary damage to the visual pathway due to adenomas. Methods Participants Eighteen patients (8 females, mean age 44.6 years, SD 13.4 years; 10

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Amin Amini, Kathleen Digre, and William T. Couldwell

the optic chiasm. 14 Although not completely understood, photophobia’s mechanism of action is thought to involve the trigeminal pathway with possible input from the pretectal nuclei, occipital lobe, and thalamus. In this report, we describe a blind patient with a history of pituitary adenoma and apoplexy who suffered from photophobia. We also review the literature for a possible alternate visual pathway that would mediate the photic signal that may induce photophobia in blind patients. Case Report History This 68-year-old woman with a 20-year history