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The management of optic chiasmatic gliomas is controversial, partly related to failure to separate out those tumors involving the optic chiasm only (chiasmatic tumors) from those also involving the hypothalamus (chiasmatic/hypothalamic tumors). The purpose of this study was: (i) to analyze the outcomes of chiasmatic and chiasmatic/hypothalamic tumors separately; and (ii) to determine the appropriateness of recommending radical surgical resection for the chiasmatic/hypothalamic tumors.
A retrospective chart review of all newly diagnosed tumors involving the optic chiasm from 1982-1996 at British Columbia’s Children’s Hospital was performed.
There were 32 patients less than 16 years of age, 14 with chiasmatic and 18 with chiasmatic/hypothalamic astrocytomas, with an average duration of follow-up of 5.8 years and 6.3 years, respectively. Ten of the patients with chiasmatic tumors and none with chiasmatic/hypothalamic tumors had neurofibromatosis I. Thirteen of the 14 chiasmatic tumors were managed with observation only, and none had progression requiring active intervention. For the chiasmatic/hypothalamic tumors, eight patients had subtotal resections (>95% resection), six had partial resections (50-95%), three had limited resections (<50%), and one had no surgery. There were fewer complications associated with the limited resections, especially with respect to hypothalamic dysfunction. There was no correlation between the extent of resection (subtotal, partial, or limited) and the time to tumor progression (average 18 months).
In conclusion, chiasmatic and chiasmatic/hypothalamic tumors are different entities, which should be separated out for the purposes of any study. For the chiasmatic/hypothalamic tumors, there was more morbidity and no prolongation of time to progression when radical resections were compared to more limited resections. Therefore, if surgery is performed, it may be appropriate to do a surgical procedure that strives only to provide a tissue diagnosis and to decompress the optic apparatus and/or ventricular system.
Cerebral dysgenesis encompasses varied disorders of brain development. Based on the understanding of these conditions provided by histopathologists, embryologists, radiologists and developmental pediatricians, surgeons are able to appropriately assist in the care of these patients. The surgeon can offer assessment of the ventriculomegaly that commonly accompanies cerebral dysgenesis in addition to providing methods to control hydrocephalus, to reconstruct cranial and facial malformations and to remove dysfunctional tissue. For most patients, surgical intervention is only one of the many factors that determine developmental prognosis. Based on the foundation built by other specialists, this review discusses cerebral dysgenesis from the perspective of historical and current surgical interventions.
The Kepler Mission is a space-based mission whose primary goal is to determine the frequency of Earth-size and larger planets in the habitable zone of solar-like stars. The mission will monitor more than 100,000 stars for patterns of transits with a differential photometric precision of 20 ppm at V = 12 for a 6.5 hour transit. It will also provide asteroseismic results on several thousand dwarf stars. It is specifically designed to continuously observe a single field of view of greater than 100 square degrees for 3.5 or more years.
This paper provides a short overview of the mission, a brief history of the mission development, expected results, new investigations by the recently chosen Participating Scientists, and the plans for the Guest Observer and Astrophysical Data Programs.
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