Journal of neurosurgery
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Journal of neurosurgery · Nov 2020
Impact of perioperative aneurysm rebleeding after subarachnoid hemorrhage.
Aneurysm rebleeding is a major cause of death and morbidity in patients with aneurysmal subarachnoid hemorrhage (SAH). Recognizing the predictors of rebleeding might help to identify patients who will benefit from acute management. This study was performed to investigate the predictors of aneurysm rebleeding and their impact on clinical outcomes in the preoperative, intraoperative, and postoperative periods. ⋯ Aneurysm rebleeding after SAH has specific characteristics in the preoperative, intraoperative, and postoperative periods, and all of these characteristics contribute to the clinical outcome. The ACoA has a higher risk of intraoperative rebleeding, and endovascular coiling could be a good candidate in terms of techniques for preventing intraoperative rebleeding, although complete aneurysm obliteration should be accomplished.
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Journal of neurosurgery · Nov 2020
The frontal longitudinal system as revealed through the fiber microdissection technique: structural evidence underpinning the direct connectivity of the prefrontal-premotor circuitry.
The purpose of this study was to investigate the morphology, connectivity, and correlative anatomy of the longitudinal group of fibers residing in the frontal area, which resemble the anterior extension of the superior longitudinal fasciculus (SLF) and were previously described as the frontal longitudinal system (FLS). ⋯ The current study provides consistent, focused, and robust evidence on the morphology, architecture, and correlative anatomy of the FLS. This fiber system participates in the axonal connectivity of the prefrontal-premotor cortices and allegedly subserves cognitive-motor functions. Based in the SLF hypersegmentation concept that has been advocated by previous authors, the FLS should be approached as a distinct frontal segment within the superior longitudinal system.
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Journal of neurosurgery · Nov 2020
Primary visual cortical thickness in correlation with visual field defects in patients with pituitary macroadenomas: a structural 7-Tesla retinotopic analysis.
Vision loss remains a debilitating complication of pituitary adenomas, although there is considerable variability in visual impairment before and after decompression surgery. Growing evidence suggests secondary damage to remote visual structures may contribute to vision loss in patients with chiasmatic compression. The present study leverages ultrahigh field 7-T MRI to study the retinotopic organization of the primary visual cortex (V1), and correlates visual defects with cortical thinning in V1 to characterize consequences of pituitary adenomas on the posterior visual system. ⋯ All 8 patients showed significant positive correlations between V1 thickness and visual defect. These findings provide retinotopic maps of localized V1 cortical neurodegeneration spatially corresponding to impairments in the visual field. These results further characterize changes in the posterior visual pathway associated with chiasmatic compression, and may prove useful in the neuroophthalmological workup for patients with pituitary macroadenoma.
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Journal of neurosurgery · Nov 2020
Time-dependent and site-dependent morphological changes in rupture-prone arteries: ovariectomized rat intracranial aneurysm model.
The pathogenesis of intracranial aneurysm rupture remains unclear. Because it is difficult to study the time course of human aneurysms and most unruptured aneurysms are stable, animal models are used to investigate the characteristics of intracranial aneurysms. The authors have newly established a rat intracranial aneurysm rupture model that features site-specific ruptured and unruptured aneurysms. In the present study the authors examined the time course of changes in the vascular morphology to clarify the mechanisms leading to rupture. ⋯ Time-dependent and site-dependent morphological changes and the level of degradation molecules may be indicative of the vulnerability of aneurysms to rupture.