Journal of neurosurgery
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Journal of neurosurgery · Feb 2020
Quantitative assessment of secondary white matter injury in the visual pathway by pituitary adenomas: a multimodal study at 7-Tesla MRI.
The objective of this study was to investigate microstructural damage caused by pituitary macroadenomas by performing probabilistic tractography of the optic tracts and radiations using 7-T diffusion-weighted MRI (DWI). These imaging findings were correlated with neuro-ophthalmological results to assess the utility of ultra-high-field MRI for objective evaluation of damage to the anterior and posterior visual pathways. ⋯ Imaging-based quantification of secondary neuronal damage from adenomas strongly correlated with neuro-ophthalmological findings. Diffusion characteristics enabled by ultra-high-field DWI may allow preoperative characterization of visual pathway damage in patients with chiasmatic compression and may inform prognosis for vision recoverability.
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Journal of neurosurgery · Feb 2020
Various modifications of a vascularized nasoseptal flap for repair of extensive skull base dural defects.
Endonasal surgery of the skull base requires watertight reconstruction of the skull base that can seal the dural defect to prevent postoperative CSF rhinorrhea and consequent intracranial complications. Although the incidence of CSF leakage has decreased significantly since the introduction in 2006 of the vascularized nasoseptal flap (the Hadad-Bassagasteguy flap), reconstruction of extensive skull base dural defects remains challenging. The authors describe a new, modified vascularized nasoseptal flap for reconstruction of extensive skull base dural defects. ⋯ Extended nasoseptal flaps are a reliable and versatile option that can be used to reconstruct extensive skull base dural defects resulting from destruction by large invasive tumors or complex endoscopic endonasal surgery. An extended nasoseptal flap that includes the entire lateral nasal wall mucosa (360° flap) is the largest endonasal vascularized flap reported to date and may be an alternative for the reconstruction of extensive skull base defects while avoiding the need for additional external approaches.
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Journal of neurosurgery · Feb 2020
Comparative StudySex-dependent posterior fossa anatomical differences in trigeminal neuralgia patients with and without neurovascular compression: a volumetric MRI age- and sex-matched case-control study.
The pathophysiology of trigeminal neuralgia (TN) in patients without neurovascular compression (NVC) is not completely understood. The objective of this retrospective study was to evaluate the hypothesis that TN patients without NVC differ from TN patient with NVC with respect to brain anatomy and demographic characteristics. ⋯ Posterior fossa volume in males was larger than posterior fossa volume in females. This finding, along with the higher incidence of TN in females, suggests that smaller posterior fossa volume might be an independent factor in the pathophysiology of TN, which warrants further study.
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Connections between the insular cortex and the amygdaloid complex have been demonstrated using various techniques. Although functionally well connected, the precise anatomical substrate through which the amygdaloid complex and the insula are wired remains unknown. In 1960, Klingler briefly described the "fasciculus amygdaloinsularis," a white matter tract connecting the posterior insula with the amygdala. The existence of such a fasciculus seems likely but has not been firmly established, and the reported literature does not include a thorough description and documentation of its anatomy. In this fiber dissection study the authors sought to elucidate the pathway connecting the insular cortex and the mesial temporal lobe. ⋯ The insula and the mesial temporal lobe are directly connected through white matter fibers in the extreme capsule, resulting in the appearance of a single amygdaloinsular fasciculus. This apparent fasciculus is part of the broader network of short association fibers of the extreme capsule, which connects the entire insular cortex with the temporal pole and the amygdaloid complex. The authors propose the term "temporoinsular projection system" (TIPS) for this complex.
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Journal of neurosurgery · Feb 2020
Prognostic significance of abnormal hematological parameters in severe traumatic brain injury requiring decompressive craniectomy.
Hematological abnormalities after severe traumatic brain injury (TBI) are common, and are associated with a poor outcome. Whether these abnormalities offer additional prognostic significance over and beyond validated TBI prognostic models is uncertain. ⋯ In isolation, INR was the best hematological prognostic parameter in severe TBI requiring decompressive craniectomy, especially when patients treated with warfarin were excluded. However, the prognostic significance of admission hematological abnormalities was mostly captured by the IMPACT prognostic model, such that they did not offer any additional prognostic information beyond the IMPACT predicted risk. These results suggest that new prognostic factors for TBI should be evaluated in conjunction with predicted risks of a comprehensive prognostic model that has been validated, such as the IMPACT prognostic model.