Journal of neurosurgery
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Journal of neurosurgery · Nov 2013
Comparative StudyHypertension in patients with cranial nerve vascular compression syndromes and comparison with a population-based cohort.
Although essential arterial hypertension (AH) represents a major health issue, its underlying causes remain unknown. An intriguing hypothesis is that AH in some cases may be caused by vascular compression of the rostral ventrolateral medulla (RVLM). Because hemifacial spasms (HFSs) are caused by vascular compression of the seventh cranial nerve in close proximity to the RVLM, one would, if this hypothesis is correct, expect to find a positive association between the occurrence of AH and chronic HFSs. Such a positive association would not be expected in patients with trigeminal neuralgia (TN), since TN is caused by vascular compression of the fifth cranial nerve, which is not close to the RVLM. ⋯ The authors suggest that the data provide supporting evidence to the theory that compression of the RVLM may be one cause of AH.
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Journal of neurosurgery · Nov 2013
Case ReportsRight parietal cortex and calculation processing: intraoperative functional mapping of multiplication and addition in patients affected by a brain tumor.
The role of parietal areas in number processing is well known. The significance of intraoperative functional mapping of these areas has been only partially explored, however, and only a few discordant data are available in the surgical literature with regard to the right parietal lobe. The purpose of this study was to evaluate the clinical impact of simple calculation in cortical electrostimulation of right-handed patients affected by a right parietal brain tumor. ⋯ These findings provide intraoperative data in support of an anatomofunctional organization for multiplication and addition within the right parietal area. Furthermore, the study shows the potential clinical relevance of intraoperative mapping of calculation in patients undergoing surgery in the right parietal area. Further and larger studies are needed to confirm these data and assess whether mapped areas are effectively essential for function.
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Journal of neurosurgery · Nov 2013
Foramen ovale puncture, lesioning accuracy, and avoiding complications: microsurgical anatomy study with clinical implications.
Foramen ovale (FO) puncture allows for trigeminal neuralgia treatment, FO electrode placement, and selected biopsy studies. The goals of this study were to demonstrate the anatomical basis of complications related to FO puncture, and provide anatomical landmarks for improvement of safety, selective lesioning of the trigeminal nerve (TN), and optimal placement of electrodes. ⋯ Knowledge of the extracranial and intracranial anatomical relationships of the FO is essential to understanding and avoiding complications during FO puncture. These data suggest that better radiographic visualization of the FO can improve lesioning accuracy depending on the part of the FO to be punctured. The angles and safety distances obtained may help the neurosurgeon minimize complications during FO puncture and TN lesioning.
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Journal of neurosurgery · Nov 2013
Nonthermal ablation with microbubble-enhanced focused ultrasound close to the optic tract without affecting nerve function.
Tumors at the skull base are challenging for both resection and radiosurgery given the presence of critical adjacent structures, such as cranial nerves, blood vessels, and brainstem. Magnetic resonance imaging-guided thermal ablation via laser or other methods has been evaluated as a minimally invasive alternative to these techniques in the brain. Focused ultrasound (FUS) offers a noninvasive method of thermal ablation; however, skull heating limits currently available technology to ablation at regions distant from the skull bone. Here, the authors evaluated a method that circumvents this problem by combining the FUS exposures with injected microbubble-based ultrasound contrast agent. These microbubbles concentrate the ultrasound-induced effects on the vasculature, enabling an ablation method that does not cause significant heating of the brain or skull. ⋯ This technique, which selectively targets the intravascular microbubbles, appears to be a promising method of noninvasively producing sharply demarcated lesions in deep brain structures while preserving function in adjacent nerves. Because of low vascularity--and thus a low microbubble concentration--some large white matter tracts appear to have some natural resistance to this type of ablation compared with gray matter. While future work is needed to develop methods of monitoring the procedure and establishing its safety at deep brain targets, the technique does appear to be a potential solution that allows FUS ablation of deep brain targets while sparing adjacent nerve structures.
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Journal of neurosurgery · Nov 2013
Long-term outcome of high-dose γ knife surgery in treatment of trigeminal neuralgia.
Despite the widespread use of Gamma Knife surgery (GKS) for trigeminal neuralgia (TN), controversy remains regarding the optimal treatment dose and target site. Among the published studies, only a few have focused on long-term outcomes (beyond 2 years) using 90 Gy, which is in the higher range of treatment doses used (70-90 Gy). ⋯ Gamma Knife surgery using a maximum dose of 90 Gy to the trigeminal nerve provides satisfactory long-term pain control, reduces the use of medication, and improves quality of life. Physicians must be aware that higher doses may be associated with an increase in bothersome sensory complications. The benefits and risks of higher dose selection must be carefully discussed with patients, since facial numbness, even if bothersome, may be an acceptable trade-off for patients with severe pain.