Journal of neurosurgery
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Journal of neurosurgery · Aug 2024
The vectorial technique: a novel neuronavigation-based tool to measure angles of exposure during skull base dissections.
The angle of exposure (AnE) represents a metric that is particularly useful for analyzing circular bony structures during skull base dissections. The authors aimed to develop and validate a neuronavigation-based method to measure the AnE. A formula based on vectorial geometry and the coordinates of three points collected with a neuronavigation system was developed to measure the AnE. ⋯ In the first illustrative application, the mean AnEs for the FMA and FLTA were 129° ± 0.9° and 243° ± 1.9°, respectively. In the second scenario, the mean AnEs were 192° ± 1.3° for the FTLA and 143° ± 2.1° for the RSA. The neuronavigation-based technique described is a highly accurate method to measure the AnE.
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Journal of neurosurgery · Aug 2024
Topographical anatomy of the subthalamic region with special interest in the human medial forebrain bundle.
The medial forebrain bundle (MFB) is a novel promising deep brain stimulation (DBS) target in severe affective disorders that courses through the subthalamic region according to tractography studies. Its potential therapeutic role arose in connection with the development of hypomania during stimulation of the subthalamic nucleus (STN) in Parkinson's disease, offering an alternative explanation for the occurrence of this side effect. However, until now its course exclusively described by tractography had not yet been confirmed by any anatomical method. The aim of this study was to fill this gap as well as to provide a detailed description of the fiber tracts surrounding the STN to facilitate a better understanding of the background of side effects occurring during STN DBS. ⋯ According to this study's findings, the streamlines of the MFB described by tractography arise from the limitations of the diffusion-weighted MRI fiber tracking method and actually correspond to subthalamic fiber bundles, especially the ansa lenticularis and lenticular fasciculus, which erroneously continue in the anterior limb of the internal capsule, toward the prefrontal cortex.
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Journal of neurosurgery · Aug 2024
Preclinical assessment of a noncooled MR thermometry-based neurosurgical laser therapy system.
MRI-guided laser interstitial thermal therapy (MRgLITT) has recently gained interest as an ablative stereotactic procedure for intractable epilepsy, movement disorders, and brain tumors. Conventionally, a LITT system consists of a laser generator and cooled laser applicator, which is a fiber optic core surrounded by a sheath through which cooled fluid is pumped. However, this footprint can make the system bulky and nonmobile, limit the maximum depth of targeting, and increase the chances of breakdown. Herein, the authors conduct a preclinical assessment of a noncooled MRgLITT system in a porcine model. ⋯ This preclinical assessment showed that the noncooled LITT system was able to precisely reach the target and create well-defined lesions within a margin of safety, without any adverse effects. MR thermometry software provided an accurate near-real-time temperature of the brain tissue, and dimensions of the lesion as visualized by the software correlated well with histopathological findings. Further studies to test the system's efficacy and safety in human subjects are in progress.
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Journal of neurosurgery · Aug 2024
Are hemodynamics responsible for inflammatory changes in venous vessel walls? A quantitative study of wall-enhancing intracranial arteriovenous malformation draining veins.
Signal enhancement of vascular walls on vessel wall MRI might be a biomarker for inflammation. It has been theorized that contrast enhancement on vessel wall imaging (VWI) in draining veins of intracranial arteriovenous malformations (AVMs) may be associated with disease progression and development of venous stenosis. The aim of this study was to investigate the relationship between vessel wall enhancement and hemodynamic stressors along AVM draining veins. ⋯ This novel multimodal investigation of hemodynamics in AVM draining veins allows for precise prediction of occurring shear- and flow-related phenomena in enhanced vessel walls. These findings may suggest low shear to be a local predisposing factor for venous stenosis in AVMs.
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Journal of neurosurgery · Aug 2024
Neglected tracts of the brainstem: transverse peduncular tract of Gudden and taenia pontis.
The anatomy and function of the brainstem have fascinated scientists for centuries; however, the brainstem remains one of the least studied regions of the human brain. As the authors delved into studying this structure, they observed a growing tendency to forget or neglect previously identified structures. The aim of this study was to describe two such structures: the transverse peduncular tract, also known as the Gudden tract, and the taenia pontis. The authors analyzed the potential effects of neglecting these structures during brainstem surgery and the implications for clinical practice. ⋯ Recently, with increasing understanding and expertise in brainstem research, surgical approaches to this area have become more common, emphasizing the importance of a detailed knowledge of the brainstem. The two structures mentioned in this paper are described in history books and were widely studied in the 19th century but have not been mentioned in modern literature. The authors propose that a deeper understanding of these structures may prove valuable in neurosurgical practice and help reduce patient comorbidity.