Journal of neurosurgery
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Journal of neurosurgery · Apr 2019
Local tumor progression treated with Gamma Knife radiosurgery: differences between patients with 2-4 versus 5-10 brain metastases based on an update of a multi-institutional prospective observational study (JLGK0901).
The Japanese Leksell Gamma Knife (JLGK)0901 study proved the efficacy of Gamma Knife radiosurgery (GKRS) in patients with 5-10 brain metastases (BMs) as compared to those with 2-4, showing noninferiority in overall survival and other secondary endpoints. However, the difference in local tumor progression between patients with 2-4 and those with 5-10 BMs has not been sufficiently examined for this data set. Thus, the authors reappraised this issue, employing the updated JLGK0901 data set with detailed observation via enhanced MRI. They applied sophisticated statistical methods to analyze the data. ⋯ Local tumor progression incidences did not differ between groups B and C. This study proved that tumor progression after GKRS without whole-brain radiation therapy for patients with 5-10 BMs was satisfactorily treated with the doses prescribed according to the JLGK0901 study protocol and that results were not inferior to those in patients with a single or 2-4 BMs.Clinical trial registration no.: UMIN000001812 (umin.ac.jp).
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Journal of neurosurgery · Apr 2019
Context-dependent relationship in high-resolution micro-ECoG studies during finger movements.
The activation of the sensorimotor cortex as measured by electrocorticographic (ECoG) signals has been correlated with contralateral hand movements in humans, as precisely as the level of individual digits. However, the relationship between individual and multiple synergistic finger movements and the neural signal as detected by ECoG has not been fully explored. The authors used intraoperative high-resolution micro-ECoG (µECoG) on the sensorimotor cortex to link neural signals to finger movements across several context-specific motor tasks. ⋯ HG-filtered µECoG signals effectively identify dominant regions associated with thumb and index finger movement. For pinch, the µECoG signal comprises a combination of the signals from individual thumb and index movements. However, while the relationship between the index finger joint angle and HG-filtered signal remains consistent between conditions, there is not a fixed relationship for thumb movement. Although the HG-filtered µECoG signal is similar in both thumb-only and pinch conditions, the actual thumb movement is markedly smaller in the pinch condition than in the thumb-only condition. This implies a nonlinear relationship between the cortical signal and the motor output for some, but importantly not all, movement types. This analysis provides insight into the tuning of the motor cortex toward specific types of motor behaviors.
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Journal of neurosurgery · Apr 2019
High-resolution in vivo imaging of peripheral nerves using optical coherence tomography: a feasibility study.
Because of their complex topography, long courses, and small diameters, peripheral nerves are challenging structures for radiological diagnostics. However, imaging techniques in the area of peripheral nerve diseases have undergone unexpected development in recent decades. They include MRI and high-resolution sonography (HRS). Yet none of those imaging techniques reaches a resolution comparable to that of histological sections. Fascicles are the smallest discernable structure. Optical coherence tomography (OCT) is the first imaging technique that is able to depict a nerve's ultrastructure at micrometer resolution. In the current study, the authors present an in vivo assessment of human peripheral nerves using OCT. ⋯ OCT is a new imaging technique that has shown promise in peripheral nerve surgery for particular questions. Its resolution exceeds that provided by recent radiological possibilities such as MRI and HRS. Since its field of view is relatively small, faster acquisition times would be highly desirable and have already been demonstrated by other groups. Currently, the method resembles an optical biopsy and can be a supplement to intraoperative sonography, giving high-resolution insight into a suspect area that has been located by sonography in advance.
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Journal of neurosurgery · Apr 2019
Clinical outcomes of normal pressure hydrocephalus in 116 patients: objective versus subjective assessment.
Objective assessment tests are commonly used to predict the response to ventriculoperitoneal (VP) shunting in patients with normal pressure hydrocephalus (NPH). Whether subjective reports of improvement after a lumbar drain (LD) trial can predict response to VP shunting remains controversial. The goal in this study was to compare clinical characteristics, complication rates, and shunt outcomes of objective and subjective LD responders who underwent VP shunt placement. ⋯ Reports of subjective improvement after LD trial in patients with NPH can be a reliable predictor of shunt response. The currently used objective assessment scales may not be sensitive enough to detect subtle changes in symptomatology after LD trial.
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The brainstem is a compact, delicate structure. The surgeon must have good anatomical knowledge of the safe entry points to safely resect intrinsic lesions. Lesions located at the lateral midbrain surface are better approached through the lateral mesencephalic sulcus (LMS). The goal of this study was to compare the surgical exposure to the LMS provided by the subtemporal (ST) approach and the paramedian and extreme-lateral variants of the supracerebellar infratentorial (SCIT) approach. ⋯ The extreme-lateral SCIT approach had the smaller area of surgical exposure; however, these differences were not statistically significant. The extreme-lateral SCIT approach presented a wider vertical and horizontal angle to the LMS compared to the other craniotomies. Also, it provides a 90° trajectory to the sulcus that facilitates the intraoperative microsurgical technique.