1,541 research outputs found
The feasibility and added value of mapping music during awake craniotomy:A systematic review
The value of mapping musical function during awake craniotomy is unclear. Hence, this systematic review was conducted to examine the feasibility and added value of music mapping in patients undergoing awake craniotomy. An extensive search, on 26 March 2021, in four electronic databases (Medline, Embase, Web of Science and Cochrane CENTRAL register of trials), using synonyms of the words âAwake Craniotomyâ and âMusic Performance,â was conducted. Patients performing music while undergoing awake craniotomy were independently included by two reviewers. This search resulted in 10 studies and 14 patients. Intraâoperative mapping of musical function was successful in 13 out of 14 patients. Isolated music disruption, defined as disruption during music tasks with intact language/speech and/or motor functions, was identified in two patients in the right superior temporal gyrus, one patient in the right and one patient in the left middle frontal gyrus and one patient in the left medial temporal gyrus. Preâoperative functional MRI confirmed these localizations in three patients. Assessment of postâoperative musical function, only conducted in seven patients by means of standardized (57%) and nonâstandardized (43%) tools, report no loss of musical function. With these results, we conclude that mapping music is feasible during awake craniotomy. Moreover, we identified certain brain regions relevant for music production and detected no decline during followâup, suggesting an added value of mapping musicality during awake craniotomy. A systematic approach to map musicality should be implemented, to improve current knowledge on the added value of mapping musicality during awake craniotomy
The SAFE-trial:Safe surgery for glioblastoma multiforme: Awake craniotomy versus surgery under general anesthesia. Study. protocol for a multicenter prospective randomized controlled trial
Background: Surgery of GBM nowadays is usually performed under general anesthesia (GA) and resections are often not as aggressive as possible, due to the chance of seriously damaging the patient with a rather low life expectancy. A surgical technique optimizing resection of the tumor in eloquent areas but preventing neurological deficits is necessary to improve survival and quality of life in these patients. Awake craniotomy (AC) with the use of cortical and subcortical stimulation has been widely implemented for low-grade glioma resections (LGG), but not yet for GBM. AC has shown to increase resection percentage and preserve quality of life in LGG and could thus be of important value in GBM surgery. Methods/design: This study is a prospective, multicenter, randomized controlled trial (RCT). Consecutive patients with a glioblastoma in or near eloquent areas (Sawaya grading II/III) will be 1:1 randomized to awake craniotomy or craniotomy under general anesthesia. 246 patients will be included in neurosurgical centers in the Netherlands and Belgium. Primary end-points are: 1) Postoperative neurological morbidity and 2) Proportion of patients with gross-total resections. Secondary end-points are: 1) Health-related quality of life; 2) Progression-free survival (PFS); 3) Overall survival (OS) and 4) Frequency and severity of Serious Adverse Effects in each group. Also, a cost-benefit analysis will be performed. All patients will receive standard adjuvant treatment with concomitant chemoradiotherapy. Discussion: This RCT should demonstrate whether AC is superior to craniotomy under GA on neurological morbidity, extent of resection and survival for glioblastoma resections in or near eloquent areas. Trial registration: Clinicaltrials.gov: NCT03861299 Netherlands Trial Register (NTR): NL758
The Impacts of Tumor and Tumor Associated Epilepsy on Subcortical Brain Structures and Long Distance Connectivity in Patients With Low Grade Glioma
Low grade gliomas in cerebral cortex often cause symptoms related to higher cerebral functions such as attention, memory and executive function before treatment is initiated. Interestingly, focal tumors residing in one cortical region can lead to a diverse range of symptoms, indicating that the impact of a tumor is extended to multiple brain regions. We hypothesize that the presence of focal glioma in the cerebral cortex leads to alterations of distant subcortical areas and essential white matter tracts. In this study, we analyzed diffusion tensor imaging scans in glioma patients to study the effect of glioma on subcortical gray matter nuclei and long-distance connectivity. We found that the caudate nucleus, putamen and thalamus were affected by cortical glioma, displaying both volumetric and diffusion alterations. The cerebellar cortex contralateral to the tumor side also showed significant volume decrease. Additionally, tractography of the cortico-striatal and cortico-thalamic projections shows similar diffusion alterations. Tumor associated epilepsy might be an important contributing factor to the found alterations. Our findings indeed confirm concurrent structural and connectivity abrasions of brain areas distant from brain tumor, and provide insights into the pathogenesis of diverse neurological symptoms in glioma patients
The impacts of tumor and tumor associated epilepsy on subcortical brain structures and long distance connectivity in patients with low grade glioma
Low grade gliomas in cerebral cortex often cause symptoms related to higher cerebral functions such as attention, memory and executive function before treatment is initiated. Interestingly, focal tumors residing in one cortical region can lead to a diverse range of symptoms, indicating that the impact of a tumor is extended to multiple brain regions. We hypothesize that the presence of focal glioma in the cerebral cortex leads to alterations of distant subcortical areas and essential white matter tracts. In this study, we analyzed diffusion tensor imaging scans in glioma patients to study the effect of glioma on subcortical gray matter nuclei and long-distance connectivity. We found that the caudate nucleus, putamen and thalamus were affected by cortical glioma, displaying both volumetric and diffusion alterations. The cerebellar cortex contralateral to the tumor side also showed significant volume decrease. Additionally, tractography of the cortico-striatal and cortico-thalamic projections shows similar diffusion alterations. Tumor associated epilepsy might be an important contributing factor to the found alterations. Our findings indeed confirm concurrent structural and connectivity abrasions of brain areas distant from brain tumor, and provide insights into the pathogenesis of diverse neurological symptoms in glioma patients
Extracranial Trigger Site Surgery for Migraine
Introduction: The headache phase of migraine could in selected cases potentially
be treated by surgical decompression of one or more âtrigger sites,â located at
frontal, temporal, nasal, and occipital sites. This systematic review with subsequent
meta-analysis aims at critically evaluating the currently available evidence for the surgical
treatment of migraine headache and to determine the effect size of this treatment in a
specific patient population.
Methods: This study was conducted following the PRISMA guidelines. An online
database search was performed. Inclusion was based on studies published between
2000 and March 2018, containing a diagnosis of migraine in compliance with the
classification of the International Headache Society. The treatment must consist of one or
more surgical procedures involving the extracranial nerves and/or arteries with outcome
data available at minimum 6 months.
Results: Eight hundred and forty-seven records were identified after duplicates were
removed, 44 full text articles were assessed and 14 records were selected for inclusion.
A total number of 627 patients were included in the analysis. A proportion of 0.38 of
patients (random effects model, 95% CI [0.30â0.46]) experienced elimination of migraine
headaches at 6â12 months follow-up. Using data from three randomized controlled
trials, the calculated odds ratio for 90â100% elimination of migraine headaches is 21.46
(random effects model, 95% CI [5.64â81.58]) for patients receiving migraine surgery
compared to sham or no surgery.
Conclusions: Migraine surgery leads to elimination of migraine headaches in 38% of
the migraine patients included in this review. However, more elaborate randomized trials
are needed with transparent reporting of patient selection, medication use, and surgical
procedures and implementing detailed and longer follow-up times
Ice cliff contribution to the tongue-wide ablation of Changri Nup Glacier, Nepal, central Himalaya
Ice cliff backwasting on debris-covered glaciers is recognized
as an important mass-loss process that is potentially responsible for the
debris-cover anomaly, i.e. the fact that debris-covered and
debris-free glacier tongues appear to have similar thinning rates in the
Himalaya. In this study, we quantify the total contribution of ice cliff
backwasting to the net ablation of the tongue of Changri Nup Glacier, Nepal,
between 2015 and 2017. Detailed backwasting and surface thinning rates were
obtained from terrestrial photogrammetry collected in November 2015 and 2016,
unmanned air vehicle (UAV) surveys conducted in November 2015, 2016 and 2017,
and Pléiades tri-stereo imagery obtained in November 2015, 2016 and 2017.
UAV- and Pléiades-derived ice cliff volume loss estimates were
3 % and 7 % less than the value calculated from the
reference terrestrial photogrammetry. Ice cliffs cover between 7 % and
8 % of the total map view area of the Changri Nup tongue. Yet from
November 2015 to November 2016 (November 2016 to November 2017), ice cliffs
contributed to 23±5 % (24±5 %) of the total ablation observed
on the tongue. Ice cliffs therefore have a net ablation rate 3.1±0.6
(3.0±0.6) times higher than the average glacier tongue surface.
However, on Changri Nup Glacier, ice cliffs still cannot compensate for the
reduction in ablation due to debris-cover. In addition to cliff enhancement,
a combination of reduced ablation and lower emergence velocities could be
responsible for the debris-cover anomaly on debris-covered tongues.</p
Orbital effects of a monochromatic plane gravitational wave with ultra-low frequency incident on a gravitationally bound two-body system
We analytically compute the long-term orbital variations of a test particle
orbiting a central body acted upon by an incident monochromatic plane
gravitational wave. We assume that the characteristic size of the perturbed
two-body system is much smaller than the wavelength of the wave. Moreover, we
also suppose that the wave's frequency is much smaller than the particle's
orbital one. We make neither a priori assumptions about the direction of the
wavevector nor on the orbital geometry of the planet. We find that, while the
semi-major axis is left unaffected, the eccentricity, the inclination, the
longitude of the ascending node, the longitude of pericenter and the mean
anomaly undergo non-vanishing long-term changes. They are not secular trends
because of the slow modulation introduced by the tidal matrix coefficients and
by the orbital elements themselves. They could be useful to indepenedently
constrain the ultra-low frequency waves which may have been indirectly detected
in the BICEP2 experiment. Our calculation holds, in general, for any
gravitationally bound two-body system whose characteristic frequency is much
larger than the frequency of the external wave. It is also valid for a generic
perturbation of tidal type with constant coefficients over timescales of the
order of the orbital period of the perturbed particle.Comment: LaTex2e, 24 pages, no figures, no tables. Changes suggested by the
referees include
Case report: High-resolution, intra-operative ”Doppler-imaging of spinal cord hemangioblastoma
Surgical resection of spinal cord hemangioblastomas remains a challenging endeavor: the neurosurgeonâs aim to reach total tumor resections directly endangers their aim to minimize post-operative neurological deficits. The currently available tools to guide the neurosurgeonâs intra-operative decision-making consist mostly of pre-operative imaging techniques such as MRI or MRA, which cannot cater to intra-operative changes in field of view. For a while now, spinal cord surgeons have adopted ultrasound and its submodalities such as Doppler and CEUS as intra-operative techniques, given their many benefits such as real-time feedback, mobility and ease of use. However, for highly vascularized lesions such as hemangioblastomas, which contain up to capillary-level microvasculature, having access to higher-resolution intra-operative vascular imaging could potentially be highly beneficial. ”Doppler-imaging is a new imaging modality especially fit for high-resolution hemodynamic imaging. Over the last decade, ”Doppler-imaging has emerged as a high-resolution, contrast-free sonography-based technique which relies on High-Frame-Rate (HFR)-ultrasound and subsequent Doppler processing. In contrast to conventional millimeter-scale (Doppler) ultrasound, the ”Doppler technique has a higher sensitivity to detect slow flow in the entire field-of-view which allows for unprecedented visualization of blood flow down to sub-millimeter resolution. In contrast to CEUS, ”Doppler is able to image high-resolution details continuously, without being contrast bolus-dependent. Previously, our team has demonstrated the use of this technique in the context of functional brain mapping during awake brain tumor resections and surgical resections of cerebral arteriovenous malformations (AVM). However, the application of ”Doppler-imaging in the context of the spinal cord has remained restricted to a handful of mostly pre-clinical animal studies. Here we describe the first application of ”Doppler-imaging in the case of a patient with two thoracic spinal hemangioblastomas. We demonstrate how ”Doppler is able to identify intra-operatively and with high-resolution, hemodynamic features of the lesion. In contrast to pre-operative MRA, ”Doppler could identify intralesional vascular details, in real-time during the surgical procedure. Additionally, we show highly detailed post-resection images of physiological human spinal cord anatomy. Finally, we discuss the necessary future steps to push ”Doppler to reach actual clinical maturity
Prime Focus Spectrograph (PFS) for the Subaru Telescope: Overview, recent progress, and future perspectives
PFS (Prime Focus Spectrograph), a next generation facility instrument on the
8.2-meter Subaru Telescope, is a very wide-field, massively multiplexed,
optical and near-infrared spectrograph. Exploiting the Subaru prime focus, 2394
reconfigurable fibers will be distributed over the 1.3 deg field of view. The
spectrograph has been designed with 3 arms of blue, red, and near-infrared
cameras to simultaneously observe spectra from 380nm to 1260nm in one exposure
at a resolution of ~1.6-2.7A. An international collaboration is developing this
instrument under the initiative of Kavli IPMU. The project is now going into
the construction phase aiming at undertaking system integration in 2017-2018
and subsequently carrying out engineering operations in 2018-2019. This article
gives an overview of the instrument, current project status and future paths
forward.Comment: 17 pages, 10 figures. Proceeding of SPIE Astronomical Telescopes and
Instrumentation 201
- âŠ