| 1. |
- Buwaider, Ali, et al.
(författare)
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Extended reality in cranial and spinal neurosurgery – a bibliometric analysis
- 2024
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Ingår i: Acta Neurochirurgica. - : Springer Nature. - 0001-6268 .- 0942-0940. ; 166:1
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Forskningsöversikt (refereegranskat)abstract
- Purpose: This bibliometric analysis of the top 100 cited articles on extended reality (XR) in neurosurgery aimed to reveal trends in this research field. Gender differences in authorship and global distribution of the most-cited articles were also addressed. Methods: A Web of Science electronic database search was conducted. The top 100 most-cited articles related to the scope of this review were retrieved and analyzed for trends in publications, journal characteristics, authorship, global distribution, study design, and focus areas. After a brief description of the top 100 publications, a comparative analysis between spinal and cranial publications was performed. Results: From 2005, there was a significant increase in spinal neurosurgery publications with a focus on pedicle screw placement. Most articles were original research studies, with an emphasis on augmented reality (AR). In cranial neurosurgery, there was no notable increase in publications. There was an increase in studies assessing both AR and virtual reality (VR) research, with a notable emphasis on VR compared to AR. Education, surgical skills assessment, and surgical planning were more common themes in cranial studies compared to spinal studies. Female authorship was notably low in both groups, with no significant increase over time. The USA and Canada contributed most of the publications in the research field. Conclusions: Research regarding the use of XR in neurosurgery increased significantly from 2005. Cranial research focused on VR and resident education while spinal research focused on AR and neuronavigation. Female authorship was underrepresented. North America provides most of the high-impact research in this area.
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| 2. |
- Li, Xiaogai, et al.
(författare)
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Influence of gravity for optimal head positions in the treatment of head injury patients
- 2011
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Ingår i: Acta Neurochirurgica. - : Springer Science and Business Media LLC. - 0001-6268 .- 0942-0940. ; 153:10, s. 2057-2064
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Brain edema is a major neurological complication of traumatic brain injury (TBI), commonly including a pathologically increased intracranial pressure (ICP) associated with poor outcome. In this study, gravitational force is suggested to have a significant impact on the pressure of the edema zone in the brain tissue and the objective of the study was to investigate the significance of head position on edema at the posterior part of the brain using a finite element (FE) model. METHODS: A detailed FE model including the meninges, brain tissue and a fully connected cerebrospinal fluid (CSF) system was used in this study. Brain tissue was modelled as a poroelastic material consisting of an elastic solid skeleton composed of neurons and neuroglia, permeated by interstitial fluid. The effect of head positions (supine and prone position) due to gravity was investigated for a localized brain edema at the posterior part of the brain. RESULTS: The water content increment at the edema zone remained nearly identical for both positions. However, the interstitial fluid pressure (IFP) inside the edema zone decreased around 15% by having the head in a prone position compared with a supine position. CONCLUSIONS: The decrease of IFP inside the edema zone by changing patient position from supine to prone has the potential to alleviate the damage to central nervous system nerves. These observations indicate that considering the patient's head position during intensive care and at rehabilitation might be of importance to the treatment of edematous regions in TBI patients.
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| 3. |
- von Holst, Hans, et al.
(författare)
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Decompressive craniectomy (DC) at the non-injured side of the brain has the potential to improve patient outcome as measured with computational simulation
- 2014
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Ingår i: Acta Neurochirurgica. - : Springer Science and Business Media LLC. - 0001-6268 .- 0942-0940. ; 156:10, s. 1961-1967
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Tidskriftsartikel (refereegranskat)abstract
- Decompressive craniectomy (DC) is efficient in reducing the intracranial pressure in several complicated disorders such as traumatic brain injury (TBI) and stroke. The neurosurgical procedure has indeed reduced the number of deaths. However, parallel with the reduced fatal cases, the number of vegetative patients has increased significantly. Mechanical stretching in axonal fibers has been suggested to contribute to the unfavorable outcome. Thus, there is a need for improving treatment procedures that allow both reduced fatal and vegetative outcomes. The hypothesis is that by performing the DC at the non-injured side of the head, stretching of axonal fibers at the injured brain tissue can be reduced, thereby having the potential to improve patient outcome. Six patients, one with TBI and five with stroke, were treated with DC and where each patient's pre- and postoperative computerized tomography (CT) were analyzed and transferred to a finite element (FE) model of the human head and brain to simulate DC both at the injured and non-injured sides of the head. Poroelastic material was used to simulate brain tissue. The computational simulation showed slightly to substantially increased axonal strain levels over 40 % on the injured side where the actual DC had been performed in the six patients. However, when the simulation DC was performed on the opposite, non-injured side, there was a substantial reduction in axonal strain levels at the injured side of brain tissue. Also, at the opposite, non-injured side, the axonal strain level was substantially lower in the brain tissue. The reduced axonal strain level could be verified by analyzing a number of coronal sections in each patient. Further analysis of axial slices showed that falx may tentatively explain part of the different axonal strain levels between the DC performances at injured and opposite, non-injured sides of the head. By using a FE method it is possible to optimize the DC procedure to a non-injured area of the head thereby having the potential to reduce axonal stretching at the injured brain tissue. The postoperative DC stretching of axonal fibers may be influenced by different anatomical structures including falx. It is suggested that including computational FE simulation images may offer guidance to reduce axonal strain level tailoring the anatomical location of DC performance in each patient.
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| 4. |
- von Holst, Hans, et al.
(författare)
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Higher impact energy in traumatic brain injury interferes with noncovalent and covalent bonds resulting in cytotoxic brain tissue edema as measured with computational simulation
- 2015
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Ingår i: Acta Neurochirurgica. - : Springer Science and Business Media LLC. - 0001-6268 .- 0942-0940. ; 157:4, s. 639-648
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Tidskriftsartikel (refereegranskat)abstract
- Cytotoxic brain tissue edema is a complicated secondary consequence of ischemic injury following cerebral diseases such as traumatic brain injury and stroke. To some extent the pathophysiological mechanisms are known, but far from completely. In this study, a hypothesis is proposed in which protein unfolding and perturbation of nucleotide structures participate in the development of cytotoxic edema following traumatic brain injury (TBI). An advanced computational simulation model of the human head was used to simulate TBI. The consequences of kinetic energy transfer following an external dynamic impact were analyzed including the intracranial pressure (ICP), strain level, and their potential influences on the noncovalent and covalent bonds in folded protein structures. The result shows that although most of the transferred kinetic energy is absorbed in the skin and three bone layers, there is a substantial amount of energy reaching the gray and white matter. The kinetic energy from an external dynamic impact has the theoretical potential to interfere not only with noncovalent but also covalent bonds when high enough. The induced mechanical strain and pressure may further interfere with the proteins, which accumulate water molecules into the interior of the hydrophobic structures of unfolded proteins. Simultaneously, the noncovalent energy-rich bonds in nucleotide adenosine-triphosphates may be perturbed as well. Based on the analysis of the numerical simulation data, the kinetic energy from an external dynamic impact has the theoretical potential to interfere not only with noncovalent, but also with covalent bonds when high enough. The subsequent attraction of increased water molecules into the unfolded protein structures and disruption of adenosine-triphosphate bonds could to some extent explain the etiology to cytotoxic edema.
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| 5. |
- von Holst, Hans, et al.
(författare)
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Increased strain levels and water content in brain tissue after decompressive craniotomy
- 2012
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Ingår i: Acta Neurochirurgica. - : Springer Science and Business Media LLC. - 0001-6268 .- 0942-0940. ; 154:9, s. 1583-1593
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Tidskriftsartikel (refereegranskat)abstract
- At present there is a debate on the effectiveness of the decompressive craniotomy (DC). Stretching of axons was speculated to contribute to the unfavourable outcome for the patients. The quantification of strain level could provide more insight into the potential damage to the axons. The aim of the present study was to evaluate the strain level and water content (WC) of the brain tissue for both the pre- and post-craniotomy period. The stretching of brain tissue was quantified retrospectively based on the computerised tomography (CT) images of six patients before and after DC by a non-linear image registration method. WC was related to specific gravity (SG), which in turn was related to the Hounsfield unit (HU) value in the CT images by a photoelectric correction according to the chemical composition of brain tissue. For all the six patients, the strain level showed a substantial increase in the brain tissue close to the treated side of DC compared with that found at the pre-craniotomy period and ranged from 24 to 55 % at the post-craniotomy period. Increase of strain level was also observed at the brain tissue opposite to the treated side, however, to a much lesser extent. The mean area of craniotomy was found to be 91.1 +/- 12.7 cm(2). The brain tissue volume increased from 27 to 127 ml, corresponding to 1.65 % and 8.13 % after DC in all six patients. Also, the increased volume seemed to correlate with increased strain level. Specifically, the overall WC of brain tissue for two patients evaluated presented a significant increase after the treatment compared with the condition seen before the treatment. Furthermore, the Glasgow Coma Scale (GCS) improved in four patients after the craniotomy, while two patients died. The GCS did not seem to correlate with the strain level. We present a new numerical method to quantify the stretching or strain level of brain tissue and WC following DC. The significant increase in strain level and WC in the post-craniotomy period may cause electrophysiological changes in the axons, resulting in loss of neuronal function. Hence, this new numerical method provides more insight of the consequences following DC and may be used to better define the most optimal size and area of the craniotomy in reducing the strain level development.
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| 6. |
- Wang, Teng, et al.
(författare)
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Designing electrode configuration of electroosmosis based edema treatment as a complement to hyperosmotic therapy
- 2021
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Ingår i: Acta Neurochirurgica. - : Springer Science and Business Media LLC. - 0001-6268 .- 0942-0940. ; 163
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Tidskriftsartikel (refereegranskat)abstract
- Background Hyperosmotic therapy is a mainstay treatment for cerebral edema. Although often effective, its disadvantages include mainly acting on the normal brain region with limited effectiveness in eliminating excess fluid in edema region. This study investigates how to configure our previously proposed novel electroosmosis based edema treatment as a complement to hyperosmotic therapy. Methods Three electrode configurations are designed to drive the excess fluid out of the edema region, including a 2-electrode, 3-electrode, and 5-electrode design. The focality and directionality of the induced electroosmotic flow (EOF) are then investigated using the same patient-specific head model with localized edema. Results The 5-electrode design shows improved EOF focality with reduced effect on the normal brain region than the other two designs. Importantly, this design also achieves better directionality driving excess edema tissue fluid to a larger region of surrounding normal brain where hyperosmotic therapy functions better. Thus, the 5-electrode design is suggested to treat edema more efficiently via a synergic effect: the excess fluid is first driven out from the edema to surrounding normal brain via EOF, where can then be treated with hyperosmotic therapy. Meanwhile, the 5-electrode design drives 2.22 mL excess fluid from the edema region in an hour comparable to the other designs, indicating a similar efficiency of EOF. Conclusions The results show the promise of our previously proposed novel electroosmosis based edema treatment can be designed to achieve better focality and directionality towards a complement to hyperosmotic therapy.
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