| 1. |
- Axelson, Hans, et al.
(författare)
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Continuous subcortical language mapping in awake glioma surgery
- 2022
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Ingår i: Frontiers in Oncology. - : Frontiers Media S.A.. - 2234-943X. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Repetitive monopolar short-train stimulation (STS) delivered from a suction probe enables continuous mapping and distance assessment of corticospinal tracts during asleep glioma resection. In this study, we explored this stimulation technique in awake glioma surgery. Fourteen patients with glioma involving language-related tracts were prospectively included. Continuous (3-Hz) cathodal monopolar STS (five pulses, 250 Hz) was delivered via the tip of a suction probe throughout tumor resection while testing language performance. At 70 subcortical locations, surgery was paused to deliver STS in a steady suction probe position. Monopolar STS influence on language performance at different subcortical locations was separated into three groups. Group 1 represented locations where STS did not produce language disturbance. Groups 2 and 3 represented subcortical locations where STS produced language interference at different threshold intensities (>= 7.5 and <= 5 mA, respectively). For validation, bipolar Penfield stimulation (PS; 60 Hz for 3 s) was used as a "gold standard" comparison method to detect close proximity to language-related tracts and classified as positive or negative regarding language interference. There was no language interference from STS in 28 locations (Group 1), and PS was negative for all sites. In Group 2 (STS threshold >= 7.5 mA; median, 10 mA), there was language interference at 18 locations, and PS (median, 4 mA) was positive in only one location. In Group 3 (STS threshold <= 5 mA; median, 5 mA), there was language interference at 24 locations, and positive PS (median 4 mA) was significantly (p < 0.01) more common (15 out of 24 locations) compared with Groups 1 and 2. Despite the continuous stimulation throughout tumor resection, there were no seizures in any of the patients. In five patients, temporary current spread to the facial nerve was observed. We conclude that continuous subcortical STS is feasibly also in awake glioma surgery and that no language interference from STS or interference at >= 7.5 mA seems to indicate safe distance to language tracts as judged by PS comparisons. STS language interference at STS <= 5 mA was not consistently confirmed by PS, which needs to be addressed.
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| 2. |
- Borota, Ljubisa, et al.
(författare)
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Complete functional recovery in a child after endovascular treatment of basilar artery occlusion caused by spontaneous dissection : a case report
- 2022
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Ingår i: Child's Nervous System. - : Springer Nature. - 0256-7040 .- 1433-0350. ; 38:8, s. 1605-1612
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Tidskriftsartikel (refereegranskat)abstract
- Stroke caused by dissection of arteries of the vertebrobasilar system in children is still poorly investigated in terms of etiology, means of treatment, course of disease, and prognosis. The aim of this report was to describe the unusual course of a spontaneous dissection of the basilar artery (BA) in a child treated with endovascular techniques and to point out that the plasticity of the brain stem can fully compensate for structural damage caused by stroke. We report the case of a 15-year-old boy who suffered a wake-up stroke with BA occlusion caused by spontaneous dissection. A blood clot was aspirated from the false lumen and the true lumen re-opened, but the patient deteriorated a few hours later, and repeated angiography revealed that the intimal flap was detached, occluding the BA again. The lumen of BA was then reconstructed by a stent. Despite a large pons infarction, the patient was completely recovered 11 months after the onset. The case was analyzed with angiograms and magnetic resonance imaging, macroscopic and microscopic pathological analysis, computed tomographic angiography, magnetic resonance-based angiography, and diffusion tensor imaging. This case illustrates that applied endovascular techniques and intensive care measures can alter the course of potentially fatal brain stem infarction. Our multimodal analysis gives new insight into the anatomical basis for the plasticity mechanism of the brain stem.
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| 3. |
- Engström, Maria, et al.
(författare)
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Neuroimaging in the Kleine-Levin Syndrome
- 2018
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Ingår i: Current Neurology and Neuroscience Reports. - Philadelphia, United States : Springer Science and Business Media LLC. - 1528-4042 .- 1534-6293. ; 18:9
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Forskningsöversikt (refereegranskat)abstract
- PURPOSE OF REVIEW: The purpose was to review the most recent literature on neuroimaging in the Kleine-Levin syndrome (KLS). We aimed to investigate if frontotemporal and thalamic dysfunction are key KLS signatures, and if recent research indicates other brain networks of interest that elucidate KLS symptomatology and aetiology.RECENT FINDINGS: In a comprehensive literature search, we found 12 original articles published 2013-2018. Most studies report deviations related to cerebral perfusion, glucose metabolism, or blood-oxygen-level-dependent responses in frontotemporal areas and/or the thalamus. Studies also report dysfunction in the temporoparietal junction and the oculomotor network that also were related to clinical parameters. We discuss these findings based on recent research on thalamocortical networks and brain stem white matter tracts. The hypothesis of frontotemporal and thalamic involvement in KLS was confirmed, and additional findings in the temporoparietal junction and the oculomotor system suggest a broader network involvement, which can be investigated by future high-resolution and multimodal imaging.
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| 4. |
- Fahlström, Markus, et al.
(författare)
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Qualitative and Visual Along-Tract Analysis of Diffusion-Based Parameters in Patients with Diffuse Gliomas
- 2024
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Ingår i: Brain Sciences. - : MDPI. - 2076-3425. ; 14:3
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Tidskriftsartikel (refereegranskat)abstract
- Background: Grade 2-3 diffuse gliomas (DGs) show extensive infiltration through white matter (WM) tracts. Along-tract analysis of WM tracts based on diffusion tensor tractography (DTI) can been performed to assess the microstructural integrity of WM tracts. The clinical implication of these DTI-related findings is still under debate, especially in tumor patients. The aim of this study was to analyze and compare diffusion-based parameters along WM tracts and variables specific to WM -tumor interactions in DGs and correlate them with preoperative neuropsychological assessment.Methods: Fourteen patients with IDH-mutated grade 2-3 DGs were included. Tumor volumes were manually segmented on 3D-FLAIR images after spatial normalisation to MNI space. DTI was acquired using a single-shot echo-planar sequence on a 3T with 48 sampling directions. DTI data were reconstructed within the MNI space using q-space diffeomorphic reconstruction (QSDR) in DSI studio. Five bilateral sets of WM tracts were reconstructed based on the HCP-1065 template. All WM tracts were stretched to the same length of 100 indices, and for each index diffusion-based parameters fractional anisotropy (FA), radial diffusivity (RD), axial diffusivity (AD), mean diffusivity (MD) and quantitative anisotropy (QA) were sampled. Tumor-related parameters (TRP); tumor volume (Tv), maximum tumor presence (MTP) and the number of sequential indices in which a tumor is present (Te) were derived based on the along-tract analysis. Normal data were constructed by calculating the average and standard deviations of contralateral and not-affected WM tracts for each diffusion-based parameter, respectively. Affected WM tracts were individually compared to normal data using a z-test. Preoperative neuropsychological assessment was performed in all subjects and correlated to results from the along-tract analysis using correlation and logistic regression models.Results: Abnormalities in diffusion-based parameters were detected in WM tracts. Topographical and quantitative information were presented within the same graph. AD and MD displayed the highest linear correlation with the TRPs. Abnormal QA showed a linear correlation with Tv per WM tract. Neuropsychological impairment was correlated with all the TRPs and with abnormal FA (p < 0.05) and abnormal QA (p < 0.01). Abnormal QA was the only independent variable able to predict the presence of neuropsychological impairment in the patients based on the linear regression analysis.Conclusions: Graphical presentation of the along-tract analysis presented in this study shows that it may be a sensitive and robust method to acquire and display topographical and qualitative information regarding WM tracts in close proximity to DGs. Further studies and refinements to the methods presented herein may advance current clinical methods for evaluating displacement and infiltrations and further aid the efforts of pre-planning surgical interventions with the goal to maximise EOR and tailor oncological treatment.
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| 5. |
- Hossain, Iftakher, et al.
(författare)
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Huge variability in restrictions of mobilization for patients with aneurysmal subarachnoid hemorrhage - A European survey of practice
- 2023
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Ingår i: BRAIN AND SPINE. - : Elsevier. - 2772-5294. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: One of the major goals of neurointensive care is to prevent secondary injuries following aSAH. Bed rest and patient immobilization are practiced in order to decrease the risk of DCI.Research question: To explore the current practices in place concerning the management of patients with aSAH, specifically, protocols and habits regarding restrictions of mobilization and HOB positioning.Material and methods: A survey was designed, modified, and approved by the panel of the Trauma & Critical Care section of the EANS to cover the practice of restrictions of patient mobilization and HOB positioning in patients with aSAH.Results: Twenty-nine physicians from 17 countries completed the questionnaire. The majority (79.3%) stated that non-secured aneurysm and the presence of an EVD were the factors related to the establishment of restriction of mobilization. The average duration of the restriction varied widely ranging between 1 and 21 days. The presence of an EVD (13.8%) was found to be the main reason to recommend restriction of HOB elevation. The average duration of restriction of HOB positioning ranged between 3 and 14 days. Rebleeding or complications related to CSF over-drainage were found to be related to these restrictions.Discussion and conclusion: Restriction of patient mobilization regimens vary widely in Europe. Current limited evidence does not support an increased risk of DCI rather the early mobilization might be beneficial. Large prospective studies and/or the initiative of a RCT are needed to understand the significance of early mobilization on the outcome of patients with aSAH.
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| 6. |
- Latini, Francesco, 1982-, et al.
(författare)
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A novel radiological classification system for cerebral gliomas: The Brain-Grid.
- 2019
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Standard radiological/topographical classifications of gliomas often do not reflect the real extension of the tumor within the lobar-cortical anatomy. Furthermore, these systems do not provide information on the relationship between tumor growth and the subcortical white matter architecture. We propose the use of an anatomically standardized grid system (the Brain-Grid) to merge serial morphological magnetic resonance imaging (MRI) scans with a representative tractographic atlas. Two illustrative cases are presented to show the potential advantages of this classification system.MRI scans of 39 patients (WHO grade II and III gliomas) were analyzed with a standardized grid created by intersecting longitudinal lines on the axial, sagittal, and coronal planes. The anatomical landmarks were chosen from an average brain, spatially normalized to the Montreal Neurological Institute (MNI) space and the Talairach space. Major white matter pathways were reconstructed with a deterministic tracking algorithm on a reference atlas and analyzed using the Brain-Grid system.In all, 48 brain grid voxels (areas defined by 3 coordinates, axial (A), coronal (C), sagittal (S) and numbers from 1 to 4) were delineated in each MRI sequence and on the tractographic atlas. The number of grid voxels infiltrated was consistent, also in the MNI space. The sub-cortical insula/basal ganglia (A3-C2-S2) and the fronto-insular region (A3-C2-S1) were most frequently involved. The inferior fronto-occipital fasciculus, anterior thalamic radiation, uncinate fasciculus, and external capsule were the most frequently associated pathways in both hemispheres.The Brain-Grid based classification system provides an accurate observational tool in all patients with suspected gliomas, based on the comparison of grid voxels on a morphological MRI and segmented white matter atlas. Important biological information on tumor kinetics including extension, speed, and preferential direction of progression can be observed and even predicted with this system. This novel classification can easily be applied to both prospective and retrospective cohorts of patients and increase our comprehension of glioma behavior.
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| 7. |
- Latini, Francesco, 1982-, et al.
(författare)
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A novel radiological classification system for cerebral gliomas: The Brain-Grid. : Classification of cerebral gliomas with Brain-Grid system
- 2019
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Ingår i: PLOS ONE. - San Francisco, California, USA : Public Library of Science (PLoS). - 1932-6203. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- PurposeStandard radiological/topographical classifications of gliomas often do not reflect the real extension of the tumor within the lobar-cortical anatomy. Furthermore, these systems do not provide information on the relationship between tumor growth and the subcortical white mat- ter architecture. We propose the use of an anatomically standardized grid system (the Brain-Grid) to merge serial morphological magnetic resonance imaging (MRI) scans with a representative tractographic atlas. Two illustrative cases are presented to show the potential advantages of this classification system.MethodsMRI scans of 39 patients (WHO grade II and III gliomas) were analyzed with a standardized grid created by intersecting longitudinal lines on the axial, sagittal, and coronal planes. The anatomical landmarks were chosen from an average brain, spatially normalized to the Mon- treal Neurological Institute (MNI) space and the Talairach space. Major white matter path- ways were reconstructed with a deterministic tracking algorithm on a reference atlas and analyzed using the Brain-Grid system.ResultsIn all, 48 brain grid voxels (areas defined by 3 coordinates, axial (A), coronal (C), sagittal (S) and numbers from 1 to 4) were delineated in each MRI sequence and on the tractographic atlas. The number of grid voxels infiltrated was consistent, also in the MNI space. The sub- cortical insula/basal ganglia (A3-C2-S2) and the fronto-insular region (A3-C2-S1) were most frequently involved. The inferior fronto-occipital fasciculus, anterior thalamic radiation, unci- nate fasciculus, and external capsule were the most frequently associated pathways in both hemispheres.ConclusionsThe Brain-Grid based classification system provides an accurate observational tool in all patients with suspected gliomas, based on the comparison of grid voxels on a morphological MRI and segmented white matter atlas. Important biological information on tumor kinetics including extension, speed, and preferential direction of progression can be observed and even predicted with this system. This novel classification can easily be applied to both prospective and retrospective cohorts of patients and increase our comprehension of glioma behavior.
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| 8. |
- Latini, Francesco, Ph.D. 1982-, et al.
(författare)
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Can diffusion tensor imaging (DTI) outperform standard magnetic resonance imaging (MRI) investigations in post-COVID-19 autoimmune encephalitis?
- 2022
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Ingår i: Upsala Journal of Medical Sciences. - : Uppsala Medical Society. - 0300-9734 .- 2000-1967. ; 127:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Neurological and psychiatric manifestations related to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection are widely recognised. Standard magnetic resonance imaging (MRI) investigations are normal in 40-80% of symptomatic patients, eventually delaying appropriate treatment when MRI is unrevealing any structural changes. The aim of this study is to investigate white matter abnormalities during an early stage of post-COVID-19 (coronavirus disease 2019) encephalitis while conventional MRI was normal. Methods: A patient with post-COVID-19 autoimmune encephalitis was investigated by serial MRIs and diffusion tensor imaging (DTI). Ten healthy control individuals (HC) were utilised as a control group for the DTI analysis. Major projection, commissural and association white matter pathways were reconstructed, and multiple diffusion parameters were analysed and then compared to the HC average using a z-test for serial examinations. Results: Eleven days after the onset of neurological symptoms, DTI revealed early white matter changes, compared with HC, when standard MRI was normal. On day 68, DTI showed multiple white matter lesions compared with HC, visible at this time also by the MRI images, indicating inflammatory changes in different association and projection white matter pathways. Conclusion: We confirm a limitation in the sensitivity of conventional MRI at the acute setting of postCOVID-19 autoimmune encephalitis. A complementary DTI investigation could be a valuable diagnostic tool in early therapeutic decisions concerning COVID-19-related neurological symptoms.
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| 9. |
- Latini, Francesco, 1982-, et al.
(författare)
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Differences in the preferential location and invasiveness of diffuse low-grade gliomas and their impact on outcome
- 2020
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Ingår i: Cancer Medicine. - : Wiley. - 2045-7634. ; 9:15, s. 5446-5458
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Low-grade gliomas (LGGs) are primary diffuse slow-growing brain tumors derived from glial cells. The management of these tumors is dependent on their location, which often harbors eloquent areas. We retrospectively recorded the location of diffuse gliomas to identify whether specific differences exist between the histological types.METHODS: We analyzed 102 patients with previous histological diagnosis of WHO-II astrocytomas (62) and WHO-II oligodendrogliomas (40) according to WHO-2016 classification. MRI sequences (T2-FLAIR) were used for tumor volume segmentation and to create a frequency map of their locations within the Montreal Neurological Institute (MNI) space. The Brain-Grid (BG) system (standardized radiological tool of intersected lines according to anatomical landmarks) was created and merged with a tractography atlas for infiltration analysis.RESULTS: Astrocytomas frequently infiltrated association and projection white matter pathways within fronto-temporo-insular regions on the left side. Oligodendrogliomas infiltrated larger white matter networks (association-commissural-projection) of the frontal lobe bilaterally. A critical number of infiltrated BG voxels (7 for astrocytomas, 10 for oligodendrogliomas) significantly predicted shorter overall survival (OS) in both groups. Bilateral tumor extension in astrocytomas and preoperative tumor volume in oligodendrogliomas were independent prognostic factors for shorter OS.CONCLUSIONS: Astrocytomas and oligodendrogliomas differ in preferential location, and this has an impact on the type and the extent of white matter involvement. The number of BG voxels infiltrated reflected different tumor invasiveness and its impact on OS in both groups. All this new information may be valuable in neurosurgical oncology to classify and plan treatment for patients with diffuse gliomas.
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| 10. |
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| 11. |
- Latini, Francesco, Ph.D. 1982-, et al.
(författare)
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New Insights Into the Anatomy, Connectivity and Clinical Implications of the Middle Longitudinal Fasciculus
- 2021
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Ingår i: Frontiers in Neuroanatomy. - : Frontiers Media S.A.. - 1662-5129. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- The middle longitudinal fascicle (MdLF) is a long, associative white matter tract connecting the superior temporal gyrus (STG) with the parietal and occipital lobe. Previous studies show different cortical terminations, and a possible segmentation pattern of the tract. In this study, we performed a post-mortem white matter dissection of 12 human hemispheres and an in vivo deterministic fiber tracking of 24 subjects acquired from the Human Connectome Project to establish whether a constant organization of fibers exists among the MdLF subcomponents and to acquire anatomical information on each subcomponent. Moreover, two clinical cases of brain tumors impinged on MdLF territories are reported to further discuss the anatomical results in light of previously published data on the functional involvement of this bundle. The main finding is that the MdLF is consistently organized into two layers: an antero-ventral segment (aMdLF) connecting the anterior STG (including temporal pole and planum polare) and the extrastriate lateral occipital cortex, and a posterior-dorsal segment (pMdLF) connecting the posterior STG, anterior transverse temporal gyrus and planum temporale with the superior parietal lobule and lateral occipital cortex. The anatomical connectivity pattern and quantitative differences between the MdLF subcomponents along with the clinical cases reported in this paper support the role of MdLF in high-order functions related to acoustic information. We suggest that pMdLF may contribute to the learning process associated with verbal-auditory stimuli, especially on left side, while aMdLF may play a role in processing/retrieving auditory information already consolidated within the temporal lobe.
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| 12. |
- Latini, Francesco, Ph.D. 1982-, et al.
(författare)
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Refined Analysis of Chronic White Matter Changes after Traumatic Brain Injury and Repeated Sports-Related Concussions: Of Use in Targeted Rehabilitative Approaches?
- 2022
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Ingår i: Journal of Clinical Medicine. - : MDPI. - 2077-0383. ; 11:2
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Tidskriftsartikel (refereegranskat)abstract
- Traumatic brain injury (TBI) or repeated sport-related concussions (rSRC) may lead to long-term memory impairment. Diffusion tensor imaging (DTI) is helpful to reveal global white matter damage but may underestimate focal abnormalities. We investigated the distribution of post-injury regional white matter changes after TBI and rSRC. Six patients with moderate/severe TBI, and 12 athletes with rSRC were included ≥6 months post-injury, and 10 (age-matched) healthy controls (HC) were analyzed. The Repeatable Battery for the Assessment of Neuropsychological Status was performed at the time of DTI. Major white matter pathways were tracked using q-space diffeomorphic reconstruction and analyzed for global and regional changes with a controlled false discovery rate. TBI patients displayed multiple classic white matter injuries compared with HC (p < 0.01). At the regional white matter analysis, the left frontal aslant tract, anterior thalamic radiation, and the genu of the corpus callosum displayed focal changes in both groups compared with HC but with different trends. Both TBI and rSRC displayed worse memory performance compared with HC (p < 0.05). While global analysis of DTI-based parameters did not reveal common abnormalities in TBI and rSRC, abnormalities to the fronto-thalamic network were observed in both groups using regional analysis of the white matter pathways. These results may be valuable to tailor individualized rehabilitative approaches for post-injury cognitive impairment in both TBI and rSRC patients.
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| 13. |
- Latini, Francesco, 1982-, et al.
(författare)
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Rethinking the standard trans-cortical approaches in the light of superficial white matter anatomy
- 2015
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Ingår i: Neural Regeneration Research. - Meadows : Medknow. - 1673-5374 .- 1876-7958. ; 10:12, s. 1906-1909
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Forskningsöversikt (refereegranskat)abstract
- A better comprehension of the superficial white matter organization is important in order to minimize potential and avoidable damage to long or intermediate association fibre bundles during every step of a surgical approach. We recently proposed a technique for cadaver specimen preparation, which seems able to identify a more systematic organization of the superficial white matter terminations. Moreover, the use of the physiological intracranial vascular network for the fixation process allowed us to constantly show main vascular landmarks associated with white matter structures. Hence three examples of standard approaches to eloquent areas are herein reanalyzed starting from the first superficial layer. New insights into the possible surgical trajectories and subsequent quantitative damages of both vessels and white matter fibres can help readapt even the most standard and widely accepted approach trough the brain cortex. A more detailed study of these fine anatomical details may become in the near future a fundamental part of the neurosurgical training and the preoperative planning.
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| 14. |
- Latini, Francesco, M.D. 1982-, et al.
(författare)
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Role of Preoperative Assessment in Predicting Tumor-Induced Plasticity in Patients with Diffuse Gliomas
- 2021
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Ingår i: Journal of Clinical Medicine. - : MDPI. - 2077-0383. ; 10:5
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Tidskriftsartikel (refereegranskat)abstract
- When diffuse gliomas (DG) affect the brain's potential to reorganize functional networks, patients can exhibit seizures and/or language/cognitive impairment. The tumor-brain interaction and the individual connectomic organization cannot be predicted preoperatively. We aimed to, first, investigate the relationship between preoperative assessment and intraoperative findings of eloquent tumors in 36 DG operated with awake surgery. Second, we also studied possible mechanisms of tumor-induced brain reorganization in these patients. FLAIR-MRI sequences were used for tumor volume segmentation and the Brain-Grid system (BG) was used as an overlay for infiltration analysis. Neuropsychological (NPS) and/or language assessments were performed in all patients. The distance between eloquent spots and tumor margins was measured. All variables were used for correlation and logistic regression analyses. Eloquent tumors were detected in 75% of the patients with no single variable able to predict this finding. Impaired NPS functions correlated with invasive tumors, crucial location (A4C2S2/A3C2S2-voxels, left opercular-insular/sub-insular region) and higher risk of eloquent tumors. Epilepsy was correlated with larger tumor volumes and infiltrated A4C2S2/A3C2S2 voxels. Language impairment was correlated with infiltrated A3C2S2 voxel. Peritumoral cortical eloquent spots reflected an early compensative mechanism with age as possible influencing factor. Preoperative NPS impairment is linked with high risk of eloquent tumors. A systematic integration of extensive cognitive assessment and advanced neuroimaging can improve our comprehension of the connectomic brain organization at the individual scale and lead to a better oncological/functional balance.
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| 15. |
- Latini, Francesco, 1982-, et al.
(författare)
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Segmentation of the inferior longitudinal fasciculus in the human brain : A white matter dissection and diffusion tensor tractography study
- 2017
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Ingår i: Brain Research. - : Elsevier. - 0006-8993 .- 1872-6240. ; 1675, s. 102-115
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Tidskriftsartikel (refereegranskat)abstract
- The inferior longitudinal fascicle (ILF) is one of the major occipital-temporal association pathways. Several studies have mapped its hierarchical segmentation to specific functions. There is, however, no consensus regarding a detailed description of ILF fibre organisation. The aim of this study was to establish whether the ILF has a constant number of subcomponents. A secondary aim was to determine the quantitative diffusion proprieties of each subcomponent and assess their anatomical trajectories and connectivity patterns. A white matter dissection of 14 post-mortem normal human hemispheres was conducted to define the course of the ILF and its subcomponents. These anatomical results were then investigated in 24 right-handed, healthy volunteers using in vivo diffusion tensor imaging (DTI) and streamline tractography. Fractional anisotropy (FA), volume, fibre length and the symmetry coefficient of each fibre group were analysed. In order to show the connectivity pattern of the ILF, we also conducted an analysis of the cortical terminations of each segment. We confirmed that the main structure of the ILF is composed of three constant components reflecting the occipital terminations: the fusiform, the lingual and the dorsolateral-occipital. ILF volume was significantly lateralised to the right. The examined indices of ILF subcomponents did not show any significant difference in lateralisation. The connectivity pattern and the quantitative distribution of ILF subcomponents suggest a pivotal role for this bundle in integrating information from highly specialised modular visual areas with activity in anterior temporal territory, which has been previously shown to be important for memory and emotions.
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| 16. |
- Latini, Francesco, M.D. 1982-
(författare)
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Significance of white matter anatomy in interpreting features and behaviour of low-grade gliomas and implications for surgical treatment
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Diffuse gliomas are extremely heterogeneous tumours characterized by slow growth but extensive infiltration. Their kinetic features reflect the complex interaction over time with the surrounding brain, influencing treatment planning and outcome. Indeed, resection of diffuse gliomas present a surgical challenge due to their invasiveness and the preferential location in eloquent regions. White matter bundles are the main eloquent limit to surgical resection, but this anatomical-functional information cannot be predicted preoperatively on the individual level. The incomplete description of the human brain connectome, the complex application of pathological/lesion model to the brain connectomic organization, and the underestimated role of white matter anatomy in radiological classification systems are among the major limitations for the comprehension of the glioma/white matter interaction. The overall aim of this thesis was to explore a new approach and new techniques to study the glioma/white matter interaction. A combination of white matter dissection and diffusion tensor tractography (DTT) was used to describe the connectomic organization of two major temporo-occipital connections, the inferior and the middle longitudinal fasciculus. This information was applied to patients with diffuse gliomas, demonstrating how white matter analysis was important to decode patient specific cognitive and language impairment. A new classification system for diffuse gliomas, the Brain-Grid, was created, merging local radiological anatomy with a DTT atlas for infiltration analysis. This standardized radiological tool provided information on subcortical extension (tumour invasiveness), speed, and preferential direction of glioma progression. Applied to a larger cohort of patients, differences were detected between diffuse gliomas subtypes. Tumour invasiveness and the preferential location, type, and extent of white matter involvement differed, impacting overall survival. Regional differences in white matter infiltration were detected among five major white matter bundles, and possible favourable morphological and diffusion features were investigated with transmission electron microscopy and DTT. Fibre diameter, myelin thickness, and the organization of the white matter fibres were different in regions with high infiltration frequency, providing a possible link to the preferential location of diffuse gliomas. Finally, the white matter connectivity, tumour-induced neuroplasticity, clinical and demographic information, preoperative assessment (neuropsychological and language evaluation) were compared with intraoperative findings during awake surgery. Neuropsychological impairment was associated with more invasive tumours and a higher risk of the intraoperative finding of eloquent tumour. The pattern of early cortical neuroplasticity seemed exhausted at the time of diagnosis, with age as a factor predicting the neuroplasticity potential. The combined use of these new techniques revealed new insights into the glioma/white matter interaction. The results provided in this thesis, describe a new way to structure the multidisciplinary perioperative management of these patients. This new information may improve the functional outcome at the individual level, resulting in prolonged survival for adults with diffuse gliomas.
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| 17. |
- Latini, Francesco, 1982-, et al.
(författare)
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Teaching Anatomy to Neuroscientific Health-Care Professionals : Are They Receiving the Best Anatomical Education?
- 2020
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Ingår i: Medical Science Educator. - : Springer Nature. - 2156-8650. ; 30:1, s. 41-45
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Tidskriftsartikel (refereegranskat)abstract
- University neuroanatomical courses seldom teach the anatomical-functional connectivity of the brain. White matter dissection improves understanding of brain connectivity, but until now has been restricted to neurosurgeons and in some cases to medical students, never to health-care non-medical professionals. Our aim was to teach white matter anatomy to medical and non-medical students to evaluate this technique in groups with different education. A standardized lab demonstration of white matter anatomy was performed with high appreciation rate in both groups, suggesting a suboptimal neuroanatomical education provided by basic course. We encourage to include this technique of teaching brain anatomy into basic neuroanatomical courses to improve the level of comprehension and competence in all health-care staff within the field of neuroscience.
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| 18. |
- Latini, Francesco, M.D. 1982-, et al.
(författare)
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The link between gliomas infiltration and white matter architecture investigated with electron microscopy and diffusion tensor imaging
- 2021
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Ingår i: NeuroImage. - : Elsevier. - 2213-1582. ; 31, s. 102735-
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Tidskriftsartikel (refereegranskat)abstract
- Diffuse low-grade gliomas display preferential locations in eloquent and secondary associative brain areas. The reason for this tendency is still unknown. We hypothesized that the intrinsic architecture and water diffusion properties of the white matter bundles in these regions may facilitate gliomas infiltration. Magnetic resonance imaging of one hundred and two low-grade gliomas patients were normalized to/and segmented in MNI space to create a probabilistic infiltration weighted gradient map. Diffusion tensor imaging (DTI)- based parameters were derived for five major white matter bundles, displaying high- and low grade of infiltration, (corpus callosum, cingulum, arcuate fasciculus, inferior fronto-occipital fasciculus and cortico-spinal tract), averaged over 20 healthy individuals acquired from the Human connectome project (HCP) database. Transmission electron microscopy (TEM) was used to analyze fiber density, diameter and g-ratio in 100 human white matter regions, sampled from cadaver specimens, reflecting areas with different gliomas infiltration frequency. Histological results and DTI-based parameters were compared in anatomical regions of high- and low grade of infiltration respectively. We detected differences in the infiltration frequency of five major white matter bundles. Regional differences within the same white matter bundles were detected by both TEM- and DTI analysis. Regions with high infiltration frequency (HIF) displayed a higher fiber density, smaller fiber diameter but higher myelin thickness and lower axial diffusivity compare compared with low infiltration frequency (LIF) regions. Our results seem to indicate that the fiber diameter, myelin thickness and the possible organization of the fibers are different in HIF compared to LIF regions and may be linked to the preferential location of diffuse low-grade gliomas.
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| 19. |
- Latini, Francesco, M.D. 1982-, et al.
(författare)
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White matter abnormalities in a patient with visual snow syndrome : New evidence from a diffusion tensor imaging study
- 2021
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Ingår i: European Journal of Neurology. - : Wiley. - 1351-5101 .- 1468-1331. ; 28:8, s. 2789-2793
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Tidskriftsartikel (refereegranskat)abstract
- Background: Visual snow syndrome (VSS) is a neurological condition characterized by flickering dots throughout the entire visual field. Both the pathophysiology and possible location of VSS are still under debate. White matter abnormalities were investigated using diffusion tensor imaging (DTI) in a patient with VSS. Methods: A 28-year-old patient with VSS and 10 healthy controls were investigated with DTI. Diffusion parametric maps were calculated and reconstructed using q-space diffeomorphic reconstruction. White matter pathways of the dorsal, ventral, integrative visual streams and thalamic connectivity were tracked. Then, they were applied to each subject's parameter map, stretched to the same length, and sampled along the tracts for regional analyses of DTI parameters. Results: Compared with healthy controls, our patient displayed higher axial diffusivity (AD) and radial diffusivity (RD) in the dorsal visual stream (cingulum, arcuate fasciculus, horizontal indirect anterior segment of the superior longitudinal fasciculus), in the ventral visual stream (fronto-occipital fasciculus, inferior longitudinal fasciculus) and in the integrative visual stream (indirect posterior component of the superior longitudinal fasciculus, vertical occipital fasciculus). Higher AD and RD were also detected in acoustic and optic radiations, and in thalamic radiations distal to the thalamus. Conclusion: This VSS patient displayed multiple, bilateral white matter changes in the temporo-parieto-occipital junction in white matter pathways related to vision. We encourage the study of white matter pathology using DTI in complex neurological syndromes including VSS.
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| 20. |
- Neves, Inês, et al.
(författare)
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Paired glioblastoma cell cultures of the fluorescent bulk tumor and non-fluorescent tumor margin display differential phenotypes and cell states across patients
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Glioblastoma is an aggressive and therapy-resistant primary brain tumor with a dismal prognosis. The inevitable recurrence is in almost all patients in contact with the resection cavity, suggesting the local peritumoral area as its origin. Glioblastoma cells of this region have seldom been studied and few authenticated models exist. We have explanted matched tissue samples from the bulk tumor and local tumor edge of 13 glioblastoma patients of which 7 were sustainable beyond passage 6. Each edge culture was more invasive and less self-renewing and tumorigenic compared to its paired bulk culture. Three pairs of edge and bulk cultures were profiled with a combined single nucleus (sn) RNA- and ATAC-sequencing. Transcriptome analysis displayed for all patients a shift towards AC-MES cell states in the edge cultures. Chromatin-accessibility profiles uncovered differential regulatory networks with edge cells being enriched for transcription factor (TF) motifs of invasion, neurons, and immune cells. We propose that edge cells have been epigenetically reprogrammed by their unique interactions with various cell types in the peritumoral region. The fact that glioblastoma edge cells display distinct epigenetic regulation compared to their bulk tumor cells has implications for therapy development that should be targeted to and tested on the relapse-causing glioblastoma edge cells.
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| 21. |
- Olivo, Gaia, et al.
(författare)
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Disruption of Accumbens and Thalamic White Matter Connectivity Revealed by Diffusion Tensor Tractography in Young Men with Genetic Risk for Obesity
- 2018
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Ingår i: Frontiers in Human Neuroscience. - : Frontiers Media SA. - 1662-5161. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Background: Neurovascular coupling is associated with white matter (WM) structural integrity, and it is regulated by specific subtypes of dopaminergic receptors. An altered activity of such receptors, highly expressed in reward-related regions, has been reported in carriers of obesity-risk alleles of the fat mass and obesity associated (FTO) gene. Among the reward-related regions, the thalamus and the nucleus accumbens are particularly vulnerable to blood pressure dysregulation due to their peculiar anatomo-vascular characteristics, and have been consistently reported to be altered in early-stage obesity. We have thus hypothesized that a disruption in thalamus and nucleus accumbens WM microstructure, possibly on neurovascular basis, could potentially be a predisposing factor underlying the enhanced risk for obesity in the risk-allele carriers.Methods: We have tested WM integrity in 21 male participants genotyped on the FTO risk single nucleotide polymorphisms (SNP) rs9939609, through a deterministic tractography analysis. Only homozygous participants (9 AA, 12 TT) were included. 11 tracts were selected and categorized as following according to our hypothesis: “risk tracts”, “obesity-associated tracts”, and a control tract (forcpes major). We investigated whether an association existed between genotype, body mass index (BMI) and WM microstructural integrity in the “risk-tracts” (anterior thalamic radiation and accumbofrontal fasciculus) compared to other tracts. Moreover, we explored whether WM diffusivity could be related to specific personality traits in terms of punishment and reward sensitivity, as measure by the BIS/BAS questionnaire.Results: An effect of the genotype and an interaction effect of genotype and BMI were detected on the fractional anisotropy (FA) of the “risk tracts”. Correlations between WM diffusivity parameters and measures of punishment and reward sensitivity were also detected in many WM tracts of both networks.Conclusions: A disruption of the structural connectivity from the nucleus accumbens and the thalamus might occur early in carriers of the FTO AA risk-allele, and possibly act as a predisposing factor to the development of obesity.
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| 22. |
- Roodakker, Kenney Roy, 1989-, et al.
(författare)
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Ecstatic and gelastic seizures relate to the hypothalamus
- 2020
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Ingår i: Epilepsy & Behavior Reports. - : Elsevier BV. - 2589-9864. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Ecstatic seizures constitute a rare form of epilepsy, and the semiology is diverse. Previously, brain areas including the temporal lobe and the insula have been identified to be involved in clinical expression. The aim of this report is to review changes in ecstatic seizures in a patient before and after operation of a hypothalamic hamartoma, and to scrutinize the relation to gelastic seizures. In this case, the ecstatic seizures disappeared after surgery of the hamartoma but reappeared eleven years later. Clinical information was retrospectively obtained from medical records, interviews, and a questionnaire covering seizure semiology that pertained to ecstatic and gelastic seizures. Our findings imply a possible connection between gelastic and ecstatic seizures, originating from a hypothalamic hamartoma. To our knowledge, this location has not previously been described in ecstatic seizures. Gelastic seizures may in this case were associated with ecstatic seizures. We speclate patients with ecstatic seizures may have an ictal activation of neuronal networks that involves the insula. Our case may add information to the growing knowledge concerning ecstatic seizures.
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| 23. |
- Roodakker, Kenney Roy, 1989-, et al.
(författare)
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Ecstatic and gelastic seizures related to the hypothalamus
- 2021
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Ingår i: Epilepsy & Behavior Reports. - : Elsevier. - 2589-9864. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- Ecstatic seizures constitute a rare form of epilepsy, and the semiology is diverse. Previously, brain areas including the temporal lobe and the insula have been identified to be involved in clinical expression. The aim of this report is to review changes in ecstatic seizures in a patient before and after operation for a hypothalamic hamartoma, and to scrutinize the relation to gelastic seizures. In this case, the ecstatic seizures disappeared after surgery of the hamartoma but reappeared eleven years later. Clinical information was retrospectively obtained from medical records, interviews, and a questionnaire covering seizure semiology that pertained to ecstatic and gelastic seizures. Our findings imply a possible connection between gelastic and ecstatic seizures, originating from a hypothalamic hamartoma. To our knowledge, this location has not previously been described in ecstatic seizures. Gelastic seizures may in this case be associated with ecstatic seizures. We speculate that patients with ecstatic seizures may have an ictal activation of neuronal networks that involve the insula. Our case may add information to the knowledge concerning ecstatic seizures. (C) 2020 The Authors. Published by Elsevier Inc.
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| 24. |
- Svedung-Wettervik, Teodor, et al.
(författare)
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Dynamics in cognition and health-related quality of life in grade 2 and 3 gliomas after surgery
- 2022
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Ingår i: Acta Neurochirurgica. - : Springer Nature. - 0001-6268 .- 0942-0940. ; 164:12, s. 3275-3284
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundThe focus of clinical management and research in gliomas has been on survival, but the interest in the treatment effects on cognition and health-related quality of life (HRQoL) is emerging. The primary aim of this study was to investigate the dynamics in cognition after brain tumor surgery for astrocytomas and oligodendrogliomas grade 2 and 3. The secondary aim was to investigate the association of postoperative changes in cognition with changes HRQoL.MethodsIn this observational study, 48 patients operated for an astrocytoma or oligodendrogliomas, grade 2 or 3, at the Department of Neurosurgery, Uppsala, Sweden, 2016–2021, were included. Cognitive and language skills were assessed with a selected test battery and HRQoL was patient-reported as assessed with RAND-36 pre- and approximately 3 months postoperatively.ResultsThere was a significant postoperative decrease in attention span and verbal learning, but the patients improved in the test for visual memory. There was no change in visual attention, executive function, verbal memory, visual organization and construction, verbal fluency, and confrontation naming. The RAND-36 variables physical function, role physical, general health, vitality, and social functioning decreased significantly after surgery. Patients operated for tumor recurrence exhibited greater deterioration in attention and a greater extent of resection correlated with a less pronounced decrease in verbal memory, but there were otherwise weak associations between the dynamics in cognition and patient-, tumor-, and treatment-variables. A decline in cognitive variables was not associated with worse HRQoL.ConclusionsAlthough both several cognitive and HRQoL domains deteriorated postoperatively, these changes did not correlate with each other. This highlights the complexity of cognitive and HRQoL dynamics in the early postoperative phase.
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| 25. |
- Svedung-Wettervik, Teodor, et al.
(författare)
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Patient-reported quality of life in grade 2 and 3 gliomas after surgery, can we do more?
- 2022
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Ingår i: Clinical neurology and neurosurgery. - : Elsevier. - 0303-8467 .- 1872-6968. ; 214
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To study the effects of surgery and the explanatory variables for patient-reported health-related quality of life (HRQoL) after brain tumor surgery for astrocytomas and oligodendrogliomas grade 2 and 3.Methods: Patients operated for an astrocytoma or an oligodendrogliomas, grade 2 or 3, at the Department of Neurosurgery, Uppsala, Sweden, 2016-2021, were included. HRQoL was assessed with RAND-36 preoperatively and 4 months postoperatively. Demographic, tumor, and treatment data were prospectively collected.Results: Sixty-two patients were included, 34 with an astrocytoma and 28 with an oligodendroglioma. Physical function, role physical, general health, vitality, and social functioning decreased significantly (p-values < 0.01) 4 months after surgery, whereas bodily pain, role emotional, and mental health remained unchanged. In Spearman analyses, younger patients deteriorated more in role physical, females worsened less often in general health but more often in social functioning than males, a higher level of education correlated with a more pronounced drop in social functioning, and a greater extent of resection corresponded to a worsening in physical function postoperatively (p-values < 0.05).Conclusions: Several HRQoL domains deteriorated after glioma surgery in specific groups of patients, particularly general health, vitality, physical, and social functions. This was only weakly explained by surgical variables. Specific groups of patients may need closer follow-ups and tailored support/rehabilitation to detect and address these HRQoL deteriorations.
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| 26. |
- Zetterling, Maria, et al.
(författare)
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Time course of neurological deficits after surgery for primary brain tumours
- 2020
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Ingår i: Acta Neurochirurgica. - : SPRINGER WIEN. - 0001-6268 .- 0942-0940. ; 162:12, s. 3005-3018
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Tidskriftsartikel (refereegranskat)abstract
- Background The postoperative course after surgery for primary brain tumours can be difficult to predict. We examined the time course of postoperative neurological deficits and analysed possible predisposing factors. Method Hundred adults with a radiological suspicion of low- or high-grade glioma were prospectively included and the postoperative course analysed. Possible predictors of postoperative neurological deterioration were evaluated. Results New postoperative neurologic deficits occurred in 37% of the patients, and in 4%, there were worsening of a preoperative deficit. In 78%, the deficits occurred directly after surgery. The probable cause of deterioration was EEG-verified seizures in 7, ischemic lesion in 5 and both in 1, resection of eloquent tissue in 6, resection close to eloquent tissue including SMA in 11 and postoperative haematoma in 1 patient. Seizures were the main cause of delayed neurological deterioration. Two-thirds of patients with postoperative deterioration showed complete regression of the deficits, and in 6% of all patients, there was a slight disturbance of the function after 3 months. Remaining deficits were found in 6% and only in patients with preoperative neurological deficits and high-grade tumours with mainly eloquent locations. Eloquent tumour location was a predictor of postoperative neurological deterioration and preoperative neurological deficits of remaining deficits. Conclusions Postoperative neurological deficits occurred in 41% and remained in 6% of patients. Remaining deficits were found in patients with preoperative neurological deficits and high-grade tumours with mainly eloquent locations. Eloquent tumour location was a predictor of neurological deterioration and preoperative neurological deficits of remaining deficits.
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