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Schneider I, Schmitgen MM, Bach C, Listunova L, Kienzle J, Sambataro F, Depping MS, Kubera KM, Roesch-Ely D, Wolf RC. Cognitive remediation therapy modulates intrinsic neural activity in patients with major depression. Psychol Med 2020; 50:2335-2345. [PMID: 31524112 DOI: 10.1017/s003329171900240x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND Cognitive impairment is a core feature of major depressive disorder (MDD). Cognitive remediation may improve cognition in MDD, yet so far, the underlying neural mechanisms are unclear. This study investigated changes in intrinsic neural activity in MDD after a cognitive remediation trial. METHODS In a longitudinal design, 20 patients with MDD and pronounced cognitive deficits and 18 healthy controls (HC) were examined using resting-state functional magnetic resonance imaging. MDD patients received structured cognitive remediation therapy (CRT) over 5 weeks. The whole-brain fractional amplitude of low-frequency fluctuations was computed before the first and after the last training session. Univariate methods were used to address regionally-specific effects, and a multivariate data analysis strategy was employed to investigate functional network strength (FNS). RESULTS MDD patients significantly improved in cognitive function after CRT. Baseline comparisons revealed increased right caudate activity and reduced activity in the left frontal cortex, parietal lobule, insula, and precuneus in MDD compared to HC. In patients, reduced FNS was found in a bilateral prefrontal system at baseline (p < 0.05, uncorrected). In MDD, intrinsic neural activity increased in right inferior frontal gyrus after CRT (p < 0.05, small volume corrected). Left inferior parietal lobule, left insula, left precuneus, and right caudate activity showed associations with cognitive improvement (p < 0.05, uncorrected). Prefrontal network strength increased in patients after CRT, but this increase was not associated with improved cognitive performance. CONCLUSIONS Our findings support the role of intrinsic neural activity of the prefrontal cortex as a possible mediator of cognitive improvement following CRT in MDD.
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Wasserthal J, Maier-Hein KH, Neher PF, Northoff G, Kubera KM, Fritze S, Harneit A, Geiger LS, Tost H, Wolf RC, Hirjak D. Multiparametric mapping of white matter microstructure in catatonia. Neuropsychopharmacology 2020; 45:1750-1757. [PMID: 32369829 PMCID: PMC7419514 DOI: 10.1038/s41386-020-0691-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 04/20/2020] [Accepted: 04/22/2020] [Indexed: 12/13/2022]
Abstract
Catatonia is characterized by motor, affective and behavioral abnormalities. To date, the specific role of white matter (WM) abnormalities in schizophrenia spectrum disorders (SSD) patients with catatonia is largely unknown. In this study, diffusion magnetic resonance imaging (dMRI) data were collected from 111 right-handed SSD patients and 28 healthy controls. Catatonic symptoms were examined on the Northoff Catatonia Rating Scale (NCRS). We used whole-brain tract-based spatial statistics (TBSS), tractometry (along tract statistics using TractSeg) and graph analytics (clustering coefficient-CCO, local betweenness centrality-BC) to provide a framework of specific WM microstructural abnormalities underlying catatonia in SSD. Following a categorical approach, post hoc analyses showed differences in fractional anisotrophy (FA) measured via tractometry in the corpus callosum, corticospinal tract and thalamo-premotor tract as well as increased CCO as derived by graph analytics of the right superior parietal cortex (SPC) and left caudate nucleus in catatonic patients (NCRS total score ≥ 3; n = 30) when compared to non-catatonic patients (NCRS total score = 0; n = 29). In catatonic patients according to DSM-IV-TR (n = 43), catatonic symptoms were associated with FA variations (tractometry) of the left corticospinal tract and CCO of the left orbitofrontal cortex, primary motor cortex, supplementary motor area and putamen. This study supports the notion that structural reorganization of WM bundles connecting orbitofrontal/parietal, thalamic and striatal regions contribute to catatonia in SSD patients.
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Al Saleh AS, Parmar HV, Vaxman I, Visram A, Hasib Sidiqi M, Muchtar E, Buadi FK, Dispenzieri A, Warsame R, Lacy MQ, Dingli D, Gonsalves WI, Wolf RC, Kourelis TV, Hogan WJ, Hayman SR, Kapoor P, Kumar SK, Gertz MA. Prognostic value of NT-ProBNP and troponin T in patients with light chain amyloidosis and kidney dysfunction undergoing autologous stem cell transplantation. Bone Marrow Transplant 2020; 56:274-277. [PMID: 32623446 DOI: 10.1038/s41409-020-0990-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/06/2020] [Accepted: 06/23/2020] [Indexed: 11/09/2022]
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Wolf RC, Rashidi M, Fritze S, Kubera KM, Northoff G, Sambataro F, Calhoun VD, Geiger LS, Tost H, Hirjak D. A Neural Signature of Parkinsonism in Patients With Schizophrenia Spectrum Disorders: A Multimodal MRI Study Using Parallel ICA. Schizophr Bull 2020; 46:999-1008. [PMID: 32162660 PMCID: PMC7345812 DOI: 10.1093/schbul/sbaa007] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Motor abnormalities in schizophrenia spectrum disorders (SSD) have increasingly attracted scientific interest in the past years. However, the neural mechanisms underlying parkinsonism in SSD are unclear. The present multimodal magnetic resonance imaging (MRI) study examined SSD patients with and without parkinsonism, as defined by a Simpson and Angus Scale (SAS) total score of ≥4 (SAS group, n = 22) or <4 (non-SAS group, n = 22). Parallel independent component analysis (p-ICA) was used to examine the covarying components among gray matter volume maps computed from structural MRI (sMRI) and fractional amplitude of low-frequency fluctuations (fALFF) maps computed from resting-state functional MRI (rs-fMRI) patient data. We found a significant correlation (P = .020, false discovery rate [FDR] corrected) between an sMRI component and an rs-fMRI component, which also significantly differed between the SAS and non-SAS group (P = .042, z = -2.04). The rs-fMRI component comprised the cortical sensorimotor network, and the sMRI component included predominantly a frontothalamic/cerebellar network. Across the patient sample, correlations adjusted for the Positive and Negative Syndrome Scale (PANSS) total scores showed a significant relationship between tremor score and loadings of the cortical sensorimotor network, as well as between glabella-salivation score, frontothalamic/cerebellar and cortical sensorimotor network loadings. These data provide novel insights into neural mechanisms of parkinsonism in SSD. Aberrant bottom-up modulation of cortical motor regions may account for these specific motor symptoms, at least in patients with SSD.
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Sambataro F, Fritze S, Rashidi M, Topor CE, Kubera KM, Wolf RC, Hirjak D. Moving forward: distinct sensorimotor abnormalities predict clinical outcome after 6 months in patients with schizophrenia. Eur Neuropsychopharmacol 2020; 36:72-82. [PMID: 32522386 DOI: 10.1016/j.euroneuro.2020.05.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Revised: 04/28/2020] [Accepted: 05/04/2020] [Indexed: 01/24/2023]
Abstract
Despite substantial efforts in the last decades, objective measures that can predict clinical outcome in patients with schizophrenia (SZ) after an acute psychotic episode are still lacking. Here, we introduced a comprehensive assessment of sensorimotor function to predict mid-term clinical outcome following an acute psychotic episode. This naturalistic follow-up of 43 patients with DSM-IV-TR diagnosis of SZ examined sensorimotor abnormalities (i.e. Neurological Soft Signs (NSS), parkinsonism, akathisia, catatonia and acute dyskinesia), psychopathology, cognition and psychosocial functioning using well-established instruments. A collection of statistical methods was used to examine the relationship between sensorimotor domain, psychopathology, cognition and psychosocial functioning. We also tested the clinical feasibility of this relationship when predicting clinical outcome after an acute psychotic episode. Longitudinal data were collected on 43 individuals after a follow-up period of >6 months. At follow-up, patients showed significantly reduced general symptom severity, as well as decreased levels of NSS, parkinsonism and catatonia. Further, NSS scores at baseline predicted PANSS negative scores and cognitive functioning at baseline. Finally, NSS scores at baseline predicted symptom change (reduction of PANSS positive and negative scores) at follow-up. In conclusion, our results suggest that NSS are significant predictors of poor clinical outcome in SZ at baseline and >6 months after an acute psychotic episode. These findings propose sensorimotor domain as state biomarker of SZ and support its predictive power with respect to treatment outcome.
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Ice LL, Bartoo GT, McCullough KB, Wolf RC, Dierkhising RA, Mara KC, Jowsey-Gregoire SG, Damlaj M, Litzow MR, Merten JA. A Prospective Survey of Outpatient Medication Adherence in Adult Allogeneic Hematopoietic Stem Cell Transplantation Patients. Biol Blood Marrow Transplant 2020; 26:1627-1634. [PMID: 32505809 DOI: 10.1016/j.bbmt.2020.05.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 05/23/2020] [Accepted: 05/26/2020] [Indexed: 11/28/2022]
Abstract
Limited data exist regarding the prevalence and outcome of medication nonadherence in the adult allogeneic hematopoietic stem cell transplantation (allo-HSCT) population. The objective of this cross-sectional survey study is to determine the prevalence of medication nonadherence to immunosuppressant and nonimmunosuppressant medications in adult recipients of allo-HSCT. An electronic survey using previously validated medication adherence scales was distributed between December 2014 and April 2015 to 200 adult patients with at least 3 months of follow-up after allo-HSCT. Immunosuppressant serum drug levels and prescription refill records were retrospectively collected to assess correlation with survey responses. In the entire cohort, 51% of subjects (n = 102) reported nonadherence to nonimmunosuppressant medications (95% confidence interval [CI], 44.07% to 57.93%) on the Morisky Medication Adherence Scale. Of the 153 patients taking oral immunosuppressant medications at the time of the survey, 58 (37.9%) reported nonadherence to immunosuppressant therapy (95% CI, 30.22% to 45.6%), as measured by the Immunosuppressant Therapy Adherence Scale. Younger age and distress were associated with medication nonadherence. Nonadherence to immunosuppressant therapy was associated with mild chronic graft-vs-host disease (cGVHD), and a similar trend was observed for moderate cGVHD. Medication nonadherence was found to be highly prevalent for both immunosuppressant and nonimmunosuppressant medications in adult allo-HSCT recipient, and further study to identify interventions to improve adherence in these patients is warranted.
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Al Saleh AS, Dispenzieri A, Muchtar E, Wolf RC, Dingli D, Lacy M, Warsame RM, Gonsalves WI, Kourelis T, Hogan WJ, Hayman SR, Kapoor P, Buadi F, Kumar S, Gertz MA. Prognostic role of beta-2 microglobulin in patients with light chain amyloidosis treated with autologous stem cell transplantation. J Clin Oncol 2020. [DOI: 10.1200/jco.2020.38.15_suppl.e20506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
e20506 Background: Autologous stem cell transplantation (ASCT) prolongs survival in patients with light chain (AL) amyloidosis. Mayo 2012 stage and increased plasma cell percentage (%PC) are known predictors for survival. Increased beta-2 microglobulin (B2M) predicts survival in patients with multiple myeloma. However, its prognostic effect in patients with AL amyloidosis undergoing ASCT is not known. Methods: We retrospectively reviewed patients who had a diagnosis of AL amyloidosis and were treated with ASCT between July-1996 and September-2017. Patients with creatinine > 1.2 mg/dL were excluded, as that affects B2M levels. The receiver operator curve was used to determine the best cutoff for B2M in predicting survival and was 2.5 mcg/mL. Baseline characteristics were compared between patients with B2M > 2.5 and ≤2.5. Progression-free survival (PFS) was defined as time from ASCT to relapse or death, whichever occurred first. Overall survival (OS) was calculated from ASCT to death of any cause. Univariate and multivariate analysis were done for OS. Results: Five-hundred patients were identified and 222 (44%) had a B2M > 2.5. These patients were more likely to be > 65 years old (32% vs. 17%, P = 0.0001), have Mayo 2012 stage III/IV (33% vs. 8%, P < 0.0001), have ≥3 organs involved (25% vs. 14%, P = 0.001), and have ≥10% PCs (56% vs. 40%, P = 0.0002) compared to patients with B2M ≤2.5. The median PFS and OS were shorter in patients with B2M > 2.5 (median PFS: 64 vs. 80 months, P = 0.03); (median OS: 104.9 vs. 175.5 months, P < 0.0001). On univariate analysis, predictors for OS included age > 65 (HR: 1.6, P = 0.001), Mayo 2012 stage III/IV (HR: 3.3, P < 0.0001), ≥3 organs involved (HR: 1.3, P = 0.06), ≥10% PC (HR: 1.5, P = 0.004), melphalan conditioning 200mg/m2 (HR: 0.28, P < 0.0001), and B2M > 2.5 (HR: 1.8, P < 0.0001). In a multivariate analysis, only Mayo 2012 stage III/IV (HR: 1.8, P = 0.006), melphalan conditioning 200mg/m2 (HR: 0.35, P < 0.0001), and B2M > 2.5 (HR: 1.7, P = 0.01) remained independent predictive of OS. Conclusions: Beta-2 microglobulin > 2.5 is an independent predictor for OS in AL amyloidosis patients undergoing ASCT and should be routinely measured.
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Bubik RJ, Barth DM, Hook C, Wolf RC, Muth JM, Mara K, Patnaik MS, Pruthi RK, Marshall AL, Litzow MR, Elliott MA, Hogan WJ, Shah MV, Begna KH, Alkhateeb H, Pardanani A, Ashrani AA, Call TG, Rivera CE, Camoriano JK, Go RS, Wolanskyj-Spinner AP, Parikh SA. Clinical outcomes of adults with hemophagocytic lymphohistiocytosis treated with the HLH-04 protocol: a retrospective analysis. Leuk Lymphoma 2020; 61:1592-1600. [PMID: 32157935 DOI: 10.1080/10428194.2020.1737684] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Hemophagocytic lymphohistiocytosis (HLH) is a rare syndrome of pathologic immune activation in children that is increasingly being recognized in adults. Efficacy data for the HLH-04 protocol in adults is lacking. This study retrospectively analyzed 31 adult patients, median age 46 years, who received HLH-04 from 1/1/2004 to 5/1/2018. HLH etiology included malignancy (n = 9), autoimmune (n = 8), infection (n = 8), and idiopathic (n = 6). Eighteen patients were evaluable for response at week 4 with 7 having no response, 11 reaching partial response, and 0 reaching complete response (CR). Six patients eventually achieved CR at a median 195 days. The 1-year overall survival (OS) was 35% and median OS was 3.2 months. Univariate analysis showed shorter survival for hemoglobin <9 g/dL (HR 4.29, p = 0.003), platelets <100 × 109/L (HR 4.06, p = 0.027), ANC <1 × 109/L (HR 5.24, p = 0.001), and total bilirubin >1.2 mg/dL (HR 3.30, p = 0.022). Outcomes of adults treated with HLH-04 remain dismal and newer treatment modalities are needed.
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Schneider I, Schmitgen MM, Boll S, Roth C, Nees F, Usai K, Herpertz SC, Wolf RC. Oxytocin modulates intrinsic neural activity in patients with chronic low back pain. Eur J Pain 2020; 24:945-955. [PMID: 32061140 DOI: 10.1002/ejp.1543] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Modulation of pain perception by oxytocin (OXT) has attracted increased scientific and clinical interest. Neural mechanisms underlying these effects are poorly understood. In this study, we aimed to investigate the effects of intranasally applied OXT on intrinsic neural activity in patients with chronic low back pain (cLBP). METHODS Twenty-four male patients with cLBP and 23 healthy males were examined using resting-state functional magnetic resonance imaging. Participants were scanned twice and received either intranasally applied OXT (24 international units) or placebo 40 min before scanning. The fractional amplitude of low-frequency fluctuations (fALFF) was computed to investigate regionally specific effects of OXT on intrinsic neural activity. In addition a multivariate statistical data analysis strategy was employed to explore OXT-effects on functional network strength. RESULTS Differential effects of OXT were observed in cLBP and healthy controls. FALFF decreased in left nucleus accumbens and right thalamus in cLBP and increased in right thalamus in healthy controls after OXT application compared to placebo. OXT also induced activity changes in bilateral thalamus, left caudate nucleus and right amygdala in cLBP. OXT was associated with increased medial frontal, parietal and occipital functional network strength, though this effect was not group-specific. Regression analyses revealed significant associations between left nucleus accumbens, left caudate nucleus and right amygdala with pain-specific psychometric scores in cLBP. CONCLUSIONS These data suggest OXT-related modulation of regional activity and neural network strength in patients with cLBP and healthy controls. In patients, distinct regions of the pain matrix may be responsive to modulation by OXT. SIGNIFICANCE Our data suggest significant oxytocin-related modulation of intrinsic regional activity and neural network strength in patients with chronic low back pain and healthy controls. In patients, distinct regions of the pain matrix may be responsive to modulation by oxytocin. Therapeutic effects of oxytocin for improved pain treatment need to be further investigated.
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Schmitgen MM, Kubera KM, Depping MS, Nolte HM, Hirjak D, Hofer S, Hasenkamp JH, Seidl U, Stieltjes B, Maier-Hein KH, Sambataro F, Sartorius A, Thomann PA, Wolf RC. Exploring cortical predictors of clinical response to electroconvulsive therapy in major depression. Eur Arch Psychiatry Clin Neurosci 2020; 270:253-261. [PMID: 31278421 DOI: 10.1007/s00406-019-01033-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 06/15/2019] [Indexed: 12/11/2022]
Abstract
Electroconvulsive therapy (ECT) is a rapid and highly effective treatment option for treatment-resistant major depressive disorder (TRD). The neural mechanisms underlying such beneficial effects are poorly understood. Exploring associations between changes of brain structure and clinical response is crucial for understanding ECT mechanisms of action and relevant for the validation of potential biomarkers that can facilitate the prediction of ECT efficacy. The aim of this explorative study was to identify cortical predictors of clinical response in TRD patients treated with ECT. We longitudinally investigated 12 TRD patients before and after ECT. Twelve matched healthy controls were studied cross sectionally. Demographical, clinical, and structural magnetic resonance imaging data at 3 T and multiple cortical markers derived from surface-based morphometry (SBM) analyses were considered. Multiple regression models were computed to identify predictors of clinical response to ECT, as reflected by Hamilton Depression Rating Scale (HAMD) score changes. Symptom severity differences pre-post-ECT were predicted by models including demographic data, clinical data and SBM of frontal, cingulate, and entorhinal structures. Using all-subsets regression, a model comprising HAMD score at baseline and cortical thickness of the left rostral anterior cingulate gyrus explained most variance in the data (multiple R2 = 0.82). The data suggest that SBM provides powerful measures for identifying biomarkers for ECT response in TRD. Rostral anterior cingulate thickness and HAMD score at baseline showed the greatest predictive power of clinical response, in contrast to cortical complexity, cortical gyrification, or demographical data.
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Fritze S, Sambataro F, Kubera KM, Bertolino AL, Topor CE, Wolf RC, Hirjak D. Neurological soft signs in schizophrenia spectrum disorders are not confounded by current antipsychotic dosage. Eur Neuropsychopharmacol 2020; 31:47-57. [PMID: 31780303 DOI: 10.1016/j.euroneuro.2019.11.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 10/29/2019] [Accepted: 11/04/2019] [Indexed: 12/20/2022]
Abstract
Neurological soft signs (NSS) have garnered increasing attention in psychiatric research on motor abnormalities in schizophrenia spectrum disorders (SSD). However, it remains unclear whether the assessment of NSS severity could have been confounded by current antipsychotic dosage. In this study, we recruited 105 patients with SSD that underwent a comprehensive motor assessment evaluating NSS and extrapyramidal motor symptoms (EPMS) by means of standardized instruments. Current antipsychotic dosage equivalence estimates were determined by the classical mean dose method (doses equivalent to 1 mg/d olanzapine). We used multiple regression analyses to describe the relationship between NSS, EPMS and antipsychotic medication. In line with our expectations, current antipsychotic dosage had no significant effects on NSS total score (p = 0.27), abnormal involuntary movements (p = 0.17), akathisia (p = 0.32) and parkinsonism (p = 0.26). Further, NSS total score had a significant effect on akathisia (p = 0.003) and parkinsonism (p = 0.0001, Bonferroni corr.), but only marginal effect on abnormal involuntary movements (p = 0.08). Our results support the notion that NSS are not significantly modulated by current antipsychotic dosage in SSD. The associations between NSS, akathisia and parkinsonism, as revealed by this study, support the genuine rather than medication-dependent origin of particular motor abnormalities in SSD.
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Ford OP, Vanó L, Alonso JA, Baldzuhn J, Beurskens MNA, Biedermann C, Bozhenkov SA, Fuchert G, Geiger B, Hartmann D, Jaspers RJE, Kappatou A, Langenberg A, Lazerson SA, McDermott RM, McNeely P, Neelis TWC, Pablant NA, Pasch E, Rust N, Schroeder R, Scott ER, Smith HM, Wegner T, Kunkel F, Wolf RC. Charge exchange recombination spectroscopy at Wendelstein 7-X. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:023507. [PMID: 32113444 DOI: 10.1063/1.5132936] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 01/16/2020] [Indexed: 06/10/2023]
Abstract
The Charge Exchange Recombination Spectroscopy (CXRS) diagnostic has become a routine diagnostic on almost all major high temperature fusion experimental devices. For the optimized stellarator Wendelstein 7-X (W7-X), a highly flexible and extensive CXRS diagnostic has been built to provide high-resolution local measurements of several important plasma parameters using the recently commissioned neutral beam heating. This paper outlines the design specifics of the W7-X CXRS system and gives examples of the initial results obtained, including typical ion temperature profiles for several common heating scenarios, toroidal flow and radial electric field derived from velocity measurements, beam attenuation via beam emission spectra, and normalized impurity density profiles under some typical plasma conditions.
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Hirjak D, Rashidi M, Kubera KM, Northoff G, Fritze S, Schmitgen MM, Sambataro F, Calhoun VD, Wolf RC. Multimodal Magnetic Resonance Imaging Data Fusion Reveals Distinct Patterns of Abnormal Brain Structure and Function in Catatonia. Schizophr Bull 2020; 46:202-210. [PMID: 31174212 PMCID: PMC6942158 DOI: 10.1093/schbul/sbz042] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Catatonia is a nosologically unspecific syndrome, which subsumes a plethora of mostly complex affective, motor, and behavioral phenomena. Although catatonia frequently occurs in schizophrenia spectrum disorders (SSD), specific patterns of abnormal brain structure and function underlying catatonia are unclear at present. Here, we used a multivariate data fusion technique for multimodal magnetic resonance imaging (MRI) data to investigate patterns of aberrant intrinsic neural activity (INA) and gray matter volume (GMV) in SSD patients with and without catatonia. Resting-state functional MRI and structural MRI data were collected from 87 right-handed SSD patients. Catatonic symptoms were examined on the Northoff Catatonia Rating Scale (NCRS). A multivariate analysis approach was used to examine co-altered patterns of INA and GMV. Following a categorical approach, we found predominantly frontothalamic and corticostriatal abnormalities in SSD patients with catatonia (NCRS total score ≥ 3; n = 24) when compared to SSD patients without catatonia (NCRS total score = 0; n = 22) matched for age, gender, education, and medication. Corticostriatal network was associated with NCRS affective scores. Following a dimensional approach, 33 SSD patients with catatonia according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision were identified. NCRS behavioral scores were associated with a joint structural and functional system that predominantly included cerebellar and prefrontal/cortical motor regions. NCRS affective scores were associated with frontoparietal INA. This study provides novel neuromechanistic insights into catatonia in SSD suggesting co-altered structure/function-interactions in neural systems subserving coordinated visuospatial functions and motor behavior.
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Schaier M, Wolf RC, Kubera K, Nagel S, Bartsch A, Zeier M, Bendszus M, Herweh C. Vasogenic Brain Edema During Maintenance Hemodialysis : Preliminary Results from Tract-based Spatial Statistics and Voxel-based Morphometry. Clin Neuroradiol 2019; 31:217-224. [PMID: 31848644 DOI: 10.1007/s00062-019-00865-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 11/21/2019] [Indexed: 12/30/2022]
Abstract
BACKGROUND Hemodialysis (HD), especially when first initiated, can cause neurological deterioration. Presumably this is due to transient cerebral edema, which has been observed using diffusion weighted magnetic resonance imaging (MRI) in experimental and human studies; however, this has not been investigated under maintenance hemodialysis (mHD). Moreover, there are no studies to date investigating regional effects of mHD on grey and white matter volumes. METHODS In this study eight patients with end stage renal disease (ESRD) were examined immediately before and after mHD sessions with multimodal MRI, including diffusion tensor imaging (DTI) and high-resolution structural imaging. Additionally, eight healthy, age-matched and sex-matched controls were examined for comparison. Data were analyzed using tract-based spatial statistics and voxel-based morphometry. RESULTS At baseline, ESRD patients had significantly reduced values of fractional anisotropy (FA) and axial diffusivity as well as bilaterally reduced grey matter volume in the insula, compared with controls. After the mHD session, FA further decreased while axial, radial, and mean diffusivity significantly increased ubiquitously throughout the white matter. Voxel-based morphometry revealed a corresponding significant increase in white matter volume in the central right hemisphere and splenium, as well as in cortical grey matter in the anterior medial frontal and cingulate cortex. None of the patients showed neurological deterioration. CONCLUSION In this study ESRD patients showed white matter changes indicative of chronic microstructural damage when compared with healthy controls, as previously reported. In addition, patients showed signs of a transient extracellular cerebral edema, which has not yet been observed in the absence of neurological symptoms.
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Hirjak D, Kubera KM, Northoff G, Fritze S, Bertolino AL, Topor CE, Schmitgen MM, Wolf RC. Cortical Contributions to Distinct Symptom Dimensions of Catatonia. Schizophr Bull 2019; 45:1184-1194. [PMID: 30753720 PMCID: PMC6811823 DOI: 10.1093/schbul/sby192] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Catatonia is a central aspect of schizophrenia spectrum disorders (SSD) and most likely associated with abnormalities in affective, motor, and sensorimotor brain regions. However, contributions of different cortical features to the pathophysiology of catatonia in SSD are poorly understood. Here, T1-weighted structural magnetic resonance imaging data at 3 T were obtained from 56 right-handed patients with SSD. Using FreeSurfer version 6.0, we calculated cortical thickness, area, and local gyrification index (LGI). Catatonic symptoms were examined on the Northoff catatonia rating scale (NCRS). Patients with catatonia (NCRS total score ≥3; n = 25) showed reduced surface area in the parietal and medial orbitofrontal gyrus and LGI in the temporal gyrus (P < .05, corrected for cluster-wise probability [CWP]) as well as hypergyrification in rostral cingulate and medial orbitofrontal gyrus when compared with patients without catatonia (n = 22; P < .05, corrected for CWP). Following a dimensional approach, a negative association between NCRS motor and behavior scores and cortical thickness in superior frontal, insular, and precentral cortex was found (34 patients with at least 1 motor and at least 1 other affective or behavioral symptom; P < .05, corrected for CWP). Positive associations were found between NCRS motor and behavior scores and surface area and LGI in superior frontal, posterior cingulate, precentral, and pericalcarine gyrus (P < .05, corrected for CWP). The data support the notion that cortical features of distinct evolutionary and genetic origin differently contribute to catatonia in SSD. Catatonia in SSD may be essentially driven by cortex variations in frontoparietal regions including regions implicated in the coordination and goal-orientation of behavior.
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Al Saleh AS, Sidiqi MH, Sidana S, Muchtar E, Dispenzieri A, Dingli D, Lacy MQ, Warsame RM, Gonsalves WI, Kourelis TV, Hogan WJ, Hayman SR, Wolf RC, Kapoor P, Buadi FK, Kumar SK, Gertz MA. Impact of consolidation therapy post autologous stem cell transplant in patients with light chain amyloidosis. Am J Hematol 2019; 94:1066-1071. [PMID: 31273808 DOI: 10.1002/ajh.25572] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 06/27/2019] [Accepted: 07/01/2019] [Indexed: 11/10/2022]
Abstract
The role of consolidation post autologous stem cell transplant in light chain amyloidosis is not well defined. We retrospectively identified patients who had light chain amyloidosis and underwent autologous stem cell transplant at the Mayo Clinic. Consolidation was defined as any treatment given after the day 100 evaluation post-transplant to maintain or deepen the response. We identified 471 patients, of whom 72 (15%) received consolidation. Patients receiving consolidation had more advanced disease (Mayo 2012 stage ≥II in 67% vs 52%, P = .02), and had lower day 100 response rates (very good partial response or better: 35% vs 84%, P < .001). After consolidation, rates of very good partial response improved from 24% to 28%, and rates of complete response improved from 11% to 40%. Patients with less than very good partial response who received consolidation, had better progression-free survival (median of 22.4 vs 8.8 months, P < .001), and the benefit was greater in those who deepened their response (median of 41 vs 8.8 months, P < .001). In patients with less than very good partial response, there was a trend for better overall survival in patients who responded to consolidation (median of 125.8 vs 74.4 months, P = .07). In patients who achieved very good partial response, or better, at day 100 post autologous stem cell transplant, consolidation did not improve progression-free or overall survival. Consolidation after autologous stem cell transplant for light chain amyloidosis improves progression-free survival for patients who achieve less than very good partial response.
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Hirjak D, Kubera KM, Bienentreu S, Thomann PA, Wolf RC. [Antipsychotic-induced motor symptoms in schizophrenic psychoses-Part 3 : Tardive dyskinesia]. DER NERVENARZT 2019; 90:472-484. [PMID: 30341543 DOI: 10.1007/s00115-018-0629-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The treatment of schizophrenic psychoses with antipsychotic drugs (AP) is often associated with an increased risk of delayed occurrence of antipsychotic-associated movement disorders. Persistence and chronicity of such symptoms are very frequent. The risk of developing tardive dyskinesia (TD) is associated with the pharmacological effect profile of a particular AP, with treatment duration and age. This systematic review article summarizes the current study situation on prevalence, risk factors, prevention and treatment options and instruments for early prediction of TD in schizophrenic psychoses. The current data situation on treatment strategies for TD is very heterogeneous. For the treatment of TD there is preliminary evidence for reduction or discontinuation of the AP, switching to clozapine, administration of benzodiazepines (clonazepam) and treatment with vesicular monoamine transporter (VMAT2) inhibitors, ginkgo biloba, amantadine or vitamin E. Although TD can be precisely diagnosed it cannot always be effectively treated. Early detection and early treatment of TD can have a favorable influence on the prognosis and the clinical outcome.
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Sidana S, Sidiqi MH, Dispenzieri A, Buadi FK, Lacy MQ, Muchtar E, Dingli D, Hayman SR, Gonsalves WI, Kapoor P, Leung N, Warsame R, Kourelis TV, Wolf RC, Hogan WJ, Kumar SK, Gertz MA. Fifteen year overall survival rates after autologous stem cell transplantation for AL amyloidosis. Am J Hematol 2019; 94:1020-1026. [PMID: 31254301 DOI: 10.1002/ajh.25566] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 06/22/2019] [Accepted: 06/24/2019] [Indexed: 01/02/2023]
Abstract
In appropriately selected patients with AL amyloidosis, autologous stem cell transplant (ASCT) is an established treatment modality with excellent outcomes and decreasing transplant related mortality (TRM) over time. We report on 15-year overall survival (OS) in 159 patients undergoing ASCT from 1996 to 2003, with median follow up of 17.1 years. Day 100 TRM was 13.2% (n = 21). The OS of ≥15 years was observed in 30% (47/159) of patients. Patients surviving ≥15 years were younger (53 vs 56 years, P = .02), less likely to have lambda as the involved light chain (62% vs 78%, P = .03) and were less likely to have heart involvement (32% vs 56%, P = .005). Median OS of patients with heart involvement vs not was 4.0 vs 11.1 years, P = .006 and actuarial 15-year OS was 23% vs 43%, respectively. A higher proportion of patients with OS ≥15 years received full-dose melphalan conditioning (81% vs 61%, P = .01), and achieved day 100 complete response (CR) (64% vs 24%, P < .001). Median OS amongst patients who achieved CR vs not was 19.3 vs 5.4 years, P < .001. Heart involvement, receiving full-dose melphalan and achieving CR remained independent predictors of OS. AL amyloidosis and related complications were the cause of death in 52% of patients overall (1-5 years post-transplant: 81%; 5-10 years: 62% and 10-15 years: 55%). These results reinforce the key role of ASCT in AL amyloidosis. With improvements in TRM and more options for relapsed disease, we expect the long-term survival post-transplant to improve significantly in the future.
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Hirjak D, Sartorius A, Kubera KM, Wolf RC. [Antipsychotic-induced motor symptoms in schizophrenic psychoses-Part 2 : Catatonic symptoms and neuroleptic malignant syndrome]. DER NERVENARZT 2019; 90:12-24. [PMID: 30128733 DOI: 10.1007/s00115-018-0581-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In rare cases, pharmacotherapy in schizophrenic psychoses can be associated with life-threatening antipsychotic-induced movement disorders. The two most severe complications are antipsychotic-associated catatonic symptoms (ACS) and neuroleptic malignant syndrome (NMS). Although both constellations necessitate rapid medical care, the diagnosis is still a clinical challenge. Although there is no established treatment of ACS (here designated as a specific subtype of catatonic symptoms), an attempt should be made with benzodiazepines and memantine can also be helpful. In severe drug-refractory cases electroconvulsive therapy (ECT) can be indicated. The NMS represents a life-threatening constellation that frequently requires intensive care unit treatment. The medicinal treatment with benzodiazepines, bromocriptine, amantadine, dantrolene and/or ECT is also advocated. Finally, this review article also summarizes the currently available literature for treatment of genuine catatonic symptoms. In conclusion, the abovementioned clinical syndromes must be rapidly recognized and treated. Early recognition and treatment of these movement disorders can under certain circumstances be lifesaving and favorably influence the later clinical outcome.
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Hirjak D, Kubera KM, Bienentreu S, Thomann PA, Wolf RC. [Antipsychotic-induced motor symptoms in schizophrenic psychoses-Part 1 : Dystonia, akathisia und parkinsonism]. DER NERVENARZT 2019; 90:1-11. [PMID: 30128734 DOI: 10.1007/s00115-018-0582-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Acute antipsychotic-induced movement disorders (AIMD) are clinically relevant since they are frequently associated with high subjective distress, and since over the long-term they can negatively impact treatment adherence of patients with schizophrenic psychoses. This review article summarizes the relevant studies on the prevalence, risk factors, prevention and treatment options and instruments for early prediction of acute AIMD in schizophrenic psychoses. The current evidence and treatment recommendations are divided into three main areas: acute dystonia, akathisia, and parkinsonism. For the treatment of acute dystonia trihexyphenidyl and biperiden have shown their efficacy. Considering pharmacological treatment of akathisia, there is some preliminary evidence for medication with lipophilic beta-receptor blockers (propranolol and pindolol), clonidine, benzodiazepines, mianserin, mirtazapine und trazodone. The treatment options for drug-induced parkinsonism include reduction or switching from one antipsychotic to another with a lower affinity for dopamine D2 receptors, amantadine or in the regular administration of anticholinergic drugs. In conclusion, acute AIMD is easily to recognize but is not always effectively and durably treated. Early recognition and treatment of acute AIMD could be associated with improved treatment outcomes.
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Hirjak D, Rashidi M, Fritze S, Bertolino AL, Geiger LS, Zang Z, Kubera KM, Schmitgen MM, Sambataro F, Calhoun VD, Weisbrod M, Tost H, Wolf RC. Patterns of co-altered brain structure and function underlying neurological soft signs in schizophrenia spectrum disorders. Hum Brain Mapp 2019; 40:5029-5041. [PMID: 31403239 DOI: 10.1002/hbm.24755] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 06/28/2019] [Accepted: 07/22/2019] [Indexed: 12/14/2022] Open
Abstract
Neurological soft signs (NSS) comprise a broad range of subtle neurological deficits and are considered to represent external markers of sensorimotor dysfunction frequently found in mental disorders of presumed neurodevelopmental origin. Although NSS frequently occur in schizophrenia spectrum disorders (SSD), specific patterns of co-altered brain structure and function underlying NSS in SSD have not been investigated so far. It is unclear whether gray matter volume (GMV) alterations or aberrant brain activity or a combination of both, are associated with NSS in SSD. Here, 37 right-handed SSD patients and 37 matched healthy controls underwent motor assessment and magnetic resonance imaging (MRI) at 3 T. NSS were examined on the Heidelberg NSS scale. We used a multivariate data fusion technique for multimodal MRI data-multiset canonical correlation and joint independent component analysis (mCCA + jICA)-to investigate co-altered patterns of GMV and intrinsic neural fluctuations (INF) in SSD patients exhibiting NSS. The mCCA + jICA model indicated two joint group-discriminating components (temporoparietal/cortical sensorimotor and frontocerebellar/frontoparietal networks) and one modality-specific group-discriminating component (p < .05, FDR corrected). NSS motor score was associated with joint frontocerebellar/frontoparietal networks in SSD patients. This study highlights complex neural pathomechanisms underlying NSS in SSD suggesting aberrant structure and function, predominantly in cortical and cerebellar systems that critically subserve sensorimotor dynamics and psychomotor organization.
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Fritze S, Bertolino AL, Kubera KM, Topor CE, Schmitgen MM, Wolf RC, Hirjak D. Differential contributions of brainstem structures to neurological soft signs in first- and multiple-episode schizophrenia spectrum disorders. Schizophr Res 2019; 210:101-106. [PMID: 31178363 DOI: 10.1016/j.schres.2019.05.041] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 05/21/2019] [Accepted: 05/26/2019] [Indexed: 11/18/2022]
Abstract
Neurological soft signs (NSS) are frequently found in patients with schizophrenia spectrum disorders (SSD) at any stage of the disease. Brainstem structures are crucial for motor control, integration of sensory input and coordination of automatic motor actions. It is unclear whether disease duration has an impact on NSS/brainstem volume relationships. We tested the hypothesis that volumes of brainstem structures differ between first-episode psychosis (FEP) and multiple-episodes psychosis (MEP) patients with SSD, and that alterations of these structures are associated with NSS. T1-weighted structural MRI data at 3 T were obtained from 92 right-handed SSD patients (27 FEP and 65 MEP). FreeSurfer vers. 6.0 was used for segmentation of brainstem structures including the medulla oblongata, pons, superior cerebellar pedunculus (SCP), and midbrain. Multiple regression analyses were used to describe the relationship between brainstem structures and distinct NSS subdomains. In FEP, pons volume had a significant effect on NSS total score (p = 0.001, Bonferroni corr.). Further, medulla oblongata (p = 0.001, Bonferroni corr.) and pons (p = 0.001, Bonferroni corr.) volumes had a significant effect on NSS motor coordination score. In MEP, significant associations between brainstem structures and NSS levels were not found. The present data support the notion that brainstem structures play an important role in the expression of NSS in SSD individuals with FEP, in contrast to individuals with MEP. Our study also emphasizes the need of better characterizing episode-specific brainstem correlates of NSS in SSD.
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Kubera KM, Rashidi M, Schmitgen MM, Barth A, Hirjak D, Sambataro F, Calhoun VD, Wolf RC. Structure/function interrelationships in patients with schizophrenia who have persistent auditory verbal hallucinations: A multimodal MRI study using parallel ICA. Prog Neuropsychopharmacol Biol Psychiatry 2019; 93:114-121. [PMID: 30890460 DOI: 10.1016/j.pnpbp.2019.03.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Revised: 02/28/2019] [Accepted: 03/13/2019] [Indexed: 12/22/2022]
Abstract
There is accumulating neuroimaging evidence for both structural and functional abnormalities in schizophrenia patients with persistent auditory verbal hallucinations (AVH). So far, the direct interrelationships between altered structural and functional changes underlying AVH are unknown. Recently, it has become possible to reveal hidden patterns of neural dysfunction not sufficiently captured by separate analysis of these two modalities. A data-driven fusion method called parallel independent component analysis (p-ICA) is able to identify maximally independent components of each imaging modality as well as the link between them. In the present study, we utilized p-ICA to study covarying components among gray matter volume maps computed from structural MRI (sMRI) and fractional amplitude of low-frequency fluctuations (fALFF) maps computed from resting-state functional MRI (rs-fMRI) data of 15 schizophrenia patients with AVH, 16 non-hallucinating schizophrenia patients (nAVH), and 19 healthy controls (HC). We found a significant correlation (r = 0.548, n = 50, p < .001) between a sMRI component and a rs-fMRI component, which was significantly different between the AVH and non AVH group (nAVH). The rs-fMRI component comprised temporal cortex and cortical midline regions, the sMRI component included predominantly fronto-temporo-parietal regions. Distinct clinical features, as measured by the Psychotic Symptoms Rating Scale (PSYRATS), were associated with two different modality specific rs-fMRI components. There was a significant correlation between a predominantly parietal resting-state network and the physical dimension of PSYRATS and the posterior cingulate/temporal cortex network and the emotional dimension of PSYRATS. These data suggest AVH-specific interrelationships between intrinsic network activity and GMV, together with modality-specific associations with distinct symptom dimensions of AVH.
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Langenberg A, Svensson J, Marchuk O, Fuchert G, Bozhenkov S, Damm H, Pasch E, Pavone A, Thomsen H, Pablant NA, Burhenn R, Wolf RC. Inference of temperature and density profiles via forward modeling of an x-ray imaging crystal spectrometer within the Minerva Bayesian analysis framework. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:063505. [PMID: 31255024 DOI: 10.1063/1.5086283] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 06/06/2019] [Indexed: 06/09/2023]
Abstract
At the Wendelstein 7-X stellarator, the X-ray imaging crystal spectrometer provides line integrated measurements of ion and electron temperatures, plasma flows, as well as impurity densities from a spectroscopic analysis of tracer impurity radiation. In order to infer the actual profiles from line integrated data, a forward modeling approach has been developed within the Minerva Bayesian analysis framework. In this framework, the inversion is realized on the basis of a complete forward model of the diagnostic, including error propagation and utilizing Gaussian processes for generation and inference of arbitrary shaped plasma parameter profiles. For modeling of line integrated data as measured by the detector, the installation geometry of the spectrometer, imaging properties of the crystal, and Gaussian detection noise are considered. The inversion of line integrated data is achieved using the maximum posterior method for plasma parameter profile inference and a Markov chain Monte Carlo sampling of the posterior distribution for calculating uncertainties of the inference process. The inversion method shows a correct and reliable inference of temperature and impurity density profiles from synthesized data within the estimated uncertainties along the whole plasma radius. The application to measured data yields a good match of derived electron temperature profiles to data of the Thomson scattering diagnostic for central electron temperatures between 2 and 5 keV using argon impurities.
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Avramidis KA, Ruess T, Mentgen F, Jin J, Wagner D, Gantenbein G, Illy S, Ioannidis C, Laqua HP, Pagonakis IG, Rzesnicki T, Thumm M, Wolf RC, Jelonnek J. Studies towards an upgraded 1.5 MW gyrotron for W7-X. EPJ WEB OF CONFERENCES 2019. [DOI: 10.1051/epjconf/201920304003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Studies towards a 1.5 MW, 140 GHz CW gyrotron, with the capability of MW-class operation also at 175 GHz, are ongoing at Karlsruhe Institute of Technology in view of a possible future upgrade of the ECRH system of the stellarator W7-X. The upgrade of the existing 1.0 MW, 140 GHz European gyrotron for W7-X has been chosen as a development path. Detailed designs of the cavity, the non-linear uptaper, and the quasi-optical launcher for the upgraded gyrotron have been obtained and have been validated numerically. In parallel, a mode generator, intended for low-power tests of the quasi-optical mode converter system of the upgraded gyrotron, has been designed, manufactured, and successfully tested.
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