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Cavallari M, Touroutoglou A, Katsumi Y, Fong TG, Schmitt E, Travison TG, Shafi MM, Libermann TA, Marcantonio ER, Alsop DC, Jones RN, Inouye SK, Dickerson BC. Relationship between cortical brain atrophy, delirium, and long-term cognitive decline in older surgical patients. Neurobiol Aging 2024; 140:130-139. [PMID: 38788524 DOI: 10.1016/j.neurobiolaging.2024.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 05/08/2024] [Accepted: 05/11/2024] [Indexed: 05/26/2024]
Abstract
In older patients, delirium after surgery is associated with long-term cognitive decline (LTCD). The neural substrates of this association are unclear. Neurodegenerative changes associated with dementia are possible contributors. We investigated the relationship between brain atrophy rates in Alzheimer's disease (AD) and cognitive aging signature regions from magnetic resonance imaging before and one year after surgery, LTCD assessed by the general cognitive performance (GCP) score over 6 years post-operatively, and delirium in 117 elective surgery patients without dementia (mean age = 76). The annual change in cortical thickness was 0.2(1.7) % (AD-signature p = 0.09) and 0.4(1.7) % (aging-signature p = 0.01). Greater atrophy was associated with LTCD (AD-signature: beta(CI) = 0.24(0.06-0.42) points of GCP/mm of cortical thickness; p < 0.01, aging-signature: beta(CI) = 0.55(0.07-1.03); p = 0.03). Atrophy rates were not significantly different between participants with and without delirium. We found an interaction with delirium severity in the association between atrophy and LTCD (AD-signature: beta(CI) = 0.04(0.00-0.08), p = 0.04; aging-signature: beta(CI) = 0.08(0.03-0.12), p < 0.01). The rate of cortical atrophy and severity of delirium are independent, synergistic factors determining postoperative cognitive decline in the elderly.
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Affiliation(s)
- Michele Cavallari
- Center for Neurological Imaging, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Alexandra Touroutoglou
- Frontotemporal Disorders Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Yuta Katsumi
- Frontotemporal Disorders Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Tamara G Fong
- Aging Brain Center, Institute for Aging Research, Hebrew SeniorLife, Harvard Medical School, Boston, MA, USA; Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Eva Schmitt
- Aging Brain Center, Institute for Aging Research, Hebrew SeniorLife, Harvard Medical School, Boston, MA, USA
| | - Thomas G Travison
- Aging Brain Center, Institute for Aging Research, Hebrew SeniorLife, Harvard Medical School, Boston, MA, USA
| | - Mouhsin M Shafi
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Towia A Libermann
- Division of Interdisciplinary Medicine and Biotechnology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; Beth Israel Deaconess Medical Center Genomics, Proteomics, Bioinformatics and Systems Biology Center, Harvard Medical School, Boston, MA, USA
| | - Edward R Marcantonio
- Divisions of General Medicine and Gerontology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - David C Alsop
- Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Richard N Jones
- Departments of Psychiatry and Human Behavior and Neurology, Brown University Warren Alpert Medical School, Providence, RI, USA
| | - Sharon K Inouye
- Aging Brain Center, Institute for Aging Research, Hebrew SeniorLife, Harvard Medical School, Boston, MA, USA; Departments of Psychiatry and Human Behavior and Neurology, Brown University Warren Alpert Medical School, Providence, RI, USA
| | - Bradford C Dickerson
- Frontotemporal Disorders Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
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Keller JA, Sigurdsson S, Schmitz Abecassis B, Kant IMJ, Van Buchem MA, Launer LJ, van Osch MJP, Gudnason V, de Bresser J. Identification of Distinct Brain MRI Phenotypes and Their Association With Long-Term Dementia Risk in Community-Dwelling Older Adults. Neurology 2024; 102:e209176. [PMID: 38471053 PMCID: PMC11033985 DOI: 10.1212/wnl.0000000000209176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 12/13/2023] [Indexed: 03/14/2024] Open
Abstract
BACKGROUND AND OBJECTIVES Individual brain MRI markers only show at best a modest association with long-term occurrence of dementia. Therefore, it is challenging to accurately identify individuals at increased risk for dementia. We aimed to identify different brain MRI phenotypes by hierarchical clustering analysis based on combined neurovascular and neurodegenerative brain MRI markers and to determine the long-term dementia risk within the brain MRI phenotype subgroups. METHODS Hierarchical clustering analysis based on 32 combined neurovascular and neurodegenerative brain MRI markers in community-dwelling individuals of the Age-Gene/Environment Susceptibility Reykjavik Study was applied to identify brain MRI phenotypes. A Cox proportional hazards regression model was used to determine the long-term risk for dementia per subgroup. RESULTS We included 3,056 participants and identified 15 subgroups with distinct brain MRI phenotypes. The phenotypes ranged from limited burden, mostly irregular white matter hyperintensity (WMH) shape and cerebral atrophy, mostly irregularly WMHs and microbleeds, mostly cortical infarcts and atrophy, mostly irregularly shaped WMH and cerebral atrophy to multiburden subgroups. Each subgroup showed different long-term risks for dementia (min-max range hazard ratios [HRs] 1.01-6.18; mean time to follow-up 9.9 ± 2.6 years); especially the brain MRI phenotype with mainly WMHs and atrophy showed a large increased risk (HR 6.18, 95% CI 3.37-11.32). DISCUSSION Distinct brain MRI phenotypes can be identified in community-dwelling older adults. Our results indicate that distinct brain MRI phenotypes are related to varying long-term risks of developing dementia. Brain MRI phenotypes may in the future assist in an improved understanding of the structural correlates of dementia predisposition.
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Affiliation(s)
- Jasmin Annica Keller
- From the Department of Radiology (J.A.K., B.S.A., M.A.V.B., M.J.P.v.O., J.d.B.), Leiden University Medical Center, the Netherlands; Icelandic Heart Association (S.S., V.G.), Kópavogur, Iceland; Clinical Artificial Intelligence Implementation and Research Lab (CAIRELab) and Department of Information Technology & Digital Innovation, Department of Digital Health (I.M.J.K.), University Medical Center Utrecht, the Netherlands; Laboratory of Epidemiology and Population Science (L.J.L.), National Institute on Aging, Bethesda, MD; and Faculty of Medicine (V.G.), University of Iceland, Reykjavik
| | - Sigurdur Sigurdsson
- From the Department of Radiology (J.A.K., B.S.A., M.A.V.B., M.J.P.v.O., J.d.B.), Leiden University Medical Center, the Netherlands; Icelandic Heart Association (S.S., V.G.), Kópavogur, Iceland; Clinical Artificial Intelligence Implementation and Research Lab (CAIRELab) and Department of Information Technology & Digital Innovation, Department of Digital Health (I.M.J.K.), University Medical Center Utrecht, the Netherlands; Laboratory of Epidemiology and Population Science (L.J.L.), National Institute on Aging, Bethesda, MD; and Faculty of Medicine (V.G.), University of Iceland, Reykjavik
| | - Bárbara Schmitz Abecassis
- From the Department of Radiology (J.A.K., B.S.A., M.A.V.B., M.J.P.v.O., J.d.B.), Leiden University Medical Center, the Netherlands; Icelandic Heart Association (S.S., V.G.), Kópavogur, Iceland; Clinical Artificial Intelligence Implementation and Research Lab (CAIRELab) and Department of Information Technology & Digital Innovation, Department of Digital Health (I.M.J.K.), University Medical Center Utrecht, the Netherlands; Laboratory of Epidemiology and Population Science (L.J.L.), National Institute on Aging, Bethesda, MD; and Faculty of Medicine (V.G.), University of Iceland, Reykjavik
| | - Ilse M J Kant
- From the Department of Radiology (J.A.K., B.S.A., M.A.V.B., M.J.P.v.O., J.d.B.), Leiden University Medical Center, the Netherlands; Icelandic Heart Association (S.S., V.G.), Kópavogur, Iceland; Clinical Artificial Intelligence Implementation and Research Lab (CAIRELab) and Department of Information Technology & Digital Innovation, Department of Digital Health (I.M.J.K.), University Medical Center Utrecht, the Netherlands; Laboratory of Epidemiology and Population Science (L.J.L.), National Institute on Aging, Bethesda, MD; and Faculty of Medicine (V.G.), University of Iceland, Reykjavik
| | - Mark A Van Buchem
- From the Department of Radiology (J.A.K., B.S.A., M.A.V.B., M.J.P.v.O., J.d.B.), Leiden University Medical Center, the Netherlands; Icelandic Heart Association (S.S., V.G.), Kópavogur, Iceland; Clinical Artificial Intelligence Implementation and Research Lab (CAIRELab) and Department of Information Technology & Digital Innovation, Department of Digital Health (I.M.J.K.), University Medical Center Utrecht, the Netherlands; Laboratory of Epidemiology and Population Science (L.J.L.), National Institute on Aging, Bethesda, MD; and Faculty of Medicine (V.G.), University of Iceland, Reykjavik
| | - Lenore J Launer
- From the Department of Radiology (J.A.K., B.S.A., M.A.V.B., M.J.P.v.O., J.d.B.), Leiden University Medical Center, the Netherlands; Icelandic Heart Association (S.S., V.G.), Kópavogur, Iceland; Clinical Artificial Intelligence Implementation and Research Lab (CAIRELab) and Department of Information Technology & Digital Innovation, Department of Digital Health (I.M.J.K.), University Medical Center Utrecht, the Netherlands; Laboratory of Epidemiology and Population Science (L.J.L.), National Institute on Aging, Bethesda, MD; and Faculty of Medicine (V.G.), University of Iceland, Reykjavik
| | - Matthias J P van Osch
- From the Department of Radiology (J.A.K., B.S.A., M.A.V.B., M.J.P.v.O., J.d.B.), Leiden University Medical Center, the Netherlands; Icelandic Heart Association (S.S., V.G.), Kópavogur, Iceland; Clinical Artificial Intelligence Implementation and Research Lab (CAIRELab) and Department of Information Technology & Digital Innovation, Department of Digital Health (I.M.J.K.), University Medical Center Utrecht, the Netherlands; Laboratory of Epidemiology and Population Science (L.J.L.), National Institute on Aging, Bethesda, MD; and Faculty of Medicine (V.G.), University of Iceland, Reykjavik
| | - Vilmundur Gudnason
- From the Department of Radiology (J.A.K., B.S.A., M.A.V.B., M.J.P.v.O., J.d.B.), Leiden University Medical Center, the Netherlands; Icelandic Heart Association (S.S., V.G.), Kópavogur, Iceland; Clinical Artificial Intelligence Implementation and Research Lab (CAIRELab) and Department of Information Technology & Digital Innovation, Department of Digital Health (I.M.J.K.), University Medical Center Utrecht, the Netherlands; Laboratory of Epidemiology and Population Science (L.J.L.), National Institute on Aging, Bethesda, MD; and Faculty of Medicine (V.G.), University of Iceland, Reykjavik
| | - Jeroen de Bresser
- From the Department of Radiology (J.A.K., B.S.A., M.A.V.B., M.J.P.v.O., J.d.B.), Leiden University Medical Center, the Netherlands; Icelandic Heart Association (S.S., V.G.), Kópavogur, Iceland; Clinical Artificial Intelligence Implementation and Research Lab (CAIRELab) and Department of Information Technology & Digital Innovation, Department of Digital Health (I.M.J.K.), University Medical Center Utrecht, the Netherlands; Laboratory of Epidemiology and Population Science (L.J.L.), National Institute on Aging, Bethesda, MD; and Faculty of Medicine (V.G.), University of Iceland, Reykjavik
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Attali D, Calligaris C, Grabli D, Slooter AJC. How to manage catatonia, Parkinson and dementia in ICU. Curr Opin Crit Care 2024; 30:151-156. [PMID: 38441073 DOI: 10.1097/mcc.0000000000001142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2024]
Abstract
PURPOSE OF REVIEW The rising prevalence of neurodegenerative and mental disorders, combined with the challenges posed by their frailty, has presented intensivists with complex issues in the intensive care unit (ICU). This review article explores specific aspects of care for patients with catatonia, Parkinson's disease (PD), and dementia within the context of the ICU, shedding light on recent developments in these fields. RECENT FINDINGS Catatonia, a neuropsychiatric syndrome with potentially life-threatening forms, remains underdiagnosed, and its etiologies are diverse. PD patients in the ICU present unique challenges related to admission criteria, dopaminergic treatment, and respiratory care. Dementia increases the risk of delirium. Delirium is associated with long-term cognitive impairment and dementia. SUMMARY While evidence is lacking, further research is needed to guide treatment for ICU patients with these comorbidities.
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Affiliation(s)
- David Attali
- GHU-Paris Psychiatrie et Neurosciences, Hôpital Sainte Anne, Université Paris Cité, Paris, France
- Institute Physics for Medicine Paris, Inserm U1273, ESPCI Paris, PSL University, CNRS UMR 8063, Paris, France
| | - Charlotte Calligaris
- GHU-Paris Psychiatrie & Neurosciences, Neurointensive Care and Neuroanesthesia Department, Sainte-Anne Hospital, Université de Paris, Paris, France
| | - David Grabli
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Paris, France
- Assistance Publique Hôpitaux de Paris, Department of Neurology, CIC Neurosciences, Hôpital Pitié-Salpêtrière, Paris, France
| | - Arjen J C Slooter
- Departments of Intensive Care Medicine and Psychiatry, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
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Hoffmann AJ, Tin AL, Vickers AJ, Shahrokni A. Preoperative frailty vs. cognitive impairment: Which one matters most for postoperative delirium among older adults with cancer? J Geriatr Oncol 2023; 14:101479. [PMID: 37001348 PMCID: PMC10530636 DOI: 10.1016/j.jgo.2023.101479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 02/07/2023] [Accepted: 03/11/2023] [Indexed: 03/31/2023]
Abstract
INTRODUCTION Limited data are available to explore the association between preoperative frailty and cognitive impairment with postoperative delirium among older adults with cancer. We explored this association in a single Comprehensive Cancer Center where postoperative delirium and frailty are assessed in routine care using the Confusion Assessment Method (CAM) and Memorial Sloan Kettering Frailty Index (MSK-FI), respectively. MATERIALS AND METHODS Retrospective study on patients with cancer, aged 65+, who underwent surgery from April 2018 to March 2019 with hospital stay ≥1 day. We used logistic regression with postoperative delirium as the outcome, primary predictor MSK-FI, adjusted for age, operative time, and preoperative albumin. As the MSK-FI includes a component related to cognitive impairment, we additionally evaluated the impact of this component, separately from the rest of the score, on the association between frailty and postoperative delirium. RESULTS Among 1,257 patients with available MSK-FI and CAM measures, 47 patients (3.7%) had postoperative delirium. Increased frailty was associated with increased risk of postoperative delirium (odds ratio [OR] 1.51; 95% confidence interval [CI] 1.26, 1.81; p < 0.001). However, this was largely related to the effect of cognitive impairment (OR 15.29; 95% CI 7.18; 32.56; p < 0.001). In patients with cognitive impairment, the association between frailty and postoperative delirium was not significant (OR 0.97; 95% CI 0.65, 1.44; p-value = 0.9), as having cognitive impairment put patients at high risk for postoperative delirium even without taking into account the other components of the MSK-FI. While the association between frailty and postoperative delirium in patients with intact cognitive function was statistically significant (OR 1.58; 95% CI 1.27, 1.96; p < 0.001), it was not clinically meaningful, particularly considering the low risk of delirium among patients with intact cognitive function (e.g., 1.3% vs 3.2% for MSK-FI 1 vs 3). DISCUSSION Cognitive function should be a greater focus than frailty, as measured by the MSK-FI, in preoperative assessment for the prediction of postoperative delirium.
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Affiliation(s)
| | - Amy L Tin
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, NY, USA
| | - Andrew J Vickers
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, NY, USA
| | - Armin Shahrokni
- Department of Medicine, Memorial Sloan Kettering Cancer Center, NY, USA.
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Schmitz-Abecassis B, Dirven L, Jiang J, Keller JA, Croese RJI, van Dorth D, Ghaznawi R, Kant IMJ, Taphoorn MJB, van Osch MJP, Koekkoek JAF, de Bresser J. MRI phenotypes of glioblastomas early after treatment are suggestive of overall patient survival. Neurooncol Adv 2023; 5:vdad133. [PMID: 37908765 PMCID: PMC10613962 DOI: 10.1093/noajnl/vdad133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2023] Open
Abstract
Background Distinguishing true tumor progression (TP) from treatment-induced abnormalities (eg, pseudo-progression (PP) after radiotherapy) on conventional MRI scans remains challenging in patients with a glioblastoma. We aimed to establish brain MRI phenotypes of glioblastomas early after treatment by combined analysis of structural and perfusion tumor characteristics and assessed the relation with recurrence rate and overall survival time. Methods Structural and perfusion MR images of 67 patients at 3 months post-radiotherapy were visually scored by a neuroradiologist. In total 23 parameters were predefined and used for hierarchical clustering analysis. Progression status was assessed based on the clinical course of each patient 9 months after radiotherapy (or latest available). Multivariable Cox regression models were used to determine the association between the phenotypes, recurrence rate, and overall survival. Results We established 4 subgroups with significantly different tumor MRI characteristics, representing distinct MRI phenotypes of glioblastomas: TP and PP rates did not differ significantly between subgroups. Regression analysis showed that patients in subgroup 1 (characterized by having mostly small and ellipsoid nodular enhancing lesions with some hyper-perfusion) had a significant association with increased mortality at 9 months (HR: 2.6 (CI: 1.1-6.3); P = .03) with a median survival time of 13 months (compared to 22 months of subgroup 2). Conclusions Our study suggests that distinct MRI phenotypes of glioblastomas at 3 months post-radiotherapy can be indicative of overall survival, but does not aid in differentiating TP from PP. The early prognostic information our method provides might in the future be informative for prognostication of glioblastoma patients.
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Affiliation(s)
- Bárbara Schmitz-Abecassis
- C.J. Gorter MRI Center, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
- Medical Delta, South-Holland, The Netherlands
| | - Linda Dirven
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
- Department of Neurology, Haaglanden Medical Center, The Hague, The Netherlands
| | - Janey Jiang
- Department of Radiology, HagaZiekenhuis, The Hague, The Netherlands
| | - Jasmin A Keller
- C.J. Gorter MRI Center, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Robert J I Croese
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
- Department of Neurology, Haaglanden Medical Center, The Hague, The Netherlands
| | - Daniëlle van Dorth
- C.J. Gorter MRI Center, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Rashid Ghaznawi
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
| | - Ilse M J Kant
- Clinical Artificial Intelligence Implementation and Research Lab (CAIRELab) and Department of Information Technology & Digital Innovation, Leiden University Medical Center, Leiden, The Netherlands
- Department of Digital Health, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Martin J B Taphoorn
- C.J. Gorter MRI Center, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
- Department of Neurology, Haaglanden Medical Center, The Hague, The Netherlands
| | | | - Johan A F Koekkoek
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
- Department of Neurology, Haaglanden Medical Center, The Hague, The Netherlands
| | - Jeroen de Bresser
- C.J. Gorter MRI Center, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
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Tract-based white matter hyperintensity patterns in patients with systemic lupus erythematosus using an unsupervised machine learning approach. Sci Rep 2022; 12:21376. [PMID: 36494508 PMCID: PMC9734118 DOI: 10.1038/s41598-022-25990-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 12/07/2022] [Indexed: 12/13/2022] Open
Abstract
Currently, little is known about the spatial distribution of white matter hyperintensities (WMH) in the brain of patients with Systemic Lupus erythematosus (SLE). Previous lesion markers, such as number and volume, ignore the strategic location of WMH. The goal of this work was to develop a fully-automated method to identify predominant patterns of WMH across WM tracts based on cluster analysis. A total of 221 SLE patients with and without neuropsychiatric symptoms from two different sites were included in this study. WMH segmentations and lesion locations were acquired automatically. Cluster analysis was performed on the WMH distribution in 20 WM tracts. Our pipeline identified five distinct clusters with predominant involvement of the forceps major, forceps minor, as well as right and left anterior thalamic radiations and the right inferior fronto-occipital fasciculus. The patterns of the affected WM tracts were consistent over the SLE subtypes and sites. Our approach revealed distinct and robust tract-based WMH patterns within SLE patients. This method could provide a basis, to link the location of WMH with clinical symptoms. Furthermore, it could be used for other diseases characterized by presence of WMH to investigate both the clinical relevance of WMH and underlying pathomechanism in the brain.
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Differential regional cerebrovascular reactivity to end-tidal gas combinations commonly seen during anaesthesia: A blood oxygenation level-dependent MRI observational study in awake adult subjects. Ugeskr Laeger 2022; 39:774-784. [PMID: 35852545 DOI: 10.1097/eja.0000000000001716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Regional cerebrovascular reactivity (rCVR) is highly variable in the human brain as measured by blood oxygenation level-dependent (BOLD) MRI to changes in both end-tidal CO 2 and O 2 . OBJECTIVES We examined awake participants under carefully controlled end-tidal gas concentrations to assess how regional CVR changes may present with end-tidal gas changes seen commonly with anaesthesia. DESIGN Observational study. SETTING Tertiary care centre, Winnipeg, Canada. The imaging for the study occurred in 2019. SUBJECTS Twelve healthy adult subjects. INTERVENTIONS Cerebral BOLD response was studied under two end-tidal gas paradigms. First end-tidal oxygen (ETO 2 ) maintained stable whereas ETCO 2 increased incrementally from hypocapnia to hypercapnia (CO 2 ramp); second ETCO 2 maintained stable whereas ETO 2 increased from normoxia to hyperoxia (O 2 ramp). BOLD images were modeled with end-tidal gas sequences split into two equal segments to examine regional CVR. MAIN OUTCOME MEASURES The voxel distribution comparing hypocapnia to mild hypercapnia and mild hyperoxia (mean F I O 2 = 0.3) to marked hyperoxia (mean F I O 2 = 0.7) were compared in a paired fashion ( P < 0.005 to reach threshold for voxel display). Additionally, type analysis was conducted on CO 2 ramp data. This stratifies the BOLD response to the CO 2 ramp into four categories of CVR slope based on segmentation (type A; +/+slope: normal response, type B +/-, type C -/-: intracranial steal, type D -/+.) Types B to D represent altered responses to the CO 2 stimulus. RESULTS Differential regional responsiveness was seen for both end-tidal gases. Hypocapnic regional CVR was more marked than hypercapnic CVR in 0.3% of voxels examined ( P < 0.005, paired comparison); the converse occurred in 2.3% of voxels. For O 2 , mild hyperoxia had more marked CVR in 0.2% of voxels compared with greater hyperoxia; the converse occurred in 0.5% of voxels. All subjects had altered regional CO 2 response based on Type Analysis ranging from 4 ± 2 to 7 ± 3% of voxels. CONCLUSION In awake subjects, regional differences and abnormalities in CVR were observed with changes in end-tidal gases common during the conduct of anaesthesia. On the basis of these findings, consideration could be given to minimising regional CVR fluctuations in patients-at-risk of neurological complications by tighter control of end-tidal gases near the individual's resting values.
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Differential regional cerebral blood flow reactivity to alterations in end-tidal gases in healthy volunteers. Can J Anaesth 2021; 68:1497-1506. [PMID: 34105067 DOI: 10.1007/s12630-021-02042-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 04/05/2021] [Accepted: 04/09/2021] [Indexed: 12/19/2022] Open
Abstract
PURPOSE Anesthesia is associated with alterations in end-tidal (ET) respiratory gases from the awake state. These alterations result in marked vasoactive changes in regional cerebral blood flow (rCBF). Altered regional cerebrovascular reactivity (rCVR) is linked to neurologic dysfunction. We examined these differences in reactivity from prior work by focusing on the ratio of vasoconstriction with hyperoxia/hypocapnia (HO/hc):vasodilation with hypercapnia (HC) using magnetic resonance imaging pseudo-continuous arterial spin labelling (pCASL) to measure rCBF and compare rCVR The distribution and magnitude of these ratios could provide insights into rCBF during clinical anesthesia and inform future research into the origins of postoperative delirium (POD). METHODS Ten healthy subjects underwent cerebral blood flow (CBF) studies using pCASL with computer-controlled delivery of ET gases to assess flow effects of hyperoxia, hypercapnia, and hyperoxia/hypocapnia as part of a larger study into cerebrovascular reactivity. The vasoconstrictor stimulus was compared with the vasodilator stimulus by the ratio HO/hc:HC. RESULTS Hyperoxia minimally decreased whole brain CBF by - 0.6%/100 mm Hg increase in ETO2. Hypercapnia increased CBF by +4.6%/mm Hg carbon dioxide (CO2) and with HO/hc CBF decreased by - 5.1%/mm Hg CO2. The brain exhibited markedly different rCVR-regional HO/hc:HC ratios varied from 7.2:1 (greater response to vasoconstriction) to 0.49:1 (greater response to vasodilation). Many of the ratios greater than 1, where vasoconstriction predominated, were seen in regions associated with memory, cognition, and executive function, including the entorhinal cortex, hippocampus, parahippocampus, and dorsolateral prefrontal cortex. CONCLUSIONS In awake humans, marked rCBF changes occurred with alterations in ET respiratory gases common under anesthesia. Such heterogeneous reactivity may be relevant to future studies to identify those at risk of POD.
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