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Hoyau E, Roux-Sibilon A, Boudiaf N, Pichat C, Cousin E, Krainik A, Jaillard A, Peyrin C, Baciu M. Aging modulates fronto-temporal cortical interactions during lexical production. A dynamic causal modeling study. Brain Lang 2018; 184:11-19. [PMID: 29913316 DOI: 10.1016/j.bandl.2018.06.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Revised: 05/20/2018] [Accepted: 06/10/2018] [Indexed: 05/12/2023]
Abstract
In this dynamic causal modeling (DCM) study, we evaluated the effect of age on the effective connectivity of a cerebral network involved in lexical production. Younger and older adults performed an object naming task during fMRI. The DCM was used to explore the interactions between four regions of interest: the occipital cortex, OC; the lateral temporal cortex, LTC; the medial temporal cortex, MTC; and the inferior frontal cortex, IFC. We mainly focused on the modulation of the fronto-temporal interaction, according to the hypothesis that aging requires strategies that modulate the access to the semantic knowledge, either through a neural reserve mechanism (increased MTC-LTC connectivity) or through a neural compensation mechanism (supplementary IFC-MTC connectivity). For younger adults, our results indicated a bi-directional interaction between the left IFC and LTC suggesting a typical activation related to lexico-semantic representations. For older adults, our results reveal the existence of bi-directional interaction between the IFC and MTC, but not between the IFC and LTC - which in turn suggests that older adults adapt a new strategy, via supplemental access to conceptual access and semantic retrieval processes. This neural compensation strategy would be facilitated by a top-down mechanism from the IFC to the MTC. We discuss our results in the context of the possible additional strategies used by older compared to younger adults, to retrieve and produce words.
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Affiliation(s)
- E Hoyau
- Univ. Grenoble Alpes, CNRS, LPNC UMR 5105, F-38000 Grenoble, France
| | - A Roux-Sibilon
- Univ. Grenoble Alpes, CNRS, LPNC UMR 5105, F-38000 Grenoble, France
| | - N Boudiaf
- Univ. Grenoble Alpes, CNRS, LPNC UMR 5105, F-38000 Grenoble, France
| | - C Pichat
- Univ. Grenoble Alpes, CNRS, LPNC UMR 5105, F-38000 Grenoble, France
| | - E Cousin
- Univ. Grenoble Alpes, CNRS, LPNC UMR 5105, F-38000 Grenoble, France; Univ. Grenoble Alpes, UMS IRMaGe CHU Grenoble, F-38000 Grenoble, France
| | - A Krainik
- Univ. Grenoble Alpes, UMS IRMaGe CHU Grenoble, F-38000 Grenoble, France; Univ. Grenoble Alpes, GIN, F-38000, Grenoble, France
| | - A Jaillard
- Univ. Grenoble Alpes, UMS IRMaGe CHU Grenoble, F-38000 Grenoble, France
| | - C Peyrin
- Univ. Grenoble Alpes, CNRS, LPNC UMR 5105, F-38000 Grenoble, France
| | - M Baciu
- Univ. Grenoble Alpes, CNRS, LPNC UMR 5105, F-38000 Grenoble, France.
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Ramanoël S, Hoyau E, Kauffmann L, Renard F, Pichat C, Boudiaf N, Krainik A, Jaillard A, Baciu M. Gray Matter Volume and Cognitive Performance During Normal Aging. A Voxel-Based Morphometry Study. Front Aging Neurosci 2018; 10:235. [PMID: 30123123 PMCID: PMC6085481 DOI: 10.3389/fnagi.2018.00235] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 07/18/2018] [Indexed: 12/21/2022] Open
Abstract
Normal aging is characterized by decline in cognitive functioning in conjunction with extensive gray matter (GM) atrophy. A first aim of this study was to determine GM volume differences related to aging by comparing two groups of participants, middle-aged group (MAG, mean age 41 years, N = 16) and older adults (OG, mean age 71 years, N = 14) who underwent an magnetic resonance images (MRI) voxel-based morphometry (VBM) evaluation. The VBM analyses included two optimized pipelines, for the cortex and for the cerebellum. Participants were also evaluated on a wide range of cognitive tests assessing both domain-general and language-specific processes, in order to examine how GM volume differences between OG and MAG relate to cognitive performance. Our results show smaller bilateral GM volume in the OG relative to the MAG, in several cerebral and right cerebellar regions involved in language and executive functions. Importantly, our results also revealed smaller GM volume in the right cerebellum in OG relative to MAG, supporting the idea of a complex cognitive role for this structure. This study provides a broad picture of cerebral, but also cerebellar and cognitive changes associated with normal aging.
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Affiliation(s)
- Stephen Ramanoël
- INSERM/CNRS, Institut Vision, Sorbonne University, Pierre and Marie Curie Universities (UPMC) Paris 06, Paris, France
| | - Elena Hoyau
- CNRS LPNC UMR 5105, University of Grenoble Alpes, Grenoble, France
| | - Louise Kauffmann
- CNRS LPNC UMR 5105, University of Grenoble Alpes, Grenoble, France
- CNRS, Grenoble INP, GIPSA-lab, University of Grenoble Alpes, Grenoble, France
| | - Félix Renard
- UMS IRMaGe Grenoble Hospital, University of Grenoble Alpes, Grenoble, France
| | - Cédric Pichat
- CNRS LPNC UMR 5105, University of Grenoble Alpes, Grenoble, France
| | - Naïla Boudiaf
- CNRS LPNC UMR 5105, University of Grenoble Alpes, Grenoble, France
| | - Alexandre Krainik
- UMS IRMaGe Grenoble Hospital, University of Grenoble Alpes, Grenoble, France
- Grenoble Institute of Neuroscience, University of Grenoble Alpes, Grenoble, France
| | - Assia Jaillard
- UMS IRMaGe Grenoble Hospital, University of Grenoble Alpes, Grenoble, France
| | - Monica Baciu
- CNRS LPNC UMR 5105, University of Grenoble Alpes, Grenoble, France
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Attyé A, Jean C, Remond P, Peyrin C, Lecler A, Boudiaf N, Aptel F, Chiquet C, Lamalle L, Krainik A. Track-weighted imaging for neuroretina: Evaluations in healthy volunteers and ischemic optic neuropathy. J Magn Reson Imaging 2018; 48:737-747. [PMID: 29292557 DOI: 10.1002/jmri.25941] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 12/14/2017] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The use of MRI-tractography to explore the human neuroretina is yet to be reported. Track-weighted imaging (TWI) was recently introduced as a qualitative tractography-based method with high anatomical contrast. PURPOSE To explore the human retina in healthy volunteers and patients with anterior ischemic optic neuropathy (AION) using TWI reconstructions. STUDY TYPE Prospective. POPULATION Twenty AION patients compared with 20 healthy volunteers. FIELD STRENGTH/SEQUENCE 3.0T MRI diffusion-weighted imaging (DWI) with b-value of 1000 s/mm2 and 60 diffusion-weighting noncollinear directions. ASSESSMENT We performed constrained spherical deconvolution from the diffusion-weighted signal and volumetric tractography method, whereby 10 million streamlines are initiated from seed points randomly distributed throughout the orbital area. We then reconstructed TWI maps with isotropic voxel size of 300 μm. STATISTICAL TESTS We tested the effect of the number of diffusion-weighting directions, ocular laterality, and ocular dominance on healthy retinal fascicles distribution. We then performed factorial analysis of variance to test the effects of the presence/absence of the fascicles on the visual field defect in patients. RESULTS In healthy volunteers, we found more temporal fascicle in right eyes (P = 0.001), more superior fascicles in dominant eyes (P = 0.014), and fewer fascicles with tractography maps based on 30 directions than those based on 45 directions (P = 9 × 10-8 ) and 60 directions (P = 6 × 10-7 ). Eight out of 20 AION patients presented with complete absence of neuroretinal fascicle, side of the disease, which was correlated with visual field mean deviation at the 6-month visit [F(1,17) = 6.97, P = 0.016]. Seven patients presented with a temporal fascicle in the injured eye; this fascicle presence was linked to visual field mean deviation at the 6-month visit [F(1,17) = 8.43, P = 0.009]. DATA CONCLUSION In AION patients, the presence of the temporal neuroretinal fascicle in the affected eye provides an objective outcome radiological sign correlated with visual performance. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018.
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Affiliation(s)
- Arnaud Attyé
- Department of Neuroradiology and MRI, Grenoble University Hospital, Grenoble, France
- University Grenoble Alpes, Grenoble, France
- IRMaGe, Inserm US 17, CNRS UMS 3552, Grenoble, France
| | - Clément Jean
- Department of Neuroradiology and MRI, Grenoble University Hospital, Grenoble, France
- University Grenoble Alpes, Grenoble, France
- IRMaGe, Inserm US 17, CNRS UMS 3552, Grenoble, France
| | - Perrine Remond
- Department of Neuroradiology and MRI, Grenoble University Hospital, Grenoble, France
- Department of Ophthalmology, Grenoble University Hospital, Grenoble, France
| | - Carole Peyrin
- University Grenoble Alpes, Grenoble, France
- Centre National de Recherche Scientifique, Laboratoire de Psychologie et Neurocognition (LPNC), Grenoble, France
| | - Augustin Lecler
- Department of Neuroradiology, Rothschild Foundation, Paris, France
| | | | - Florent Aptel
- University Grenoble Alpes, Grenoble, France
- Department of Ophthalmology, Grenoble University Hospital, Grenoble, France
| | - Christophe Chiquet
- University Grenoble Alpes, Grenoble, France
- Department of Ophthalmology, Grenoble University Hospital, Grenoble, France
| | - Laurent Lamalle
- University Grenoble Alpes, Grenoble, France
- IRMaGe, Inserm US 17, CNRS UMS 3552, Grenoble, France
| | - Alexandre Krainik
- Department of Neuroradiology and MRI, Grenoble University Hospital, Grenoble, France
- University Grenoble Alpes, Grenoble, France
- IRMaGe, Inserm US 17, CNRS UMS 3552, Grenoble, France
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Remond P, Attyé A, Lecler A, Lamalle L, Boudiaf N, Aptel F, Krainik A, Chiquet C. The Central Bright Spot Sign: A Potential New MR Imaging Sign for the Early Diagnosis of Anterior Ischemic Optic Neuropathy due to Giant Cell Arteritis. AJNR Am J Neuroradiol 2017; 38:1411-1415. [PMID: 28495949 DOI: 10.3174/ajnr.a5205] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 02/25/2017] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE A rapid identification of the etiology of anterior ischemic optic neuropathy is crucial because it determines therapeutic management. Our aim was to assess MR imaging to study the optic nerve head in patients referred with anterior ischemic optic neuropathy, due to either giant cell arteritis or the nonarteritic form of the disease, compared with healthy subjects. MATERIALS AND METHODS Fifteen patients with giant cell arteritis-related anterior ischemic optic neuropathy and 15 patients with nonarteritic anterior ischemic optic neuropathy from 2 medical centers were prospectively included in our study between August 2015 and May 2016. Fifteen healthy subjects and patients had undergone contrast-enhanced, flow-compensated, 3D T1-weighted MR imaging. The bright spot sign was defined as optic nerve head enhancement with a 3-grade ranking system. Two radiologists and 1 ophthalmologist independently performed blinded evaluations of MR imaging sequences with this scale. Statistical analysis included interobserver agreement. RESULTS MR imaging scores were significantly higher in patients with giant cell arteritis-related anterior ischemic optic neuropathy than in patients with nonarteritic anterior ischemic optic neuropathy (P ≤ .05). All patients with giant cell arteritis-related anterior ischemic optic neuropathy (15/15) and 7/15 patients with nonarteritic anterior ischemic optic neuropathy presented with the bright spot sign. No healthy subjects exhibited enhancement of the anterior part of the optic nerve. There was a significant relationship between the side of the bright spot and the side of the anterior ischemic optic neuropathy (P ≤ .001). Interreader agreement was good for observers (κ = 0.815). CONCLUSIONS Here, we provide evidence of a new MR imaging sign that identifies the acute stage of giant cell arteritis-related anterior ischemic optic neuropathy; patients without this central bright spot sign always had a nonarteritic pathophysiology and therefore did not require emergency corticosteroid therapy.
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Affiliation(s)
- P Remond
- From the Department of Neuroradiology and MRI (P.R., A.A., A.K.), SFR RMN Neurosciences
- Department of Ophthalmology (P.R., F.A., C.C.), University Hospital of Grenoble, Grenoble, France
| | - A Attyé
- From the Department of Neuroradiology and MRI (P.R., A.A., A.K.), SFR RMN Neurosciences
- University Grenoble Alpes (A.A., L.L., N.B., A.K.), IRMaGe, Grenoble, France
| | - A Lecler
- Department of Neuroradiology (A.L.), Rothschild Foundation, Paris, France
| | - L Lamalle
- University Grenoble Alpes (A.A., L.L., N.B., A.K.), IRMaGe, Grenoble, France
| | - N Boudiaf
- University Grenoble Alpes (A.A., L.L., N.B., A.K.), IRMaGe, Grenoble, France
| | - F Aptel
- Department of Ophthalmology (P.R., F.A., C.C.), University Hospital of Grenoble, Grenoble, France
| | - A Krainik
- From the Department of Neuroradiology and MRI (P.R., A.A., A.K.), SFR RMN Neurosciences
- University Grenoble Alpes (A.A., L.L., N.B., A.K.), IRMaGe, Grenoble, France
| | - C Chiquet
- Department of Ophthalmology (P.R., F.A., C.C.), University Hospital of Grenoble, Grenoble, France
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Boudiaf N, Warnking J, Moreaud O, Pietras J, Condamine E, Fournet N, Bossant A, Baciu M, Krainik A. Vasoréactivité cérébrale et déclin cognitif dans le vieillissement sain et au stade précoce du vieillissement pathologique. J Neuroradiol 2017. [DOI: 10.1016/j.neurad.2017.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Boudiaf N, Laboissière R, Cousin É, Fournet N, Krainik A, Baciu M. Behavioral evidence for a differential modulation of semantic processing and lexical production by aging: a full linear mixed-effects modeling approach. Neuropsychol Dev Cogn B Aging Neuropsychol Cogn 2016; 25:1-22. [PMID: 27883290 DOI: 10.1080/13825585.2016.1257100] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The effect of normal aging on lexical production and semantic processing was evaluated in 72 healthy participants. Four tasks were used, picture naming (PN), picture categorization (PC), numerical judgment (NJ), and color judgment (CJ). The dependence of reaction time (RT) and correct responses with age was accounted by mixed-effects models. Participants underwent neuropsychological testing for verbal, executive, and memory functions. The RTs increase significantly with age for all tasks. After parceling out the non-specific cognitive decline, as reflected by the NJ task, the RT for the PN task decreases with age. Behavioral data were interpreted in relation with neuropsychological scores. Our results suggest that (a) naming becomes more automatic and semantic processing slightly more difficult with age, and (b) a non-specific general slowdown of cognitive processing occurs with age. Lexical production remained unaltered, based on compensatory automatic processes. This study also suggests a possible slowdown of semantic processing, even in normal aging.
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Affiliation(s)
- Naïla Boudiaf
- a Université Grenoble Alpes , LPNC , Grenoble , France.,b CNRS, LPNC UMR 5105 , Grenoble , France
| | - Rafael Laboissière
- a Université Grenoble Alpes , LPNC , Grenoble , France.,b CNRS, LPNC UMR 5105 , Grenoble , France
| | - Émilie Cousin
- a Université Grenoble Alpes , LPNC , Grenoble , France.,b CNRS, LPNC UMR 5105 , Grenoble , France.,d UMS IRMaGe, IRM 3T Recherche , Université Grenoble Alpes , Grenoble , France
| | - Nathalie Fournet
- a Université Grenoble Alpes , LPNC , Grenoble , France.,c Université Savoie Mont Blanc , LPNC , Chambéry , France
| | - Alexandre Krainik
- d UMS IRMaGe, IRM 3T Recherche , Université Grenoble Alpes , Grenoble , France.,e GIN-Neuroimagerie Fonctionnelle et Perfusion Cérébrale , Université Grenoble Alpes , Grenoble , France
| | - Monica Baciu
- a Université Grenoble Alpes , LPNC , Grenoble , France.,b CNRS, LPNC UMR 5105 , Grenoble , France
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Baciu M, Boudiaf N, Cousin E, Perrone-Bertolotti M, Pichat C, Fournet N, Chainay H, Lamalle L, Krainik A. Functional MRI evidence for the decline of word retrieval and generation during normal aging. Age (Dordr) 2016; 38:3. [PMID: 26711670 PMCID: PMC5005885 DOI: 10.1007/s11357-015-9857-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 11/06/2015] [Indexed: 05/19/2023]
Abstract
This fMRI study aimed to explore the effect of normal aging on word retrieval and generation. The question addressed is whether lexical production decline is determined by a direct mechanism, which concerns the language operations or is rather indirectly induced by a decline of executive functions. Indeed, the main hypothesis was that normal aging does not induce loss of lexical knowledge, but there is only a general slowdown in retrieval mechanisms involved in lexical processing, due to possible decline of the executive functions. We used three tasks (verbal fluency, object naming, and semantic categorization). Two groups of participants were tested (Young, Y and Aged, A), without cognitive and psychiatric impairment and showing similar levels of vocabulary. Neuropsychological testing revealed that older participants had lower executive function scores, longer processing speeds, and tended to have lower verbal fluency scores. Additionally, older participants showed higher scores for verbal automatisms and overlearned information. In terms of behavioral data, older participants performed as accurate as younger adults, but they were significantly slower for the semantic categorization and were less fluent for verbal fluency task. Functional MRI analyses suggested that older adults did not simply activate fewer brain regions involved in word production, but they actually showed an atypical pattern of activation. Significant correlations between the BOLD (Blood Oxygen Level Dependent) signal of aging-related (A > Y) regions and cognitive scores suggested that this atypical pattern of the activation may reveal several compensatory mechanisms (a) to overcome the slowdown in retrieval, due to the decline of executive functions and processing speed and (b) to inhibit verbal automatic processes. The BOLD signal measured in some other aging-dependent regions did not correlate with the behavioral and neuropsychological scores, and the overactivation of these uncorrelated regions would simply reveal dedifferentiation that occurs with aging. Altogether, our results suggest that normal aging is associated with a more difficult access to lexico-semantic operations and representations by a slowdown in executive functions, without any conceptual loss.
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Affiliation(s)
- M Baciu
- Univ. Grenoble Alpes, LPNC, F-38040, Grenoble, France.
- CNRS, LPNC UMR 5105, F-38040, Grenoble, France.
| | - N Boudiaf
- Univ. Grenoble Alpes, LPNC, F-38040, Grenoble, France
- CNRS, LPNC UMR 5105, F-38040, Grenoble, France
| | - E Cousin
- Univ. Grenoble Alpes, LPNC, F-38040, Grenoble, France
- CNRS, LPNC UMR 5105, F-38040, Grenoble, France
- UMS IRMaGe CHU Grenoble, Univ. Grenoble Alpes, F-38043, Grenoble, France
| | - M Perrone-Bertolotti
- Univ. Grenoble Alpes, LPNC, F-38040, Grenoble, France
- CNRS, LPNC UMR 5105, F-38040, Grenoble, France
| | - C Pichat
- Univ. Grenoble Alpes, LPNC, F-38040, Grenoble, France
- CNRS, LPNC UMR 5105, F-38040, Grenoble, France
| | - N Fournet
- CNRS, LPNC UMR 5105, F-38040, Grenoble, France
- Univ. Savoie Montblanc, LPNC, F-73000, Chambéry, France
| | - H Chainay
- Laboratoire d'Etude des Mécanismes Cognitifs, Université Lumière Lyon 2, F-69676, Bron, France
| | - L Lamalle
- UMS IRMaGe CHU Grenoble, Univ. Grenoble Alpes, F-38043, Grenoble, France
| | - A Krainik
- UMS IRMaGe CHU Grenoble, Univ. Grenoble Alpes, F-38043, Grenoble, France
- GIN Univ. Grenoble Alpes, F-38043, Grenoble, France
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Suruki RY, Daugherty JB, Boudiaf N, Albers FC. P221 Evaluation of exacerbation frequency and re-hospitalisation, and risk for subsequent exacerbations in asthma patients in a UK primary care setting. Thorax 2015. [DOI: 10.1136/thoraxjnl-2015-207770.357] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Boudiaf N, Attyé A, Warnking JM, Troprès I, Lamalle L, Pietras J, Krainik A. BOLD fMRI of cerebrovascular reactivity in the middle cerebral artery territory: A 100 volunteers' study. J Neuroradiol 2015; 42:338-44. [PMID: 26031884 DOI: 10.1016/j.neurad.2015.04.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 03/26/2015] [Accepted: 04/05/2015] [Indexed: 11/15/2022]
Abstract
BACKGROUND AND PURPOSE The assessment of cerebrovascular reactivity (CVR) has shown promising results for its use in medical diagnosis and prognosis, especially in patients suffering from severe intracranial arterial stenosis. However, its quantification remains uncertain because of a large variability inherent in brain anatomy and in methodological settings. To overcome this variability, we provide lateralization index (LI) values for CVR within the middle cerebral artery territory to detect CVR impairment. MATERIALS AND METHODS We assessed CVR in 100 volunteers (41 females; 47.52 ± 21.58 years) without cervico-encephalic arterial stenosis using BOLD-fMRI contrast with a block-design hypercapnic challenge. Averaged end-tidal CO2 was used as a physiological regressor for statistical analyses with a general linear model. We measured %BOLD signal-change in segmented gray matter regions of interest in the middle cerebral artery territory (MCA). We calculated a laterality index according to the following formula: LI=(CVRleft-CVRright)/(CVRleft+CVRright). We tested the effects of methodological settings (i.e. hypercapnic gas, gas administration means, MR acquisition and sex) on %BOLD signal change and LI values with analysis of variance. RESULTS No adverse effects of the hypercapnic challenge were reported. LI values were independent of experimental conditions. Mean LI calculated in MCA territories was 0.016 ± 0.031, giving the lower and upper limits of 95% (m ± 2SD) of this population distribution at]-0.05; 0.08[. CONCLUSION LI can effectively help us to overcome measurement variabilities. Therefore, it can be used to detect abnormal asymmetries in CVR and identify patients at higher risk of ischemic stroke.
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Affiliation(s)
- Naïla Boudiaf
- Université Grenoble Alpes 3bis, CNRS, LPNC, 38000 Grenoble, France; Université Savoie 3, LPNC, 73000 Chambéry, France.
| | - Arnaud Attyé
- Inserm, université Grenoble Alpes, GIN, CHU de Grenoble, 38000 Grenoble, France; Department of Neuroradiology and MRI, University Hospital of Grenoble-IFR1, Grenoble, France
| | - Jan M Warnking
- Inserm, université Grenoble Alpes, GIN, CHU de Grenoble, 38000 Grenoble, France
| | - Irène Troprès
- Inserm, université Grenoble Alpes, GIN, CHU de Grenoble, 38000 Grenoble, France; Inserm, université Grenoble Alpes, CNRS, IRMaGe, CHU de Grenoble, 38000 Grenoble, France
| | - Laurent Lamalle
- Inserm, université Grenoble Alpes, CNRS, IRMaGe, CHU de Grenoble, 38000 Grenoble, France
| | - Johan Pietras
- Inserm, université Grenoble Alpes, CNRS, IRMaGe, CHU de Grenoble, 38000 Grenoble, France
| | - Alexandre Krainik
- Inserm, université Grenoble Alpes, GIN, CHU de Grenoble, 38000 Grenoble, France; Inserm, université Grenoble Alpes, CNRS, IRMaGe, CHU de Grenoble, 38000 Grenoble, France; Department of Neuroradiology and MRI, University Hospital of Grenoble-IFR1, Grenoble, France
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