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Simic T, Desjardins MÈ, Courson M, Bedetti C, Houzé B, Brambati SM. Treatment-induced neuroplasticity after anomia therapy in post-stroke aphasia: A systematic review of neuroimaging studies. BRAIN AND LANGUAGE 2023; 244:105300. [PMID: 37633250 DOI: 10.1016/j.bandl.2023.105300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 05/02/2023] [Accepted: 06/21/2023] [Indexed: 08/28/2023]
Abstract
We systematically reviewed the literature on neural changes following anomia treatment post-stroke. We conducted electronic searches of CINAHL, Cochrane Trials, Embase, Ovid MEDLINE, MEDLINE-in-Process and PsycINFO databases; two independent raters assessed all abstracts and full texts. Accepted studies reported original data on adults with post-stroke aphasia, who received behavioural treatment for anomia, and magnetic resonance brain imaging (MRI) pre- and post-treatment. Search results yielded 2481 citations; 33 studies were accepted. Most studies employed functional MRI and the quality of reporting neuroimaging methodology was variable, particularly for pre-processing steps and statistical analyses. The most methodologically robust data were synthesized, focusing on pre- versus post-treatment contrasts. Studies more commonly reported increases (versus decreases) in activation following naming therapy, primarily in the left supramarginal gyrus, and left/bilateral precunei. Our findings highlight the methodological heterogeneity across MRI studies, and the paucity of robust evidence demonstrating direct links between brain and behaviour in anomia rehabilitation.
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Affiliation(s)
- Tijana Simic
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal (CRIUGM), 4545 Queen Mary R.d., Montréal, QC H3W 1W4, Canada; Département de Psychologie, Université de Montréal, 90 Vincent-d'Indy Avenue, Montréal, QC H2V 2S9, Canada; Hôpital du Sacré-Cœur de Montréal (HSCM), 5400 Boul Gouin O, Montréal, QC H4J 1C5, Canada.
| | - Marie-Ève Desjardins
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal (CRIUGM), 4545 Queen Mary R.d., Montréal, QC H3W 1W4, Canada; Département de Psychologie, Université de Montréal, 90 Vincent-d'Indy Avenue, Montréal, QC H2V 2S9, Canada; Hôpital du Sacré-Cœur de Montréal (HSCM), 5400 Boul Gouin O, Montréal, QC H4J 1C5, Canada
| | - Melody Courson
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal (CRIUGM), 4545 Queen Mary R.d., Montréal, QC H3W 1W4, Canada; Département de Psychologie, Université de Montréal, 90 Vincent-d'Indy Avenue, Montréal, QC H2V 2S9, Canada
| | - Christophe Bedetti
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal (CRIUGM), 4545 Queen Mary R.d., Montréal, QC H3W 1W4, Canada
| | - Bérengère Houzé
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal (CRIUGM), 4545 Queen Mary R.d., Montréal, QC H3W 1W4, Canada; Département de Psychologie, Université de Montréal, 90 Vincent-d'Indy Avenue, Montréal, QC H2V 2S9, Canada
| | - Simona Maria Brambati
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal (CRIUGM), 4545 Queen Mary R.d., Montréal, QC H3W 1W4, Canada; Département de Psychologie, Université de Montréal, 90 Vincent-d'Indy Avenue, Montréal, QC H2V 2S9, Canada; Hôpital du Sacré-Cœur de Montréal (HSCM), 5400 Boul Gouin O, Montréal, QC H4J 1C5, Canada
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Masson-Trottier M, Dash T, Berroir P, Ansaldo AI. French Phonological Component Analysis and aphasia recovery: A bilingual perspective on behavioral and structural data. Front Hum Neurosci 2022; 16:752121. [PMID: 36211123 PMCID: PMC9535680 DOI: 10.3389/fnhum.2022.752121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 09/08/2022] [Indexed: 11/13/2022] Open
Abstract
Studies show bilingualism entails an advantage in cognitive control tasks. There is evidence of a bilingual advantage in the context of aphasia, resulting in better cognitive outcomes and recovery in bilingual persons with aphasia compared to monolingual peers. This bilingual advantage also results in structural changes in the right hemisphere gray matter. Very few studies have examined the so-called bilingual advantage by reference to specific anomia therapy efficacy. This study aims to compare the effect of French-Phonological Component Analysis (Fr-PCA) in monolinguals and bilingual persons with aphasia, both at the linguistic and cognitive control level, and to examine the structural impact of left hemisphere lesion location and right hemisphere structural data. Eight participants with chronic aphasia received Fr-PCA for a total of 15 h over 5 weeks. The results showed improved accuracy for treated words and generalization to untreated items and discourse in both groups, and improved Flanker task performance for some participants. Bilingual participants improved more than monolinguals for picture-naming tasks and narrative discourse. Damage to the left postcentral gyrus and the middle frontal gyrus was associated with less therapy-induced improvement. Additionally, left hemisphere damage to the inferior parietal gyrus and postcentral gyrus was associated with reduced cognitive control pre-therapy. Undamaged right hemisphere cortical thicknesses were significantly different between groups; the inferior frontal gyrus and the middle frontal gyrus were greater for the bilingual participants and correlated with cognitive control skills. These results suggest a bilingual advantage in anomia recovery following Fr-PCA, potentially resulting from enhanced cognitive control abilities that could be supported by right hemisphere neural reserve.
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Affiliation(s)
- Michèle Masson-Trottier
- Laboratoire de Plasticité Cérébrale, Communication et Vieillissement, Centre de Recherche de l’Institut de Gériatrie de Montréal, Montréal, QC, Canada
- École d’Orthophonie et d’Audiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada
| | - Tanya Dash
- Laboratoire de Plasticité Cérébrale, Communication et Vieillissement, Centre de Recherche de l’Institut de Gériatrie de Montréal, Montréal, QC, Canada
| | - Pierre Berroir
- Laboratoire de Plasticité Cérébrale, Communication et Vieillissement, Centre de Recherche de l’Institut de Gériatrie de Montréal, Montréal, QC, Canada
| | - Ana Inés Ansaldo
- Laboratoire de Plasticité Cérébrale, Communication et Vieillissement, Centre de Recherche de l’Institut de Gériatrie de Montréal, Montréal, QC, Canada
- École d’Orthophonie et d’Audiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada
- *Correspondence: Ana Inés Ansaldo,
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Li R, Mukadam N, Kiran S. Functional MRI evidence for reorganization of language networks after stroke. HANDBOOK OF CLINICAL NEUROLOGY 2022; 185:131-150. [PMID: 35078595 DOI: 10.1016/b978-0-12-823384-9.00007-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
In this chapter, we review fMRI evidence for language reorganization in individuals with poststroke aphasia. Several studies in the current literature have utilized fMRI as a tool to understand patterns of functional reorganization in poststroke aphasia. Consistent with previous models that have been proposed to explain the trajectory of language recovery, differential patterns of language processing and language recovery have been identified across individuals with poststroke aphasia in different stages of recovery. Overall, a global network breakdown typically occurs in the early stages of aphasia recovery, followed by normalization in "traditional" left hemisphere language networks. Depending on individual characteristics, right hemisphere regions and bilateral domain-general regions may be further recruited. The main takeaway of this chapter is that poststroke aphasia recovery does not depend on individual neural regions, but rather involves a complex interaction among regions in larger networks. Many of the unresolved issues and contrastive findings in the literature warrant further research with larger groups of participants and standard protocols of fMRI implementation.
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Affiliation(s)
- Ran Li
- Department of Speech, Language and Hearing Sciences, Boston University, Boston, MA, United States
| | - Nishaat Mukadam
- Department of Speech, Language and Hearing Sciences, Boston University, Boston, MA, United States
| | - Swathi Kiran
- Department of Speech, Language and Hearing Sciences, Boston University, Boston, MA, United States.
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Lwi SJ, Herron TJ, Curran BC, Ivanova MV, Schendel K, Dronkers NF, Baldo JV. Auditory Comprehension Deficits in Post-stroke Aphasia: Neurologic and Demographic Correlates of Outcome and Recovery. Front Neurol 2021; 12:680248. [PMID: 34456845 PMCID: PMC8397517 DOI: 10.3389/fneur.2021.680248] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 07/09/2021] [Indexed: 11/30/2022] Open
Abstract
Introduction: One of the most challenging symptoms of aphasia is an impairment in auditory comprehension. The inability to understand others has a direct impact on a person's quality of life and ability to benefit from treatment. Despite its importance, limited research has examined the recovery pattern of auditory comprehension and instead has focused on aphasia recovery more generally. Thus, little is known about the time frame for auditory comprehension recovery following stroke, and whether specific neurologic and demographic variables contribute to recovery and outcome. Methods: This study included 168 left hemisphere chronic stroke patients stroke patients with auditory comprehension impairments ranging from mild to severe. Univariate and multivariate lesion-symptom mapping (LSM) was used to identify brain regions associated with auditory comprehension outcomes on three different tasks: Single-word comprehension, yes/no sentence comprehension, and comprehension of sequential commands. Demographic variables (age, gender, and education) were also examined for their role in these outcomes. In a subset of patients who completed language testing at two or more time points, we also analyzed the trajectory of recovery in auditory comprehension using survival curve-based time compression. Results: LSM analyses revealed that poor single-word auditory comprehension was associated with lesions involving the left mid- to posterior middle temporal gyrus, and portions of the angular and inferior-middle occipital gyri. Poor yes/no sentence comprehension was associated almost exclusively with the left mid-posterior middle temporal gyrus. Poor comprehension of sequential commands was associated with lesions in the left posterior middle temporal gyrus. There was a small region of convergence between the three comprehension tasks, in the very posterior portion of the left middle temporal gyrus. The recovery analysis revealed that auditory comprehension scores continued to improve beyond the first year post-stroke. Higher education was associated with better outcome on all auditory comprehension tasks. Age and gender were not associated with outcome or recovery slopes. Conclusions: The current findings suggest a critical role for the posterior left middle temporal gyrus in the recovery of auditory comprehension following stroke, and that spontaneous recovery of auditory comprehension can continue well beyond the first year post-stroke.
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Affiliation(s)
- Sandy J Lwi
- Veterans Affairs Northern California Health Care System, Martinez, CA, United States
| | - Timothy J Herron
- Veterans Affairs Northern California Health Care System, Martinez, CA, United States
| | - Brian C Curran
- Veterans Affairs Northern California Health Care System, Martinez, CA, United States
| | - Maria V Ivanova
- Department of Psychology, University of California, Berkeley, Berkeley, CA, United States
| | - Krista Schendel
- Veterans Affairs Northern California Health Care System, Martinez, CA, United States
| | - Nina F Dronkers
- Department of Psychology, University of California, Berkeley, Berkeley, CA, United States
| | - Juliana V Baldo
- Veterans Affairs Northern California Health Care System, Martinez, CA, United States
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Li R, Perrachione TK, Tourville JA, Kiran S. Representation of semantic typicality in brain activation in healthy adults and individuals with aphasia: A multi-voxel pattern analysis. Neuropsychologia 2021; 158:107893. [PMID: 34022187 DOI: 10.1016/j.neuropsychologia.2021.107893] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 03/31/2021] [Accepted: 05/13/2021] [Indexed: 11/28/2022]
Abstract
This study aimed to investigate brain regions that show different activation patterns between semantically typical and atypical items in both healthy adults and individuals with aphasia (PWA). Eighteen neurologically healthy adults and twenty-one PWA participated in an fMRI semantic feature verification task that included typical and atypical stimuli from five different semantic categories. A whole-brain searchlight multi-voxel pattern analysis (MVPA) was conducted to classify brain activation patterns between typical and atypical conditions in each participant group separately. Behavioral responses were faster and more accurate for typical vs. atypical items across both groups. The searchlight MVPA identified two significant clusters in healthy adults: left middle occipital gyrus and right calcarine cortex, but no significant clusters were found in PWA. A follow-up analysis in PWA revealed a significant association between neural classification of semantic typicality in the left middle occipital gyrus and reaction times in the fMRI task. When the typicality effect was examined for each semantic category at the univariate level, significance was identified in the visual cortex for fruits in both groups of participants. These findings suggest that semantic typicality was modulated in the visual cortex in healthy individuals, but to a lesser extent in the same region in PWA.
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Affiliation(s)
- Ran Li
- Department of Speech, Language & Hearing Sciences, Boston University, Boston, MA, USA.
| | - Tyler K Perrachione
- Department of Speech, Language & Hearing Sciences, Boston University, Boston, MA, USA
| | - Jason A Tourville
- Department of Speech, Language & Hearing Sciences, Boston University, Boston, MA, USA
| | - Swathi Kiran
- Department of Speech, Language & Hearing Sciences, Boston University, Boston, MA, USA
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Schevenels K, Price CJ, Zink I, De Smedt B, Vandermosten M. A Review on Treatment-Related Brain Changes in Aphasia. NEUROBIOLOGY OF LANGUAGE (CAMBRIDGE, MASS.) 2020; 1:402-433. [PMID: 37215585 PMCID: PMC10158631 DOI: 10.1162/nol_a_00019] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 06/29/2020] [Indexed: 05/24/2023]
Abstract
Numerous studies have investigated brain changes associated with interventions targeting a range of language problems in patients with aphasia. We strive to integrate the results of these studies to examine (1) whether the focus of the intervention (i.e., phonology, semantics, orthography, syntax, or rhythmic-melodic) determines in which brain regions changes occur; and (2a) whether the most consistent changes occur within the language network or outside, and (2b) whether these are related to individual differences in language outcomes. The results of 32 studies with 204 unique patients were considered. Concerning (1), the location of treatment-related changes does not clearly depend on the type of language processing targeted. However, there is some support that rhythmic-melodic training has more impact on the right hemisphere than linguistic training. Concerning (2), we observed that language recovery is not only associated with changes in traditional language-related structures in the left hemisphere and homolog regions in the right hemisphere, but also with more medial and subcortical changes (e.g., precuneus and basal ganglia). Although it is difficult to draw strong conclusions, because there is a lack of systematic large-scale studies on this topic, this review highlights the need for an integrated approach to investigate how language interventions impact on the brain. Future studies need to focus on larger samples preserving subject-specific information (e.g., lesion effects) to cope with the inherent heterogeneity of stroke-induced aphasia. In addition, recovery-related changes in whole-brain connectivity patterns need more investigation to provide a comprehensive neural account of treatment-related brain plasticity and language recovery.
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Affiliation(s)
- Klara Schevenels
- Experimental Oto-Rhino-Laryngology, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Cathy J. Price
- Welcome Centre for Human Neuroimaging, Institute of Neurology, University College London, UK
| | - Inge Zink
- Experimental Oto-Rhino-Laryngology, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Bert De Smedt
- Parenting and Special Education Research Unit, Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium
| | - Maaike Vandermosten
- Experimental Oto-Rhino-Laryngology, Department of Neurosciences, KU Leuven, Leuven, Belgium
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Johnson JP, Meier EL, Pan Y, Kiran S. Treatment-related changes in neural activation vary according to treatment response and extent of spared tissue in patients with chronic aphasia. Cortex 2019; 121:147-168. [PMID: 31627014 DOI: 10.1016/j.cortex.2019.08.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 06/21/2019] [Accepted: 08/23/2019] [Indexed: 11/25/2022]
Abstract
Neuroimaging studies of aphasia recovery have linked treatment-related improvements in language processing to changes in functional brain activation in left hemisphere language regions and their right hemisphere homologues. Although there is some consensus that better behavioral outcomes are achieved when activation is restored to the left hemisphere, the circumstances that dictate how and why regions in both hemispheres respond to naming therapy are still unclear. In this study, an fMRI picture-naming task was used to examine 16 regions of interest in 26 patients with chronic aphasia before and after 12 weeks of semantic naming treatment. Ten control patients who did not receive treatment and 17 healthy controls were also scanned. Naming therapy resulted in a significant increase in cortical activation, an effect that was largely driven by patients who responded most favorably to treatment, as patients who responded less favorably (as well as those who did not receive treatment) had little change in activation over time. Relative to healthy controls, patients had higher pre-treatment activation in the bilateral inferior frontal gyri (IFG) and lower activation in the bilateral angular gyri; after treatment, they had higher activation in bilateral IFG, as well as in the right middle frontal gyrus. These results suggest that the predominant effect of beneficial naming treatment was an upregulation of traditional language areas and their right hemisphere homologues and, in particular, regions associated with phonological and semantic/executive semantic processing, as well as broader domain general functions. Additionally, in some left hemisphere regions, post-treatment changes in activation were greater when there was more damage than when there was less damage, indicating that spared tissue in otherwise highly damaged regions can be modulated by treatment.
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Affiliation(s)
- Jeffrey P Johnson
- Aphasia Research Laboratory, Department of Speech, Language & Hearing Sciences, Sargent College of Health & Rehabilitation Sciences, Boston University, Boston, MA, USA.
| | - Erin L Meier
- Aphasia Research Laboratory, Department of Speech, Language & Hearing Sciences, Sargent College of Health & Rehabilitation Sciences, Boston University, Boston, MA, USA
| | - Yue Pan
- Aphasia Research Laboratory, Department of Speech, Language & Hearing Sciences, Sargent College of Health & Rehabilitation Sciences, Boston University, Boston, MA, USA
| | - Swathi Kiran
- Aphasia Research Laboratory, Department of Speech, Language & Hearing Sciences, Sargent College of Health & Rehabilitation Sciences, Boston University, Boston, MA, USA
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Meier EL, Johnson JP, Pan Y, Kiran S. A lesion and connectivity-based hierarchical model of chronic aphasia recovery dissociates patients and healthy controls. NEUROIMAGE-CLINICAL 2019; 23:101919. [PMID: 31491828 PMCID: PMC6702239 DOI: 10.1016/j.nicl.2019.101919] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Revised: 06/05/2019] [Accepted: 06/30/2019] [Indexed: 12/28/2022]
Abstract
Traditional models of left hemisphere stroke recovery propose that reactivation of remaining ipsilesional tissue is optimal for language processing whereas reliance on contralesional right hemisphere homologues is less beneficial or possibly maladaptive in the chronic recovery stage. However, neuroimaging evidence for this proposal is mixed. This study aimed to elucidate patterns of effective connectivity in patients with chronic aphasia in light of healthy control connectivity patterns and in relation to damaged tissue within left hemisphere regions of interest and according to performance on a semantic decision task. Using fMRI and dynamic causal modeling, biologically-plausible models within four model families were created to correspond to potential neural recovery patterns, including Family A: Left-lateralized connectivity (i.e., no/minimal damage), Family B: Bilateral anterior-weighted connectivity (i.e., posterior damage), Family C: Bilateral posterior-weighted connectivity (i.e., anterior damage) and Family D: Right-lateralized connectivity (i.e., extensive damage). Controls exhibited a strong preference for left-lateralized network models (Family A) whereas patients demonstrated a split preference for Families A and C. At the level of connections, controls exhibited stronger left intrahemispheric task-modulated connections than did patients. Within the patient group, damage to left superior frontal structures resulted in greater right intrahemispheric connectivity whereas damage to left ventral structures resulted in heightened modulation of left frontal regions. Lesion metrics best predicted accuracy on the fMRI task and aphasia severity whereas left intrahemispheric connectivity predicted fMRI task reaction times. These results are discussed within the context of the hierarchical recovery model of chronic aphasia. The semantic network in neurologically-intact, healthy controls was characterized by left-lateralized connectivity. Patient connectivity was split between left-lateralized and bilateral, posterior-weighted (i.e., anterior damage) models. Controls solely recruited LITG-driven connections whereas patients recruited a distributed network of connections. Within the patient group, intra- and inter-hemispheric connections were related to lesion site and/or size. Lesion size predicted aphasia severity and fMRI task accuracy, and effective connectivity predicted task reaction times.
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Affiliation(s)
- Erin L Meier
- Department of Speech, Language, & Hearing Sciences, Sargent College of Health and Rehabilitation Sciences, Boston University, 635 Commonwealth Avenue, Room 326, Boston, MA 02215, United States of America.
| | - Jeffrey P Johnson
- Department of Speech, Language, & Hearing Sciences, Sargent College of Health and Rehabilitation Sciences, Boston University, 635 Commonwealth Avenue, Room 326, Boston, MA 02215, United States of America
| | - Yue Pan
- Department of Speech, Language, & Hearing Sciences, Sargent College of Health and Rehabilitation Sciences, Boston University, 635 Commonwealth Avenue, Room 326, Boston, MA 02215, United States of America
| | - Swathi Kiran
- Department of Speech, Language, & Hearing Sciences, Sargent College of Health and Rehabilitation Sciences, Boston University, 635 Commonwealth Avenue, Room 326, Boston, MA 02215, United States of America
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9
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Meier EL, Johnson JP, Kiran S. Left frontotemporal effective connectivity during semantic feature judgments in patients with chronic aphasia and age-matched healthy controls. Cortex 2018; 108:173-192. [PMID: 30243049 PMCID: PMC6234086 DOI: 10.1016/j.cortex.2018.08.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 08/01/2018] [Accepted: 08/08/2018] [Indexed: 12/15/2022]
Abstract
Traditional models of neural reorganization of language skills in patients with chronic stroke-induced aphasia (PWA) propose activation of reperfused or spared left hemisphere tissue results in the most favorable language outcomes. However, these models do not fully explain variable behavioral recovery patterns observed in chronic patients. Instead, investigation of connectivity patterns of critical network nodes may elucidate better-informed recovery models. In the present study, we combined fMRI and dynamic causal modeling (DCM) to examine effective connectivity of a simple three-node left hemisphere network during a semantic feature decision task in 25 PWA and 18 age-matched neurologically intact healthy controls. The DCM model space utilized in Meier, Kapse, & Kiran (2016), which was organized according to exogenous input to one of three regions (i.e., left inferior frontal gyrus, pars triangularis [LIFGtri], left posterior middle temporal gyrus [LpMTG], or left middle frontal gyrus [LMFG]) implicated in various levels of lexical-semantic processing, was interrogated. This model space included all possible combinations of uni- and bidirectional task-modulated connections between LIFGtri, LMFG and LpMTG, resulting in 72 individual models that were partitioned into three separate families (i.e., Family #1: Input to LIFGtri, Family #2: Input to LMFG, Family #3: Input to LpMTG). Family-wise Bayesian model selection revealed Family #2: Input to LMFG best fit both patient and control data at a group level. Both groups relied heavily on LMFG's modulation of the other two model regions. By contrast, between-group differences in task-modulated coupling of LIFGtri and LpMTG were observed. Within the patient group, the strength of activity in LIFGtri and connectivity of LpMTG → LIFGtri were positively associated with lexical-semantic abilities inside and outside of the scanner, whereas greater recruitment of LpMTG was associated with poorer lexical-semantic skills.
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Affiliation(s)
- Erin L Meier
- Sargent College of Health & Rehabilitation Sciences, Boston University, United States.
| | - Jeffrey P Johnson
- Sargent College of Health & Rehabilitation Sciences, Boston University, United States
| | - Swathi Kiran
- Sargent College of Health & Rehabilitation Sciences, Boston University, United States
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10
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The Neural and Behavioral Correlates of Anomia Recovery following Personalized Observation, Execution, and Mental Imagery Therapy: A Proof of Concept. Neural Plast 2018; 2018:5943759. [PMID: 30154837 PMCID: PMC6092994 DOI: 10.1155/2018/5943759] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 04/11/2018] [Accepted: 06/13/2018] [Indexed: 11/18/2022] Open
Abstract
The impact of sensorimotor strategies on aphasia recovery has rarely been explored. This paper reports on the efficacy of personalized observation, execution, and mental imagery (POEM) therapy, a new approach designed to integrate sensorimotor and language-based strategies to treat verb anomia, a frequent aphasia sign. Two participants with verb anomia were followed up in a pre-/posttherapy fMRI study. POEM was administered in a massed stimulation schedule, with personalized stimuli, resulting in significant improvement in both participants, with both trained and untrained items. Given that the latter finding is rarely reported in the literature, the evidence suggests that POEM favors the implementation of a word retrieval strategy that can be integrated and generalized. Changes in fMRI patterns following POEM reflect a reduction in the number of recruited areas supporting naming and the recruitment of brain areas that belong to the language and mirror neuron systems. The data provide evidence on the efficacy of POEM for verb anomia, while pointing to the added value of combined language and sensorimotor strategies for recovery from verb anomia, contributing to the consolidation of a word retrieval strategy that can be better generalized to untrained words. Future studies with a larger sample of participants are required to further explore this avenue.
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11
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Wilson SM, Yen M, Eriksson DK. An adaptive semantic matching paradigm for reliable and valid language mapping in individuals with aphasia. Hum Brain Mapp 2018; 39:3285-3307. [PMID: 29665223 PMCID: PMC6045968 DOI: 10.1002/hbm.24077] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 03/26/2018] [Accepted: 03/30/2018] [Indexed: 11/08/2022] Open
Abstract
Research on neuroplasticity in recovery from aphasia depends on the ability to identify language areas of the brain in individuals with aphasia. However, tasks commonly used to engage language processing in people with aphasia, such as narrative comprehension and picture naming, are limited in terms of reliability (test-retest reproducibility) and validity (identification of language regions, and not other regions). On the other hand, paradigms such as semantic decision that are effective in identifying language regions in people without aphasia can be prohibitively challenging for people with aphasia. This paper describes a new semantic matching paradigm that uses an adaptive staircase procedure to present individuals with stimuli that are challenging yet within their competence, so that language processing can be fully engaged in people with and without language impairments. The feasibility, reliability and validity of the adaptive semantic matching paradigm were investigated in sixteen individuals with chronic post-stroke aphasia and fourteen neurologically normal participants, in comparison to narrative comprehension and picture naming paradigms. All participants succeeded in learning and performing the semantic paradigm. Test-retest reproducibility of the semantic paradigm in people with aphasia was good (Dice coefficient = 0.66), and was superior to the other two paradigms. The semantic paradigm revealed known features of typical language organization (lateralization; frontal and temporal regions) more consistently in neurologically normal individuals than the other two paradigms, constituting evidence for validity. In sum, the adaptive semantic matching paradigm is a feasible, reliable and valid method for mapping language regions in people with aphasia.
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Affiliation(s)
- Stephen M. Wilson
- Department of Hearing and Speech SciencesVanderbilt University Medical CenterNashvilleTennessee
| | - Melodie Yen
- Department of Hearing and Speech SciencesVanderbilt University Medical CenterNashvilleTennessee
| | - Dana K. Eriksson
- Department of SpeechLanguage, and Hearing Sciences, University of ArizonaTucsonArizona
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Marcotte K, Laird L, Bitan T, Meltzer JA, Graham SJ, Leonard C, Rochon E. Therapy-Induced Neuroplasticity in Chronic Aphasia After Phonological Component Analysis: A Matter of Intensity. Front Neurol 2018; 9:225. [PMID: 29686646 PMCID: PMC5900891 DOI: 10.3389/fneur.2018.00225] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 03/22/2018] [Indexed: 11/13/2022] Open
Abstract
Despite the growing evidence regarding the importance of intensity and dose in aphasia therapy, few well-controlled studies contrasting the effects of intensive and non-intensive treatment have been conducted to date. Phonological components analysis (PCA) treatment for anomia has been associated with improvements in some patients with chronic aphasia; however, the effect of treatment intensity has not yet been studied with PCA. Thus, the aim of the present study was to identify the effect of intensity on neural processing associated with word retrieval abilities after PCA treatment. We used functional magnetic resonance imaging to examine therapy-induced changes in activation during an overt naming task in two patients who suffered from a stroke in the left middle cerebral artery territory. P1 received intensive PCA treatment whereas P2 received the standard, non-intensive, PCA treatment. Behavioral results indicate that both standard and intensive conditions yielded improved naming performance with treated nouns, but the changes were only significant for the patient who received the intensive treatment. The improvements were found to be long lasting as both patients maintained improved naming at 2-months follow-ups. The associated neuroimaging data indicate that the two treatment conditions were associated with different neural activation changes. The patient who received the standard PCA showed significant increase in activation with treatment in the right anterior cingulate, as well as extensive areas in bilateral posterior and lateral cortices. By contrast, the patient who received intensive PCA showed more decreases in activation following the treatment. Unexpectedly, this patient showed subcortical increase in activation, specifically in the right caudate nucleus. We speculate that the recruitment of the caudate nucleus and the anterior cingulate in these patients reflects the need to suppress errors to improve naming. Thus, both short-term intensive and standard, non-intensive, PCA treatment can improve word retrieval in chronic aphasia, but neuroimaging data suggest that improved naming is associated with different neural activation patterns in the two treatment conditions.
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Affiliation(s)
- Karine Marcotte
- Centre de recherche de l'Hôpital du Sacré-Coeur de Montréal, Montréal, QC, Canada.,École d'orthophonie et d'audiologie, Faculté de médecine, Université de Montréal, Montréal, QC, Canada
| | - Laura Laird
- Department of Speech-Language Pathology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada.,Toronto Rehabilitation Institute - University Health Network, Toronto, ON, Canada
| | - Tali Bitan
- Department of Speech-Language Pathology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada.,Department of Psychology, IIPDM, IBBR, University of Haifa, Haifa, Israel
| | - Jed A Meltzer
- Department of Speech-Language Pathology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada.,Rotman Research Institute - Baycrest Centre, Toronto, ON, Canada.,Department of Psychology, University of Toronto, Toronto, ON, Canada.,Heart and Stroke Foundation, Canadian Partnership for Stroke Recovery, Ottawa, ON, Canada
| | - Simon J Graham
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada.,Physical Sciences Platform, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
| | - Carol Leonard
- Department of Speech-Language Pathology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada.,Heart and Stroke Foundation, Canadian Partnership for Stroke Recovery, Ottawa, ON, Canada.,Audiology and Speech-Language Pathology Program, School of Rehabilitation Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Elizabeth Rochon
- Department of Speech-Language Pathology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada.,Toronto Rehabilitation Institute - University Health Network, Toronto, ON, Canada.,Heart and Stroke Foundation, Canadian Partnership for Stroke Recovery, Ottawa, ON, Canada.,Rehabilitation Sciences Institute, University of Toronto, Toronto, ON, Canada
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13
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Shuster LI. Considerations for the Use of Neuroimaging Technologies for Predicting Recovery of Speech and Language in Aphasia. AMERICAN JOURNAL OF SPEECH-LANGUAGE PATHOLOGY 2018; 27:291-305. [PMID: 29497745 DOI: 10.1044/2018_ajslp-16-0180] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 01/16/2018] [Indexed: 06/08/2023]
Abstract
PURPOSE The number of research articles aimed at identifying neuroimaging biomarkers for predicting recovery from aphasia continues to grow. Although the clinical use of these biomarkers to determine prognosis has been proposed, there has been little discussion of how this would be accomplished. This is an important issue because the best translational science occurs when translation is considered early in the research process. The purpose of this clinical focus article is to present a framework to guide the discussion of how neuroimaging biomarkers for recovery from aphasia could be implemented clinically. METHOD The genomics literature reveals that implementing genetic testing in the real-world poses both opportunities and challenges. There is much similarity between these opportunities and challenges and those related to implementing neuroimaging testing to predict recovery in aphasia. Therefore, the Center for Disease Control's model list of questions aimed at guiding the review of genetic testing has been adapted to guide the discussion of using neuroimaging biomarkers as predictors of recovery in aphasia. CONCLUSION The adapted model list presented here is a first and useful step toward initiating a discussion of how neuroimaging biomarkers of recovery could be employed clinically to provide improved quality of care for individuals with aphasia.
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Affiliation(s)
- Linda I Shuster
- Department of Speech, Language, and Hearing Sciences, Western Michigan University, Kalamazoo
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14
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Blank IA, Kiran S, Fedorenko E. Can neuroimaging help aphasia researchers? Addressing generalizability, variability, and interpretability. Cogn Neuropsychol 2017; 34:377-393. [PMID: 29188746 PMCID: PMC6157596 DOI: 10.1080/02643294.2017.1402756] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Neuroimaging studies of individuals with brain damage seek to link brain structure and activity to cognitive impairments, spontaneous recovery, or treatment outcomes. To date, such studies have relied on the critical assumption that a given anatomical landmark corresponds to the same functional unit(s) across individuals. However, this assumption is fallacious even across neurologically healthy individuals. Here, we discuss the severe implications of this issue, and argue for an approach that circumvents it, whereby: (i) functional brain regions are defined separately for each subject using fMRI, allowing for inter-individual variability in their precise location; (ii) the response profile of these subject-specific regions are characterized using various other tasks; and (iii) the results are averaged across individuals, guaranteeing generalizabliity. This method harnesses the complementary strengths of single-case studies and group studies, and it eliminates the need for post hoc "reverse inference" from anatomical landmarks back to cognitive operations, thus improving data interpretability.
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Affiliation(s)
- Idan A Blank
- a McGovern Institute for Brain Research , Massachusetts Institute of Technology , Cambridge , MA , USA
| | - Swathi Kiran
- b Department of Speech Language and Hearing Sciences, Aphasia Research Laboratory , Sargent College, Boston University , Boston , MA , USA
| | - Evelina Fedorenko
- c Department of Psychiatry , Massachusetts General Hospital , Charlestown , MA , USA
- d Department of Psychiatry , Harvard Medical School , Boston , MA , USA
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15
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Crosson B, Hampstead BM, Krishnamurthy LC, Krishnamurthy V, McGregor KM, Nocera JR, Roberts S, Rodriguez AD, Tran SM. Advances in neurocognitive rehabilitation research from 1992 to 2017: The ascension of neural plasticity. Neuropsychology 2017; 31:900-920. [PMID: 28857600 DOI: 10.1037/neu0000396] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVE The last 25 years have seen profound changes in neurocognitive rehabilitation that continue to motivate its evolution. Although the concept of nervous system plasticity was discussed by William James (1890), the foundation for experience-based plasticity had not reached the critical empirical mass to seriously impact rehabilitation research until after 1992. The objective of this review is to describe how the emergence of neural plasticity has changed neurocognitive rehabilitation research. METHOD The important developments included (a) introduction of a widely available tool that could measure brain plasticity (i.e., functional MRI); (b) development of new structural imaging techniques that could define limits of and opportunities for neural plasticity; (c) deployment of noninvasive brain stimulation to leverage neural plasticity for rehabilitation; (d) growth of a literature indicating that exercise has positively impacts neural plasticity, especially for older persons; and (e) enhancement of neural plasticity by creating interventions that generalize beyond the boundaries of treatment activities. Given the massive literature, each of these areas is developed by example. RESULTS The expanding influence of neural plasticity has provided new models and tools for neurocognitive rehabilitation in neural injuries and disorders, as well as methods for measuring neural plasticity and predicting its limits and opportunities. Early clinical trials have provided very encouraging results. CONCLUSION Now that neural plasticity has gained a firm foothold, it will continue to influence the evolution of neurocognitive rehabilitation research for the next 25 years and advance rehabilitation for neural injuries and disease. (PsycINFO Database Record
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Affiliation(s)
- Bruce Crosson
- Veterans Affairs Rehabilitation Research and Development Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center
| | - Benjamin M Hampstead
- Neuropsychology Section, Department of Mental Health Services, Veterans Affairs Ann Arbor Healthcare Systems
| | | | | | | | | | | | - Amy D Rodriguez
- Atlanta Veterans Affairs Rehabilitation Research and Development Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center
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16
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Wortman-Jutt S, Edwards DJ. Transcranial Direct Current Stimulation in Poststroke Aphasia Recovery. Stroke 2017; 48:820-826. [PMID: 28174328 DOI: 10.1161/strokeaha.116.015626] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 11/17/2016] [Accepted: 12/15/2016] [Indexed: 11/16/2022]
Affiliation(s)
- Susan Wortman-Jutt
- From the Burke Rehabilitation Hospital, White Plains, NY (S.W.-J.); Neuromodulation and Human Motor Control Laboratory, Burke Medical Research Institute, White Plains, NY (D.J.E.); Department of Neurology, Weill-Cornell Medical College, New York, NY (D.J.E.); School of Medical and Health Sciences, Edith Cowan University, Western Australia (D.J.E.); and Beth-Israel Deaconess Medical Center, Harvard Medical School, Boston, MA (D.J.E.).
| | - Dylan J Edwards
- From the Burke Rehabilitation Hospital, White Plains, NY (S.W.-J.); Neuromodulation and Human Motor Control Laboratory, Burke Medical Research Institute, White Plains, NY (D.J.E.); Department of Neurology, Weill-Cornell Medical College, New York, NY (D.J.E.); School of Medical and Health Sciences, Edith Cowan University, Western Australia (D.J.E.); and Beth-Israel Deaconess Medical Center, Harvard Medical School, Boston, MA (D.J.E.)
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17
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Griffis JC, Nenert R, Allendorfer JB, Vannest J, Holland S, Dietz A, Szaflarski JP. The canonical semantic network supports residual language function in chronic post-stroke aphasia. Hum Brain Mapp 2016; 38:1636-1658. [PMID: 27981674 DOI: 10.1002/hbm.23476] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 11/11/2016] [Accepted: 11/15/2016] [Indexed: 12/28/2022] Open
Abstract
Current theories of language recovery after stroke are limited by a reliance on small studies. Here, we aimed to test predictions of current theory and resolve inconsistencies regarding right hemispheric contributions to long-term recovery. We first defined the canonical semantic network in 43 healthy controls. Then, in a group of 43 patients with chronic post-stroke aphasia, we tested whether activity in this network predicted performance on measures of semantic comprehension, naming, and fluency while controlling for lesion volume effects. Canonical network activation accounted for 22%-33% of the variance in language test scores. Whole-brain analyses corroborated these findings, and revealed a core set of regions showing positive relationships to all language measures. We next evaluated the relationship between activation magnitudes in left and right hemispheric portions of the network, and characterized how right hemispheric activation related to the extent of left hemispheric damage. Activation magnitudes in each hemispheric network were strongly correlated, but four right frontal regions showed heightened activity in patients with large lesions. Activity in two of these regions (inferior frontal gyrus pars opercularis and supplementary motor area) was associated with better language abilities in patients with larger lesions, but poorer language abilities in patients with smaller lesions. Our results indicate that bilateral language networks support language processing after stroke, and that right hemispheric activations related to extensive left hemispheric damage occur outside of the canonical semantic network and differentially relate to behavior depending on the extent of left hemispheric damage. Hum Brain Mapp 38:1636-1658, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Joseph C Griffis
- Department of Psychology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Rodolphe Nenert
- Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jane B Allendorfer
- Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama
| | | | - Scott Holland
- Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Aimee Dietz
- University of Cincinnati Academic Health Center, Cincinnati, Ohio
| | - Jerzy P Szaflarski
- Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama
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18
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Lee YS, Zreik JT, Hamilton RH. Patterns of neural activity predict picture-naming performance of a patient with chronic aphasia. Neuropsychologia 2016; 94:52-60. [PMID: 27864027 DOI: 10.1016/j.neuropsychologia.2016.11.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 10/06/2016] [Accepted: 11/13/2016] [Indexed: 10/20/2022]
Abstract
Naming objects represents a substantial challenge for patients with chronic aphasia. This could be in part because the reorganized compensatory language networks of persons with aphasia may be less stable than the intact language systems of healthy individuals. Here, we hypothesized that the degree of stability would be instantiated by spatially differential neural patterns rather than either increased or diminished amplitudes of neural activity within a putative compensatory language system. We recruited a chronic aphasic patient (KL; 66 year-old male) who exhibited a semantic deficit (e.g., often said "milk" for "cow" and "pillow" for "blanket"). Over the course of four behavioral sessions involving a naming task performed in a mock scanner, we identified visual objects that yielded an approximately 50% success rate. We then conducted two fMRI sessions in which the patient performed a naming task for multiple exemplars of those objects. Multivoxel pattern analysis (MVPA) searchlight revealed differential activity patterns associated with correct and incorrect trials throughout intact brain regions. The most robust and largest cluster was found in the right occipito-temporal cortex encompassing fusiform cortex, lateral occipital cortex (LOC), and middle occipital cortex, which may account for the patient's propensity for semantic naming errors. None of these areas were found by a conventional univariate analysis. By using an alternative approach, we extend current evidence for compensatory naming processes that operate through spatially differential patterns within the reorganized language system.
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Affiliation(s)
- Yune Sang Lee
- Department of Speech and Hearing Science, The Ohio State University, Columbus, OH, USA.
| | - Jihad T Zreik
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - Roy H Hamilton
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA.
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19
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Darkow R, Martin A, Würtz A, Flöel A, Meinzer M. Transcranial direct current stimulation effects on neural processing in post-stroke aphasia. Hum Brain Mapp 2016; 38:1518-1531. [PMID: 27859982 DOI: 10.1002/hbm.23469] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 10/14/2016] [Accepted: 11/06/2016] [Indexed: 12/18/2022] Open
Abstract
Non-invasive transcranial direct current stimulation (tDCS) can enhance recovery after stroke. However, fundamental knowledge about how tDCS impacts neural processing in the lesioned human brain is currently lacking. In the present study, it was investigated how tDCS modulates brain function in patients with post-stroke language impairment (aphasia). In a cross-over, randomized trial, patients named pictures of common objects during functional magnetic resonance imaging (fMRI). Concurrently, excitatory (anodal-) or sham-tDCS (1 mA, 20 min, or 30 s, respectively) was administered to the left primary motor cortex, a montage with demonstrated potential to improve aphasic language. By choosing stimuli that could reliable be named by the patients, the authors aimed to derive a pure measure of stimulation effects that was independent of treatment or performance effects and to assess how tDCS interacts with the patients' residual language network. Univariate fMRI data analysis revealed reduced activity in domain-general regions mediating high-level cognitive control during anodal-tDCS. Independent component functional network analysis demonstrated selectively increased language network activity and an inter-correlated shift from higher to lower frequency bands, indicative of increased within-network communication. Compared with healthy controls, anodal-tDCS resulted in overall "normalization" of brain function in the patients. These results demonstrate for the first time how tDCS modulates neural processing in stroke patients. Such information is crucial to assure that behavioral treatments targeting specific neural circuits overlap with regions that are modulated by tDCS, thereby maximizing stimulation effects during therapy. Hum Brain Mapp 38:1518-1531, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Robert Darkow
- Department of Neurology, NeuroCure Clinical Research Center, and Center of Stroke Research Berlin, Berlin, Charité University Medicine, Berlin, 10117, Germany
| | - Andrew Martin
- The University of Queensland, Centre for Clinical Research, Brisbane Queensland, 4029, Australia
| | - Anna Würtz
- Department of Neurology, NeuroCure Clinical Research Center, and Center of Stroke Research Berlin, Berlin, Charité University Medicine, Berlin, 10117, Germany
| | - Agnes Flöel
- Department of Neurology, NeuroCure Clinical Research Center, and Center of Stroke Research Berlin, Berlin, Charité University Medicine, Berlin, 10117, Germany
| | - Marcus Meinzer
- Department of Neurology, NeuroCure Clinical Research Center, and Center of Stroke Research Berlin, Berlin, Charité University Medicine, Berlin, 10117, Germany.,The University of Queensland, Centre for Clinical Research, Brisbane Queensland, 4029, Australia
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20
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Chouinard B, Boliek C, Cummine J. How to Interpret and Critique Neuroimaging Research: A Tutorial on Use of Functional Magnetic Resonance Imaging in Clinical Populations. AMERICAN JOURNAL OF SPEECH-LANGUAGE PATHOLOGY 2016; 25:269-289. [PMID: 27537490 DOI: 10.1044/2016_ajslp-15-0013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 12/30/2015] [Indexed: 06/06/2023]
Abstract
PURPOSE Magnetic resonance imaging (MRI), an influential experimental approach, provides valuable information about clinical disorders that can be used to select and/or refine speech and language interventions. Functional MRI (fMRI) in particular is becoming a widespread methodological tool for investigating speech and language. However, because MRI is relatively new and complex, potential consumers need to be able to critically assess the methods used in order to appraise results and conclusions. The authors offer a tutorial that (a) relays foundational knowledge related to the collection and analysis of MRI data in general and fMRI data specifically and (b) presents strategies for evaluating studies that utilize fMRI methods. METHOD This tutorial outlines methodological considerations that should be addressed by fMRI researchers and noted by consumers of the research, including clinicians and behavioral researchers who work with neurogenic communication disorders. RESULTS Readers will be able to evaluate a neuroimaging publication and identify the methodological strengths and weaknesses that potentially influence the integrity of reported findings and interpretations. CONCLUSION This tutorial provides information and strategies that can be used to critically evaluate studies that collect, analyze, and interpret fMRI data. The tutorial concludes with a summary checklist to guide critical appraisal.
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21
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Validity and reliability of four language mapping paradigms. NEUROIMAGE-CLINICAL 2016; 16:399-408. [PMID: 28879081 PMCID: PMC5574842 DOI: 10.1016/j.nicl.2016.03.015] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 03/01/2016] [Accepted: 03/20/2016] [Indexed: 11/22/2022]
Abstract
Language areas of the brain can be mapped in individual participants with functional MRI. We investigated the validity and reliability of four language mapping paradigms that may be appropriate for individuals with acquired aphasia: sentence completion, picture naming, naturalistic comprehension, and narrative comprehension. Five neurologically normal older adults were scanned on each of the four paradigms on four separate occasions. Validity was assessed in terms of whether activation patterns reflected the known typical organization of language regions, that is, lateralization to the left hemisphere, and involvement of the left inferior frontal gyrus and the left middle and/or superior temporal gyri. Reliability (test-retest reproducibility) was quantified in terms of the Dice coefficient of similarity, which measures overlap of activations across time points. We explored the impact of different absolute and relative voxelwise thresholds, a range of cluster size cutoffs, and limitation of analyses to a priori potential language regions. We found that the narrative comprehension and sentence completion paradigms offered the best balance of validity and reliability. However, even with optimal combinations of analysis parameters, there were many scans on which known features of typical language organization were not demonstrated, and test-retest reproducibility was only moderate for realistic parameter choices. These limitations in terms of validity and reliability may constitute significant limitations for many clinical or research applications that depend on identifying language regions in individual participants. Validity and reliability were investigated for four language mapping paradigms. Narrative comprehension and sentence completion paradigms performed best. Lateralization to the left hemisphere was not always apparent. Test-retest reproducibility was only moderate.
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22
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Meier EL, Kapse KJ, Kiran S. The Relationship between Frontotemporal Effective Connectivity during Picture Naming, Behavior, and Preserved Cortical Tissue in Chronic Aphasia. Front Hum Neurosci 2016; 10:109. [PMID: 27014039 PMCID: PMC4792868 DOI: 10.3389/fnhum.2016.00109] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Accepted: 02/29/2016] [Indexed: 11/17/2022] Open
Abstract
While several studies of task-based effective connectivity of normal language processing exist, little is known about the functional reorganization of language networks in patients with stroke-induced chronic aphasia. During oral picture naming, activation in neurologically intact individuals is found in "classic" language regions involved with retrieval of lexical concepts [e.g., left middle temporal gyrus (LMTG)], word form encoding [e.g., left posterior superior temporal gyrus, (LpSTG)], and controlled retrieval of semantic and phonological information [e.g., left inferior frontal gyrus (LIFG)] as well as domain-general regions within the multiple demands network [e.g., left middle frontal gyrus (LMFG)]. After stroke, lesions to specific parts of the left hemisphere language network force reorganization of this system. While individuals with aphasia have been found to recruit similar regions for language tasks as healthy controls, the relationship between the dynamic functioning of the language network and individual differences in underlying neural structure and behavioral performance is still unknown. Therefore, in the present study, we used dynamic causal modeling (DCM) to investigate differences between individuals with aphasia and healthy controls in terms of task-induced regional interactions between three regions (i.e., LIFG, LMFG, and LMTG) vital for picture naming. The DCM model space was organized according to exogenous input to these regions and partitioned into separate families. At the model level, random effects family wise Bayesian Model Selection revealed that models with driving input to LIFG best fit the control data whereas models with driving input to LMFG best fit the patient data. At the parameter level, a significant between-group difference in the connection strength from LMTG to LIFG was seen. Within the patient group, several significant relationships between network connectivity parameters, spared cortical tissue, and behavior were observed. Overall, this study provides some preliminary findings regarding how neural networks for language reorganize for individuals with aphasia and how brain connectivity relates to underlying structural integrity and task performance.
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Affiliation(s)
- Erin L. Meier
- Department of Speech Language and Hearing Sciences, Aphasia Research Laboratory, Sargent College, Boston University, BostonMA, USA
| | | | - Swathi Kiran
- Department of Speech Language and Hearing Sciences, Aphasia Research Laboratory, Sargent College, Boston University, BostonMA, USA
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23
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The relationships between the amount of spared tissue, percent signal change, and accuracy in semantic processing in aphasia. Neuropsychologia 2016; 84:113-26. [PMID: 26775192 DOI: 10.1016/j.neuropsychologia.2015.10.019] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 09/10/2015] [Accepted: 10/12/2015] [Indexed: 12/31/2022]
Abstract
Recovery from aphasia, loss of language following a cerebrovascular incident (stroke), is a complex process involving both left and right hemispheric regions. In our study, we analyzed the relationships between semantic processing behavioral data, lesion size and location, and percent signal change from functional magnetic resonance imaging (fMRI) data. This study included 14 persons with aphasia in the chronic stage of recovery (six or more months post stroke), along with normal controls, who performed semantic processing tasks of determining whether a written semantic feature matched a picture or whether two written words were related. Using region of interest (ROI) analysis, we found that left inferior frontal gyrus pars opercularis and pars triangularis, despite significant damage, were the only regions to correlate with behavioral accuracy. Additionally, bilateral frontal regions including superior frontal gyrus, middle frontal gyrus, and anterior cingulate appear to serve as an assistive network in the case of damage to traditional language regions that include inferior frontal gyrus, middle temporal gyrus, supramarginal gyrus, and angular gyrus. Right hemisphere posterior regions including right middle temporal gyrus, right supramarginal gyrus, and right angular gyrus are engaged in the case of extensive damage to left hemisphere language regions. Additionally, right inferior frontal gyrus pars orbitalis is presumed to serve a monitoring function. These results reinforce the importance of the left hemisphere in language processing in aphasia, and provide a framework for the relative importance of left and right language regions in the brain.
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24
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Interhemispheric Plasticity following Intermittent Theta Burst Stimulation in Chronic Poststroke Aphasia. Neural Plast 2016; 2016:4796906. [PMID: 26881111 PMCID: PMC4736997 DOI: 10.1155/2016/4796906] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 11/01/2015] [Accepted: 11/10/2015] [Indexed: 12/31/2022] Open
Abstract
The effects of noninvasive neurostimulation on brain structure and function in chronic poststroke aphasia are poorly understood. We investigated the effects of intermittent theta burst stimulation (iTBS) applied to residual language-responsive cortex in chronic patients using functional and anatomical MRI data acquired before and after iTBS. Lateralization index (LI) analyses, along with comparisons of inferior frontal gyrus (IFG) activation and connectivity during covert verb generation, were used to assess changes in cortical language function. Voxel-based morphometry (VBM) was used to assess effects on regional grey matter (GM). LI analyses revealed a leftward shift in IFG activity after treatment. While left IFG activation increased, right IFG activation decreased. Changes in right to left IFG connectivity during covert verb generation also decreased after iTBS. Behavioral correlations revealed a negative relationship between changes in right IFG activation and improvements in fluency. While anatomical analyses did not reveal statistically significant changes in grey matter volume, the fMRI results provide evidence for changes in right and left IFG function after iTBS. The negative relationship between post-iTBS changes in right IFG activity during covert verb generation and improvements in fluency suggests that iTBS applied to residual left-hemispheric language areas may reduce contralateral responses related to language production and facilitate recruitment of residual language areas after stroke.
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25
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Ulm L, McMahon K, Copland D, de Zubicaray GI, Meinzer M. Neural Mechanisms Underlying Perilesional Transcranial Direct Current Stimulation in Aphasia: A Feasibility Study. Front Hum Neurosci 2015; 9:550. [PMID: 26500522 PMCID: PMC4595771 DOI: 10.3389/fnhum.2015.00550] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 09/21/2015] [Indexed: 01/29/2023] Open
Abstract
Little is known about the neural mechanisms by which transcranial direct current stimulation (tDCS) impacts on language processing in post-stroke aphasia. This was addressed in a proof-of-principle study that explored the effects of tDCS application in aphasia during simultaneous functional magnetic resonance imaging (fMRI). We employed a single subject, cross-over, sham-tDCS controlled design, and the stimulation was administered to an individualized perilesional stimulation site that was identified by a baseline fMRI scan and a picture naming task. Peak activity during the baseline scan was located in the spared left inferior frontal gyrus and this area was stimulated during a subsequent cross-over phase. tDCS was successfully administered to the target region and anodal- vs. sham-tDCS resulted in selectively increased activity at the stimulation site. Our results thus demonstrate that it is feasible to precisely target an individualized stimulation site in aphasia patients during simultaneous fMRI, which allows assessing the neural mechanisms underlying tDCS application. The functional imaging results of this case report highlight one possible mechanism that may have contributed to beneficial behavioral stimulation effects in previous clinical tDCS trials in aphasia. In the future, this approach will allow identifying distinct patterns of stimulation effects on neural processing in larger cohorts of patients. This may ultimately yield information about the variability of tDCS effects on brain functions in aphasia.
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Affiliation(s)
- Lena Ulm
- Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia
| | - Katie McMahon
- Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD, Australia
| | - David Copland
- Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia
- School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Greig I. de Zubicaray
- Faculty of Health, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
| | - Marcus Meinzer
- Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia
- School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, QLD, Australia
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Kiran S, Meier EL, Kapse KJ, Glynn PA. Changes in task-based effective connectivity in language networks following rehabilitation in post-stroke patients with aphasia. Front Hum Neurosci 2015; 9:316. [PMID: 26106314 PMCID: PMC4460429 DOI: 10.3389/fnhum.2015.00316] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Accepted: 05/18/2015] [Indexed: 11/19/2022] Open
Abstract
In this study, we examined regions in the left and right hemisphere language network that were altered in terms of the underlying neural activation and effective connectivity subsequent to language rehabilitation. Eight persons with chronic post-stroke aphasia and eight normal controls participated in the current study. Patients received a 10 week semantic feature-based rehabilitation program to improve their skills. Therapy was provided on atypical examples of one trained category while two control categories were monitored; the categories were counterbalanced across patients. In each fMRI session, two experimental tasks were conducted: (a) picture naming and (b) semantic feature verification of trained and untrained categories. Analysis of treatment effect sizes revealed that all patients showed greater improvements on the trained category relative to untrained categories. Results from this study show remarkable patterns of consistency despite the inherent variability in lesion size and activation patterns across patients. Across patients, activation that emerged as a function of rehabilitation on the trained category included bilateral IFG, bilateral SFG, LMFG, and LPCG for picture naming; and bilateral IFG, bilateral MFG, LSFG, and bilateral MTG for semantic feature verification. Analysis of effective connectivity using Dynamic Causal Modeling (DCM) indicated that LIFG was the consistently significantly modulated region after rehabilitation across participants. These results indicate that language networks in patients with aphasia resemble normal language control networks and that this similarity is accentuated by rehabilitation.
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Affiliation(s)
- Swathi Kiran
- Aphasia Research Laboratory, Speech Language and Hearing Sciences, Sargent College, Boston University Boston MA, USA
| | - Erin L Meier
- Aphasia Research Laboratory, Speech Language and Hearing Sciences, Sargent College, Boston University Boston MA, USA
| | - Kushal J Kapse
- Aphasia Research Laboratory, Speech Language and Hearing Sciences, Sargent College, Boston University Boston MA, USA
| | - Peter A Glynn
- Feinberg School of Medicine, Northwestern University Chicago IL, USA
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Chu RKO, Braun AR, Meltzer JA. MEG-based detection and localization of perilesional dysfunction in chronic stroke. NEUROIMAGE-CLINICAL 2015; 8:157-69. [PMID: 26106540 PMCID: PMC4473381 DOI: 10.1016/j.nicl.2015.03.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 03/20/2015] [Accepted: 03/23/2015] [Indexed: 11/13/2022]
Abstract
Post-stroke impairment is associated not only with structural lesions, but also with dysfunction in surviving perilesional tissue. Previous studies using equivalent current dipole source localization of MEG/EEG signals have demonstrated a preponderance of slow-wave activity localized to perilesional areas. Recent studies have also demonstrated the utility of nonlinear analyses such as multiscale entropy (MSE) for quantifying neuronal dysfunction in a wide range of pathologies. The current study utilized beamformer-based reconstruction of signals in source space to compare spectral and nonlinear measures of electrical activity in perilesional and healthy cortices. Data were collected from chronic stroke patients and healthy controls, both young and elderly. We assessed relative power in the delta (1–4 Hz), theta (4–7 Hz), alpha (8–12 Hz) and beta (15–30 Hz) frequency bands, and also measured the nonlinear complexity of electrical activity using MSE. Perilesional tissue exhibited a general slowing of the power spectrum (increased delta/theta, decreased beta) as well as a reduction in MSE. All measures tested were similarly sensitive to changes in the posterior perilesional regions, but anterior perilesional dysfunction was detected better by MSE and beta power. The findings also suggest that MSE is specifically sensitive to electrophysiological dysfunction in perilesional tissue, while spectral measures were additionally affected by an increase in rolandic beta power with advanced age. Furthermore, perilesional electrophysiological abnormalities in the left hemisphere were correlated with the degree of language task-induced activation in the right hemisphere. Finally, we demonstrate that single subject spectral and nonlinear analyses can identify dysfunctional perilesional regions within individual patients that may be ideal targets for interventions with noninvasive brain stimulation. We assessed the spontaneous MEG activity of perilesional tissue in stroke. We observed perilesional spectral slowing and reduced signal complexity. We demonstrate a method to identify dysfunctional tissue within a single subject.
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Affiliation(s)
- Ron K O Chu
- University of Toronto, Department of Psychology, 100 St. George Street, 4th Floor, Sidney Smith Hall, Toronto, ON M5S 3G3, Canada ; Rotman Research Institute, Baycrest Centre, 3560 Bathurst St., Toronto, ON M6A 2E1, Canada
| | - Allen R Braun
- Language Section, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Jed A Meltzer
- University of Toronto, Department of Psychology, 100 St. George Street, 4th Floor, Sidney Smith Hall, Toronto, ON M5S 3G3, Canada ; University of Toronto, Department of Speech-Language Pathology, 160-500 University Avenue, Toronto, ON M5G 1V7, Canada ; Rotman Research Institute, Baycrest Centre, 3560 Bathurst St., Toronto, ON M6A 2E1, Canada ; Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, 600 Peter Morand Cres., Suite 201, Ottawa, ON K1G 5Z3, Canada
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Bonakdarpour B, Beeson P, DeMarco A, Rapcsak S. Variability in blood oxygen level dependent (BOLD) signal in patients with stroke-induced and primary progressive aphasia. Neuroimage Clin 2015; 8:87-94. [PMID: 26106531 PMCID: PMC4473284 DOI: 10.1016/j.nicl.2015.03.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Revised: 02/27/2015] [Accepted: 03/18/2015] [Indexed: 12/04/2022]
Abstract
Although fMRI is increasingly used to assess language-related brain activation in patients with aphasia, few studies have examined the hemodynamic response function (HRF) in perilesional, and contralesional areas of the brain. In addition, the relationship between HRF abnormalities and other variables such as lesion size and severity of aphasia has not been explored. The objective of this study was to investigate changes in HRF signal during language-related neural activation in patients with stroke-induced aphasia (SA). We also examined the status of the HRF in patients with aphasia due to nonvascular etiology, namely, primary progressive aphasia (PPA). Five right handed SA patients, three PPA patients, and five healthy individuals participated in the study. Structural damage was quantified with T1-weighted MR images. Functional MR imaging was performed with long trial event-related design and an overt naming task to measure BOLD signal time to peak (TTP) and percent signal change (ΔS). In SA patients, the average HRF TTP was significantly delayed in the left hemisphere regions involved in naming compared to healthy participants and PPA patients. However, ΔS was not different in SA patients compared to the other two groups. Delay in HRF TTP in the left hemisphere naming network of SA patients was correlated with lesion size and showed a negative correlation with global language function. There were no significant differences in the HRF TTP and ΔS in the right hemisphere homologues of the naming network or in the left and the right occipital control regions across the three groups. In PPA patients, HRF had a normal pattern. Our results indicate that abnormal task-related HRF is primarily found in the left hemisphere language network of SA patients and raise the possibility that abnormal physiology superimposed on structural damage may contribute to the clinical deficit. Follow-up investigations in a larger sample of age-matched healthy individuals, SA, and PPA patients will be needed to further confirm and extend our findings.
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Affiliation(s)
- B. Bonakdarpour
- Cognitive Neurology and Alzheimer Disease Center, Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - P.M. Beeson
- Department of Speech, Language and Hearing Sciences, University of Arizona, Tucson, AZ, USA
| | - A.T. DeMarco
- Department of Speech, Language and Hearing Sciences, University of Arizona, Tucson, AZ, USA
| | - S.Z. Rapcsak
- Department of Speech, Language and Hearing Sciences, University of Arizona, Tucson, AZ, USA
- Department of Neurology, University of Arizona, Tucson, USA
- Southern Arizona VA Health Care System, Tucson, AZ, USA
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Schönberger E, Heim S, Meffert E, Pieperhoff P, da Costa Avelar P, Huber W, Binkofski F, Grande M. The neural correlates of agrammatism: Evidence from aphasic and healthy speakers performing an overt picture description task. Front Psychol 2014; 5:246. [PMID: 24711802 PMCID: PMC3968764 DOI: 10.3389/fpsyg.2014.00246] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 03/05/2014] [Indexed: 11/22/2022] Open
Abstract
Functional brain imaging studies have improved our knowledge of the neural localization of language functions and the functional reorganization after a lesion. However, the neural correlates of agrammatic symptoms in aphasia remain largely unknown. The present fMRI study examined the neural correlates of morpho-syntactic encoding and agrammatic errors in continuous language production by combining three approaches. First, the neural mechanisms underlying natural morpho-syntactic processing in a picture description task were analyzed in 15 healthy speakers. Second, agrammatic-like speech behavior was induced in the same group of healthy speakers to study the underlying functional processes by limiting the utterance length. In a third approach, five agrammatic participants performed the picture description task to gain insights in the neural correlates of agrammatism and the functional reorganization of language processing after stroke. In all approaches, utterances were analyzed for syntactic completeness, complexity, and morphology. Event-related data analysis was conducted by defining every clause-like unit (CLU) as an event with its onset-time and duration. Agrammatic and correct CLUs were contrasted. Due to the small sample size as well as heterogeneous lesion sizes and sites with lesion foci in the insula lobe, inferior frontal, superior temporal and inferior parietal areas the activation patterns in the agrammatic speakers were analyzed on a single subject level. In the group of healthy speakers, posterior temporal and inferior parietal areas were associated with greater morpho-syntactic demands in complete and complex CLUs. The intentional manipulation of morpho-syntactic structures and the omission of function words were associated with additional inferior frontal activation. Overall, the results revealed that the investigation of the neural correlates of agrammatic language production can be reasonably conducted with an overt language production paradigm.
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Affiliation(s)
- Eva Schönberger
- Section Neurological Cognition Research, Department of Neurology, Uniklinik RWTH Aachen Aachen, Germany
| | - Stefan Heim
- Section Neurological Cognition Research, Department of Neurology, Uniklinik RWTH Aachen Aachen, Germany ; Department of Psychiatry, Psychotherapy and Psychosomatics, Uniklinik RWTH Aachen Aachen, Germany ; Research Centre Juelich, Institute of Neuroscience and Medicine (INM-1) Juelich, Germany
| | - Elisabeth Meffert
- Section Neurological Cognition Research, Department of Neurology, Uniklinik RWTH Aachen Aachen, Germany ; Department of Psychiatry, Psychotherapy and Psychosomatics, Uniklinik RWTH Aachen Aachen, Germany
| | - Peter Pieperhoff
- Research Centre Juelich, Institute of Neuroscience and Medicine (INM-1) Juelich, Germany
| | - Patricia da Costa Avelar
- Section Neurological Cognition Research, Department of Neurology, Uniklinik RWTH Aachen Aachen, Germany
| | - Walter Huber
- Section Neurological Cognition Research, Department of Neurology, Uniklinik RWTH Aachen Aachen, Germany
| | - Ferdinand Binkofski
- Section Neurological Cognition Research, Department of Neurology, Uniklinik RWTH Aachen Aachen, Germany
| | - Marion Grande
- Section Neurological Cognition Research, Department of Neurology, Uniklinik RWTH Aachen Aachen, Germany
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Jarso S, Li M, Faria A, Davis C, Leigh R, Sebastian R, Tsapkini K, Mori S, Hillis AE. Distinct mechanisms and timing of language recovery after stroke. Cogn Neuropsychol 2014; 30:454-75. [PMID: 24472056 PMCID: PMC3979443 DOI: 10.1080/02643294.2013.875467] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The "language network" is remarkably stable across language tasks but changes in response to injury to specific components or in response to "disconnection" of input to one component. We investigated network changes during language recovery, hypothesizing that language recovery takes place through distinct mechanisms: (a) reperfusion; (b) recovery from diaschisis; (c) recovery from structural disconnection; and (d) "reorganization" of language, whereby various components assume function of a damaged component. We also tested the hypothesis that "reorganization" depends on: the language task, level of performance, size and site of stroke, and time post onset. We tested these hypotheses in five participants who had structural, perfusion, and functional imaging utilizing spelling, reading, word generation, and picture naming tasks at acute and subsequent stages after ischaemic stroke. These cases illustrate different mechanisms of aphasia recovery or illustrate that reorganization of language acutely depends on individual variables in addition to size and site of stroke.
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Affiliation(s)
- Samson Jarso
- a Russell H. Morgan Department of Radiology and Radiological Science , The Johns Hopkins University School of Medicine , Baltimore , MA , USA
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van Hees S, McMahon K, Angwin A, de Zubicaray G, Read S, Copland DA. A functional MRI study of the relationship between naming treatment outcomes and resting state functional connectivity in post-stroke aphasia. Hum Brain Mapp 2014; 35:3919-31. [PMID: 24453137 DOI: 10.1002/hbm.22448] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 10/11/2013] [Accepted: 11/29/2013] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND The majority of studies investigating the neural mechanisms underlying treatment in people with aphasia have examined task-based brain activity. However, the use of resting-state fMRI may provide another method of examining the brain mechanisms responsible for treatment-induced recovery, and allows for investigation into connectivity within complex functional networks METHODS Eight people with aphasia underwent 12 treatment sessions that aimed to improve object naming. Half the sessions employed a phonologically-based task, and half the sessions employed a semantic-based task, with resting-state fMRI conducted pre- and post-treatment. Brain regions in which the amplitude of low frequency fluctuations (ALFF) correlated with treatment outcomes were used as seeds for functional connectivity (FC) analysis. FC maps were compared from pre- to post-treatment, as well as with a group of 12 healthy older controls RESULTS Pre-treatment ALFF in the right middle temporal gyrus (MTG) correlated with greater outcomes for the phonological treatment, with a shift to the left MTG and supramarginal gyrus, as well as the right inferior frontal gyrus, post-treatment. When compared to controls, participants with aphasia showed both normalization and up-regulation of connectivity within language networks post-treatment, predominantly in the left hemisphere CONCLUSIONS The results provide preliminary evidence that treatments for naming impairments affect the FC of language networks, and may aid in understanding the neural mechanisms underlying the rehabilitation of language post-stroke.
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Affiliation(s)
- Sophia van Hees
- Centre for Clinical Research, University of Queensland, Brisbane, Australia; School of Health and Rehabilitation Sciences, University of Queensland, Brisbane, Australia
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Ulm L, Wohlrapp D, Meinzer M, Steinicke R, Schatz A, Denzler P, Klehmet J, Dohle C, Niedeggen M, Meisel A, Winter Y. A circle-monitor for computerised assessment of visual neglect in peripersonal space. PLoS One 2013; 8:e82892. [PMID: 24349387 PMCID: PMC3861461 DOI: 10.1371/journal.pone.0082892] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 10/28/2013] [Indexed: 11/19/2022] Open
Abstract
UNLABELLED Current assessment of visual neglect involves paper-and-pencil tests or computer-based tasks. Both have been criticised because of their lack of ecological validity as target stimuli can only be presented in a restricted visual range. This study examined the user-friendliness and diagnostic strength of a new "Circle-Monitor" (CM), which enlarges the range of the peripersonal space, in comparison to a standard paper-and-pencil test (Neglect-Test, NET). METHODS Ten stroke patients with neglect and ten age-matched healthy controls were examined by the NET and the CM test comprising of four subtests (Star Cancellation, Line Bisection, Dice Task, and Puzzle Test). RESULTS The acceptance of the CM in elderly controls and neglect patients was high. Participants rated the examination by CM as clear, safe and more enjoyable than NET. Healthy controls performed at ceiling on all subtests, without any systematic differences between the visual fields. Both NET and CM revealed significant differences between controls and patients in Line Bisection, Star Cancellation and visuo-constructive tasks (NET: Figure Copying, CM: Puzzle Test). Discriminant analyses revealed cross-validated assignment of patients and controls to groups was more precise when based on the CM (hit rate 90%) as compared to the NET (hit rate 70%). CONCLUSION The CM proved to be a sensitive novel tool to diagnose visual neglect symptoms quickly and accurately with superior diagnostic validity compared to a standard neglect test while being well accepted by patients. Due to its upgradable functions the system may also be a valuable tool not only to test for non-visual neglect symptoms, but also to provide treatment and assess its outcome.
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Affiliation(s)
- Lena Ulm
- NeuroCure Clinical Research Center and Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Dorota Wohlrapp
- NeuroCure Clinical Research Center and Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Marcus Meinzer
- Center for Stroke Research Berlin, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Robert Steinicke
- Center for Stroke Research Berlin, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Alexej Schatz
- Department of Biology, Humboldt University Berlin and Cluster of Excellence NeuroCure, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | | | - Juliane Klehmet
- NeuroCure Clinical Research Center and Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Christian Dohle
- Center for Stroke Research Berlin, Charité – Universitätsmedizin Berlin, Berlin, Germany
- Median Klinik Berlin-Kladow, Berlin, Germany
- Center for Rehabilitation Research, University of Potsdam, Potsdam, Germany
| | - Michael Niedeggen
- Department of Educational Science and Psychology, Free University Berlin, Berlin, Germany
- * E-mail: (AM); (MN)
| | - Andreas Meisel
- NeuroCure Clinical Research Center and Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Center for Stroke Research Berlin, Charité – Universitätsmedizin Berlin, Berlin, Germany
- * E-mail: (AM); (MN)
| | - York Winter
- Department of Biology, Humboldt University Berlin and Cluster of Excellence NeuroCure, Charité - Universitätsmedizin Berlin, Berlin, Germany
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Thompson CK, Riley EA, den Ouden DB, Meltzer-Asscher A, Lukic S. Training verb argument structure production in agrammatic aphasia: behavioral and neural recovery patterns. Cortex 2013; 49:2358-76. [PMID: 23514929 PMCID: PMC3759546 DOI: 10.1016/j.cortex.2013.02.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Revised: 09/06/2012] [Accepted: 02/04/2013] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Neuroimaging and lesion studies indicate a left hemisphere network for verb and verb argument structure processing, involving both frontal and temporoparietal brain regions. Although their verb comprehension is generally unimpaired, it is well known that individuals with agrammatic aphasia often present with verb production deficits, characterized by an argument structure complexity hierarchy, indicating faulty access to argument structure representations for production and integration into syntactic contexts. Recovery of verb processing in agrammatism, however, has received little attention and no studies have examined the neural mechanisms associated with improved verb and argument structure processing. In the present study we trained agrammatic individuals on verbs with complex argument structure in sentence contexts and examined generalization to verbs with less complex argument structure. The neural substrates of improved verb production were examined using functional magnetic resonance imaging (fMRI). METHODS Eight individuals with chronic agrammatic aphasia participated in the study (four experimental and four control participants). Production of three-argument verbs in active sentences was trained using a sentence generation task emphasizing the verb's argument structure and the thematic roles of sentential noun phrases. Before and after training, production of trained and untrained verbs was tested in naming and sentence production and fMRI scans were obtained, using an action naming task. RESULTS Significant pre- to post-training improvement in trained and untrained (one- and two-argument) verbs was found for treated, but not control, participants, with between-group differences found for verb naming, production of verbs in sentences, and production of argument structure. fMRI activation derived from post-treatment compared to pre-treatment scans revealed upregulation in cortical regions implicated for verb and argument structure processing in healthy controls. CONCLUSIONS Training verb deficits emphasizing argument structure and thematic role mapping is effective for improving verb and sentence production and results in recruitment of neural networks engaged for verb and argument structure processing in healthy individuals.
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Affiliation(s)
- Cynthia K. Thompson
- Aphasia and Neurolinguistics Research Laboratory, Department of Communication Sciences and Disorders, Northwestern University, Evanston, IL, USA
- Department of Neurology, Northwestern University, Evanston, IL, USA
- Cognitive Neurology and Alzheimer’s Disease Center, Northwestern University, Evanston, IL, USA
| | - Ellyn A. Riley
- Department of Communication Sciences and Disorders, Bowling Green State University, USA
| | - Dirk-Bart den Ouden
- Department of Communication Sciences and Disorders, University of South Carolina, USA
| | - Aya Meltzer-Asscher
- Linguistics Department, Tel Aviv University, Israel
- Sagol School of Neuroscience, Tel Aviv University, Israel
| | - Sladjana Lukic
- Aphasia and Neurolinguistics Research Laboratory, Department of Communication Sciences and Disorders, Northwestern University, Evanston, IL, USA
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Kiran S, Ansaldo A, Bastiaanse R, Cherney LR, Howard D, Faroqi-Shah Y, Meinzer M, Thompson CK. Neuroimaging in aphasia treatment research: standards for establishing the effects of treatment. Neuroimage 2013; 76:428-35. [PMID: 23063559 PMCID: PMC3552150 DOI: 10.1016/j.neuroimage.2012.10.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 07/06/2012] [Accepted: 10/05/2012] [Indexed: 11/29/2022] Open
Abstract
The goal of this paper is to discuss experimental design options available for establishing the effects of treatment in studies that aim to examine the neural mechanisms associated with treatment-induced language recovery in aphasia, using functional magnetic resonance imaging (fMRI). We present both group and single-subject experimental or case-series design options for doing this and address advantages and disadvantages of each. We also discuss general components of and requirements for treatment research studies, including operational definitions of variables, criteria for defining behavioral change and treatment efficacy, and reliability of measurement. Important considerations that are unique to neuroimaging-based treatment research are addressed, pertaining to the relation between the selected treatment approach and anticipated changes in language processes/functions and how such changes are hypothesized to map onto the brain.
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Affiliation(s)
- Swathi Kiran
- Boston University, Sargent College of Health and Rehabilitation Sciences, Boston, MA 02215, USA.
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Kiran S. What is the nature of poststroke language recovery and reorganization? ISRN NEUROLOGY 2012; 2012:786872. [PMID: 23320190 PMCID: PMC3540797 DOI: 10.5402/2012/786872] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 11/05/2012] [Indexed: 12/16/2022]
Abstract
This review focuses on three main topics related to the nature of poststroke language recovery and reorganization. The first topic pertains to the nature of anatomical and physiological substrates in the infarcted hemisphere in poststroke aphasia, including the nature of the hemodynamic response in patients with poststroke aphasia, the nature of the peri-infarct tissue, and the neuronal plasticity potential in the infarcted hemisphere. The second section of the paper reviews the current neuroimaging evidence for language recovery in the acute, subacute, and chronic stages of recovery. The third and final section examines changes in connectivity as a function of recovery in poststroke aphasia, specifically in terms of changes in white matter connectivity, changes in functional effective connectivity, and changes in resting state connectivity after stroke. While much progress has been made in our understanding of language recovery, more work needs to be done. Future studies will need to examine whether reorganization of language in poststroke aphasia corresponds to a tighter, more coherent, and efficient network of residual and new regions in the brain. Answering these questions will go a long way towards being able to predict which patients are likely to recover and may benefit from future rehabilitation.
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Affiliation(s)
- Swathi Kiran
- Department of Speech, Language, and Hearing Sciences, Sargent College of Health & Rehabilitation Sciences, Boston University, 635 Commonwealth Avenue, Boston, MA 02215, USA ; Massachusetts General Hospital, Boston, MA, USA
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Farrajota L, Maruta C, Maroco J, Martins IP, Guerreiro M, de Mendonça A. Speech therapy in primary progressive aphasia: a pilot study. Dement Geriatr Cogn Dis Extra 2012; 2:321-31. [PMID: 22962556 PMCID: PMC3435530 DOI: 10.1159/000341602] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Primary progressive aphasia (PPA) is a neurodegenerative disorder with no effective pharmacological treatment. Cognition-based interventions are adequate alternatives, but their benefit has not been thoroughly explored. Our aim was to study the effect of speech and language therapy (SLT) on naming ability in PPA. METHODS An open parallel prospective longitudinal study involving two centers was designed to compare patients with PPA submitted to SLT (1 h/week for 11 months) with patients receiving no therapy. Twenty patients were enrolled and undertook baseline language and neuropsychological assessments; among them, 10 received SLT and 10 constituted an age- and education-matched historical control group. The primary outcome measure was the change in group mean performance on the Snodgrass and Vanderwart naming test between baseline and follow-up assessments. RESULTS Intervention and control groups did not significantly differ on demographic and clinical variables at baseline. A mixed repeated measures ANOVA revealed a significant main effect of therapy (F(1,18) = 10.763; p = 0.005) on the performance on the Snodgrass and Vanderwart naming test. CONCLUSION Although limited by a non-randomized open study design with a historical control group, the present study suggests that SLT may have a benefit in PPA, and it should prompt a randomized, controlled, rater-blind clinical trial.
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Affiliation(s)
- Luísa Farrajota
- Memory Clinic, Faculty of Medicine of Lisbon and Hospital de Santa Maria, Lisbon, Portugal
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Farrajota L, Maruta C, Maroco J, Martins IP, Guerreiro M, de Mendonça A. Speech therapy in primary progressive aphasia: a pilot study. Dement Geriatr Cogn Dis Extra 2012. [PMID: 22962556 DOI: 10.1159/000341602000341602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Primary progressive aphasia (PPA) is a neurodegenerative disorder with no effective pharmacological treatment. Cognition-based interventions are adequate alternatives, but their benefit has not been thoroughly explored. Our aim was to study the effect of speech and language therapy (SLT) on naming ability in PPA. METHODS An open parallel prospective longitudinal study involving two centers was designed to compare patients with PPA submitted to SLT (1 h/week for 11 months) with patients receiving no therapy. Twenty patients were enrolled and undertook baseline language and neuropsychological assessments; among them, 10 received SLT and 10 constituted an age- and education-matched historical control group. The primary outcome measure was the change in group mean performance on the Snodgrass and Vanderwart naming test between baseline and follow-up assessments. RESULTS Intervention and control groups did not significantly differ on demographic and clinical variables at baseline. A mixed repeated measures ANOVA revealed a significant main effect of therapy (F(1,18) = 10.763; p = 0.005) on the performance on the Snodgrass and Vanderwart naming test. CONCLUSION Although limited by a non-randomized open study design with a historical control group, the present study suggests that SLT may have a benefit in PPA, and it should prompt a randomized, controlled, rater-blind clinical trial.
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Affiliation(s)
- Luísa Farrajota
- Memory Clinic, Faculty of Medicine of Lisbon and Hospital de Santa Maria, Lisbon, Portugal
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