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Abbott N, Love T. Bridging the Divide: Brain and Behavior in Developmental Language Disorder. Brain Sci 2023; 13:1606. [PMID: 38002565 PMCID: PMC10670267 DOI: 10.3390/brainsci13111606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 11/14/2023] [Accepted: 11/16/2023] [Indexed: 11/26/2023] Open
Abstract
Developmental language disorder (DLD) is a heterogenous neurodevelopmental disorder that affects a child's ability to comprehend and/or produce spoken and/or written language, yet it cannot be attributed to hearing loss or overt neurological damage. It is widely believed that some combination of genetic, biological, and environmental factors influences brain and language development in this population, but it has been difficult to bridge theoretical accounts of DLD with neuroimaging findings, due to heterogeneity in language impairment profiles across individuals and inconsistent neuroimaging findings. Therefore, the purpose of this overview is two-fold: (1) to summarize the neuroimaging literature (while drawing on findings from other language-impaired populations, where appropriate); and (2) to briefly review the theoretical accounts of language impairment patterns in DLD, with the goal of bridging the disparate findings. As will be demonstrated with this overview, the current state of the field suggests that children with DLD have atypical brain volume, laterality, and activation/connectivity patterns in key language regions that likely contribute to language difficulties. However, the precise nature of these differences and the underlying neural mechanisms contributing to them remain an open area of investigation.
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Affiliation(s)
- Noelle Abbott
- School of Speech, Language, and Hearing Sciences, San Diego State University, San Diego, CA 92182, USA;
- San Diego State University/University of California San Diego Joint Doctoral Program in Language and Communicative Disorders, San Diego, CA 92182, USA
| | - Tracy Love
- School of Speech, Language, and Hearing Sciences, San Diego State University, San Diego, CA 92182, USA;
- San Diego State University/University of California San Diego Joint Doctoral Program in Language and Communicative Disorders, San Diego, CA 92182, USA
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Ivanova MV, Pappas I, Inglis B, Pracar AL, Herron TJ, Baldo JV, Kayser AS, D’Esposito M, Dronkers NF. Cerebral perfusion in post-stroke aphasia and its relationship to residual language abilities. Brain Commun 2023; 6:fcad252. [PMID: 38162898 PMCID: PMC10757451 DOI: 10.1093/braincomms/fcad252] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 05/26/2023] [Accepted: 09/28/2023] [Indexed: 01/03/2024] Open
Abstract
Stroke alters blood flow to the brain resulting in damaged tissue and cell death. Moreover, the disruption of cerebral blood flow (perfusion) can be observed in areas surrounding and distal to the lesion. These structurally preserved but suboptimally perfused regions may also affect recovery. Thus, to better understand aphasia recovery, the relationship between cerebral perfusion and language needs to be systematically examined. In the current study, we aimed to evaluate (i) how stroke affects perfusion outside of lesioned areas in chronic aphasia and (ii) how perfusion in specific cortical areas and perilesional tissue relates to language outcomes in aphasia. We analysed perfusion data from a large sample of participants with chronic aphasia due to left hemisphere stroke (n = 43) and age-matched healthy controls (n = 25). We used anatomically defined regions of interest that covered the frontal, parietal, and temporal areas of the perisylvian cortex in both hemispheres, areas typically known to support language, along with several control regions not implicated in language processing. For the aphasia group, we also looked at three regions of interest in the perilesional tissue. We compared perfusion levels between the two groups and investigated the relationship between perfusion levels and language subtest scores while controlling for demographic and lesion variables. First, we observed that perfusion levels outside the lesioned areas were significantly reduced in frontal and parietal regions in the left hemisphere in people with aphasia compared to the control group, while no differences were observed for the right hemisphere regions. Second, we found that perfusion in the left temporal lobe (and most strongly in the posterior part of both superior and middle temporal gyri) and inferior parietal areas (supramarginal gyrus) was significantly related to residual expressive and receptive language abilities. In contrast, perfusion in the frontal regions did not show such a relationship; no relationship with language was also observed for perfusion levels in control areas and all right hemisphere regions. Third, perilesional perfusion was only marginally related to language production abilities. Cumulatively, the current findings demonstrate that blood flow is reduced beyond the lesion site in chronic aphasia and that hypoperfused neural tissue in critical temporoparietal language areas has a negative impact on behavioural outcomes. These results, using perfusion imaging, underscore the critical and general role that left hemisphere posterior temporal regions play in various expressive and receptive language abilities. Overall, the study highlights the importance of exploring perfusion measures in stroke.
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Affiliation(s)
- Maria V Ivanova
- Department of Psychology, University of California, Berkeley, CA 94720, USA
- Research Service, VA Northern California Health Care System, Martinez, CA 94553, USA
| | - Ioannis Pappas
- Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA 90033, USA
| | - Ben Inglis
- Henry H. Wheeler, Jr. Brain Imaging Center, University of California, Berkeley, CA 94720, USA
| | - Alexis L Pracar
- Department of Psychology, University of California, Berkeley, CA 94720, USA
| | - Timothy J Herron
- Research Service, VA Northern California Health Care System, Martinez, CA 94553, USA
| | - Juliana V Baldo
- Research Service, VA Northern California Health Care System, Martinez, CA 94553, USA
| | - Andrew S Kayser
- Division of Neurology, San Francisco VA Health Care System, San Francisco, CA 94121, USA
- Department of Neurology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Mark D’Esposito
- Department of Psychology, University of California, Berkeley, CA 94720, USA
- Neurology Service, VA Northern California Health Care System, Martinez, CA 94553, USA
| | - Nina F Dronkers
- Department of Psychology, University of California, Berkeley, CA 94720, USA
- Depertment of Neurology, University of California, Davis, CA 95817, USA
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Ivanova MV, Pappas I. Understanding recovery of language after stroke: insights from neurovascular MRI studies. FRONTIERS IN LANGUAGE SCIENCES 2023; 2:1163547. [PMID: 38162928 PMCID: PMC10757818 DOI: 10.3389/flang.2023.1163547] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
Stroke causes a disruption in blood flow to the brain that can lead to profound language impairments. Understanding the mechanisms of language recovery after stroke is crucial for the prognosis and effective rehabilitation of people with aphasia. While the role of injured brain structures and disruptions in functional connectivity have been extensively explored, the relationship between neurovascular measures and language recovery in both early and later stages has not received sufficient attention in the field. Fully functioning healthy brain tissue requires oxygen and nutrients to be delivered promptly via its blood supply. Persistent decreases in blood flow after a stroke to the remaining non-lesioned tissue have been shown to contribute to poor language recovery. The goal of the current paper is to critically examine stroke studies looking at the relationship between different neurovascular measures and language deficits and mechanisms of language recovery via changes in neurovascular metrics. Measures of perfusion or cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) provide complementary approaches to understanding neurovascular mechanisms post stroke by capturing both cerebral metabolic demands and mechanical vascular properties. While CBF measures indicate the amount of blood delivered to a certain region and serve as a proxy for metabolic demands of that area, CVR indices reflect the ability of the vasculature to recruit blood flow in response to a shortage of oxygen, such as when one is holding their breath. Increases in CBF during recovery beyond the site of the lesion have been shown to promote language gains. Similarly, CVR changes, when collateral vessels are recruited to help reorganize the flow of blood in hypoperfused regions, have been related to functional recovery post stroke. In the current review, we highlight the main findings in the literature investigating neurovascular changes in stroke recovery with a particular emphasis on how language abilities can be affected by changes in CBF and CVR. We conclude by summarizing existing methodological challenges and knowledge gaps that need to be addressed in future work in this area, outlining a promising avenue of research.
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Affiliation(s)
- Maria V. Ivanova
- Department of Psychology, University of California, Berkeley, Berkeley, CA, United States
| | - Ioannis Pappas
- USC Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, United States
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Shah-Basak P, Boukrina O, Li XR, Jebahi F, Kielar A. Targeted neurorehabilitation strategies in post-stroke aphasia. Restor Neurol Neurosci 2023; 41:129-191. [PMID: 37980575 PMCID: PMC10741339 DOI: 10.3233/rnn-231344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2023]
Abstract
BACKGROUND Aphasia is a debilitating language impairment, affecting millions of people worldwide. About 40% of stroke survivors develop chronic aphasia, resulting in life-long disability. OBJECTIVE This review examines extrinsic and intrinsic neuromodulation techniques, aimed at enhancing the effects of speech and language therapies in stroke survivors with aphasia. METHODS We discuss the available evidence supporting the use of transcranial direct current stimulation (tDCS), repetitive transcranial magnetic stimulation, and functional MRI (fMRI) real-time neurofeedback in aphasia rehabilitation. RESULTS This review systematically evaluates studies focusing on efficacy and implementation of specialized methods for post-treatment outcome optimization and transfer to functional skills. It considers stimulation target determination and various targeting approaches. The translation of neuromodulation interventions to clinical practice is explored, emphasizing generalization and functional communication. The review also covers real-time fMRI neurofeedback, discussing current evidence for efficacy and essential implementation parameters. Finally, we address future directions for neuromodulation research in aphasia. CONCLUSIONS This comprehensive review aims to serve as a resource for a broad audience of researchers and clinicians interested in incorporating neuromodulation for advancing aphasia care.
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Affiliation(s)
| | - Olga Boukrina
- Kessler Foundation, Center for Stroke Rehabilitation Research, West Orange, NJ, USA
| | - Xin Ran Li
- School of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Fatima Jebahi
- Department of Speech, Languageand Hearing Sciences, University of Arizona, Tucson, AZ, USA
| | - Aneta Kielar
- Department of Speech, Languageand Hearing Sciences, University of Arizona, Tucson, AZ, USA
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Walenski M, Chen Y, Litcofsky KA, Caplan D, Kiran S, Rapp B, Parrish TB, Thompson CK. Perilesional Perfusion in Chronic Stroke-Induced Aphasia and Its Response to Behavioral Treatment Interventions. NEUROBIOLOGY OF LANGUAGE (CAMBRIDGE, MASS.) 2022; 3:345-363. [PMID: 35685084 PMCID: PMC9169892 DOI: 10.1162/nol_a_00068] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 02/02/2022] [Indexed: 05/28/2023]
Abstract
Stroke-induced alterations in cerebral blood flow (perfusion) may contribute to functional language impairments in chronic aphasia, particularly in perilesional tissue. Abnormal perfusion in this region may also serve as a biomarker for predicting functional improvements with behavioral treatment interventions. Using pseudo-continuous arterial spin labeling in magnetic resonance imaging (MRI), we examined perfusion in chronic aphasia, in perilesional rings in the left hemisphere and their right hemisphere homologues. In the left hemisphere we found a gradient pattern of decreasing perfusion closer to the lesion. The opposite pattern was found in the right hemisphere, with significantly increased perfusion close to the lesion homologue. Perfusion was also increased in the right hemisphere lesion homologue region relative to the surrounding tissue. We next examined changes in perfusion in two groups: one group who underwent MRI scanning before and after three months of a behavioral treatment intervention that led to significant language gains, and a second group who was scanned twice at a three-month interval without a treatment intervention. For both groups, there was no difference in perfusion over time in either the left or the right hemisphere. Moreover, within the treatment group pre-treatment perfusion scores did not predict treatment response; neither did pre-treatment perfusion predict post-treatment language performance. These results indicate that perfusion is chronically abnormal in both hemispheres, but chronically abnormal perfusion did not change in response to our behavioral treatment interventions, and did not predict responsiveness to language treatment.
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Affiliation(s)
- Matthew Walenski
- Department of Communication Sciences and Disorders, East Carolina University, Greenville, NC
- Center for the Neurobiology of Language Recovery, Northwestern University, Evanston, IL
| | - Yufen Chen
- Center for the Neurobiology of Language Recovery, Northwestern University, Evanston, IL
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Evanston, IL
| | - Kaitlyn A. Litcofsky
- Center for the Neurobiology of Language Recovery, Northwestern University, Evanston, IL
- Department of Communication Sciences and Disorders, School of Communication, Northwestern University, Evanston, IL
| | - David Caplan
- Center for the Neurobiology of Language Recovery, Northwestern University, Evanston, IL
- Massachusetts General Hospital, Department of Neurology, Harvard Medical School, Boston, MA
| | - Swathi Kiran
- Center for the Neurobiology of Language Recovery, Northwestern University, Evanston, IL
- Department of Speech, Language, and Hearing, College of Health & Rehabilitation, Boston University, Boston, MA
| | - Brenda Rapp
- Center for the Neurobiology of Language Recovery, Northwestern University, Evanston, IL
- Department of Cognitive Science, Krieger School of Arts & Sciences, Johns Hopkins University, Baltimore, MD
| | - Todd B. Parrish
- Center for the Neurobiology of Language Recovery, Northwestern University, Evanston, IL
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Evanston, IL
| | - Cynthia K. Thompson
- Center for the Neurobiology of Language Recovery, Northwestern University, Evanston, IL
- Department of Communication Sciences and Disorders, School of Communication, Northwestern University, Evanston, IL
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Evanston, IL
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Revealing the Neuroimaging Mechanism of Acupuncture for Poststroke Aphasia: A Systematic Review. Neural Plast 2022; 2022:5635596. [PMID: 35494482 PMCID: PMC9050322 DOI: 10.1155/2022/5635596] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 02/21/2022] [Accepted: 03/29/2022] [Indexed: 11/18/2022] Open
Abstract
Background Aphasia is a common symptom in stroke patients, presenting with the impairment of spontaneous speech, repetition, naming, auditory comprehension, reading, and writing function. Multiple rehabilitation methods have been suggested for the recovery of poststroke aphasia, including medication treatment, behavioral therapy, and stimulation approach. Acupuncture has been proven to have a beneficial effect on improving speech functions in repetition, oral speech, reading, comprehension, and writing ability. Neuroimaging technology provides a visualized way to explore cerebral neural activity, which helps reveal the therapeutic effect of acupuncture therapy. In this systematic review, we aim to reveal and summarize the neuroimaging mechanism of acupuncture therapy on poststroke aphasia to provide the foundation for further study. Methods Seven electronic databases were searched including PubMed, Web of Science, Embase, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, the Wanfang databases, and the Chinese Scientific Journal Database. After screening the studies according to the inclusion and exclusion criteria, we summarized the neuroimaging mechanism of acupuncture on poststroke aphasia, as well as the utilization of acupuncture therapy and the methodological characteristics. Result After searching, 885 articles were retrieved. After removing the literature studies, animal studies, and case reports, 16 studies were included in the final analysis. For the acupuncture type, 10 studies used manual acupuncture and 5 studies used electroacupuncture, while body acupuncture (10 studies), scalp acupuncture (7 studies), and tongue acupuncture (8 studies) were applied for poststroke aphasia patients. Based on blood oxygen level-dependent (BOLD) and diffusion tensor imaging (DTI) technologies, 4 neuroimaging analysis methods were used including amplitude of low-frequency fluctuation (ALFF), regional homogeneity (ReHo), seed-based analysis, and independent component analysis (ICA). Two studies reported the instant acupuncture effect, and 14 studies reported the constant acupuncture's effect on poststroke aphasia patients. 5 studies analyzed the correlation between the neuroimaging outcomes and the clinical language scales. Conclusion In this systematic review, we found that the mechanism of acupuncture's effect might be associated with the activation and functional connectivity of language-related brain areas, such as brain areas around Broca's area and Wernicke's area in the left inferior temporal gyrus, supramarginal gyrus, middle frontal gyrus, and inferior frontal gyrus. However, these studies were still in the preliminary stage. Multicenter randomized controlled trials (RCT) with large sample sizes were needed to verify current evidence, as well as to explore deeply the neuroimaging mechanisms of acupuncture's effects.
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Sheppard SM, Meier EL, Kim KT, Breining BL, Keator LM, Tang B, Caffo BS, Hillis AE. Neural correlates of syntactic comprehension: A longitudinal study. BRAIN AND LANGUAGE 2022; 225:105068. [PMID: 34979477 PMCID: PMC9232253 DOI: 10.1016/j.bandl.2021.105068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 12/18/2021] [Accepted: 12/20/2021] [Indexed: 06/14/2023]
Abstract
Broca's area is frequently implicated in sentence comprehension but its specific role is debated. Most lesion studies have investigated deficits at the chronic stage. We aimed (1) to use acute imaging to predict which left hemisphere stroke patients will recover sentence comprehension; and (2) to better understand the role of Broca's area in sentence comprehension by investigating acute deficits prior to functional reorganization. We assessed comprehension of canonical and noncanonical sentences in 15 patients with left hemisphere stroke at acute and chronic stages. LASSO regression was used to conduct lesion symptom mapping analyses. Patients with more severe word-level comprehension deficits and a greater proportion of damage to supramarginal gyrus and superior longitudinal fasciculus were likely to experience acute deficits prior to functional reorganization. Broca's area was only implicated in chronic deficits. We propose that when temporoparietal regions are damaged, intact Broca's area can support syntactic processing after functional reorganization occurs.
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Affiliation(s)
- Shannon M Sheppard
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States; Department of Communication Sciences & Disorders, Chapman University, Irvine, CA 92618, United States.
| | - Erin L Meier
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States
| | - Kevin T Kim
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States
| | - Bonnie L Breining
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States
| | - Lynsey M Keator
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States
| | - Bohao Tang
- Department of Biostatics, Johns Hopkins School of Public Health, Baltimore, MD 21287, United States
| | - Brian S Caffo
- Department of Biostatics, Johns Hopkins School of Public Health, Baltimore, MD 21287, United States
| | - Argye E Hillis
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States; Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States; Department of Cognitive Science, Krieger School of Arts and Sciences, Johns Hopkins University, Baltimore, MD 21218, United States
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Editorial: New Perspectives and Methodologies in the Diagnosis and Rehabilitation of Aphasia. Brain Sci 2021; 11:brainsci11111508. [PMID: 34827507 PMCID: PMC8615359 DOI: 10.3390/brainsci11111508] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 11/11/2021] [Indexed: 01/14/2023] Open
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