Aphasia Neuroplasticity Review

Szaflarski et al. (2013)

Reference

AuthorsSzaflarski JP, Allendorfer JB, Banks C, Vannest J, Holland SK
TitleRecovered vs. not-recovered from post-stroke aphasia: the contributions from the dominant and non-dominant hemispheres
ReferenceRestor Neurol Neurosci 2013; 31: 347-360
PMID23482065
DOI10.3233/rnn-120267

Participants

LanguageUS English
Inclusion criteria
Number of individuals with aphasia27
Number of control participants0
Were any of the participants included in any previous studies?No
Is age reported for patients and controls, and matched?Yes (recovered: mean 50 ± 13 years; non-recovered: mean 51 ± 13 years)
Is sex reported for patients and controls, and matched?Yes (males: 15; females: 12)
Is handedness reported for patients and controls, and matched?Yes (right: 27; left: 0)
Is time post stroke onset reported and appropriate to the study design?Yes (recovered: mean 2.1 ± 2.1 years; non-recovered: mean 4.9 ± 3.1 years)
To what extent is the nature of aphasia characterized?Severity only
Language evaluationTT, BNT, semantic fluency, phonemic fluency, PPVT, complex ideation subtest of BDAE
Aphasia severityRecovered: TT mean 43 ± 1, >= 41; non-recovered: TT mean 23 ± 12, < 41
Aphasia typeNot stated
First stroke only?Not stated
Stroke typeNot stated
To what extent is the lesion distribution characterized?Lesion overlay
Lesion extentRecovered: median 9.2 cc, range 2.2-26.5 cc; non-recovered: median 74 cc, range 5.1-206.0 cc
Lesion locationL MCA
Participants notes

Imaging

ModalityfMRI
Is the study cross-sectional or longitudinal?Cross-sectional
If longitudinal, at what time point(s) were imaging data acquired?
If longitudinal, was there any intervention between the time points?
Is the scanner described?No (Phillips 3 Tesla; model not stated)
Is the timing of stimulus presentation and image acquisition clearly described and appropriate?Yes
Design typeBlock
Total images acquired330
Are the imaging acquisition parameters, including coverage, adequately described and appropriate?Yes (whole brain)
Is preprocessing and intrasubject coregistration adequately described and appropriate?Yes
Is first level model fitting adequately described and appropriate?Yes
Is intersubject normalization adequately described and appropriate?Yes
Imaging notes

Conditions

Are the conditions clearly described?Yes
ConditionResponse typeRepetitionsAll groups could do?All individuals could do?
semantic decisionButton press10NoNo
tone decisionButton press12NoNo
Conditions notes

Contrasts

Are the contrasts clearly described?Yes

Contrast 1: semantic decision vs tone decision

Language conditionSemantic decision
Control conditionTone decision
Are the conditions matched for visual demands?Yes
Are the conditions matched for auditory demands?Yes
Are the conditions matched for motor demands?Yes
Are the conditions matched for cognitive/executive demands?Yes
Is accuracy matched between the language and control tasks for all relevant groups?Appear mismatched
Is reaction time matched between the language and control tasks for all relevant groups?Unknown, not reported
Behavioral data notesAccuracy appears similar in the non-recovered group, but not in the recovered group
Are control data reported in this paper or another that is referenced?Yes
Does the contrast selectively activate plausible relevant language regions in the control group?Yes
Are activations lateralized in the control data?Yes
Control activation notesControl data in Kim et al. (2011) and Szaflarski et al. (2008); L frontal and temporal, plus other semantic regions
Contrast notes

Analyses

Are the analyses clearly described?Yes

Voxelwise analysis 1

First level contrastSemantic decision vs tone decision
Analysis classCross-sectional between two groups with aphasia
Group(s)Aphasia not recovered (n = 18) vs recovered (n = 9)
Covariate
Is the second level contrast valid in terms of the group(s), time point(s), and measures involved?Yes
Is accuracy matched across the second level contrast?Appear mismatched
Is reaction time matched across the second level contrast?Unknown, not reported
Behavioral data notesInteraction of group by condition not reported; non-recovered patients were significantly less accurate only on the semantic decision condition, but they actually showed a smaller difference between conditions than the recovered patients
Type of analysisVoxelwise
Search volumeWhole brain
Correction for multiple comparisonsClusterwise correction based on 3dClustSim
SoftwareAFNI
Voxelwise p.05
Cluster extent4.16 cc
Statistical detailsCluster-defining threshold (CDT) p < 0.05 too lenient
Findings↑ L dorsolateral prefrontal cortex
↑ L superior parietal
↑ L cerebellum
↑ R cerebellum
↓ R posterior STG
Findings notes

ROI analysis 1

First level contrastSemantic decision vs tone decision
Analysis classCross-sectional correlation with language or other measure
Group(s)Aphasia (recovered and non-recovered)
CovariateBNT
Is the second level contrast valid in terms of the group(s), time point(s), and measures involved?Yes
Is accuracy matched across the second level contrast?Unknown, not reported
Is reaction time matched across the second level contrast?Unknown, not reported
Behavioral data notes
Type of analysisRegions of interest (ROI)
ROI typeFunctional
How many ROIs are there?4
What are the ROI(s)?(1) bilateral cerebellum; (2) R pSTG; (3) L superior parietal lobule; (4) L superior frontal gyrus
How are the ROI(s) defined?Regions that were differentially recruited between recovered and non-recovered patients; average t scores from individual SPMs
Correction for multiple comparisonsFamilywise error (FWE)
Statistical detailsCircular because defined based on recovered status
Findings↑ L dorsolateral prefrontal cortex
Findings notes

ROI analysis 2

First level contrastSemantic decision vs tone decision
Analysis classCross-sectional correlation with language or other measure
Group(s)Aphasia (recovered and non-recovered)
CovariateSemantic fluency
Is the second level contrast valid in terms of the group(s), time point(s), and measures involved?Yes
Is accuracy matched across the second level contrast?Unknown, not reported
Is reaction time matched across the second level contrast?Unknown, not reported
Behavioral data notes
Type of analysisRegions of interest (ROI)
ROI typeFunctional
How many ROIs are there?4
What are the ROI(s)?(1) bilateral cerebellum; (2) R pSTG; (3) L superior parietal lobule; (4) L superior frontal gyrus
How are the ROI(s) defined?Regions that were differentially recruited between recovered and non-recovered patients; average t scores from individual SPMs
Correction for multiple comparisonsFamilywise error (FWE)
Statistical detailsCircular because defined based on recovered status
Findings↑ L dorsolateral prefrontal cortex
Findings notes

ROI analysis 3

First level contrastSemantic decision vs tone decision
Analysis classCross-sectional correlation with language or other measure
Group(s)Aphasia (recovered and non-recovered)
CovariateSingle word comprehension (PPVT)
Is the second level contrast valid in terms of the group(s), time point(s), and measures involved?Yes
Is accuracy matched across the second level contrast?Unknown, not reported
Is reaction time matched across the second level contrast?Unknown, not reported
Behavioral data notes
Type of analysisRegions of interest (ROI)
ROI typeFunctional
How many ROIs are there?4
What are the ROI(s)?(1) bilateral cerebellum; (2) R pSTG; (3) L superior parietal lobule; (4) L superior frontal gyrus
How are the ROI(s) defined?Regions that were differentially recruited between recovered and non-recovered patients; average t scores from individual SPMs
Correction for multiple comparisonsFamilywise error (FWE)
Statistical detailsCircular because defined based on recovered status
Findings↑ L dorsolateral prefrontal cortex
Findings notes

ROI analysis 4

First level contrastSemantic decision vs tone decision
Analysis classCross-sectional correlation with language or other measure
Group(s)Aphasia (recovered and non-recovered)
CovariateBDAE complex ideation subtest
Is the second level contrast valid in terms of the group(s), time point(s), and measures involved?Yes
Is accuracy matched across the second level contrast?Unknown, not reported
Is reaction time matched across the second level contrast?Unknown, not reported
Behavioral data notes
Type of analysisRegions of interest (ROI)
ROI typeFunctional
How many ROIs are there?4
What are the ROI(s)?(1) bilateral cerebellum; (2) R pSTG; (3) L superior parietal lobule; (4) L superior frontal gyrus
How are the ROI(s) defined?Regions that were differentially recruited between recovered and non-recovered patients; average t scores from individual SPMs
Correction for multiple comparisonsFamilywise error (FWE)
Statistical detailsCircular because defined based on recovered status
Findings↑ L dorsolateral prefrontal cortex
Findings notes

ROI analysis 5

First level contrastSemantic decision vs tone decision
Analysis classCross-sectional correlation with language or other measure
Group(s)Aphasia (recovered and non-recovered)
CovariatePhonemic fluency
Is the second level contrast valid in terms of the group(s), time point(s), and measures involved?Yes
Is accuracy matched across the second level contrast?Unknown, not reported
Is reaction time matched across the second level contrast?Unknown, not reported
Behavioral data notes
Type of analysisRegions of interest (ROI)
ROI typeFunctional
How many ROIs are there?4
What are the ROI(s)?(1) bilateral cerebellum; (2) R pSTG; (3) L superior parietal lobule; (4) L superior frontal gyrus
How are the ROI(s) defined?Regions that were differentially recruited between recovered and non-recovered patients; average t scores from individual SPMs
Correction for multiple comparisonsFamilywise error (FWE)
Statistical detailsCircular because defined based on recovered status
Findings↓ R posterior STG
Findings notes

ROI analysis 6

First level contrastSemantic decision vs tone decision
Analysis classCross-sectional correlation with language or other measure
Group(s)Aphasia (recovered and non-recovered)
CovariateSemantic decision accuracy
Is the second level contrast valid in terms of the group(s), time point(s), and measures involved?Yes
Is accuracy matched across the second level contrast?Accuracy is covariate
Is reaction time matched across the second level contrast?Unknown, not reported
Behavioral data notes
Type of analysisRegions of interest (ROI)
ROI typeFunctional
How many ROIs are there?4
What are the ROI(s)?(1) bilateral cerebellum; (2) R pSTG; (3) L superior parietal lobule; (4) L superior frontal gyrus
How are the ROI(s) defined?Regions that were differentially recruited between recovered and non-recovered patients; average t scores from individual SPMs
Correction for multiple comparisonsFamilywise error (FWE)
Statistical detailsCircular because defined based on recovered status
FindingsNone
Findings notes

Notes

Excluded analyses