Aphasia Neuroplasticity Review

Fridriksson et al. (2012b)

Reference

AuthorsFridriksson J, Richardson JD, Fillmore P, Cai B
TitleLeft hemisphere plasticity and aphasia recovery
ReferenceNeuroImage 2012b; 60: 854-863
PMID22227052
DOI10.1016/j.neuroimage.2011.12.057

Participants

LanguageUS English
Inclusion criteria
Number of individuals with aphasia29 (plus 1 excluded: contraindications to MRI)
Number of control participants14
Were any of the participants included in any previous studies?Yes (26 of 30 patients were included in Fridriksson (2010))
Is age reported for patients and controls, and matched?Yes (mean 59.2 years, range 33-81 years)
Is sex reported for patients and controls, and matched?No (males: 14; females: 16; not stated for controls)
Is handedness reported for patients and controls, and matched?No
Is time post stroke onset reported and appropriate to the study design?Yes (mean 51.1 months, range 6-350 months)
To what extent is the nature of aphasia characterized?Severity and type
Language evaluationWAB
Aphasia severityAQ mean 57.9 ± 25.8, range 17.2-95.2
Aphasia type13 Broca's, 10 anomic, 3 conduction, 2 Wernicke's, 1 global, 1 transcortical motor
First stroke only?Yes
Stroke typeMixed etiologies
To what extent is the lesion distribution characterized?Lesion overlay
Lesion extentRange 7.7-420.5 cc
Lesion locationL MCA
Participants notesDemographic data includes excluded patient

Imaging

ModalityfMRI
Is the study cross-sectional or longitudinal?Longitudinal—chronic treatment
If longitudinal, at what time point(s) were imaging data acquired?T1: pre-treatment/chronic; T2: post-treatment/~4 weeks later; note that there were two separate sessions per time point, as well as another two sessions midway through treatment that are not analyzed in this paper
If longitudinal, was there any intervention between the time points?Anomia treatment using a cueing hierarchy, 3 hours/day, 5 days/week, 2 weeks, with a 1-week gap between the two weeks
Is the scanner described?Yes (Siemens Trio 3 Tesla)
Is the timing of stimulus presentation and image acquisition clearly described and appropriate?No (timing of stimuli within the silent periods is unclear)
Design typeEvent-related
Total images acquired120
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 notessparse sampling; 26 patients were also scanned with arterial spin labelling

Conditions

Are the conditions clearly described?Yes
ConditionResponse typeRepetitionsAll groups could do?All individuals could do?
picture namingWord (overt)80YesUnknown
viewing abstract picturesNone40N/AN/A
Conditions notes

Contrasts

Are the contrasts clearly described?Yes

Contrast 1: picture naming vs viewing abstract pictures

Language conditionPicture naming
Control conditionViewing abstract pictures
Are the conditions matched for visual demands?Yes
Are the conditions matched for auditory demands?No
Are the conditions matched for motor demands?No
Are the conditions matched for cognitive/executive demands?No
Is accuracy matched between the language and control tasks for all relevant groups?N/A, tasks not comparable
Is reaction time matched between the language and control tasks for all relevant groups?N/A, tasks not comparable
Behavioral data notes
Are control data reported in this paper or another that is referenced?Somewhat
Does the contrast selectively activate plausible relevant language regions in the control group?No
Are activations lateralized in the control data?Somewhat
Control activation notesControl data in Fridriksson et al. (2007); motor activations are prominent; there is some L frontal activation but little temporal activation in either hemisphere
Contrast notes

Analyses

Are the analyses clearly described?No* (moderate limitation) (see specific limitation(s) below)

ROI analysis 1

First level contrastPicture naming vs viewing abstract pictures
Analysis classLongitudinal correlation with language or other measure
Group(s)Aphasia T2 vs T1
CovariateΔ picture naming 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 typeOther
How many ROIs are there?3
What are the ROI(s)?(1) perilesional L hemisphere language regions; (2) perilesional L hemisphere non-language regions; (3) undamaged non-perilesional L hemisphere language regions
How are the ROI(s) defined?Based on individual lesions and control activation for picture naming
Correction for multiple comparisonsNo correction
Statistical details
FindingsOther
Findings notesChange in perilesional non-language regions positively correlated with improvement in accuracy

ROI analysis 2

First level contrastPicture naming vs viewing abstract pictures
Analysis classLongitudinal correlation with language or other measure
Group(s)Aphasia T2 vs T1
CovariateΔ (decrease in) semantic errors
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 typeOther
How many ROIs are there?3
What are the ROI(s)?(1) perilesional L hemisphere language regions; (2) perilesional L hemisphere non-language regions; (3) undamaged non-perilesional L hemisphere language regions
How are the ROI(s) defined?Based on individual lesions and control activation for picture naming
Correction for multiple comparisonsNo correction
Statistical details
FindingsOther
Findings notesChange in undamaged non-perilesional language regions negatively correlated with decrease in semantic errors

ROI analysis 3

First level contrastPicture naming vs viewing abstract pictures
Analysis classLongitudinal correlation with language or other measure
Group(s)Aphasia T2 vs T1
CovariateΔ (decrease in) phonological paraphasias
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 typeOther
How many ROIs are there?3
What are the ROI(s)?(1) perilesional L hemisphere language regions; (2) perilesional L hemisphere non-language regions; (3) undamaged non-perilesional L hemisphere language regions
How are the ROI(s) defined?Based on individual lesions and control activation for picture naming
Correction for multiple comparisonsNo correction
Statistical details
FindingsOther
Findings notesChange in perilesional language regions, and change in undamaged non-perilesional language regions, negatively correlated with decrease in phonological paraphasias

ROI analysis 4

First level contrastPicture naming vs viewing abstract pictures
Analysis classCross-sectional correlation with language or other measure
Group(s)Aphasia T1
CovariateSubsequent Δ (T2 vs T1) picture naming accuracy
Is the second level contrast valid in terms of the group(s), time point(s), and measures involved?Somewhat (T1 behavioral measure should be included in model)
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 typeOther
How many ROIs are there?3
What are the ROI(s)?(1) perilesional L hemisphere language regions; (2) perilesional L hemisphere non-language regions; (3) undamaged non-perilesional L hemisphere language regions
How are the ROI(s) defined?Based on individual lesions and control activation for picture naming
Correction for multiple comparisonsNo correction
Statistical details
FindingsNone
Findings notes

ROI analysis 5

First level contrastPicture naming vs viewing abstract pictures
Analysis classCross-sectional correlation with language or other measure
Group(s)Aphasia T1
CovariateSubsequent Δ (T2 vs T1, decrease in) semantic errors
Is the second level contrast valid in terms of the group(s), time point(s), and measures involved?Somewhat (T1 behavioral measure should be included in model)
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 typeOther
How many ROIs are there?3
What are the ROI(s)?(1) perilesional L hemisphere language regions; (2) perilesional L hemisphere non-language regions; (3) undamaged non-perilesional L hemisphere language regions
How are the ROI(s) defined?Based on individual lesions and control activation for picture naming
Correction for multiple comparisonsNo correction
Statistical details
FindingsOther
Findings notesChange in perilesional language regions correlated with decrease in phonological paraphasias

ROI analysis 6

First level contrastPicture naming vs viewing abstract pictures
Analysis classCross-sectional correlation with language or other measure
Group(s)Aphasia T1
CovariateSubsequent Δ (T2 vs T1, decrease in) phonological paraphasias
Is the second level contrast valid in terms of the group(s), time point(s), and measures involved?Somewhat (T1 behavioral measure should be included in model)
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 typeOther
How many ROIs are there?3
What are the ROI(s)?(1) perilesional L hemisphere language regions; (2) perilesional L hemisphere non-language regions; (3) undamaged non-perilesional L hemisphere language regions
How are the ROI(s) defined?Based on individual lesions and control activation for picture naming
Correction for multiple comparisonsNo correction
Statistical details
FindingsNone
Findings notes

Notes

Excluded analyses(1) breakdown of frontal, temporal and parietal components of masks, because stepwise regression not described in sufficient detail; (2) pASL rCBF predictors not task-based; (3) ancillary analyses based on total naming responses instead of accuracy; (4) ancillary analyses after excluding one patient