Aphasia Neuroplasticity Review

Fridriksson et al. (2010)

Reference

AuthorsFridriksson J, Bonilha L, Baker JM, Moser D, Rorden C
TitleActivity in preserved left hemisphere regions predicts anomia severity in aphasia
ReferenceCereb Cortex 2010; 20: 1013-1019
PMID19687294
DOI10.1093/cercor/bhp160

Participants

LanguageUS English
Inclusion criteria
Number of individuals with aphasia15
Number of control participants9
Were any of the participants included in any previous studies?No
Is age reported for patients and controls, and matched?Yes (mean 61.9 years, range 41-81 years)
Is sex reported for patients and controls, and matched?No (males: 7; females: 8; 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 29.7 months, > 6 months)
To what extent is the nature of aphasia characterized?Severity and type
Language evaluationWAB
Aphasia severityAQ mean 77.1, range 47.1-93.7
Aphasia type10 anomic, 3 Broca's, 2 conduction
First stroke only?Yes
Stroke typeIschemic only
To what extent is the lesion distribution characterized?Lesion overlay
Lesion extentNot stated
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?Yes (Siemens Trio 3 Tesla)
Is the timing of stimulus presentation and image acquisition clearly described and appropriate?No (exact timing of picture presentation not specified)
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

Conditions

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

Contrasts

Are the contrasts clearly described?Yes

Contrast 1: picture naming (correct trials) vs viewing abstract pictures

Language conditionPicture naming (correct trials)
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?Somewhat
Are activations lateralized in the control data?Somewhat
Control activation notesL-lateralized frontal and temporal activations, but also bilateral visual, motor and auditory
Contrast notes

Analyses

Are the analyses clearly described?Yes

Voxelwise analysis 1

First level contrastPicture naming (correct trials) vs viewing abstract pictures
Analysis classCross-sectional correlation with language or other measure
Group(s)Aphasia
CovariatePicture 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?Yes, correct trials only
Is reaction time matched across the second level contrast?Unknown, not reported
Behavioral data notes
Type of analysisVoxelwise
Search volumeWhole brain
Correction for multiple comparisonsClusterwise correction with with GRFT and lenient voxelwise p
SoftwareFSL 4.1
Voxelwise p~.02 (z > 2)
Cluster extentBased on GRFT
Statistical details
Findings↑ L IFG pars orbitalis
↑ L occipital
↑ L anterior cingulate
Findings notesGreater activation was associated with better picture naming; L IFG pars orbitalis activation classified as middle frontal gyrus in the paper, but coordinates suggest otherwise

Voxelwise analysis 2

First level contrastPicture naming (correct trials) vs viewing abstract pictures
Analysis classCross-sectional aphasia vs control
Group(s)Aphasia vs control
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?Yes, correct trials only
Is reaction time matched across the second level contrast?Unknown, not reported
Behavioral data notes
Type of analysisVoxelwise
Search volumeWhole brain
Correction for multiple comparisonsClusterwise correction with with GRFT and lenient voxelwise p
SoftwareFSL 4.1
Voxelwise p~.02 (z > 2)
Cluster extentBased on GRFT
Statistical details
FindingsNone
Findings notes

ROI analysis 1

First level contrastPicture naming (correct trials) vs viewing abstract pictures
Analysis classCross-sectional correlation with language or other measure
Group(s)Aphasia
CovariatePicture 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?Yes, correct trials only
Is reaction time matched across the second level contrast?Unknown, not reported
Behavioral data notes
Type of analysisRegion of interest (ROI)
ROI typeFunctional
How many ROIs are there?1
What are the ROI(s)?A single ROI comprising 3 regions where activation in patients was correlated with picture naming accuracy: the L IFG pars orbitalis, occipital lobe, and anterior cingulate
How are the ROI(s) defined?Based on SPM analysis 1
Correction for multiple comparisonsOne only
Statistical detailsThe purpose of this analysis was to determine whether these regions were recruited in the patients with better naming, or not activated in the patients with worse naming, relative to the control mean
FindingsOther
Findings notesPatients with better naming showed greater activation than controls, while the patients with poorer naming showed less activation than controls.

Complex analysis 1

First level contrastPicture naming (correct trials) vs viewing abstract pictures
Analysis classCross-sectional correlation with language or other measure
Group(s)Aphasia
CovariateLesion status of each voxel
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?Yes, correct trials only
Is reaction time matched across the second level contrast?Unknown, not reported
Behavioral data notes
Type of analysisComplex
Statistical detailsVLSM was used to identify any regions in which damage was predictive of activation in the regions identified in SPM analysis 1, considered as a single ROI. There was no correction for multiple comparisons, and the analysis is appropriately presented as exploratory.
FindingsOther
Findings notesOnly in the L IFG pars opercularis was damage predictive of reduced activation in the potentially compensatory network.

Notes

Excluded analyses