Aphasia Neuroplasticity Review

Richter et al. (2008)

Reference

AuthorsRichter M, Miltner WH, Straube T
TitleAssociation between therapy outcome and right-hemispheric activation in chronic aphasia
ReferenceBrain 2008; 131: 1391-1401
PMID18349055
DOI10.1093/brain/awn043

Participants

LanguageGerman
Inclusion criteriaMain deficits in production rather than comprehension
Number of individuals with aphasia16 (plus 8 excluded: 5 completed only one of the two sessions; 3 unable to perform the tasks)
Number of control participants8
Were any of the participants included in any previous studies?No
Is age reported for patients and controls, and matched?Yes (mean 58.3 years; range 42-73 years)
Is sex reported for patients and controls, and matched?Yes (males: 12; females: 4)
Is handedness reported for patients and controls, and matched?Yes (right: 16; left: 0)
Is time post stroke onset reported and appropriate to the study design?No (> 12 months; actual TPO not stated)
To what extent is the nature of aphasia characterized?Comprehensive battery
Language evaluationAAT, two subtests of ANELT
Aphasia severityTT range 5-50
Aphasia type7 anomic, 7 Broca's, 2 global; it was an inclusion criterion that the main deficits were in production
First stroke only?Not stated
Stroke typeNot stated
To what extent is the lesion distribution characterized?Individual lesions
Lesion extentNot stated
Lesion locationL
Participants notes

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, ~2 weeks later
If longitudinal, was there any intervention between the time points?CIAT, 3 hours/day, 10 days
Is the scanner described?Yes (Siemens Vision plus 1.5 Tesla)
Is the timing of stimulus presentation and image acquisition clearly described and appropriate?No (minor discrepancies in description of timing)
Design typeBlock
Total images acquired134
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?No (lesion impact not addressed)
Imaging notes

Conditions

Are the conditions clearly described?Yes
ConditionResponse typeRepetitionsAll groups could do?All individuals could do?
reading words silentlyWord (covert)4YesUnknown
word stem completionWord (covert)4YesUnknown
restNone10 (?)N/AN/A
Conditions notesPreliminary data on the tasks suggests that patients would have been able to perform them, and patients were interviewed regarding the tasks after each fMRI session, however the outcomes of these interviews are not reported

Contrasts

Are the contrasts clearly described?Yes

Contrast 1: reading words silently vs rest

Language conditionReading words silently
Control conditionRest
Are the conditions matched for visual demands?No
Are the conditions matched for auditory demands?Yes
Are the conditions matched for motor demands?Yes
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?Unknown
Are activations lateralized in the control data?Unknown
Control activation notesAppears to be somewhat L-lateralized frontal, but not well visualized
Contrast notes

Contrast 2: word stem completion vs rest

Language conditionWord stem completion
Control conditionRest
Are the conditions matched for visual demands?No
Are the conditions matched for auditory demands?Yes
Are the conditions matched for motor demands?Yes
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?Unknown
Are activations lateralized in the control data?No
Control activation notesBilateral frontal; other regions not well visualized
Contrast notes

Analyses

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

Voxelwise analysis 1

First level contrastReading words silently vs rest
Analysis classCross-sectional aphasia vs control
Group(s)Aphasia T1 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?Unknown, not reported
Is reaction time matched across the second level contrast?Unknown, not reported
Behavioral data notes
Type of analysisVoxelwise
Search volumeR hemisphere
Correction for multiple comparisonsMixed** (major limitation)
SoftwareBrainVoyager QX 1.7
Voxelwise pR IFG/R insula ROI: .005; elsewhere: .001
Cluster extentR IFG/R insula ROI: 0.108 cc; elsewhere: none
Statistical details
Findings↑ R IFG
↑ R insula
Findings notes

Voxelwise analysis 2

First level contrastWord stem completion vs rest
Analysis classCross-sectional aphasia vs control
Group(s)Aphasia T1 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?Unknown, not reported
Is reaction time matched across the second level contrast?Unknown, not reported
Behavioral data notes
Type of analysisVoxelwise
Search volumeR hemisphere
Correction for multiple comparisonsMixed** (major limitation)
SoftwareBrainVoyager QX 1.7
Voxelwise pR IFG/R insula ROI: .005; elsewhere: .001
Cluster extentR IFG/R insula ROI: 0.108 cc; elsewhere: none
Statistical details
Findings↑ R dorsal precentral
Findings notes

Voxelwise analysis 3

First level contrastReading words silently vs rest
Analysis classCross-sectional correlation with language or other measure
Group(s)Aphasia T1
CovariateSubsequent Δ (T2 vs T1) overall language measure (composite measure of AAT spontaneous speech, token test, ANELT auditory comprehensibility, ANELT semantic comprehensibility)
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 analysisVoxelwise
Search volumeR hemisphere
Correction for multiple comparisonsNo correction
SoftwareBrainVoyager QX 1.7
Voxelwise p.05
Cluster extentNone
Statistical detailsNature of thresholding not entirely clear, so coded according to best guess
Findings↑ R IFG
↑ R insula
↑ R ventral precentral/inferior frontal junction
↑ R posterior MTG
Findings notesIncreased activity correlated with more behavioral improvement

Voxelwise analysis 4

First level contrastWord stem completion vs rest
Analysis classCross-sectional correlation with language or other measure
Group(s)Aphasia T1
CovariateSubsequent Δ (T2 vs T1) overall language measure (composite measure of AAT spontaneous speech, token test, ANELT auditory comprehensibility, ANELT semantic comprehensibility)
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 analysisVoxelwise
Search volumeR hemisphere
Correction for multiple comparisonsNo correction
SoftwareBrainVoyager QX 1.7
Voxelwise p.05
Cluster extentNone
Statistical detailsNature of thresholding not entirely clear, so coded according to best guess
Findings↑ R IFG
↑ R insula
Findings notesIncreased activity correlated with more behavioral improvement

Voxelwise analysis 5

First level contrastReading words silently vs rest
Analysis classLongitudinal change in aphasia
Group(s)Aphasia T2 vs T1
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?Unknown, not reported
Is reaction time matched across the second level contrast?Unknown, not reported
Behavioral data notes
Type of analysisVoxelwise
Search volumeR hemisphere
Correction for multiple comparisonsMixed** (major limitation)
SoftwareBrainVoyager QX 1.7
Voxelwise pR IFG/R insula ROI: .005; elsewhere: .001
Cluster extentR IFG/R insula ROI: 0.108 cc; elsewhere: none
Statistical details
FindingsNone
Findings notes

Voxelwise analysis 6

First level contrastWord stem completion vs rest
Analysis classLongitudinal change in aphasia
Group(s)Aphasia T2 vs T1
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?Unknown, not reported
Is reaction time matched across the second level contrast?Unknown, not reported
Behavioral data notes
Type of analysisVoxelwise
Search volumeR hemisphere
Correction for multiple comparisonsMixed** (major limitation)
SoftwareBrainVoyager QX 1.7
Voxelwise pR IFG/R insula ROI: .005; elsewhere: .001
Cluster extentR IFG/R insula ROI: 0.108 cc; elsewhere: none
Statistical details
FindingsNone
Findings notes

ROI analysis 1

First level contrastReading words silently vs rest
Analysis classCross-sectional correlation with language or other measure
Group(s)Aphasia T1
CovariateSubsequent Δ (T2 vs T1) overall language measure (composite measure of AAT spontaneous speech, token test, ANELT auditory comprehensibility, ANELT semantic comprehensibility)
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 analysisRegion of interest (ROI)
ROI typeFunctional
How many ROIs are there?1
What are the ROI(s)?L IFG/insula or L perilesional
How are the ROI(s) defined?Peak activations in individual patients in L IFG/insula or L perilesional regions (somewhat unclear)
Correction for multiple comparisonsOne only
Statistical details
FindingsNone
Findings notes

ROI analysis 2

First level contrastWord stem completion vs rest
Analysis classCross-sectional correlation with language or other measure
Group(s)Aphasia T1
CovariateSubsequent Δ (T2 vs T1) overall language measure (composite measure of AAT spontaneous speech, token test, ANELT auditory comprehensibility, ANELT semantic comprehensibility)
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 analysisRegion of interest (ROI)
ROI typeFunctional
How many ROIs are there?1
What are the ROI(s)?L IFG/insula or L perilesional
How are the ROI(s) defined?Peak activations in individual patients in L IFG/insula or L perilesional regions (somewhat unclear)
Correction for multiple comparisonsOne only
Statistical details
FindingsNone
Findings notes

ROI analysis 3

First level contrastReading words silently vs rest
Analysis classLongitudinal correlation with language or other measure
Group(s)Aphasia T2 vs T1
CovariateΔ overall language measure (composite measure of AAT spontaneous speech, token test, ANELT auditory comprehensibility, ANELT semantic comprehensibility)
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) R IFG/insula; (2) R precentral; (3) R MTG; (4) L IFG/insula or L perilesional
How are the ROI(s) defined?Regions where T1 activation was correlated with subsequent improvement, along with the previously defined left hemisphere ROI
Correction for multiple comparisonsNo correction
Statistical detailsCircular because functional ROIs based on related contrast on same data
Findings↓ R posterior MTG
Findings notesDecreased activity over time correlated with more behavioral improvement

ROI analysis 4

First level contrastWord stem completion vs rest
Analysis classLongitudinal correlation with language or other measure
Group(s)Aphasia T2 vs T1
CovariateΔ overall language measure (composite measure of AAT spontaneous speech, token test, ANELT auditory comprehensibility, ANELT semantic comprehensibility)
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?3
What are the ROI(s)?(1, 2) two clusters within R IFG/insula ROI; (3) L IFG/insula or L perilesional
How are the ROI(s) defined?Regions where T1 activation was correlated with subsequent improvement, along with the previously defined left hemisphere ROI
Correction for multiple comparisonsNo correction
Statistical detailsCircular because functional ROIs based on related contrast on same data
Findings↓ R IFG
↓ R insula
Findings notesDecreased activity over time correlated with more behavioral improvement

Notes

Excluded analyses