Aphasia Neuroplasticity Review

Richter et al. (2008)

Reference

Authors	Richter M, Miltner WH, Straube T
Title	Association between therapy outcome and right-hemispheric activation in chronic aphasia
Reference	Brain 2008; 131: 1391-1401
PMID	18349055
DOI	10.1093/brain/awn043

Participants

Language	German
Inclusion criteria	Main deficits in production rather than comprehension
Number of individuals with aphasia	16 (plus 8 excluded: 5 completed only one of the two sessions; 3 unable to perform the tasks)
Number of control participants	8
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 evaluation	AAT, two subtests of ANELT
Aphasia severity	TT range 5-50
Aphasia type	7 anomic, 7 Broca's, 2 global; it was an inclusion criterion that the main deficits were in production
First stroke only?	Not stated
Stroke type	Not stated
To what extent is the lesion distribution characterized?	Individual lesions
Lesion extent	Not stated
Lesion location	L
Participants notes	—

Imaging

Modality	fMRI
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 type	Block
Total images acquired	134
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

Condition	Response type	Repetitions	All groups could do?	All individuals could do?
reading words silently	Word (covert)	4	Yes	Unknown
word stem completion	Word (covert)	4	Yes	Unknown
rest	None	10 (?)	N/A	N/A

Conditions notes

Preliminary 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 condition	Reading words silently
Control condition	Rest
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 notes	Appears to be somewhat L-lateralized frontal, but not well visualized
Contrast notes	—

Contrast 2: word stem completion vs rest

Language condition	Word stem completion
Control condition	Rest
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 notes	Bilateral 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 contrast	Reading words silently vs rest
Analysis class	Cross-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 analysis	Voxelwise
Search volume	R hemisphere
Correction for multiple comparisons	Mixed** (major limitation)
Software	BrainVoyager QX 1.7
Voxelwise p	R IFG/R insula ROI: .005; elsewhere: .001
Cluster extent	R IFG/R insula ROI: 0.108 cc; elsewhere: none
Statistical details	—
Findings	↑ R IFG ↑ R insula
Findings notes	—

Voxelwise analysis 2

First level contrast	Word stem completion vs rest
Analysis class	Cross-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 analysis	Voxelwise
Search volume	R hemisphere
Correction for multiple comparisons	Mixed** (major limitation)
Software	BrainVoyager QX 1.7
Voxelwise p	R IFG/R insula ROI: .005; elsewhere: .001
Cluster extent	R IFG/R insula ROI: 0.108 cc; elsewhere: none
Statistical details	—
Findings	↑ R dorsal precentral
Findings notes	—

Voxelwise analysis 3

First level contrast	Reading words silently vs rest
Analysis class	Cross-sectional correlation with language or other measure
Group(s)	Aphasia T1
Covariate	Subsequent 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 analysis	Voxelwise
Search volume	R hemisphere
Correction for multiple comparisons	No correction
Software	BrainVoyager QX 1.7
Voxelwise p	.05
Cluster extent	None
Statistical details	Nature 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 notes	Increased activity correlated with more behavioral improvement

Voxelwise analysis 4

First level contrast	Word stem completion vs rest
Analysis class	Cross-sectional correlation with language or other measure
Group(s)	Aphasia T1
Covariate	Subsequent 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 analysis	Voxelwise
Search volume	R hemisphere
Correction for multiple comparisons	No correction
Software	BrainVoyager QX 1.7
Voxelwise p	.05
Cluster extent	None
Statistical details	Nature of thresholding not entirely clear, so coded according to best guess
Findings	↑ R IFG ↑ R insula
Findings notes	Increased activity correlated with more behavioral improvement

Voxelwise analysis 5

First level contrast	Reading words silently vs rest
Analysis class	Longitudinal 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 analysis	Voxelwise
Search volume	R hemisphere
Correction for multiple comparisons	Mixed** (major limitation)
Software	BrainVoyager QX 1.7
Voxelwise p	R IFG/R insula ROI: .005; elsewhere: .001
Cluster extent	R IFG/R insula ROI: 0.108 cc; elsewhere: none
Statistical details	—
Findings	None
Findings notes	—

Voxelwise analysis 6

First level contrast	Word stem completion vs rest
Analysis class	Longitudinal 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 analysis	Voxelwise
Search volume	R hemisphere
Correction for multiple comparisons	Mixed** (major limitation)
Software	BrainVoyager QX 1.7
Voxelwise p	R IFG/R insula ROI: .005; elsewhere: .001
Cluster extent	R IFG/R insula ROI: 0.108 cc; elsewhere: none
Statistical details	—
Findings	None
Findings notes	—

ROI analysis 1

First level contrast	Reading words silently vs rest
Analysis class	Cross-sectional correlation with language or other measure
Group(s)	Aphasia T1
Covariate	Subsequent 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 analysis	Region of interest (ROI)
ROI type	Functional
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 comparisons	One only
Statistical details	—
Findings	None
Findings notes	—

ROI analysis 2

First level contrast	Word stem completion vs rest
Analysis class	Cross-sectional correlation with language or other measure
Group(s)	Aphasia T1
Covariate	Subsequent 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 analysis	Region of interest (ROI)
ROI type	Functional
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 comparisons	One only
Statistical details	—
Findings	None
Findings notes	—

ROI analysis 3

First level contrast	Reading words silently vs rest
Analysis class	Longitudinal correlation with language or other measure
Group(s)	Aphasia T2 vs T1
Covariate	Δ 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 analysis	Regions of interest (ROI)
ROI type	Functional
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 comparisons	No correction
Statistical details	Circular because functional ROIs based on related contrast on same data
Findings	↓ R posterior MTG
Findings notes	Decreased activity over time correlated with more behavioral improvement

ROI analysis 4

First level contrast	Word stem completion vs rest
Analysis class	Longitudinal correlation with language or other measure
Group(s)	Aphasia T2 vs T1
Covariate	Δ 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 analysis	Regions of interest (ROI)
ROI type	Functional
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 comparisons	No correction
Statistical details	Circular because functional ROIs based on related contrast on same data
Findings	↓ R IFG ↓ R insula
Findings notes	Decreased activity over time correlated with more behavioral improvement

Notes

Excluded analyses

—