Aphasia Neuroplasticity Review

Geranmayeh et al. (2016)

Reference

Authors	Geranmayeh F, Leech R, Wise RJ
Title	Network dysfunction predicts speech production after left hemisphere stroke
Reference	Neurology 2016; 86: 1296-1305
PMID	26962070
DOI	10.1212/wnl.0000000000002537

Participants

Language	UK English
Inclusion criteria	No severe receptive aphasia
Number of individuals with aphasia	53
Number of control participants	24
Were any of the participants included in any previous studies?	No
Is age reported for patients and controls, and matched?	Yes (mean 62 ± 14 years, range 26-83 years)
Is sex reported for patients and controls, and matched?	No (males: 32; females: 21; controls were mostly female, unlike patients)
Is handedness reported for patients and controls, and matched?	Yes (right: 50; left: 3)
Is time post stroke onset reported and appropriate to the study design?	Yes (mean 111 ± 27 days, range 84-200 days)
To what extent is the nature of aphasia characterized?	Comprehensive battery
Language evaluation	CAT, QPA
Aphasia severity	"relatively mild stroke"; 17 patients were so mild that they were not aphasic per the CAT
Aphasia type	Not stated
First stroke only?	No
Stroke type	Not stated
To what extent is the lesion distribution characterized?	Lesion overlay
Lesion extent	Mean 25.4 ± 13.5 cc, range 0.3-168.0 cc
Lesion location	L; modest R involvement in 7 cases
Participants notes	Prior strokes were allowed only if no aphasia resulted

Imaging

Modality	fMRI
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?	Yes
Design type	Event-related
Total images acquired	213
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	sparse sampling; mini-blocks of 2-4 trials

Conditions

Are the conditions clearly described?

Yes

Condition	Response type	Repetitions	All groups could do?	All individuals could do?
propositional speech production	Sentence (overt)	60	Yes	No
counting	Multiple words (overt)	48	Yes	Unknown
target decision	Button press	48	Yes	Unknown
rest	None	45	N/A	N/A

Conditions notes

—

Contrasts

Are the contrasts clearly described?

Yes

Contrast 1: propositional speech production vs rest

Language condition	Propositional speech production
Control condition	Rest
Are the conditions matched for visual demands?	No
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?	No
Control activation notes	Control data for univariate analysis in Geranmayeh et al. (2014), but note that the present paper does not describe a univariate analysis; control activations reflect speech rather than language
Contrast notes	—

Contrast 2: propositional speech production vs counting

Language condition	Propositional speech production
Control condition	Counting
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?	Yes
Are activations lateralized in the control data?	Yes
Control activation notes	Control data for univariate analysis in Geranmayeh et al. (2014), but note that the present paper does not describe a univariate analysis; control activations are L frontal, L pSTS, L SMA, L > R occipito-temporal
Contrast notes	—

Contrast 3: propositional speech production vs target decision

Language condition	Propositional speech production
Control condition	Target decision
Are the conditions matched for visual demands?	No
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?	No
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	—
Contrast notes	—

Analyses

Are the analyses clearly described?

No (see specific limitation(s) below)

ROI analysis 1

First level contrast	Propositional speech production vs rest
Analysis class	Cross-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?	No, different
Is reaction time matched across the second level contrast?	Unknown, not reported
Behavioral data notes	Difference in AICW/trial
Type of analysis	Regions of interest (ROI)
ROI type	Functional
How many ROIs are there?	4
What are the ROI(s)?	(1) L fronto-temporo-parietal network; (2) R fronto-temporo-parietal network; (3) cingulo-opercular network; (4) default mode network
How are the ROI(s) defined?	Identified using ICA in controls
Correction for multiple comparisons	No correction
Statistical details	Circular because ROIs defined in one group
Findings	↑ L insula ↑ L anterior cingulate ↑ R insula ↑ R anterior cingulate
Findings notes	—

ROI analysis 2

First level contrast	Propositional speech production vs counting
Analysis class	Cross-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?	No, different
Is reaction time matched across the second level contrast?	Unknown, not reported
Behavioral data notes	Difference in AICW/trial
Type of analysis	Regions of interest (ROI)
ROI type	Functional
How many ROIs are there?	4
What are the ROI(s)?	(1) L fronto-temporo-parietal network; (2) R fronto-temporo-parietal network; (3) cingulo-opercular network; (4) default mode network
How are the ROI(s) defined?	Identified using ICA in controls
Correction for multiple comparisons	No correction
Statistical details	Circular because ROIs defined in one group
Findings	↑ L insula ↑ L anterior cingulate ↑ R insula ↑ R anterior cingulate ↓ L IFG ↓ L inferior parietal lobule ↓ L posterior inferior temporal gyrus/fusiform gyrus
Findings notes	—

ROI analysis 3

First level contrast	Propositional speech production vs target decision
Analysis class	Cross-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?	No, different
Is reaction time matched across the second level contrast?	Unknown, not reported
Behavioral data notes	Difference in AICW/trial
Type of analysis	Regions of interest (ROI)
ROI type	Functional
How many ROIs are there?	4
What are the ROI(s)?	(1) L fronto-temporo-parietal network; (2) R fronto-temporo-parietal network; (3) cingulo-opercular network; (4) default mode network
How are the ROI(s) defined?	Identified using ICA in controls
Correction for multiple comparisons	No correction
Statistical details	Circular because ROIs defined in one group
Findings	None
Findings notes	—

Complex analysis 1

First level contrast	Propositional speech production vs rest
Analysis class	Cross-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?	No, different
Is reaction time matched across the second level contrast?	Unknown, not reported
Behavioral data notes	Difference in AICW/trial
Type of analysis	Complex
Statistical details	Activity was compared between pairs of ICA-derived networks. However, circularity was introduced because the networks were defined based on the control group.
Findings	Other
Findings notes	Patients showed greater differential activation than controls between (1) L fronto-temporo-parietal network and the DMN; (2) R fronto-temporo-parietal network and the DMN; (3) cingulo-opercular network and the DMN.

Complex analysis 2

First level contrast	Propositional speech production vs rest
Analysis class	Cross-sectional correlation with language or other measure
Group(s)	Aphasia
Covariate	Appropriate information-carrying words
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 analysis	Complex
Statistical details	Multiple regression was used to determine whether differential activation between networks was predictive of the behavioral measure: appropriate information-carrying words. There is no issue of circularity with this analysis since it involved only individuals with aphasia.
Findings	Other
Findings notes	Differential activation between L fronto-temporo-parietal network and the DMN was positively correlated with AICW. Differential activation between R fronto-temporo-parietal network and the DMN was negatively correlated with AICW.

Complex analysis 3

First level contrast	Propositional speech production vs rest
Analysis class	Cross-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?	No, different
Is reaction time matched across the second level contrast?	Unknown, not reported
Behavioral data notes	Difference in AICW/trial
Type of analysis	Complex
Statistical details	PPI analyses were used to investigate how the speech condition modulated functional connectivity between (1) L fronto-temporo-parietal network and the DMN; (2) R fronto-temporo-parietal network and the DMN. However, circularity was introduced because the networks were defined based on the control group.
Findings	Other
Findings notes	In controls, the L FTP network reduced connectivity with the DMN during speech, while the R FTP network increased connectivity with the DMN during speech. Both of these interactions were significantly decreased in patients. This was also true for contrasts 2 and 3.

Notes

Excluded analyses

It is mentioned that LFTP and DMN activation did not correlate with speech performance, but insufficient details are provided regarding this analysis