Aphasia Neuroplasticity Review

Brownsett et al. (2014)

Reference

AuthorsBrownsett SL, Warren JE, Geranmayeh F, Woodhead Z, Leech R, Wise RJ
TitleCognitive control and its impact on recovery from aphasic stroke
ReferenceBrain 2014; 137: 242-254
PMID24163248
DOI10.1093/brain/awt289

Participants

LanguageUK English
Inclusion criteriaNo involvement of ACA territory
Number of individuals with aphasia16 (plus 3 excluded: 2 withdrew after attempting first scan; 1 had severe dysarthria)
Number of control participants17
Were any of the participants included in any previous studies?No
Is age reported for patients and controls, and matched?Yes (mean 60 years, range 37-84 years)
Is sex reported for patients and controls, and matched?Yes (males: 11; females: 5)
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?Yes (mean 4 years, range 6 months-11 years)
To what extent is the nature of aphasia characterized?Not at all
Language evaluationNot stated
Aphasia severityNot stated
Aphasia typeNot stated, but all had auditory comprehension and repetition deficits, and all could at least attempt to repeat
First stroke only?Not stated
Stroke typeNot stated
To what extent is the lesion distribution characterized?Lesion overlay
Lesion extentNot stated
Lesion locationL temporal and parietal cortex; 4 extended into the frontal lobe; no lesions involved ACA territory
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?Patients: T1: acclimatization/chronic (but used in some analyses); T2: pre-treatment/chronic (not stated how long after T1); T3: post-treatment/~4 weeks later; controls: T1: pre-training; T2: post-training/~2 weeks later
If longitudinal, was there any intervention between the time points?Patients: home-based therapy consisting of auditory discrimination and repetition tasks for 3 or 4 weeks between T2 and T3; control: 2 weeks of similar training using noise vocoded speech
Is the scanner described?Yes (Philips Intera 3 Tesla)
Is the timing of stimulus presentation and image acquisition clearly described and appropriate?No* (moderate limitation) (timing of sentence presentation not described; sparse event-related design, but ITI of only 8 s and consistent linear order of listening and repetition trials could make it difficult to disentangle hemodynamic responses to listening and repeating trials)
Design typeEvent-related
Total images acquired168 (patients); 280 (controls)
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?No* (moderate limitation) (consistent linear order of listening and repetition trials could make it difficult to disentangle hemodynamic responses to listening and repeating trials)
Is intersubject normalization adequately described and appropriate?Yes
Imaging notessparse sampling; different task structure in controls (two repetition trials per listening trial) raises concerns about comparisons between groups

Conditions

Are the conditions clearly described?No (paradigm was different in patients and controls, and is not described in sufficient detail for patients)
ConditionResponse typeRepetitionsAll groups could do?All individuals could do?
listening to sentencesNoneaphasia: not stated; control: 40N/AN/A
repeating sentences (sentence from previous trial)Sentence (overt)aphasia: not stated; control: 40YesNo
listening to noise vocoded sentences (control only)None40 (control)N/AN/A
repeating noise vocoded sentences (control only)Sentence (overt)80 (control)YesUnknown
listening to segmented white noiseNoneaphasia: not stated; control: 40N/AN/A
Conditions notesIn two patients, only single words were produced

Contrasts

Are the contrasts clearly described?Yes

Contrast 1: listening to sentences vs listening to segmented white noise

Language conditionListening to sentences
Control conditionListening to segmented white noise
Are the conditions matched for visual demands?Yes
Are the conditions matched for auditory demands?Yes
Are the conditions matched for motor demands?Yes
Are the conditions matched for cognitive/executive demands?Yes
Is accuracy matched between the language and control tasks for all relevant groups?N/A, no behavioral measure
Is reaction time matched between the language and control tasks for all relevant groups?N/A, no timeable task
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

Contrast 2: listening to sentences (patients) or listening to noise vocoded sentences (controls) vs listening to segmented white noise

Language conditionListening to sentences (patients) or listening to noise vocoded sentences (controls)
Control conditionListening to segmented white noise
Are the conditions matched for visual demands?Yes
Are the conditions matched for auditory demands?Yes
Are the conditions matched for motor demands?Yes
Are the conditions matched for cognitive/executive demands?Yes
Is accuracy matched between the language and control tasks for all relevant groups?N/A, no behavioral measure
Is reaction time matched between the language and control tasks for all relevant groups?N/A, no timeable task
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?Yes

Voxelwise analysis 1

First level contrastListening to sentences vs listening to segmented white noise
Analysis classCross-sectional aphasia vs control
Group(s)Aphasia (T2 and T3) vs control (T1 and T2)
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?N/A, no timeable task
Behavioral data notesSignificant difference in accuracy of subsequent repetition
Type of analysisVoxelwise
Search volumeWhole brain
Correction for multiple comparisonsClusterwise correction with with GRFT and lenient voxelwise p
SoftwareFSL (FEAT 5.98)
Voxelwise p~.01 (z > 2.3)
Cluster extentBased on GRFT
Statistical details
Findings↑ L insula
↑ L anterior cingulate
↑ R insula
↑ R anterior cingulate
↓ L SMA/medial prefrontal
↓ L precuneus
↓ L posterior cingulate
↓ R SMA/medial prefrontal
↓ R precuneus
↓ R posterior cingulate
Findings notesFindings are approximate since description is partially in terms of networks; at the earlier time point only, patients also showed reduced activity in left ventral prefrontal cortex and right medial planum temporale

Voxelwise analysis 2

First level contrastListening to sentences (patients) or listening to noise vocoded sentences (controls) vs listening to segmented white noise
Analysis classCross-sectional aphasia vs control
Group(s)Aphasia (T2 and T3) vs control (T1 and T2)
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, matched
Is reaction time matched across the second level contrast?N/A, no timeable task
Behavioral data notesNo significant difference in accuracy of subsequent repetition
Type of analysisVoxelwise
Search volumeWhole brain
Correction for multiple comparisonsClusterwise correction with with GRFT and lenient voxelwise p
SoftwareFSL (FEAT 5.98)
Voxelwise p~.01 (z > 2.3)
Cluster extentBased on GRFT
Statistical details
FindingsNone
Findings notes

ROI analysis 1

First level contrastListening to sentences vs listening to segmented white noise
Analysis classCross-sectional correlation with language or other measure
Group(s)Aphasia mean of T1, T2, T3
CovariatePicture description score (CAT), mean of T1, T2, T3
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?N/A, no timeable task
Behavioral data notesReferring to accuracy of subsequent repetition; correlation with picture description is not reported
Type of analysisRegion of interest (ROI)
ROI typeFunctional
How many ROIs are there?1
What are the ROI(s)?Dorsal anterior cingulate cortex/midline superior frontal gyrus
How are the ROI(s) defined?Contrast of listening to vocoded speech and listening to normal speech in controls
Correction for multiple comparisonsOne only
Statistical detailsSame result obtained with age and lesion volume included in the model
Findings↑ L SMA/medial prefrontal
↑ L anterior cingulate
↑ R SMA/medial prefrontal
↑ R anterior cingulate
Findings notesIncreased activation of dACC/SFG was correlated with higher scores on picture description

Notes

Excluded analysesLongitudinal analyses, since these were null findings that were not the focus of this paper