Aphasia Neuroplasticity Review

Sreedharan et al. (2019b)

Reference

AuthorsSreedharan S, Chandran A, Yanamala VR, Sylaja PN, Kesavadas C, Sitaram R
TitleSelf-regulation of language areas using real-time functional MRI in stroke patients with expressive aphasia
ReferenceBrain Imaging Behav 2019b; None:
PMID31089955
DOI10.1007/s11682-019-00106-7

Participants

LanguageMalayalam
Inclusion criteriaBroca's aphasia or anomic aphasia; comprehension relatively preserved; "motivated for speech therapy"
Number of individuals with aphasia8 (plus 3 excluded: 2 for claustrophobia; 1 for transportation issues)
Number of control participants4
Were any of the participants included in any previous studies?No
Is age reported for patients and controls, and matched?No (range 18-68 years; controls were younger)
Is sex reported for patients and controls, and matched?Yes (males: 7; females: 1)
Is handedness reported for patients and controls, and matched?Yes (right: 8; left: 0)
Is time post stroke onset reported and appropriate to the study design?No (6-22 weeks; patients at different subacute stages of recovery)
To what extent is the nature of aphasia characterized?Severity only
Language evaluationWAB translated into Malayalam
Aphasia severityAQ range approximately 50-80
Aphasia typeBroca's or anomic
First stroke only?Not stated
Stroke typeNot stated
To what extent is the lesion distribution characterized?Individual lesions
Lesion extentNot stated
Lesion location7 L MCA, 1 bilateral MCA
Participants notes

Imaging

ModalityfMRI
Is the study cross-sectional or longitudinal?Longitudinal—mixed
If longitudinal, at what time point(s) were imaging data acquired?Neurofeedback group: T1: pre-treatment/subacute; T2: 1-5 weeks later; T3: 2-6 weeks after T1; T4: 3-11 weeks after T1; T5: 4-12 weeks after T1; T6: 5-12 weeks after T1; no training group: T1: subacute; T2: 2-12 weeks later; controls: T1: start of study; T2: 1-4 weeks later; T3: 3-5 weeks after T1; T4: 4-8 weeks after T1; T5: 7-37 weeks after T1; T6: 12-43 weeks after T1
If longitudinal, was there any intervention between the time points?4 patients received 4 additional sessions involving neurofeedback training, while 4 patients received treatment as usual
Is the scanner described?Yes (Siemens Avanto 1.5 Tesla)
Is the timing of stimulus presentation and image acquisition clearly described and appropriate?No* (moderate limitation) (picture naming events consistently located between blocks)
Design typeMixed
Total images acquiredprobably 964
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) (event timing will make conditions difficult to disentangle)
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?
neurofeedback (try to activate language areas)Other24UnknownUnknown
restNone24N/AN/A
picture namingOtherfirst and last timepoints: 48; other timepoints: 0NoNo
word generationMultiple words (covert)5UnknownUnknown
Conditions notesSuggested strategies to activate language areas included "making a speech, having a conversation, reciting a poem or any other form of language activity performed covertly"; picture naming task involved covert word response and button press; picture naming task not used in any contrast; word generation task used only to generate ROIs

Contrasts

Are the contrasts clearly described?Yes

Contrast 1: neurofeedback (try to activate language areas) vs rest

Language conditionNeurofeedback (try to activate language areas)
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 notesTask activated L IFG and L STG in controls (Fig. 8c), but no data on other regions, and language activations were not lateralized (Fig. 9d)
Contrast notes

Analyses

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

ROI analysis 1

First level contrastNeurofeedback (try to activate language areas) vs rest
Analysis classCross-sectional aphasia vs control
Group(s)Aphasia mean of T1, T2, T3, T4, T5, T6 (neurofeedback patients) or T1, T2 (no training patients) vs control mean
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?N/A, no behavioral measure
Is reaction time matched across the second level contrast?N/A, no timeable task
Behavioral data notes
Type of analysisRegions of interest (ROI)
ROI typeFunctional
How many ROIs are there?4
What are the ROI(s)?(1) L Broca's area (IFG pars opercularis and triangularis); (2) L Wernicke's area (pSTG); (3-4) homotopic counterparts
How are the ROI(s) defined?Individual activations within AAL ROIs on a separate word generation localizer
Correction for multiple comparisonsNo direct comparison
Statistical details
Findings↓ L IFG pars opercularis
↓ L IFG pars triangularis
↓ L posterior STG
↓ R IFG pars opercularis
↓ R IFG pars triangularis
↓ R posterior STG
Findings notes

ROI analysis 2

First level contrastNeurofeedback (try to activate language areas) vs rest
Analysis classCross-sectional between two groups with aphasia
Group(s)Aphasia with neurofeedback training (n = 4) mean of T4, T5, T6 vs no training (n = 4) T2
Covariate
Is the second level contrast valid in terms of the group(s), time point(s), and measures involved?Somewhat (no treatment effect; second half measures rather than measures of change)
Is accuracy matched across the second level contrast?N/A, no behavioral measure
Is reaction time matched across the second level contrast?N/A, no timeable task
Behavioral data notes
Type of analysisRegions of interest (ROI)
ROI typeFunctional
How many ROIs are there?15
What are the ROI(s)?(1) L Broca's area (IFG pars opercularis and triangularis); (2) L Wernicke's area (pSTG); (3-4) homotopic counterparts; (5) L MFG; (6) L PrCG; (7) L Rolandic operculum; (8) L insula; (9) L IFG pars orbitalis; (10) L MFG orbital; (11) L SMG; (12) L MTG; (13) L PoCG; (14) L AG; (15) L HG
How are the ROI(s) defined?(1-4) individual activations within AAL ROIs on a separate word generation localizer; (5-15) AAL
Correction for multiple comparisonsNo correction
Statistical details
Findings↑ L ventral precentral/inferior frontal junction
↑ L somato-motor
Findings notes

Complex analysis 1

First level contrastNeurofeedback (try to activate language areas) vs rest
Analysis classCross-sectional aphasia vs control
Group(s)Aphasia mean of T1, T2, T3, T4, T5, T6 (neurofeedback patients) or T1, T2 (no training patients) vs control mean
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?N/A, no behavioral measure
Is reaction time matched across the second level contrast?N/A, no timeable task
Behavioral data notes
Type of analysisComplex
Statistical detailsSignal change in L IFG and L pSTG ROIs was computed, along with functional connectivity between these ROIs. Neurofeedback values were calculated based on signal change as well as correlation between the ROIs. Group differences in neurofeedback values were compared, but not quantified statistically.
FindingsOther
Findings notesPatients received lower neurofeedback values than controls, due to lower signal changes and lower functional connectivity.

Notes

Excluded analyses(1) individual participant analyses in Fig. 10; (2) comparisons between groups at each time point (Fig. 11), which yielded similar results to comparisons averaged across time points; (3) vague statements about temporal trends in Figs. 12, 13, and 14