Aphasia Neuroplasticity Review

Johnson et al. (2019)

Reference

AuthorsJohnson JP, Meier EL, Pan Y, Kiran S
TitleTreatment-related changes in neural activation vary according to treatment response and extent of spared tissue in patients with chronic aphasia
ReferenceCortex 2019; 121: 147-168
PMID31627014
DOI10.1016/j.cortex.2019.08.016

Participants

LanguageUS English
Inclusion criteriaAnomia
Number of individuals with aphasia30 (plus 5 excluded: 2 withdrew from non-treatment arm; 3 fMRI acquisition errors; 1 did not complete treatment and post-treatment scanning (but of these latter 4, one must have at least completed the non-treatment arm))
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 (treated group: mean 62.8 ± 10.2 years, range 42-80 years; untreated group: mean 59.0 ± 11.8 years, range 39-79 years)
Is sex reported for patients and controls, and matched?Yes (males: 21; females: 9)
Is handedness reported for patients and controls, and matched?Yes (right: 27; left: 3)
Is time post stroke onset reported and appropriate to the study design?Yes (treated group: mean 58.3 ± 51.8 months, range 12-170 months; untreated group: mean 85.2 ± 141.9 months, range 10-467 months)
To what extent is the nature of aphasia characterized?Severity only
Language evaluationWAB, BNT, PPT
Aphasia severityTreated group: AQ mean 60.1 ± 24.0, range 11.7-95.2; untreated group: AQ mean 65.8 ± 24.6, range 26.9-91.5
Aphasia typeNot stated
First stroke only?Not stated
Stroke typeNot stated
To what extent is the lesion distribution characterized?Lesion overlay
Lesion extentTreated group: 136.6 ± 81.1 cc, range 11.7-317.1 cc; untreated group: 112.7 ± 94.6 cc, range 1.6-317.1 cc
Lesion locationMostly MCA with a few extending into PCA
Participants notesThere were 26 patients in the treated group and 10 in the untreated group, but 6 patients overlapped between the two groups (they joined the treated group after completing the untreated phase)

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, ~12 weeks later
If longitudinal, was there any intervention between the time points?Semantic naming treatment, 2 sessions/week
Is the scanner described?Yes (Siemens Trio 3 Tesla, except for 2 patients on a Siemens Prisma 3 Tesla)
Is the timing of stimulus presentation and image acquisition clearly described and appropriate?No* (moderate limitation) (total images not stated; short ITI and minimal jitter)
Design typeEvent-related
Total images acquirednot stated
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) (unclear whether there was sufficient resting data to allow the key contrast to be computed)
Is intersubject normalization adequately described and appropriate?Yes
Imaging notes

Conditions

Are the conditions clearly described?Yes
ConditionResponse typeRepetitionsAll groups could do?All individuals could do?
picture naming (trained items)Word (overt)36UnknownUnknown
picture naming (untrained items, from control category)Word (overt)36UnknownUnknown
picture naming (untrained items, from experimental categories)Word (overt)36UnknownUnknown
viewing scrambled images and saying "skip"Word (overt)36UnknownUnknown
restNoneimplicit baselineN/AN/A
Conditions notesThe untrained group were not actually trained on "trained items"; no accuracy data for untrained group (except for lack of change between T1 and T2)

Contrasts

Are the contrasts clearly described?Yes

Contrast 1: picture naming (trained items) vs rest

Language conditionPicture naming (trained items)
Control conditionRest
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?No
Are activations lateralized in the control data?No
Control activation notesMost ROIs deactivated in controls
Contrast notes

Analyses

Are the analyses clearly described?Yes

ROI analysis 1

First level contrastPicture naming (trained items) vs rest
Analysis classCross-sectional aphasia vs control
Group(s)Aphasia treated T1 (n = 26) 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
Type of analysisRegions of interest (ROI)
ROI typeAnatomical
How many ROIs are there?16
What are the ROI(s)?(1) L IFGorb; (2) L IFGtri; (3) L IFGop; (4) L MFG; (5) L PrCG; (6) L MTG; (7) L SMG; (8) L AG; (9-16) homotopic counterparts
How are the ROI(s) defined?AAL but lesioned voxels were excluded from ROIs on an individual basis
Correction for multiple comparisonsNo correction
Statistical details
Findings↑ L IFG pars triangularis
↑ R IFG pars triangularis
↓ L angular gyrus
Findings notesSignificant interaction of ROI by group

ROI analysis 2

First level contrastPicture naming (trained items) vs rest
Analysis classCross-sectional aphasia vs control
Group(s)Aphasia treated T2 (n = 26) 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
Type of analysisRegions of interest (ROI)
ROI typeAnatomical
How many ROIs are there?16
What are the ROI(s)?(1) L IFGorb; (2) L IFGtri; (3) L IFGop; (4) L MFG; (5) L PrCG; (6) L MTG; (7) L SMG; (8) L AG; (9-16) homotopic counterparts
How are the ROI(s) defined?AAL but lesioned voxels were excluded from ROIs on an individual basis
Correction for multiple comparisonsNo correction
Statistical details
Findings↑ L IFG pars triangularis
↑ R IFG pars opercularis
↑ R IFG pars triangularis
Findings notesSignificant interaction of ROI by group; patients also showed more activity than controls across the average of all ROIs

ROI analysis 3

First level contrastPicture naming (trained items) vs rest
Analysis classLongitudinal change in aphasia
Group(s)Aphasia untreated (n = 10) 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?Yes, matched
Is reaction time matched across the second level contrast?Unknown, not reported
Behavioral data notes
Type of analysisRegions of interest (ROI)
ROI typeAnatomical
How many ROIs are there?16
What are the ROI(s)?(1) L IFGorb; (2) L IFGtri; (3) L IFGop; (4) L MFG; (5) L PrCG; (6) L MTG; (7) L SMG; (8) L AG; (9-16) homotopic counterparts
How are the ROI(s) defined?AAL but lesioned voxels were excluded from ROIs on an individual basis
Correction for multiple comparisonsNo correction
Statistical details
FindingsNone
Findings notesNo main effect of time or interaction of time by ROI

Complex analysis 1

First level contrastPicture naming (trained items) vs rest
Analysis classLongitudinal change in aphasia
Group(s)Aphasia treated (n = 26) 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?No, different
Is reaction time matched across the second level contrast?Unknown, not reported
Behavioral data notes
Type of analysisComplex
Statistical detailsA linear model was constructed to examine the relationship between proportion of spared tissue in each L hemisphere ROI and changes in activation over time. The model is not described in sufficient detail.
FindingsOther
Findings notesThere was a significant 3-way interaction of time by ROI by spared tissue, such that in some regions (AG, MFG, IFG orb, SMG), less spared tissue was associated with greater increases in activation, while in others (PrCG, IFG op, IFG tri), less spared tissue was associated with greater decreases in activation.

Notes

Excluded analyses(1) the treated group showed an increase in activation over time averaged across all ROIs, and a near-significant interaction of time by hemisphere such that greater increases were observed in the right hemisphere; (2) "responders" showed an increase in activation over time averaged across all ROIs, while "nonresponders" did not (excluded because not anatomically specific, but also note that the definition of responders vs nonresponders was somewhat arbitrary)