Aphasia Neuroplasticity Review

Cao et al. (1999)

Reference

AuthorsCao Y, Vikingstad EM, George KP, Johnson AF, Welch KM
TitleCortical language activation in stroke patients recovering from aphasia with functional MRI
ReferenceStroke 1999; 30: 2331-2340
PMID10548667
DOI10.1161/01.str.30.11.2331

Participants

LanguageUS English
Inclusion criteriaAphasia with significant recovery over months to years (ADPASS > 70th percentile)
Number of individuals with aphasia6 (plus 2 excluded: 1 unable to reliably describe performance post-scan; 1 due to head motion)
Number of control participants37
Were any of the participants included in any previous studies?No
Is age reported for patients and controls, and matched?Yes (range 20-56 years)
Is sex reported for patients and controls, and matched?Yes (males: 1; females: 5)
Is handedness reported for patients and controls, and matched?Yes (right: 6; left: 0)
Is time post stroke onset reported and appropriate to the study design?Yes (range 5-32 months)
To what extent is the nature of aphasia characterized?Severity and type
Language evaluationADP
Aphasia severityADPASS percentile range 73-99
Aphasia type3 anomic, 1 conduction, 1 recovered, 1 transcortical sensory
First stroke only?Yes
Stroke typeIschemic only
To what extent is the lesion distribution characterized?Individual lesions
Lesion extentExtents are reported in three dimensions
Lesion location4 L MCA, 2 L ICA
Participants notes

Imaging

ModalityfMRI
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 (Magnex Scientific 3 Tesla)
Is the timing of stimulus presentation and image acquisition clearly described and appropriate?Yes
Design typeBlock
Total images acquired40
Are the imaging acquisition parameters, including coverage, adequately described and appropriate?Yes (axial, perisylvian only)
Is preprocessing and intrasubject coregistration adequately described and appropriate?Yes
Is first level model fitting adequately described and appropriate?No (first level cross-correlation analysis unclear)
Is intersubject normalization adequately described and appropriate?N/A—no intersubject normalization
Imaging notes

Conditions

Are the conditions clearly described?Yes
ConditionResponse typeRepetitionsAll groups could do?All individuals could do?
picture namingWord (covert)4YesYes
viewing nonsense drawingsNone4N/AN/A
Conditions notes

Contrasts

Are the contrasts clearly described?Yes

Contrast 1: picture naming vs viewing nonsense drawings

Language conditionPicture naming
Control conditionViewing nonsense drawings
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?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?Somewhat
Control activation notesInsufficient data to assess the control activation pattern
Contrast notes

Analyses

Are the analyses clearly described?Yes

ROI analysis 1

First level contrastPicture naming vs viewing nonsense drawings
Analysis classCross-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?Unknown, not reported
Is reaction time matched across the second level contrast?Unknown, not reported
Behavioral data notes
Type of analysisRegions of interest (ROI)
ROI typeMixed
How many ROIs are there?6
What are the ROI(s)?(1) L IFG and MFG; (2) L pSTG, AG and SMG; (3) R IFG and MFG; (4) R pSTG, AG and SMG; (5) frontal LI; (6) temporal LI
How are the ROI(s) defined?(1-4) individual anatomical images; activation quantified in terms of extent
Correction for multiple comparisonsNo correction
Statistical details
Findings↑ R IFG
↑ R dorsolateral prefrontal cortex
↑ R supramarginal gyrus
↑ R angular gyrus
↑ R posterior STG
↓ LI (frontal)
↓ LI (temporal)
Findings notes

ROI analysis 2

First level contrastPicture naming vs viewing nonsense drawings
Analysis classCross-sectional correlation with language or other measure
Group(s)Aphasia
CovariatePicture naming (outside scanner)
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 analysisRegions of interest (ROI)
ROI typeMixed
How many ROIs are there?6
What are the ROI(s)?(1) L IFG and MFG; (2) L pSTG, AG and SMG; (3) R IFG and MFG; (4) R pSTG, AG and SMG; (5) frontal LI; (6) temporal LI
How are the ROI(s) defined?(1-4) individual anatomical images; activation quantified in terms of extent
Correction for multiple comparisonsNo correction
Statistical details
Findings↑ LI (frontal)
Findings notes

Notes

Excluded analyses(1) verb generation study with n = 4 patients; (2) individual patient results; (3) whole brain and whole hemisphere activation measures