Aphasia Neuroplasticity Review

Rosen et al. (2000)

Reference

AuthorsRosen HJ, Petersen SE, Linenweber MR, Snyder AZ, White DA, Chapman L, Dromerick AW, Fiez JA, Corbetta M
TitleNeural correlates of recovery from aphasia after damage to left inferior frontal cortex
ReferenceNeurology 2000; 55: 1883-1894
PMID11134389
DOI10.1212/wnl.55.12.1883

Participants

LanguageUS English
Inclusion criteriaL IFG, possibly extending to neighboring regions
Number of individuals with aphasia6
Number of control participants14
Were any of the participants included in any previous studies?Yes (1 participant was reported in a previous case study)
Is age reported for patients and controls, and matched?No (mean 47 years, range 32-72 years; control participants not age-matched)
Is sex reported for patients and controls, and matched?Yes (males: 3; females: 3)
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 0.5-7.6 years)
To what extent is the nature of aphasia characterized?Severity and type
Language evaluationWAB (except BDAE in 1 patient), reading pseudowords, word stem completion, verb generation, reading single words
Aphasia severityAQ range 74-97 (missing in 1 patient)
Aphasia type3 anomic, 1 Broca's, 1 not stated, 1 recovered
First stroke only?Yes
Stroke typeNot stated
To what extent is the lesion distribution characterized?Individual lesions
Lesion extentRange 10.7-117.5 cc
Lesion locationL IFG, extending to neighboring areas in most cases
Participants notesOf the 14 controls, 6 were studied with PET and 8 with fMRI

Imaging

ModalityPET and 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 961 EXACT HR; Siemens Vision 1.5 Tesla)
Is the timing of stimulus presentation and image acquisition clearly described and appropriate?No (fMRI timing description is inconsistent)
Design typeMixed
Total images acquiredPET: 10; fMRI: 384-768
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 notes1 patient scanned on different PET scanner, and not scanned with fMRI; controls had different fMRI sequence to patients

Conditions

Are the conditions clearly described?Yes
ConditionResponse typeRepetitionsAll groups could do?All individuals could do?
word stem completion (PET)Word (overt)4YesYes
reading pseudowords aloud (PET)Word (overt)4YesNo
rest (PET)None2N/AN/A
word stem completion (fMRI)Word (covert)15-30 (?)YesYes
rest (fMRI)None15-30 (?)N/AN/A
Conditions notesPseudoword reading condition not analyzed in this paper

Contrasts

Are the contrasts clearly described?Yes

Contrast 1: word stem completion (PET) vs rest (PET)

Language conditionWord stem completion (PET)
Control conditionRest (PET)
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?Yes
Control activation notesL IFG, L ITG, L anterior fusiform
Contrast notes

Contrast 2: word stem completion (fMRI) vs rest (fMRI)

Language conditionWord stem completion (fMRI)
Control conditionRest (fMRI)
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?Somewhat
Are activations lateralized in the control data?Yes
Control activation notesL IFG, L intraparietal sulcus
Contrast notes

Analyses

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

Voxelwise analysis 1

First level contrastWord stem completion (PET) vs rest (PET)
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?No, different
Is reaction time matched across the second level contrast?Yes, matched
Behavioral data notes
Type of analysisVoxelwise
Search volumeWhole brain
Correction for multiple comparisonsUnclear or not stated
Softwarenot stated
Voxelwise p
Cluster extent
Statistical detailsCorrection for multiple comparisons unclear; there may be circularity in only correcting for the number of regions that seemed to show differences
Findings↑ L SMA/medial prefrontal
↑ R IFG
↑ R Heschl's gyrus
↓ L IFG
Findings notes

Voxelwise analysis 2

First level contrastWord stem completion (fMRI) vs rest (fMRI)
Analysis classCross-sectional aphasia vs control
Group(s)Aphasia (n = 5) 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 analysisVoxelwise
Search volumeWhole brain
Correction for multiple comparisonsNo direct comparison
Softwarenot stated
Voxelwise p
Cluster extent
Statistical detailsQualitative comparison on p. 1888
Findings↑ R IFG
↓ L IFG
Findings notes

ROI analysis 1

First level contrastWord stem completion (fMRI) vs rest (fMRI)
Analysis classCross-sectional aphasia vs control
Group(s)Aphasia (n = 5) 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 typeFunctional
How many ROIs are there?2
What are the ROI(s)?(1) R IFG; (2) SMA
How are the ROI(s) defined?Not stated but seem to be functional
Correction for multiple comparisonsNo correction
Statistical detailsPossibly circular because not clear how ROIs defined
Findings↑ R IFG
Findings notes

Notes

Excluded analyses(1) the authors also observe that the two patients with the best language outcomes retained perilesional activation in the L IFG; (2) two non-significant correlational analyses involving only 5 patients, but note that the main fMRI analyses have been included even though n = 5