Compensatory Reorganization in
Recovery from Aphasia after Stroke
Bruce Crosson, Ph.D.
Brain Rehabilitation Research Center
Malcom Randall VA Medical Center
and
Department of Clinical & Health Psychology
University of Florida
Gainesville, Florida
Only published work or work presented at meetings is included in these slides.
Collaborators
Rehabilitation
Leslie Gonzalez Rothi, Ph.D.
Katherine S. Richards, M.S.
Christina E. Wierenga, M.S.
M. Allison Cato, Ph.D.
Flo Singletary, M.A.
Maribel Ciampiti, M.A.
Beth Holliway, M.A.
Amy Rodriguez, M.A.
Susan Leon, M.A.
Cynthia Beaulieu, Ph.D.
R. Bruce Parkinson, M.S.
Megan E. Gaiefsky, M.S.
Anastasia M. Raymer, Ph.D.
Lynn M. Maher, Ph.D.
Tim W. Conway, Ph.D.
NeuroImaging
Richard W. Briggs, Ph.D.
Keith D. White, Ph.D.
Anna Bacon Moore, Ph.D.
Megan Gaiefsky, M.S.
Kaundinya Gopinath, Ph.D.
Tim W. Conway, Ph.D.
K. K. Peck, Ph.D.
David Soltysik, Ph.D.
Christina Milsted
Michelle Benjamin, M.S.
Keith McGregor
R. Bruce Parkinson, M.S.
Ashley Wabnitz
Trista Perez
Yu-ling Chang, M.S.
Ashley Orynich
Funding Sources
NIDCD #P50 DC03888
Leslie J. Gonzalez Rothi, Center Director; Bruce Crosson and Richard
Briggs Imaging Core PIs
VA RR&D #F2182C
Leslie J. Gonzalez Rothi, Center Director; Bruce Crosson Imaging Core
Coordinator
VA RR&D #B3470S
Bruce Crosson, PI (Research Career Scientist)
VA RR&D #C2602V
Anna Moore, PI (Research Career Development Award)
VA RR&D ##B3480H
Tim W. Conway, PI (Associate Investigator Award)
Reorganization of Language in Aphasia:
Left or Right Hemisphere?
1. RECOVERY: Does reorganization of function
occur primarily in perilesional cortex of the
dominant hemisphere (left) or in the previously
nondominant (right) hemisphere?
2. REHAB: Does rehabilitation influence the
hemisphere to which language reorganizes?
Review from: Crosson, B. (in press). Functional neuroimaging of
impaired language: Aphasia. In Hillary & DeLuca (eds.) Functional
Neuroimaging in Clinical Populations. New York: Guilford.
RECOVERY REVIEW
Conclusion #1
Good Recovery: small lesions, greater perilesional than righthemisphere reorganization
Poor Recovery: large lesions, greater right-hemisphere than
perilesional reorganization
References: Cao et al., 1999; Heiss et al., 1997, 1999; Karbe et al.,
1998; Perani et al., 2003; Rosen et al., 2000
Sentence Generation: 4 Patients with Syntactic Impairments
M62
F15
L
L
R
R
M10
L
M31
L
R
McGregor et al., POSTER: 11 – 12:30 Saturday
R
RECOVERY REVIEW
Conclusion #2
Shifts to right-hemisphere homologues of damaged left-hemisphere
areas
References: Blank et al., 2003; Calvert et al., 2000; Lazar et al., 2000;
Thulborn, 1999; Weiller et al., 1995).
RECOVERY REVIEW
Conclusion #3
Role of Intention / Attention Mechanisms in Reorganization
Anterior lesion with intact basal ganglia: Reorganization of language
production to the right frontal lobe
Anterior + basal ganglia lesion: Bilateral frontal activity during
language production
Reference: (Kim et al., 2002).
Lesions: S01 and S02
S01
S02
Caudate
Putamen
Thalamus
L
L
Crosson et al. (2005) Journal of Cognitive Neuroscience
Activity (fMRI Task: Event-Related Word Generation)
(Using Selective Detrending)
Activity Volume (microliters)
2000
S01: Basal
Ganglia
Lesion
S02: No
Basal Ganglia
Lesion
1500
1000
Left
Right
500
0
pre-SMA
Lateral
Frontal
pre-SMA
Lateral
Frontal
Crosson et al. (2005) Journal of Cognitive Neuroscience
REHABILITATION REVIEW
Conclusion #1
Treatment outcome affected by lesion size and location
Correlations between Naming Improvement
and Basal Ganglia Lesion Extent:
Partial Correlations Controlling for Anterior Cortical Lesion Extent
r
p
Object naming improvement vs. basal
ganglia (N=13)
-.749
.005
Action naming improvement vs. basal
ganglia (N=12)
-.785
.004
Parkinson et al., POSTER: 11 – 12:30 Saturday
Hypotheses about Basal Ganglia
Basal ganglia involved in suppression of behavior / cognition
Damaged anterior language production mechanisms produce
noisy output, hampering production
Intact basal ganglia suppress noisy output
Correlations between Naming Improvement and Cortical Lesion Extent:
Partial Correlation Controlling for Basal Ganglia Lesion Extent
r
Anterior lesion vs.
object naming
improvement (N=13)
Anterior lesion vs.
action naming
improvement (N=12)
p
.858
<.0005
.821
.002
Parkinson et al., POSTER: 11 – 12:30 Saturday
Critical Cortex Lesion Size and Perilesional Activity
Large Lesion
Chronic
Aphasia
Cases
Perilesional Activity Impossible:
R Hemisphere Best Substrate
Perilesional Activity “Noisy”
Competes with R Hemisphere
Perilesional Reorganization Optimal:
L Hemisphere Best Substrate
Small Lesion
REHABILITATION REVIEW
Conclusion #2
It may be possible to influence the hemisphere in which
language functions are performed through treatment
00-008: Pre- and Post-Tx Images
Frontal Activity
Before Training
RIGHT
LEFT
After Training
RIGHT
LEFT
Crosson et al. (2005) Journal of Cognitive Neuroscience
REHABILITATION REVIEW
Conclusion #3
“Activity” during fMRI does not signify contribution to language
It might even be detrimental
References: Martin et al., 2004; Naeser et al., 2005; Rosen et al.,
2000
REHABILITATION REVIEW
Conclusion #4
Activity in right-hemisphere homologues of damaged lefthemisphere language cortex can be critical for rehabilitation
Reference: Musso et al., 1999
REHABILITATION REVIEW
Conclusion #5
Reactivating intact left-hemisphere language cortex can
also be critical in rehabilitation
Syntactic Mapping Treatment
(fMRI Task: Active Sentence Generation from Picture)
G01 Outcome:
Improved word order
in sentences with
generalization to
narrative sample
X = -40
X = -52
J02 Outcome:
Improved word order
in sentences with no
generalization to
narrative sample
G01 Post-Treatment
G01 Pre-Treatment
Medial
Lateral
X = -45
J02 Pre-Treatment
Medial
Lateral
J02 Post-Treatment
X = -47
X = -56
X = -36
Lateral
X = -48
Medial
X = -54
Medial
Lateral
Wierenga et al. (in press) Journal of the International
Neuropsychological Society
Phonological Rehabilitation (Nonsense Syllable Repetition)
PRE
POST
Right
Auditory
BA 42
Left
Auditory
BA42
Chang et al., POSTER: 9 – 10:30 Friday
Take Home Messages
1. Both the left and right hemispheres participate in
recovery from and rehabilitation for aphasia. The
degree of right vs. left participation depends on
the patient, the size of the lesion, the location of
the lesion, and the language function in question.
2. It may be possible to manipulate intentional
mechanisms to change the hemisphere from
which language production is performed if that is
desirable.
3. Activity in a structure (in the left or right
hemisphere) during functional neuroimaging
tasks does not mean it is making a positive
contribution to performance.
Posters, bibliography, and slides of completed work at
www.BIRC.phhp.ufl.edu