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Abstract:
Recruitment of spared left- and/or right-hemisphere areas are
considered primary candidates for language recovery in aphasia
(Heiss et al., 1999; Musso et al., 1999; Weiller, 1995). No
studies, however, have examined the neural correlates of recovery
of specific language functions resulting from treatment. In this
study, six right-handed patients with agrammatic aphasia secondary
to a single left MCA stroke served as subjects. Two patients
underwent 20 weeks of treatment resulting in improved production
and comprehension of syntactically simple and complex sentences.
FMRI studies of sentence comprehension were completed pre- and
post-treatment. The other four patients served as controls; one
received repeat fMRI scans at five-month intervals. The fMRI task
required matching pictures to auditorily presented object- and
subject-cleft sentences and single words. Thirty-two contiguous
4-mm axial slices were obtained using whole-brain echo-planar
imaging and analyzed using SPM96. Pre-treatment scans showed
activation of the right-homologue of Wernicke's area (BA 22) and BA
46 for Subject 1 under sentence versus word conditions; Subject 2
showed activation in the right and left angular gyri.
Post-treatment, activation in the right-homologues of Broca's area
(BA 44, 45), Wernicke's area and adjacent cortex (BA 22, 21, 37)
was noted for both subjects; Subject 2 also recruited spared
left-perisylvian areas. Control subjects showed no changes on
repeat behavioral testing or fMRI scans. (Supported by
McDonnell-Pew Foundation; NIH grants DC01948, NS30863).
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