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Changes of right-hemispheric activation after constraint-induced, intensive language action therapy in chronic aphasia: fMRI evidence from auditory semantic processing.

Mohr B, Difrancesco S, Harrington K, Evans S, Pulvermüller F - Front Hum Neurosci (2014)

Bottom Line: All patients demonstrated significant clinical improvements of language functions after therapy.This activation increase was stronger for highly ambiguous sentences than for unambiguous ones.These results suggest that the known language improvements brought about by intensive constraint-induced language action therapy at least in part relies on circuits within the right-hemispheric homologs of left-perisylvian language areas, which are most strongly activated in the processing of semantically complex language.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychiatry, Charité Universitätsmedizin, Campus Benjamin Franklin Berlin, Germany.

ABSTRACT
The role of the two hemispheres in the neurorehabilitation of language is still under dispute. This study explored the changes in language-evoked brain activation over a 2-week treatment interval with intensive constraint induced aphasia therapy (CIAT), which is also called intensive language action therapy (ILAT). Functional magnetic resonance imaging (fMRI) was used to assess brain activation in perilesional left hemispheric and in homotopic right hemispheric areas during passive listening to high and low-ambiguity sentences and non-speech control stimuli in chronic non-fluent aphasia patients. All patients demonstrated significant clinical improvements of language functions after therapy. In an event-related fMRI experiment, a significant increase of BOLD signal was manifest in right inferior frontal and temporal areas. This activation increase was stronger for highly ambiguous sentences than for unambiguous ones. These results suggest that the known language improvements brought about by intensive constraint-induced language action therapy at least in part relies on circuits within the right-hemispheric homologs of left-perisylvian language areas, which are most strongly activated in the processing of semantically complex language.

No MeSH data available.


Related in: MedlinePlus

Lesion overlap map for patients who successfully underwent fMRI scanning before and after aphasia therapy. Color indicates the number of patients with damage at each voxel.
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Figure 1: Lesion overlap map for patients who successfully underwent fMRI scanning before and after aphasia therapy. Color indicates the number of patients with damage at each voxel.

Mentions: To obtain a lesion map identifying the sites of major damage in each patient's brain, damaged tissue was identified using the Automatic Lesion Identification (ALI) toolbox (Seghier et al., 2008). This method involves augmenting the standard generative model for unified segmentation (as implemented in SPM8) with an empirical prior for a “lesioned tissue class” that is optimized iteratively. Healthy gray and white matter tissue maps were established by segmenting structural brain images of a group of age matched neuro-typical individuals (60 individuals, mean = 61, min = 43, max = 75 years) taken from a wider reported corpus (Peelle, 2012). These healthy gray and white matter segmentations, following normalization and smoothing, were used as the basis for establishing outlier gray and white matter in the patient group (i.e., lesioned tissue) using a fuzzy clustering procedure. Individual binary lesion images were combined to create a lesion probability map, showing the spatial extent and anatomical overlap of lesions for the group of patients (see Figure 1). Across the patients, damage covered a number of key left-hemisphere language regions around and extending from the Sylvian fissure, including the inferior and middle frontal gyrus, inferior and superior temporal gyrus (STG), inferior parietal areas, hippocampus, and left insula. The damage also extended to underlying white matter, following the curve of the arcuate fasciculus.


Changes of right-hemispheric activation after constraint-induced, intensive language action therapy in chronic aphasia: fMRI evidence from auditory semantic processing.

Mohr B, Difrancesco S, Harrington K, Evans S, Pulvermüller F - Front Hum Neurosci (2014)

Lesion overlap map for patients who successfully underwent fMRI scanning before and after aphasia therapy. Color indicates the number of patients with damage at each voxel.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4231973&req=5

Figure 1: Lesion overlap map for patients who successfully underwent fMRI scanning before and after aphasia therapy. Color indicates the number of patients with damage at each voxel.
Mentions: To obtain a lesion map identifying the sites of major damage in each patient's brain, damaged tissue was identified using the Automatic Lesion Identification (ALI) toolbox (Seghier et al., 2008). This method involves augmenting the standard generative model for unified segmentation (as implemented in SPM8) with an empirical prior for a “lesioned tissue class” that is optimized iteratively. Healthy gray and white matter tissue maps were established by segmenting structural brain images of a group of age matched neuro-typical individuals (60 individuals, mean = 61, min = 43, max = 75 years) taken from a wider reported corpus (Peelle, 2012). These healthy gray and white matter segmentations, following normalization and smoothing, were used as the basis for establishing outlier gray and white matter in the patient group (i.e., lesioned tissue) using a fuzzy clustering procedure. Individual binary lesion images were combined to create a lesion probability map, showing the spatial extent and anatomical overlap of lesions for the group of patients (see Figure 1). Across the patients, damage covered a number of key left-hemisphere language regions around and extending from the Sylvian fissure, including the inferior and middle frontal gyrus, inferior and superior temporal gyrus (STG), inferior parietal areas, hippocampus, and left insula. The damage also extended to underlying white matter, following the curve of the arcuate fasciculus.

Bottom Line: All patients demonstrated significant clinical improvements of language functions after therapy.This activation increase was stronger for highly ambiguous sentences than for unambiguous ones.These results suggest that the known language improvements brought about by intensive constraint-induced language action therapy at least in part relies on circuits within the right-hemispheric homologs of left-perisylvian language areas, which are most strongly activated in the processing of semantically complex language.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychiatry, Charité Universitätsmedizin, Campus Benjamin Franklin Berlin, Germany.

ABSTRACT
The role of the two hemispheres in the neurorehabilitation of language is still under dispute. This study explored the changes in language-evoked brain activation over a 2-week treatment interval with intensive constraint induced aphasia therapy (CIAT), which is also called intensive language action therapy (ILAT). Functional magnetic resonance imaging (fMRI) was used to assess brain activation in perilesional left hemispheric and in homotopic right hemispheric areas during passive listening to high and low-ambiguity sentences and non-speech control stimuli in chronic non-fluent aphasia patients. All patients demonstrated significant clinical improvements of language functions after therapy. In an event-related fMRI experiment, a significant increase of BOLD signal was manifest in right inferior frontal and temporal areas. This activation increase was stronger for highly ambiguous sentences than for unambiguous ones. These results suggest that the known language improvements brought about by intensive constraint-induced language action therapy at least in part relies on circuits within the right-hemispheric homologs of left-perisylvian language areas, which are most strongly activated in the processing of semantically complex language.

No MeSH data available.


Related in: MedlinePlus