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White matter impairment in the speech network of individuals with autism spectrum disorder.

Peeva MG, Tourville JA, Agam Y, Holland B, Manoach DS, Guenther FH - Neuroimage Clin (2013)

Bottom Line: We found a weaker connection between the left vPMC and the supplementary motor area in the ASD group.This pathway has been hypothesized to underlie the initiation of speech motor programs.Therapies that result in normalization of this pathway may hold particular promise for improving speech output in ASD.

View Article: PubMed Central - PubMed

Affiliation: Center for Computational Neuroscience and Neural Technology, Boston University, 677 Beacon Street, Boston, MA 02215, USA.

ABSTRACT
Impairments in language and communication are core features of Autism Spectrum Disorder (ASD), and a substantial percentage of children with ASD do not develop speech. ASD is often characterized as a disorder of brain connectivity, and a number of studies have identified white matter impairments in affected individuals. The current study investigated white matter integrity in the speech network of high-functioning adults with ASD. Diffusion tensor imaging (DTI) scans were collected from 18 participants with ASD and 18 neurotypical participants. Probabilistic tractography was used to estimate the connection strength between ventral premotor cortex (vPMC), a cortical region responsible for speech motor planning, and five other cortical regions in the network of areas involved in speech production. We found a weaker connection between the left vPMC and the supplementary motor area in the ASD group. This pathway has been hypothesized to underlie the initiation of speech motor programs. Our results indicate that a key pathway in the speech production network is impaired in ASD, and that this impairment can occur even in the presence of normal language abilities. Therapies that result in normalization of this pathway may hold particular promise for improving speech output in ASD.

No MeSH data available.


Related in: MedlinePlus

Individual examples of the left SMA–vPMC tract. The connection distribution of the SMA–vPMC tract is illustrated for 5 NT participants (left column) and 5 ASD participants (right column). Lighter shades represent voxels with more successful streamlines passing through them (see Methods for details). For each subject, the Y coordinate was chosen to highlight the largest cross-section of the tract. L: left hemisphere. R: right hemisphere. Y: location of the slice along the anterior–posterior axis of the Montreal Neurological Institute coordinate frame.
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f0010: Individual examples of the left SMA–vPMC tract. The connection distribution of the SMA–vPMC tract is illustrated for 5 NT participants (left column) and 5 ASD participants (right column). Lighter shades represent voxels with more successful streamlines passing through them (see Methods for details). For each subject, the Y coordinate was chosen to highlight the largest cross-section of the tract. L: left hemisphere. R: right hemisphere. Y: location of the slice along the anterior–posterior axis of the Montreal Neurological Institute coordinate frame.

Mentions: Table 3 provides mean tract strengths for the ASD and NT groups, along with p values for differences in tract strengths between the groups. Of the 10 tracks analyzed, only the tract between left SMA and left vPMC showed a significant between-group difference in tract strength, with the ASD group having a weaker tract strength between these regions. A MANOVA comparing head motion parameters between the two groups found no significant difference (Wilks' Λ = 0.737; p = 0.150), indicating that the difference in the left SMA–vPMC tract strength was unlikely to be the result of motion artifacts. Fig. 2 shows the left SMA–vPMC tract for 5 subjects from each group (randomly chosen) to give a sense of variability across individuals.


White matter impairment in the speech network of individuals with autism spectrum disorder.

Peeva MG, Tourville JA, Agam Y, Holland B, Manoach DS, Guenther FH - Neuroimage Clin (2013)

Individual examples of the left SMA–vPMC tract. The connection distribution of the SMA–vPMC tract is illustrated for 5 NT participants (left column) and 5 ASD participants (right column). Lighter shades represent voxels with more successful streamlines passing through them (see Methods for details). For each subject, the Y coordinate was chosen to highlight the largest cross-section of the tract. L: left hemisphere. R: right hemisphere. Y: location of the slice along the anterior–posterior axis of the Montreal Neurological Institute coordinate frame.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3815014&req=5

f0010: Individual examples of the left SMA–vPMC tract. The connection distribution of the SMA–vPMC tract is illustrated for 5 NT participants (left column) and 5 ASD participants (right column). Lighter shades represent voxels with more successful streamlines passing through them (see Methods for details). For each subject, the Y coordinate was chosen to highlight the largest cross-section of the tract. L: left hemisphere. R: right hemisphere. Y: location of the slice along the anterior–posterior axis of the Montreal Neurological Institute coordinate frame.
Mentions: Table 3 provides mean tract strengths for the ASD and NT groups, along with p values for differences in tract strengths between the groups. Of the 10 tracks analyzed, only the tract between left SMA and left vPMC showed a significant between-group difference in tract strength, with the ASD group having a weaker tract strength between these regions. A MANOVA comparing head motion parameters between the two groups found no significant difference (Wilks' Λ = 0.737; p = 0.150), indicating that the difference in the left SMA–vPMC tract strength was unlikely to be the result of motion artifacts. Fig. 2 shows the left SMA–vPMC tract for 5 subjects from each group (randomly chosen) to give a sense of variability across individuals.

Bottom Line: We found a weaker connection between the left vPMC and the supplementary motor area in the ASD group.This pathway has been hypothesized to underlie the initiation of speech motor programs.Therapies that result in normalization of this pathway may hold particular promise for improving speech output in ASD.

View Article: PubMed Central - PubMed

Affiliation: Center for Computational Neuroscience and Neural Technology, Boston University, 677 Beacon Street, Boston, MA 02215, USA.

ABSTRACT
Impairments in language and communication are core features of Autism Spectrum Disorder (ASD), and a substantial percentage of children with ASD do not develop speech. ASD is often characterized as a disorder of brain connectivity, and a number of studies have identified white matter impairments in affected individuals. The current study investigated white matter integrity in the speech network of high-functioning adults with ASD. Diffusion tensor imaging (DTI) scans were collected from 18 participants with ASD and 18 neurotypical participants. Probabilistic tractography was used to estimate the connection strength between ventral premotor cortex (vPMC), a cortical region responsible for speech motor planning, and five other cortical regions in the network of areas involved in speech production. We found a weaker connection between the left vPMC and the supplementary motor area in the ASD group. This pathway has been hypothesized to underlie the initiation of speech motor programs. Our results indicate that a key pathway in the speech production network is impaired in ASD, and that this impairment can occur even in the presence of normal language abilities. Therapies that result in normalization of this pathway may hold particular promise for improving speech output in ASD.

No MeSH data available.


Related in: MedlinePlus