Limits...
EEG hyper-connectivity in high-risk infants is associated with later autism.

Orekhova EV, Elsabbagh M, Jones EJ, Dawson G, Charman T, Johnson MH, BASIS Te - J Neurodev Disord (2014)

Bottom Line: As a group, high-risk infants who were later diagnosed with ASD demonstrated elevated phase-lagged alpha-range connectivity as compared to both low-risk infants and high-risk infants who did not go on to ASD.These effects were not attributable to differences in behavior during the EEG session or to differences in spectral power.The results suggest that early hyper-connectivity in the alpha frequency range is an important feature of the ASD neurophysiological phenotype.

View Article: PubMed Central - PubMed

Affiliation: Centre for Brain and Cognitive Development, School of Psychology, Birkbeck, University of London, Henry Welcome Building, London, WC1E 7HX UK.

ABSTRACT

Background: It has been previously reported that structural and functional brain connectivity in individuals with autism spectrum disorders (ASD) is atypical and may vary with age. However, to date, no measures of functional connectivity measured within the first 2 years have specifically associated with a later ASD diagnosis.

Methods: In the present study, we analyzed functional brain connectivity in 14-month-old infants at high and low familial risk for ASD using electroencephalography (EEG). EEG was recorded while infants attended to videos. Connectivity was assessed using debiased weighted phase lag index (dbWPLI). At 36 months, the high-risk infants were assessed for symptoms of ASD.

Results: As a group, high-risk infants who were later diagnosed with ASD demonstrated elevated phase-lagged alpha-range connectivity as compared to both low-risk infants and high-risk infants who did not go on to ASD. Hyper-connectivity was most prominent over frontal and central areas. The degree of hyper-connectivity at 14 months strongly correlated with the severity of restricted and repetitive behaviors in participants with ASD at 3 years. These effects were not attributable to differences in behavior during the EEG session or to differences in spectral power.

Conclusions: The results suggest that early hyper-connectivity in the alpha frequency range is an important feature of the ASD neurophysiological phenotype.

No MeSH data available.


Related in: MedlinePlus

Group differences in alpha-range connectivity between HR-ASD (N= 10) and comparison groups (LR,N= 26; HR-no-ASD,N= 18). (A) Networks of increased connections in infants with ASD. NBS showed significantly higher functional connectivity in HR-ASD infants as compared to both LR and HR-no-ASD infants. The nodes (electrodes) and edges of the hyper-connected networks are loosely modeled on the standard brain image. (B) Overlap of the NBS clusters of the elevated connections revealed by HR-ASD vs. LR and HR-ASD vs. HR-no-ASD comparisons. (C) Difference between numbers of connections elevated (Mann-Whitney, P < 0.05, uncorrected) in the HR-ASD group and in comparison groups. Positive values correspond to a greater number of elevated connections in HR-ASD infants than in the comparison groups. Negative values correspond to a greater number of elevated connections in the comparison groups. Note clustering of over-connected sites over fronto-central regions.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4232695&req=5

Fig2: Group differences in alpha-range connectivity between HR-ASD (N= 10) and comparison groups (LR,N= 26; HR-no-ASD,N= 18). (A) Networks of increased connections in infants with ASD. NBS showed significantly higher functional connectivity in HR-ASD infants as compared to both LR and HR-no-ASD infants. The nodes (electrodes) and edges of the hyper-connected networks are loosely modeled on the standard brain image. (B) Overlap of the NBS clusters of the elevated connections revealed by HR-ASD vs. LR and HR-ASD vs. HR-no-ASD comparisons. (C) Difference between numbers of connections elevated (Mann-Whitney, P < 0.05, uncorrected) in the HR-ASD group and in comparison groups. Positive values correspond to a greater number of elevated connections in HR-ASD infants than in the comparison groups. Negative values correspond to a greater number of elevated connections in the comparison groups. Note clustering of over-connected sites over fronto-central regions.

Mentions: For the HR-ASD vs. LR group comparison, the NBS identified one widespread pairwise cluster of hyper-connected regions in the HR-ASD group (N of nodes = 108, N of edges = 609, P = 0.035, Figure 2A; see also Additional file 2: Figure S5). A similar result was obtained for the HR-ASD vs. HR-no-ASD comparison (N of nodes = 113, N of edges = 841, P = 0.015, Figure 2A). When the analysis was repeated separately for the ‘social’ and ‘nonsocial’ videos, similar NBS results were obtained, suggesting that alpha hyper-connectivity occurs in infants that go on to ASD regardless of the type of video presented (see Additional file 2: Figure S6). The connections that were elevated in infants with ASD in relation to both LR and HR-no-ASD infants are plotted in Figure 2B. The electrodes with the greatest number of elevated connections were located in left fronto-central and right fronto-centro-temporal regions (Figure 2C).Figure 2


EEG hyper-connectivity in high-risk infants is associated with later autism.

Orekhova EV, Elsabbagh M, Jones EJ, Dawson G, Charman T, Johnson MH, BASIS Te - J Neurodev Disord (2014)

Group differences in alpha-range connectivity between HR-ASD (N= 10) and comparison groups (LR,N= 26; HR-no-ASD,N= 18). (A) Networks of increased connections in infants with ASD. NBS showed significantly higher functional connectivity in HR-ASD infants as compared to both LR and HR-no-ASD infants. The nodes (electrodes) and edges of the hyper-connected networks are loosely modeled on the standard brain image. (B) Overlap of the NBS clusters of the elevated connections revealed by HR-ASD vs. LR and HR-ASD vs. HR-no-ASD comparisons. (C) Difference between numbers of connections elevated (Mann-Whitney, P < 0.05, uncorrected) in the HR-ASD group and in comparison groups. Positive values correspond to a greater number of elevated connections in HR-ASD infants than in the comparison groups. Negative values correspond to a greater number of elevated connections in the comparison groups. Note clustering of over-connected sites over fronto-central regions.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4232695&req=5

Fig2: Group differences in alpha-range connectivity between HR-ASD (N= 10) and comparison groups (LR,N= 26; HR-no-ASD,N= 18). (A) Networks of increased connections in infants with ASD. NBS showed significantly higher functional connectivity in HR-ASD infants as compared to both LR and HR-no-ASD infants. The nodes (electrodes) and edges of the hyper-connected networks are loosely modeled on the standard brain image. (B) Overlap of the NBS clusters of the elevated connections revealed by HR-ASD vs. LR and HR-ASD vs. HR-no-ASD comparisons. (C) Difference between numbers of connections elevated (Mann-Whitney, P < 0.05, uncorrected) in the HR-ASD group and in comparison groups. Positive values correspond to a greater number of elevated connections in HR-ASD infants than in the comparison groups. Negative values correspond to a greater number of elevated connections in the comparison groups. Note clustering of over-connected sites over fronto-central regions.
Mentions: For the HR-ASD vs. LR group comparison, the NBS identified one widespread pairwise cluster of hyper-connected regions in the HR-ASD group (N of nodes = 108, N of edges = 609, P = 0.035, Figure 2A; see also Additional file 2: Figure S5). A similar result was obtained for the HR-ASD vs. HR-no-ASD comparison (N of nodes = 113, N of edges = 841, P = 0.015, Figure 2A). When the analysis was repeated separately for the ‘social’ and ‘nonsocial’ videos, similar NBS results were obtained, suggesting that alpha hyper-connectivity occurs in infants that go on to ASD regardless of the type of video presented (see Additional file 2: Figure S6). The connections that were elevated in infants with ASD in relation to both LR and HR-no-ASD infants are plotted in Figure 2B. The electrodes with the greatest number of elevated connections were located in left fronto-central and right fronto-centro-temporal regions (Figure 2C).Figure 2

Bottom Line: As a group, high-risk infants who were later diagnosed with ASD demonstrated elevated phase-lagged alpha-range connectivity as compared to both low-risk infants and high-risk infants who did not go on to ASD.These effects were not attributable to differences in behavior during the EEG session or to differences in spectral power.The results suggest that early hyper-connectivity in the alpha frequency range is an important feature of the ASD neurophysiological phenotype.

View Article: PubMed Central - PubMed

Affiliation: Centre for Brain and Cognitive Development, School of Psychology, Birkbeck, University of London, Henry Welcome Building, London, WC1E 7HX UK.

ABSTRACT

Background: It has been previously reported that structural and functional brain connectivity in individuals with autism spectrum disorders (ASD) is atypical and may vary with age. However, to date, no measures of functional connectivity measured within the first 2 years have specifically associated with a later ASD diagnosis.

Methods: In the present study, we analyzed functional brain connectivity in 14-month-old infants at high and low familial risk for ASD using electroencephalography (EEG). EEG was recorded while infants attended to videos. Connectivity was assessed using debiased weighted phase lag index (dbWPLI). At 36 months, the high-risk infants were assessed for symptoms of ASD.

Results: As a group, high-risk infants who were later diagnosed with ASD demonstrated elevated phase-lagged alpha-range connectivity as compared to both low-risk infants and high-risk infants who did not go on to ASD. Hyper-connectivity was most prominent over frontal and central areas. The degree of hyper-connectivity at 14 months strongly correlated with the severity of restricted and repetitive behaviors in participants with ASD at 3 years. These effects were not attributable to differences in behavior during the EEG session or to differences in spectral power.

Conclusions: The results suggest that early hyper-connectivity in the alpha frequency range is an important feature of the ASD neurophysiological phenotype.

No MeSH data available.


Related in: MedlinePlus