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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

Probability of group differences as a function of between-electrode distance.Ordinate: Z-scores, Mann-Whitney U-test; abscissa: Euclidian distance between electrodes, where 1 corresponds to the maximal possible distance. Each pair of electrodes is represented by a dot. Red dots show Z values higher or lower then 1.96 (P < 0.05, two-tailed). For both HR-ASD (N = 10) vs. LR (N = 26) (left panel) and HR-ASD (N = 18) vs. HR-no-ASD (N = 18) (right panel) comparisons, the increased connectivity values in the HR-ASD group are observed irrespective of inter-electrode distance.
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Fig3: Probability of group differences as a function of between-electrode distance.Ordinate: Z-scores, Mann-Whitney U-test; abscissa: Euclidian distance between electrodes, where 1 corresponds to the maximal possible distance. Each pair of electrodes is represented by a dot. Red dots show Z values higher or lower then 1.96 (P < 0.05, two-tailed). For both HR-ASD (N = 10) vs. LR (N = 26) (left panel) and HR-ASD (N = 18) vs. HR-no-ASD (N = 18) (right panel) comparisons, the increased connectivity values in the HR-ASD group are observed irrespective of inter-electrode distance.

Mentions: It has been previously suggested that children with ASD have a decreased long-to-short EEG connectivity ratio [49]. To check whether the hyper-connectivity in the HR-ASD group was due to short- or long-range connections, we plotted the probability of group differences in connectivity (Z-scores, Mann-Whitney U-test) as a function of between-electrode Euclidian distance (Figure 3). Inspection of the plots indicates that increased connectivity in the HR-ASD group does not depend on scalp electrode distances (see also Additional file 2: Figure S10).Figure 3


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)

Probability of group differences as a function of between-electrode distance.Ordinate: Z-scores, Mann-Whitney U-test; abscissa: Euclidian distance between electrodes, where 1 corresponds to the maximal possible distance. Each pair of electrodes is represented by a dot. Red dots show Z values higher or lower then 1.96 (P < 0.05, two-tailed). For both HR-ASD (N = 10) vs. LR (N = 26) (left panel) and HR-ASD (N = 18) vs. HR-no-ASD (N = 18) (right panel) comparisons, the increased connectivity values in the HR-ASD group are observed irrespective of inter-electrode distance.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Fig3: Probability of group differences as a function of between-electrode distance.Ordinate: Z-scores, Mann-Whitney U-test; abscissa: Euclidian distance between electrodes, where 1 corresponds to the maximal possible distance. Each pair of electrodes is represented by a dot. Red dots show Z values higher or lower then 1.96 (P < 0.05, two-tailed). For both HR-ASD (N = 10) vs. LR (N = 26) (left panel) and HR-ASD (N = 18) vs. HR-no-ASD (N = 18) (right panel) comparisons, the increased connectivity values in the HR-ASD group are observed irrespective of inter-electrode distance.
Mentions: It has been previously suggested that children with ASD have a decreased long-to-short EEG connectivity ratio [49]. To check whether the hyper-connectivity in the HR-ASD group was due to short- or long-range connections, we plotted the probability of group differences in connectivity (Z-scores, Mann-Whitney U-test) as a function of between-electrode Euclidian distance (Figure 3). Inspection of the plots indicates that increased connectivity in the HR-ASD group does not depend on scalp electrode distances (see also Additional file 2: Figure S10).Figure 3

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