scholarly journals Quasi-periodic patterns of brain activity in individuals with Attention-Deficit/Hyperactivity Disorder

2018 ◽  
Author(s):  
Anzar Abbas ◽  
Yasmine Bassil ◽  
Shella Keilholz
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Functional Connectivity ◽  
Attention Deficit ◽  
Brain Activity ◽  
Spatiotemporal Pattern ◽  
Periodic Patterns ◽  
Default Mode ◽  
Analysis Techniques ◽  
Hyperactivity Disorder ◽  
And Task

Individuals with attention-deficit/hyperactivity disorder have been shown to have disrupted functional connectivity in the default mode and task positive networks. Traditional fMRI analysis techniques that focus on static changes in functional connectivity have been successful in identifying differences between healthy controls and individuals with ADHD. However, such analyses are unable to explain the mechanisms behind the functional connectivity differences observed. Here, we study dynamic changes in functional connectivity in individuals with ADHD through investigation of quasi-periodic patterns (QPPs). QPPs are reliably recurring low-frequency spatiotemporal patterns in the brain linked to infra-slow electrical activity. They have been shown to contribute to functional connectivity observed through static analysis techniques. We find that QPPs contribute to functional connectivity specifically in regions that are disrupted during ADHD. Individuals with ADHD also show differences in the spatiotemporal pattern observed within the QPPs. This difference results in a weaker contribution of QPPs to functional connectivity in the default mode and task positive networks. We conclude that quasi-periodic patterns provide insight into the mechanisms behind functional connectivity differences seen in individuals with ADHD. This allows for a better understanding of the etiology of the disorder and development of effective treatments.

Brain development in attention deficit hyperactivity disorder: A neuroimaging perspective review

2016 ◽  
Vol 33 (S1) ◽  
pp. S357-S357 ◽  
Author(s):  
V. Pereira ◽  
P. de Castro-Manglano ◽  
C. Soutullo Esperon
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Functional Connectivity ◽  
Brain Development ◽  
Attention Deficit ◽  
Default Mode Network ◽  
Brain Connectivity ◽  
Child And Adolescent Psychiatry ◽  
Global Perspective ◽  
Default Mode ◽  
Hyperactivity Disorder

IntroductionAttention deficit hyperactivity disorder (ADHD) is a challenge in child and adolescent psychiatry. In the recent decades many studies with longitudinal designs have used neuroimaging with ADHD patients, suggesting its neurodevelopmental origin.ObjectivesStudy the findings of neuroimaging (MRI, fMRI, DTI, PET) techniques on ADHD patients from a longitudinal point of view, looking also for the potential influence of treatments and other predictors (i.e. genetics).AimsTo provide a global perspective of all the recent findings on ADHD patients with the neuroimaging technics, focusing on longitudinal measurements of the changes in brain development.MethodsWe conducted a review of the literature in the databases Pubmed and ScienceDirect (terms ADHD, neuroimaging, MRI, fMRI, DTI, PET, functional connectivity, metilphenidate and cortical thickness). We focused on studies using neuroimaging techniques with ADHD patients, looking at their populations, methodologies and results.ResultsThe studies found abnormalities in the structure of grey matter, activity and brain connectivity in many neural networks, with particular involvement of the fronto-parietal and Default Mode Network. There is also convergent evidence for white matter pathology and disrupted anatomical connectivity in ADHD. In addition, dysfunctional connectivity during rest and during cognitive tasks has been demonstrated.ConclusionsThis evidence describe ADHD as a brain development disorder, with delays and disruptions in the global development of the central nervous system that compromises grey and white matters, most evident in the prefrontal cortex, parietal and posterior cingulate cortices, as well as basal ganglia, damaging activity and structural and functional connectivity of various brain networks, especially the fronto-striato-parietal and default mode network.Disclosure of interestThe authors have not supplied their declaration of competing interest.

scholarly journals Brain-behavior patterns define a dimensional biotype in medication-naïve adults with attention-deficit hyperactivity disorder

2017 ◽  
Author(s):  
Hsiang-Yuan Lin ◽  
Luca Cocchi ◽  
Andrew Zalesky ◽  
Jinglei Lv ◽  
Alistair Perry ◽  
...  
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Functional Connectivity ◽  
Attention Deficit ◽  
Resting State ◽  
Adult Adhd ◽  
Healthy Controls ◽  
Clustering Methods ◽  
Childhood Onset ◽  
Default Mode ◽  
Hyperactivity Disorder

AbstractBackgroundChildhood-onset attention-deficit hyperactivity disorder (ADHD) in adults is clinically heterogeneous and commonly presents with different patterns of cognitive deficits. It is unclear if this clinical heterogeneity expresses a dimensional or categorical difference in ADHD.MethodsWe first studied differences in functional connectivity in multi-echo resting-state functional magnetic resonance imaging (rs-fMRI) acquired from 80 medication-naïve adults with ADHD and 123 matched healthy controls. We then used canonical correlation analysis (CCA) to identify latent relationships between symptoms and patterns of altered functional connectivity (dimensional biotype) in patients. Clustering methods were implemented to test if the individual associations between resting-state brain connectivity and symptoms reflected a non-overlapping categorical biotype.ResultsAdults with ADHD showed stronger functional connectivity compared to healthy controls, predominantly between the default-mode, cingulo-opercular and subcortical networks. CCA identified a single mode of brain-symptom co-variation, corresponding to an ADHD dimensional biotype. This dimensional biotype is characterized by a unique combination of altered connectivity correlating with symptoms of hyperactivity-impulsivity, inattention, and intelligence. Clustering analyses did not support the existence of distinct categorical biotypes of adult ADHD.ConclusionsOverall, our data advance a novel finding that the reduced functional segregation between default-mode and cognitive control networks supports a clinically important dimensional biotype of childhood-onset adult ADHD. Despite the heterogeneity of its presentation, our work suggests that childhood-onset adult ADHD is a single disorder characterized by dimensional brain-symptom mediators.

scholarly journals Quasi-periodic patterns contribute to functional connectivity in the brain

2018 ◽  
Author(s):  
Anzar Abbas ◽  
Michaël Belloy ◽  
Amrit Kashyap ◽  
Jacob Billings ◽  
Maysam Nezafati ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Neural Activity ◽  
Resting State ◽  
Low Frequency ◽  
Spatiotemporal Pattern ◽  
List Type ◽  
Periodic Patterns ◽  
Default Mode ◽  
The Brain ◽  
And Task

AbstractFunctional connectivity is widely used to study the coordination of activity between brain regions over time. Functional connectivity in the default mode and task positive networks is particularly important for normal brain function. However, the processes that give rise to functional connectivity in the brain are not fully understood. It has been postulated that low-frequency neural activity plays a key role in establishing the functional architecture of the brain. Quasi-periodic patterns (QPPs) are a reliably observable form of low-frequency neural activity that involve the default mode and task positive networks. Here, QPPs from resting-state and working memory task-performing individuals were acquired. The spatiotemporal pattern, strength, and frequency of the QPPs between the two groups were compared and the contribution of QPPs to functional connectivity in the brain was measured. In task-performing individuals, the spatiotemporal pattern of the QPP changes, particularly in task-relevant regions, and the QPP tends to occur with greater strength and frequency. Differences in the QPPs between the two groups could partially account for the variance in functional connectivity between resting-state and task-performing individuals. The QPPs contribute strongly to connectivity in the default mode and task positive networks and to the strength of anti-correlation seen between the two networks. Many of the connections affected by QPPs are also disrupted during several neurological disorders. These findings contribute to understanding the dynamic neural processes that give rise to functional connectivity in the brain and how they may be disrupted during disease.HighlightsQuasi-periodic patterns (QPPs) of low-frequency activity contribute to functional connectivityThe spatiotemporal pattern of QPPs differs between resting-state and task-performing individualsQPPs account for significant functional connectivity in the DMN and TPN during rest and task performanceChanges in functional connectivity in these networks may reflect differences in QPPs

scholarly journals Brain–behavior patterns define a dimensional biotype in medication-naïve adults with attention-deficit hyperactivity disorder

2018 ◽  
Vol 48 (14) ◽  
pp. 2399-2408 ◽  
Author(s):  
Hsiang-Yuan Lin ◽  
Luca Cocchi ◽  
Andrew Zalesky ◽  
Jinglei Lv ◽  
Alistair Perry ◽  
...  
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Functional Connectivity ◽  
Attention Deficit ◽  
Resting State ◽  
Adult Adhd ◽  
Healthy Controls ◽  
Clustering Methods ◽  
Childhood Onset ◽  
Default Mode ◽  
Hyperactivity Disorder

AbstractBackgroundChildhood-onset attention-deficit hyperactivity disorder (ADHD) in adults is clinically heterogeneous and commonly presents with different patterns of cognitive deficits. It is unclear if this clinical heterogeneity expresses a dimensional or categorical difference in ADHD.MethodsWe first studied differences in functional connectivity in multi-echo resting-state functional magnetic resonance imaging (rs-fMRI) acquired from 80 medication-naïve adults with ADHD and 123 matched healthy controls. We then used canonical correlation analysis (CCA) to identify latent relationships between symptoms and patterns of altered functional connectivity (dimensional biotype) in patients. Clustering methods were implemented to test if the individual associations between resting-state brain connectivity and symptoms reflected a non-overlapping categorical biotype.ResultsAdults with ADHD showed stronger functional connectivity compared to healthy controls, predominantly between the default-mode, cingulo-opercular and subcortical networks. CCA identified a single mode of brain–symptom co-variation, corresponding to an ADHD dimensional biotype. This dimensional biotype is characterized by a unique combination of altered connectivity correlating with symptoms of hyperactivity-impulsivity, inattention, and intelligence. Clustering analyses did not support the existence of distinct categorical biotypes of adult ADHD.ConclusionsOverall, our data advance a novel finding that the reduced functional segregation between default-mode and cognitive control networks supports a clinically important dimensional biotype of childhood-onset adult ADHD. Despite the heterogeneity of its presentation, our work suggests that childhood-onset adult ADHD is a single disorder characterized by dimensional brain–symptom mediators.

scholarly journals Brain functional connectivity abnormalities in attention‐deficit hyperactivity disorder

2016 ◽  
Vol 6 (12) ◽  
Author(s):  
Richard B. Silberstein ◽  
Andrew Pipingas ◽  
Maree Farrow ◽  
Florence Levy ◽  
Con K. Stough ◽  
...  
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Functional Connectivity ◽  
Attention Deficit ◽  
Hyperactivity Disorder ◽  
Brain Functional Connectivity
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