VACCINE

Brain Connectivity • August 2015
Shared Brain Connectivity Issues, Symptoms, and Comorbidities
in Autism Spectrum Disorder, Attention Deficit/Hyperactivity Disorder,
and Tourette Syndrome
Author information
Kern JK1, Geier DA1, King PG2,
Sykes LK2, Mehta JA3, Geier MR1.
1. Institute of Chronic Illnesses, Inc., Silver Spring, Maryland
2. CoMeD, Inc. , Silver Spring, Maryland
3. Communication Sciences & Disorders
Texas Woman’s University, Denton, Texas
Abstract
The prevalence of neurodevelopmental disorders, including autism spectrum disorder (ASD), attention deficit/
hyperactivity disorder (ADHD), and Tourette syndrome (TS), has increased over the past two decades. Currently,
about one in six children in the United States is diagnosed as having a neurodevelopmental disorder. Evidence
suggests that ASD, ADHD, and TS have similar neuropathology, which includes long-range underconnectivity
and short-range overconnectivity. They also share similar symptomatology with considerable overlap in their
core and associated symptoms and a frequent overlap in their comorbid conditions. Consequently, it is apparent
that ASD, ADHD, and TS diagnoses belong to a broader spectrum of neurodevelopmental illness. Biologically,
long-range underconnectivity and short-range overconnectivity are plausibly related to neuronal insult (e.g., neurotoxicity,
neuroinflammation, excitotoxicity, sustained microglial activation, proinflammatory cytokines, toxic
exposure, and oxidative stress). Therefore, these disorders may a share a similar etiology. The main purpose
of this review is to critically examine the evidence that ASD, ADHD, and TS belong to a broader spectrum of
neurodevelopmental illness, an abnormal connectivity spectrum disorder, which results from neural long-range
underconnectivity and short-range overconnectivity. The review also discusses the possible reasons for these
neuropathological connectivity findings. In addition, this review examines the role and issue of axonal injury and
regeneration in order to better understand the neuropathophysiological interplay between short- and long-range
axons in connectivity issues.
“The prevalence of
neurodevelopmental disorders, including
autism spectrum disorder (ASD),
attention deficit/hyperactivity disorder (ADHD),
and Tourette syndrome (TS), has increased over
the past two decades. Currently, about one in six
children in the United States is diagnosed
as having a neurodevelopmental disorder.”
[this defines a pandemic of neurological disorders]
http://www.ncbi.nlm.nih.gov/pubmed/25602622