What are Autistic Spectrum Disorders?

Jul 29

Is your child struggling to meet normal developmental milestones? Do they avoid eye contact? Do they seem to struggle with communication and social interaction? Do they have difficulty processing sensory stimulation? They may be dealing with an autism spectrum disorder, or ASD.

Autism spectrum disorders include a broad range of conditions characterized by challenges with social skills, repetitive behaviors, sensory integration, speech production, and nonverbal communication. Autism has become increasingly prevalent in recent years. Autistic disorders have a profound impact on the quality of life of affected individuals.

What are the Different Types of Autistic Spectrum Disorders?

There are many subtypes of autism, and it is important to know your child’s subtype when attempting to life plan or even plan for treatment. In 2013, the American Psychiatric Association merged four distinct autism diagnoses into one umbrella diagnosis of autism spectrum disorder (ASD). They included autistic disorder, childhood disintegrative disorder, pervasive developmental disorder-not otherwise specified (PDD-NOS) and Asperger syndrome. For the purposes of this discussion, we will consider ASD in general, but nuances between the subtypes are important.

How Common are Autistic Spectrum Disorders?

According to the National Institute of Mental Health, 1.9% of 8-year-old children were identified as having ASD in 2016. ASD is 4.3 times more common in boys than in girls. ASD is reported to occur in all racial and ethnic groups (7).

What are the Symptoms of Autistic Spectrum Disorders?

There are two common features found in autism spectrum disorders: impaired social communication, and restricted or repetitive sensory and motor behaviors.

Children with ASD demonstrate deficits in social-emotional reciprocity, manifesting as reduced sharing of interests and emotions, or abnormal social approach and failure of normal back-and-forth conversation.

They may also show deficits in nonverbal communication, abnormal eye contact and body language, or deficits in understanding and use of gestures.

They may also show deficits in developing, maintaining, and understanding relationships.

ASD children may also show stereotyped or repetitive motor movements, use of objects, or speech.

They tend to insist on sameness, with inflexible adherence to routines, or ritualized patterns of verbal and nonverbal behavior.

They show highly restricted, fixated interests that are abnormal in intensity or focus.

They also demonstrate hyperactivity or hyporeactivity to sensory input, or unusual interests in sensory aspects of the environment. They may show apparent indifference to pain or temperature, or adverse responses to specific sounds or textures (10).

What Causes Autistic Spectrum Disorders?

There doesn’t seem to be any single specific cause of ASD, but a complicated combination of genetic and environmental factors appears to be involved (34).

Autism also appears to involve the immune system. Individuals diagnosed with ASD have alterations in immune cells such as T cells, B cells, monocytes, natural killer cells, and dendritic cells. Many individuals diagnosed with ASD also demonstrate alterations in immunoglobulins and increased autoantibodies (35).

Neuroinflammation is involved in the development of ASD. Microglia are the brain’s immune cells, and ASD subjects demonstrate activation of microglia in different brain regions, involving increased cell number or cell density, morphological alterations, and phenotypic shifts (36).

Children with autism may also demonstrate impaired detoxification capacity and may suffer from chronic oxidative stress. Asperger patients seem to have chronic low detoxifying capacity (37).

Despite many beliefs in popular culture, current evidence suggests that environmental factors such as vaccination, maternal smoking, thimerosal exposure, and assisted reproductive technologies do not increase the risk of ASD. However, advanced parental age is associated with higher risk of ASD. Birth complications that are associated with trauma or ischemia and hypoxia have also shown strong links to ASD, whereas other pregnancy-related factors such as maternal obesity, maternal diabetes, and caesarian section have shown a less strong (but significant) association with risk of ASD (38).

Regardless of causation, it is critically important that affected children are identified as early as possible. A study by Clifford et al (1) attempted to follow babies through the first 3 years of life and predict which may be affected with ASD by surveying mothers about their child’s temperament and other social patterns. They found that in the first year of life, those with less positive emotional reactivity ultimately had higher rates of ASD diagnoses. From 6 months of age, and continuing into the second year of life, high-risk children later diagnosed with ASD showed increased perceptual sensitivity. Throughout the second year, they showed lower rates of smiling, laughing, and cuddling. By the second birthday, higher rates of negative affect including sadness, shyness and low sooth-ability were evident.

These findings are important, as the best outcomes for autism start with early interventions. Autistic spectrum disorders are lifelong conditions. Treatments for ASD are not cures, but rather are intended to improve social function, enhance quality of life and increase abilities to perform activities of daily living. The earlier these therapies are started, the more likely the child will be able to function independently as an adult.

What Happens in the Brain in Autistic Spectrum Disorders?

There are myriad neurochemical, histopathological, and neuroanatomical problems that have been identified in ASD.

Neurotransmitters play a significant role in ASD. Many of the behaviors in autism have been linked to dysfunction in the midbrain dopaminergic system (39). Neurotransmitter function can become impaired in many different ways, including by the influence of the gut microbiome, as gut bacteria secrete peptides that influence neurotransmitter function. There are several specific imbalances in gut microflora that have been identified in ASD which can directly influence brain neurotransmitter function (11).

It appears that patterns of brain connectivity are dysfunctional in ASD. Functional neuroimaging research in autism spectrum disorder has reported patterns of decreased long-range, within-network, and interhemispheric connectivity. Research has also reported increased corticostriatal connectivity and between-network connectivity for default and attentional networks (12). These networks play crucial roles in attention, focus, and behavior modulation.

The cerebellum plays a major role in the development of autism. The presence of abnormal cerebellar anatomy, abnormal neurotransmitter systems, oxidative stress, cerebellar motor and cognitive deficits, and neuroinflammation have all been demonstrated in children with autism.

Cerebellar genetics, cerebellar immune function, oxidative stress and mitochondrial dysfunction, GABAergic and glutamatergic systems, cholinergic, dopaminergic, serotonergic, and oxytocin related changes in autism, motor control and cognitive deficits, cerebellar coordination of movements and cognition, gene-environment interactions all appear to be important in the development of ASD (13).

It appears that there is abnormal early prefrontal cortex maturation in ASD. In autism there has been shown to be disorganization of cortical networks within layer 1 of the lateral prefrontal cortex, leading to the development of an imbalance between excitation and inhibition in autism (14). There also is a tendency towards overgrowth of the frontal cortex during the early postnatal period, leading to further abnormal brain connectivity (15).

The orbitofrontal cortex (OFC) is involved in assessing the emotional significance of events and stimuli, emotion-based learning, allocation of attentional resources, and social cognition.

Research has demonstrated changes in the ratio of excitation/inhibition in the OFC of adults with ASD, with an overall weakening and likely disorganization of excitatory signals and a relative strengthening of local inhibition. These changes impair OFC communication with the limbic system (the emotional brain), and the amygdala (the brain’s threat detector). This dysfunction may provide the anatomic basis for disrupted transmission of signals for social interactions and emotions in autism (16).

The anterior insula is involved in interoceptive, affective and empathic processes. The insula provides the ability to understand what is happening in your own body, as well as the ability to emotionally relate to others. Evidence suggests it is part of a "salience network" integrating external sensory stimuli with internal states. The anterior insula as a consistent locus of hypoactivity in autism, and dysfunctional anterior insula connectivity thus has an important role in the development of ASD (17).

The basal ganglia are involved in both motor and non-motor functions, including higher order cognition, social interactions, speech, and repetitive behaviors. Neuropathology and neuroimaging findings in autism cases revealed volumetric changes and altered cell density in select basal ganglia nuclei. The basal ganglia likely have a critical role to play in maintaining an inhibitory balance between cortical and subcortical structures, critical for normal motor actions and cognitive functions. In autism, this inhibitory balance is disturbed, which impairs key pathways that affect normal cortical network activity (18).

Several studies confirm that most of the individuals with an autism spectrum disorder have some degree of sensory dysfunction related to disorders of processing auditory, visual, vestibular, and/or tactile stimuli. Central auditory processing disorders have been demonstrated in many studies. Several studies have reported deterioration in speech perception and expression in patients with autism spectrum disorders, which may also be related to central auditory processing disorders in this unique group of individuals (19).

The vestibular system has been recently highlighted as the cornerstone of the multisensory cortex and of the dorsal hippocampus related to spatial cognition. The vestibular system plays a foundational role in sensory integration, as it is the only system that creates a directional framework for other sensory input to bind with. Cognitive development goes through a critical period dependent on the vestibular otolithic sensory perception of gravity. Impaired vestibular integration leads to many features common in ASD (20).

Vestibular dysfunction has been demonstrated in Autistic children. ASD children exhibited increased vestibulo-ocular reflex gain, the ratio of eye velocity to head velocity, indicating a possible lack of cerebellar inhibitory input to brainstem vestibular nuclei, which may be due to alterations in cerebellum and brainstem circuitry (21).

Patterns of oculomotor behavior have also been shown to be impaired in ASD children. Impaired eye movements demonstrate atypical cortical processing, which is involved in eye movement triggering and attentional processes in children with autism spectrum disorders (22).

Research has shown abnormalities in oculomotor function in patients with high functioning autism provide preliminary evidence for involvement of a number of brain regions including the dorsolateral prefrontal cortex (DLPFC) and the frontal eye fields (FEFs), and possibly the basal ganglia and parietal lobes (6).

It has been proposed that children with autism and AD may have difficulty utilizing visual feedback during motor learning tasks, and changes within the cerebellum, which is implicated in motor learning, are known to be more pronounced in autism compared to Asperger’s. These findings collectively imply functional impairment of the cerebellar network and its inflow and outflow tracts that underpin saccade adaptation (23).

Individuals with autism spectrum disorder (ASD) show atypical visual scanning paths during social interaction and when viewing faces, and recent evidence suggests that they also show abnormal eye movement dynamics and accuracy when viewing less complex and non-social stimuli. Control of eye movement is supported by discrete circuits within the cerebellum and brainstem - two brain regions implicated in magnetic resonance (MR) morphometry and histopathological studies of ASD. Fast eye movements of individuals with ASD show reduced accuracy, elevated variability in accuracy across trials, and reduced peak velocity and prolonged duration. In addition, their fast eye movements take longer to accelerate to peak velocity. Deficits precisely and consistently directing eye movements suggest impairment in the error-reducing function of the cerebellum in ASD. These findings suggest that both cerebellar and brainstem abnormalities contribute to altered sensorimotor control in ASD (24).

Eye tracking holds potential for the early detection of autism spectrum disorders. Research has investigated the fixation times of ASD and neurotypical children ages 4-6 watching a 10-second video of a female speaking. ASD children showed significant reductions in fixation time at six areas of interest. Fixation times at the mouth and body could significantly discriminate ASD from neurotypicals with a classification accuracy of 85.1%, sensitivity of 86.5%, and specificity of 83.8% (25).

We also know that those with ASD struggle with sensory integration. At times wearing a shirt or a handshake can feel like sharp or crushing pain, leading to difficulty with social interaction. Blakemore et al (2) performed a study of Asperger syndrome, a more functional version of Autism. ASD and control subjects received electrical stimulus, and they ranked their perception of the sensation. When the examiner administered the stimulus, both groups found it to be aggravating, but when the subject stimulated themselves, the control group were more tolerant of the sensation. The Asperger group found that both types of stimulus to be more aggravating than the control group. This shows that those with ASD can struggle with everyday sensory stimulation. Sensory integration and proprioceptive exercises have been shown to have positive outcomes for these symptoms (3).

Gaze fixation is impaired in ASD from an early age. Research has investigated infant gaze holding in ASD. It demonstrated that 6-9-month-old infants that had the shortest time of fixation with their eyes went on to be diagnosed with ASD at 36 months (6).

How are Autistic Spectrum Disorders Usually Treated?

The most common therapies for ASD include applied behavioral analysis (ABA), occupational therapy, speech therapy, physical therapy, and pharmacological therapy. These forms of treatment work to minimize the impact of the deficits seen in ASD, and to maximize functional independence and quality of life (8).

While these approaches yield significant benefit, particularly when started as early as possible, they are largely about skill development and symptom reduction. They often fail to address underlying patterns of neurological dysfunction that give rise to ASD symptoms.

Psychiatric medications are also often employed to manage symptoms, ranging from antidepressants to antipsychotics. While these can be helpful, they all have the potential to create negative side effects (40).

How is the NeuroRescue Program Different?

We employ a wide variety of therapies that have been shown to be beneficial in autism spectrum disorders. Our therapies are all based on cutting-edge neuroscience research, and all are validated in scientific literature.

Your child’s NeuroRescue Program therapies may include transcranial electrical stimulation to improve sociability and behavior (26), or transcranial magnetic stimulation to decrease irritability, hyperactivity, and repetitive behavior (27). We reserve these therapies for individuals over the age of 18, however unfortunately ASD symptoms invariably persist into adulthood. Their therapy protocol may involve hyperbaric oxygen therapy to reduce repetitive, self-stimulatory and stereotypical behaviors, and impairments in communication, sensory perception, and social interaction (28). It may involve laser photobiomodulation to reduce irritability and other associated symptoms and behaviors (29). It may involve vestibular rehabilitation exercises to improve balance and postural control (30), or even exercises performed in a virtual reality environment to improve social interaction and cognition (31). It may involve probiotics and other forms of supplementation to address the inflammatory and dysbiotic aspects of your child’s condition (32).

We will usually employ specific modalities to activate the brainstem, vestibular system, cerebellum, basal ganglia, parietal and frontal lobes, which are all integral in the control of eye movements. Among other things, eye movement therapies have been shown to reduce anxiety and stress in ASD adults. We find that these exercises can improve the deficits in modulation of attention, focus and emotion typically seen with ASD (6).

Every NeuroRescue Program is different, with your child’s therapies chosen based on your diagnostic testing and the realities of your condition. It is impossible to take a cookie-cutter approach to the treatment of a condition as complex as ASD. The therapy plan we develop will be specific to their brain, and theirs alone.

How Does the NeuroRescue Program Work?

We design your unique NeuroRescue Program to be among the most comprehensive diagnostic and therapeutic protocol available today. We create individual NeuroRescue Programs based on a comprehensive analysis of every relevant neurological system and pathway, using gold-standard, cutting edge neurodiagnostic technologies and examination procedures and state-of-the-art therapies.

Our examination allows us to identify the areas and pathways of your child’s brain that are involved in their unique presentation of ASD. We do this by precisely quantifying the function of their visual, vestibular, and proprioceptive systems through computerized analysis of eye movements, inner ear reflexes, and balance in a host of different sensory conditions.

We employ technologies including Videooculography and Saccadometry to measure several classes of eye movements. We use Video Head Impulse Testing to measure the function of the inner ear, and Computerized Dynamic Posturography to assess balance in different sensory conditions.

We use NeuroSensoryMotor Integration testing to evaluate hand-eye coordination and cognition, and Virtualis testing to assess dynamic eye tracking and perception of vertical in a virtual reality environment.

We combine all of this with a comprehensive physical and neurological examination of your child’s sensory, motor, autonomic, and cognitive systems. We review any relevant laboratory testing, radiological imaging, and prior neurodiagnostic testing, and integrate that information with our findings.

We use this information to identify which parts of your child’s nervous system are working properly, which systems are struggling, and the precise point at which their systems fatigue.

We can then design a NeuroRescue Program that is unique and specific to your child’s clinical presentation. Their NeuroRescue Program works to rejuvenate and reintegrate the damaged neurons and pathways in their central and peripheral nervous systems. It works to improve energy, endurance, and functional capacity within their involved fragile systems.

We use our technologies and procedures to not only see what we need to address, but also when it is time to stop and let them rest. We address their impaired neurological function from multiple angles of therapy, and provide metabolic support to improve neurological recovery.

While we cannot bring back neurons that have been lost, the NeuroRescue Program allows us to take the pathways that remain and maximize their efficiency and endurance. And by focusing on the integration of systems, we can do more than just get pathways working better, we can get them working together again.

It is important to understand that ASD is a lifelong condition, and will require management and rehabilitation in the long term. While we do not purport to be able to cure ASD, we do regularly find that our ASD patients develop enhanced social communication, improved behavioral regulation, and improved motor skills. We see that their ability to make progress with traditional therapy programs is enhanced. This gives us our best opportunity to return your child to living a healthy, vibrant, and fulfilling life.

Your Next Best Step:

Living with an autistic spectrum disorder can be challenging. While we cannot cure these conditions, there is hope for functional improvement and an enhanced quality of life. To see if the NeuroRescue Program is right for you, contact one of our patient care coordinators to schedule your Discovery Day.

And remember, it’s never too late to start getting better.