Share This Article
Is Autism a Neurological Disorder? Here is your guide to knowing all about Autism.
Certain mental health conditions manifest themselves from birth, and autism is one of them. It is possible that you have seen or met children that behave in ways that are not considered “normal.” They may stare at you overtly for long periods, make weird noises, or appear to not listen to you.
If so, the conclusion of an autism diagnosis would be correct. Undoubtedly, autism is a neurological disorder because its main source of origin and impact has to do with the nervous system. But first, let’s take a look at what neurological disorders are.
What are Neurological Disorders?
Neurodevelopment disorders are a group of conditions characterized by an early onset and persistent course that are believed to be the result of disruptions to normal brain development or the nervous system.
Neurological disorders are different from anxiety and depression in that they must have their onset during childhood. They are also believed to result from significant delays or disruptions in brain development that persist into adulthood.
Although when it comes to their nature, neurodevelopmental disorders are heterogeneous, yet they often overlap and share common risk factors. Furthermore, there are many neurological disorders out of which autism spectrum disorder, intellectual disability, and attention deficit hyperactive disorder (ADHD) are the most common developmental disabilities.
Autism Spectrum Disorder
Autism spectrum disorder (asd) is a neurological and developmental disorder that involves persistent deficits in language and perceptual and motor development, repetitive patterns of behaviour, deficits in non verbal communication, restricted interests and social interaction deficits.
Thus, the answer to the question “Is autism a neurological disorder?” is yes. One of the most important criteria of autism spectrum disorder as given in the DSM 5 is that it manifests itself during the early developmental period and cause clinically significant impairment in social, occupational or other important areas of functioning.
Theory of mind is a term that refers to the ability to understand not only your own mental states such as beliefs, intentions and desires, but also to understand that other people have beliefs, intentions and desires that may be different from yours.
Autism research suggests that one of the main problems for people with asd is that they do not possess a theory of mind, failing to understand that other people have their own points of view.
A recent study by the Centers for Disease Control and Prevention (Baio, 2014) reported that the rate of autistic disorder among children is about 1 in 68. Autism is usually identified before a child is 30 months of age and diagnostic stability over the childhood years is quite high. Lord and colleagues (2006) report that children diagnosed with autism by age 2 tend to be similarly diagnosed at age 9.
Recent research also suggests that early signs of problems with social communication skills can be detected in the first 6 months of an infant’s life. When scanning the world around them, typically developing infants from 2 to 6 months of age focus increasingly on the face and especially the eyes of others. This focus allows infants to better understand those caring for them and helps facilitate later social interaction.
In contrast, children with developing asd show a significant decline in their focus on the eyes of others from 2 to 6 months of age and this decline continues until 24 months—at which point it is approximately half the level of focus as that seen in typically developing children. In contrast, while their attention to other people’s eyes decreases, infants later diagnosed with autism spectrum disorder show a significant increase in their focus on inanimate objects, which is double the level of typically developing children by 24 months.
Why is ASD a Neurological Disorder?
The reason why autism is classified under neurological disorders and not viewed as a mental health condition is that it is characterised by neuropathology and brain atrophy in addition to behavioural impairments. This brain expansion is frequently accompanied by an increase in intracranial volume.
It has been discovered that Alzheimer’s disease associated amyloid-β precursor protein (APP), especially its neuroprotective processing product, secreted APP α, is found to be highly elevated in individuals with asd. This gave rise to the “anabolic hypothesis” of autism aetiology, according to which numerous symptoms of autism may be caused by interneuronal misconnections caused by neuronal overgrowth in the brain.
Symptoms of Autism Spectrum Disorder
Asd symptoms can range widely as children with autism differ amongst themselves in their capabilities and impairments. But the most commonly noted ones are as follows:
- Deficits in social interactions – Autistic children often do not show any need for affection or contact with others. They exhibit problems in controlling their facial expressions, understanding other people’s feelings or engaging in social interaction. Several studies, however, have questioned the traditional view that people with asd are emotionally flat. These studies have characterized the seeming inability of autistic children to understand other’s body language or facial expressions and respond to others as a lack of social skills—a deficit in the ability to attend to social cues from others.
Indeed, neuroimaging studies have revealed that children with autism show decreased activity in the medial prefrontal cortex, a region associated with understanding the mental states of others, but increased activation in the ventral occipitotemporal regions involved in object perception.
- Stereotyped or repetitive behaviors, use of objects, or speech (e.g., simple motor stereotypies, lining up toys or flipping objects).
- Hyper- or hyporeactivity to sensory input or unusual interest in sensory aspects of the environment (e.g., apparent indifference to pain/temperature, excessive smelling or touching of objects, visual fascination with lights or movement).
- Self-stimulation is often characteristic of children with autism. It usually takes the form of such repetitive movements as head banging, spinning, and rocking, which may continue by the hour.
- Insistence on sameness, inflexible adherence to routines, or ritualized patterns of verbal or nonverbal behavior (e.g., extreme distress at small changes, difficulties with transitions, rigid thinking patterns, need to take same route or eat same food every day).
According to the DSM 5 criteria (https://www.autismspeaks.org/autism-diagnosis-criteria-) dsm-5, these disturbances are not better explained by intellectual disability or global developmental delay. Intellectual disability and autism spectrum disorder frequently co-occur; to make co morbid diagnoses of asd and intellectual disability, social communication should be below that expected for general developmental level.
1. Types of Autism Spectrum Disorders
As the name suggests, autism is a spectrum and thus, while some people with asd need substantial support in their daily functioning, others can live or work with no or little support.
ASD is used as an umbrella term for the group of complex developmental disability or disorders that make up autism. The term “spectrum” also refers to the wide range of symptoms and severity as mentioned previously. There are namely three types of autism spectrum disorders.
1.1 Autistic Disorder
This is also called “classical autism”. When most people hear the word “autism,” they actually visualize this disorder. People with autism disorder typically exhibit odd habits and interests, major language impairments, and problems in communication and social interactions. It is considered to be the most severe form of autism. Thus, they undoubtedly require a high level of support.
1.2 Asperger Syndrome
It is a mild form of asd. People with asperger’s disorder are seen as “high functioning” individuals with average to above average IQ and no speech impediments. People with this disorder have the traditional autism difficulties but what sets them apart from the other asd disorders is that they have less severe symptoms, strong language and cognitive skills, do well academically and in work environments.
1.3 Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS)
Also known as “atypical autism,” Pervasive Developmental Disorders are the category reserved for people who partially match the requirements for the other two forms of ASD, i.e., while certain symptoms may be present, others are completely irrelevant; although they might have some problems, they don’t look serious. In such a case, when they do not fit into either of the subtypes, PDD is given to them.
Individuals with Pervasive developmental disorder only suffer from social communication challenges. People who have this neurological disease have:
- Impairment beyond age 3 – Children under the age of three are not eligible for this diagnosis.
- A few odd behaviours – They have shown challenges that are consistent with some indications of autism.
- A few unusual behaviors -They might not exhibit all of the symptoms of autism or they might exhibit ones that aren’t typically seen in people with autism.
2. Diagnosis of Autism Spectrum Disorders
2.1 In Children
Because people with asd not only have varying symptoms which may differ in their intensity, but also differences in how these symptoms manifest themselves and impact the mental health functioning of the individual, diagnosis of asd is not an easy one.
There is no medical test for its diagnosis. Generally, the DSM 5 criteria is followed to make the diagnosis, wherein the individual must meet the specified requirements in order to classify for a diagnosis of asd.
At well child checkups the healthcare provider checks whether the child has met the developmental milestones expected of children their particular age. If not, a multidisciplinary team composed of child psychologists, child neurologists, psychiatrist, speech therapist, developmental pediatricians and other specialists who diagnose and treat ASD in children comes together to make a thorough assessment for a comprehensive evaluation.
A comprehensive neurological evaluation as well as in-depth cognitive and language tests will be performed by the team members. Children with delayed speech development should also have their hearing evaluated since hearing issues might result in behaviours that could be misconstrued for ASD.
2.2 In older children or adolescents
When ASD symptoms are present in older children and adolescents attending school, caregivers and teachers are frequently the first to notice them. The special education team at the school may do an initial examination and then suggest that a kid have a secondary evaluation with their primary care physician or a someone who specialises in ASD.
The caretakers may discuss their social difficulties, particularly issues with subtle social communication, or repetitive behaviors with the medical professionals.
It may be difficult to understand body language, facial expressions, or tone of voice due to these subtle social communication disparities. Children and teenagers who are older may have problems understanding sarcasm, comedy, or figures of speech. Additionally, they could struggle to make friends with their peers.
3. Causes of Autism Spectrum Disorder
Given the complexity of the disorder, it comes as no surprise that asd occurs due to multiple factors. Here are the most plausible ones:
3.1 Gene Function
Based on current evidence, it appears that distinct and multiple genes contribute to autism spectrum disorder. For certain kids, a genetic condition like Rett syndrome or fragile X syndrome may be linked to autism spectrum disorder.
Other children may be more susceptible to autism spectrum disorder due to genetic mutations. Other gene mutations may influence how the brain develops, how brain cells communicate, or even how severe a symptom is. While some genetic changes appear to be inherited, others develop on their own. Previously, studies have linked these mutations to problems with synaptic function, i.e., how nerve cells communicate with each other.
Twin and sibling studies have shown that there is a very strong heritable component in autism. For instance, 2 to 14 percent of siblings of children diagnosed with autism also have the disorder, and approximately 20 percent have some symptoms of the disorder.
Researchers are trying to determine what portion of the genetic risk is inherited (52 percent) and what portion is due to de novo mutations (3 percent). De novo mutations are those that occur in the egg or sperm and are passed on to every cell in the child’s body, despite not appearing in the parents’ DNA.
It seems that much of the risk for autism is indeed inherited from one’s parents. However, a significant portion of risk also arises due to de novo mutations. This is important to know, because as we learn about factors that increase the likelihood of genetic mutations, we can take steps to try to decrease their occurrence.
For instance, genetic mutations have been reported to occur at higher rates in the sperm of older men, and there is now converging evidence that older father age at a child’s birth is associated with increased risk of autism.
3.2 Environmental Factors
The role that environmental factors play to develop asd is not fully known. However, at the moment, scientists are looking at the potential causes of autism spectrum disease, including viruses, drugs, pregnancy difficulties, and air pollution.
3.3 Other Autism Risk Factors
Some science news suggests that having a sibling with ASD, experiencing complications at birth or being born to older parents may also increase the risk for developing autism. Autism also tends to occur more frequently among individuals having tuberous sclerosis.
4. Treatment of Autism Spectrum Disorders
The treatment prognosis for many children with autism is poor in part because so many people with asd are insufficiently treated. Moreover, many children with autism are subjected to a range of fads and “novel” approaches that have little to no support for their effectiveness. The good news, however, is that intensive behavioral treatments have proven to be effective for many people with asd.
4.1 Behavioural Intervention
For years, it was assumed that there was no effective way to treat people with autism. In 1987, Ivar Lovaas reported that an intensive behavioral intervention administered via one-on-one meetings with the child for over 40 hours per week for 2 years resulted in positive results. The intervention was based on discrimination training strategies (reinforcement) and contingent aversive techniques (punishment).
The treatment plan typically enlists parents or family members in the process and emphasizes teaching children to learn from and have social interactions with “normal” peers in real-world situations.
Of the treated children in the study by Lovaas and colleagues, 47 percent achieved normal intellectual and educational functioning, compared with only 2 percent of children in the untreated control condition.
More recent versions of this intensive behavioral approach have continued to demonstrate success. Geraldine Dawson and colleagues (2010) recently showed that toddlers (18–30 months old) with autism who were randomly assigned to receive the Early Start Denver Model (ESDM) intervention showed significant improvements in IQ (an average of a 17-point increase), language, and adaptive behavior as well as a decrease in symptoms of autism.
The ESDM intervention involves more than 20 hours per week of intensive behavioral work with the child and family members focused on interpersonal exchanges, verbal and nonverbal communication, and adult sensitivity to children’s cues.
Children receiving the ESDM intervention also showed greater cortical activation when viewing other people’s faces (compared to objects), which in turn was correlated with greater improvements in the children’s social communication skills. Although treatments like this one are extremely time consuming, their powerful results suggest that behavioral interventions can cause improvements in people diagnosed with autism.
There are several medications that can help with associated symptoms of asd like anxiety, sadness, and obsessive-compulsive disorder. However, even after several clinical trials, no medication to cure asd has been found as of now. If there are serious issues with the child’s behavior, they are treated with antipsychotic drugs.
Anticonvulsant medications are used to treat seizures. ASD patients’ impulsivity and hyperactivity can be successfully reduced with the aid of medication used to treat attention deficit disorder. Before implementing any dubious therapy, parents, family member or caregivers of the patients should exercise caution.