What is a Neurodevelopmental Disorder?
Neurodevelopmental Disorders
Neurodevelopmental disorders are conditions that affect how a child’s brain develops. They can involve differences in movement, thinking, learning, emotions and behavior.
These conditions range from mild to severe and can affect many parts of a child’s life.
Neurodevelopmental conditions include attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder, Tourette syndrome and developmental coordination disorder, and they often occur alongside related challenges such as sensory processing difficulties and obsessive-compulsive symptoms. Because these conditions involve many of the same brain circuits, they often overlap, and many children have more than one.
How Common Are Neurodevelopmental Disorders?
A CDC study of data from 1997 to 2008 found that about 1 in 7 children (13.87%) had a developmental disability. Over those 12 years, the number rose by 17%, or about 1.8 million more children. During that time, diagnoses of ADHD rose by 33% and diagnoses of autism rose by 289.5% (1). Some of this increase likely reflects greater awareness and better diagnosis.
Boys were about twice as likely as girls to have a developmental disability, and these conditions occur in all racial and ethnic groups. The reasons for the rise are not yet fully understood (1).
What Causes Neurodevelopmental Disorders?
The causes of these conditions are still being studied. Genetics play a major role, and a family history is an important risk factor. Neurodevelopmental conditions appear to share some genetic features with each other and with some psychiatric conditions (2).
Other factors linked to a higher risk include low birth weight, alcohol or tobacco exposure during pregnancy, and exposure to lead (3).
Researchers are also exploring whether environmental toxins (4), screen and technology use (5), changes in physical activity (6) and social media (7) may play a role. These questions are far from settled. Genetics appear to be the main driver, but these other factors may contribute in some children.
There is a lot of misinformation about what causes neurodevelopmental conditions. To be clear, vaccines do not cause autism (8, 9). Research has found differences in gut function and in how the body processes certain substances in some autistic children (10, 11), which may make some children more sensitive to environmental and metabolic stresses (12).
Birth complications (13) and early brain injuries (14) have also been linked to neurodevelopmental conditions. In many cases, genetic risk may combine with an early event, such as a period of low oxygen during a difficult birth, a head injury or an early infection.
What Are the Signs of Neurodevelopmental Disorders?
Signs depend on the specific condition. Many of these conditions affect behavior, self-control, emotional regulation, memory and learning. Problems with coordination are also common, involving both large movements and fine motor skills. Some children have poor posture or low muscle tone, and may be slow to crawl, walk or learn to ride a bike.
How Do Neurodevelopmental Disorders Affect the Brain?
Neurodevelopmental disorders involve differences in how several important brain regions and pathways work and work together. These include the following areas.
The frontal and prefrontal cortex. These areas handle executive functions like reasoning, planning and self-control. Differences here can contribute to inattention, disorganization and impulsivity (15).
The limbic system. These structures deep in the brain help regulate emotions. Differences here can contribute to emotional outbursts, difficulty handling stress, meltdowns and agitation (16).
The basal ganglia. These circuits receive input from across the brain and help regulate communication between brain regions. They act like the brain’s gas and brake pedals, helping start and stop thoughts, emotions and movements. Differences here can contribute to impulsivity, obsessive or compulsive behaviors, trouble with emotional control, and problems with attention (17).
The brainstem. The brainstem handles many essential functions. Its reticular activating system is the brain’s main arousal system, helping activate the frontal lobes and other brain regions. Differences here can contribute to inattention, fatigue, poor concentration and sleep problems (18).
The cerebellum. The cerebellum helps control balance, walking and both large and fine movements, and it is also involved in many thinking processes. Differences in the cerebellum have been linked to many neurodevelopmental conditions, especially autism (19).
How the Brain Develops
The brain can be affected in many ways during development. During much of pregnancy, the developing brain adds about 250,000 nerve cells per minute. Healthy brain development depends on several key stages: producing huge numbers of new brain cells; moving those cells to the right places, where they begin to specialize; grouping similar cells into distinct regions; forming countless connections between nerve cells; and pruning away unneeded connections while strengthening the important ones. That last step, called synaptic pruning, continues long after birth (20).
At birth, much of the brain’s wiring is still forming, and the brain depends on input from the environment to build its pathways. Much of this input comes from movement. The brain needs signals from muscles and joints to help the spinal cord, brainstem, cerebellum and higher brain areas develop.
The brain develops through movement, but newborns don’t yet know how to move on purpose. That’s why babies are born with primitive reflexes, automatic movements triggered by touch, pressure or changes in position. These are why babies flail and squirm, and why stroking a baby’s cheek makes them start to suckle. Primitive reflexes are a kind of evolutionary leftover built into the spinal cord and brainstem.
When a baby receives sensory input, a primitive reflex triggers a movement, which sends signals from the muscles and joints back up to the spinal cord, brainstem and brain. This input helps nerve cells in the brain stabilize and connect into pathways. As these pathways mature, they send signals back down that help switch off the primitive reflexes.
Dozens of primitive reflexes have been identified. One example is the Babinski reflex. If you stroke the bottom of a baby’s foot, the toes fan upward. As the nervous system matures, usually by age 1 to 2, the same touch makes the toes curl down instead. Most primitive reflexes fade during the first years of life.
For various reasons, some children continue to show primitive reflexes into later childhood, adolescence or even adulthood. In adults, the return of these reflexes after they have faded can be a sign of a brain injury or other neurological problem.
Primitive reflexes matter because the brain areas they stimulate do more than control simple movements. These areas also act as communication hubs that help the brain wire together. When they don’t develop well, communication across the brain may be less efficient. Retained primitive reflexes have been found in a range of neurodevelopmental conditions (21, 22, 23), and some research suggests that exercises to help these reflexes fade may be helpful (24).
Higher Brain Control and Response Inhibition
Retained primitive reflexes relate to how the brain develops from the bottom up. As children grow, development from the top down becomes just as important. The midbrain, part of the brainstem, is a key relay for light and sound coming into the brain. It is involved in movement, helps drive stress responses, and contains areas that help activate the frontal lobes and emotional centers.
As higher brain areas like the prefrontal cortex and basal ganglia develop, they help regulate these lower areas. Some of their pathways support executive functions like planning, finishing tasks, working memory and big-picture thinking. Others support emotional regulation. And others support what is called response inhibition.
These regulating systems develop slowly and aren’t fully mature until around age 25. Response inhibition depends on areas such as the dorsolateral prefrontal cortex and its connections with the basal ganglia. It is the ability to tune out things that don’t matter, such as the feel of fabric on your skin, the hum of the air conditioner or movement in the background. When these systems are still developing or not working well, a child may have trouble filtering out distractions, and daily life can become a series of “hey, something shiny” moments.
The systems involved in response inhibition also help with emotional and behavioral control. When they struggle, a range of emotional and behavioral symptoms can appear.
Eye movements. Many of the brain areas involved in response inhibition also control specific eye movements, and differences in eye movements are common in neurodevelopmental conditions (25). The frontal lobe helps produce saccades, the quick jumps the eyes make from one target to another. Saccades are important for attention, and children with difficulties in saccades often have attention problems (26).
Smooth pursuit, the ability to follow a moving target smoothly, depends largely on the parietal lobes. These are also the areas that receive touch and pressure input and hold the brain’s map of the body. Differences in smooth pursuit have been found in sensory processing difficulties and related conditions, and some research suggests eye movement training may help (27).
The dorsolateral prefrontal cortex, which is central to response inhibition, also produces anti-saccades. In an anti-saccade, a person must hold back the automatic urge to look at a new target and instead look the opposite way. This takes higher-level self-control. Research has linked difficulties with anti-saccades to problems with response inhibition (28), and we use anti-saccade exercises with the goal of strengthening attention, emotional control and behavioral regulation.
How Are Neurodevelopmental Disorders Usually Treated?
Neurodevelopmental conditions are treated with many types of therapy, including occupational therapy, speech therapy, physical therapy, behavioral therapy and, in some cases, medication.
Medications can be very helpful for managing certain symptoms. Because they act wherever a particular brain chemical is used, they can also cause side effects, so they need careful management by your child’s prescriber (29).
How the NeuroRescue Program Can Help
Our care is designed to work alongside your child’s pediatrician, therapists and school team, never in place of them. Please don’t change any of your child’s medications without talking with their prescriber.
Primitive reflexes. Our neurodevelopmental programs begin with a thorough check for retained primitive reflexes. When we find them, we design a set of specific exercises to help them fade. Because these exercises are simple, we often teach parents to do them at home, and we can also do them in the clinic as part of an intensive program.
Higher brain function. From there, we focus on the higher brain systems that need support, including the frontal, parietal and temporal lobes, the midbrain, the cerebellum and the basal ganglia. We identify which systems are struggling through examination and testing, then focus therapy on those systems and how they work together. Every program is built around your child’s history, exam findings and test results from their Discovery Day.
Other therapies. Depending on your child’s needs, their program may include eye movement exercises aimed at attention and focus, and rhythm and timing training with the Interactive Metronome, which has been studied in children with attention and coordination difficulties (30). It may also include vestibular exercises to improve balance and posture, which have been studied in children with autism (31); exercises in a virtual reality environment, which have been studied for supporting social interaction and thinking skills (32); low-level laser therapy, which one study found reduced irritability in children and adolescents with autism (33); and nutritional support, including diet changes and probiotics (34).
For patients 18 and older, transcranial magnetic stimulation (TMS) may be an option. At our clinic, TMS is provided by our psychiatric mental health nurse practitioner.
Every NeuroRescue Program is different, with therapies chosen based on your child’s testing and needs. No two brains are alike, and no two programs are either.
How the NeuroRescue Program Works
Your child’s NeuroRescue Program begins with their Discovery Day. We start with a detailed history of your child’s development and life on a timeline, along with a neurological exam done at a pace that works for your child. This helps us understand the factors that may have contributed to where they are now, and identify related conditions that may be making it harder to move forward.
We measure how your child’s visual, vestibular and balance systems are working through computerized analysis of eye movements, inner ear reflexes and balance under different conditions. Our testing includes videonystagmography and saccadometry to measure several types of eye movements, the video head impulse test to measure inner ear reflexes, and CAPS computerized posturography to assess balance under different sensory conditions. We also 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 this with a thorough physical and neurological exam of your child’s sensory, motor, autonomic and cognitive systems. We also review any relevant lab work, imaging and prior testing, and integrate it with our findings.
Together, this helps us understand your child’s strengths, which systems are struggling, and how quickly they tire. We use that information to design a personal NeuroRescue Program, aimed at improving function and endurance in the systems that need support. Our testing also helps us decide when to push and when to let your child rest.
Our goal is to help your child feel more comfortable, capable and confident at home, at school and with friends.
Your Next Step
Living with a neurodevelopmental condition can be challenging, but many symptoms can be managed, function can improve, and quality of life can often get better. To find out if the NeuroRescue Program is right for your child, contact one of our patient care coordinators to schedule a Discovery Day.
It’s never too late to take the next step.
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