Signs of a Neurological (Neurodevelopmental) Disorder in Kids
A parent-friendly guide—through the lens of Dr. Robert Melillo’s work, primitive reflexes, and what mainstream pediatrics says about screening
Quick safety note: This article is educational and isn’t medical advice. If you’re worried about your child—especially if you notice loss of skills, seizure-like episodes, or a sudden change in behavior—contact your pediatrician promptly (or urgent care/emergency services if symptoms are acute).
When parents say, “Something feels off,” they’re rarely reacting to one isolated behavior. More often, they’re noticing a pattern.
A child may be bright and funny but melts down at ordinary noise. Athletic, yet constantly crashing into furniture. Chatty at home, but socially withdrawn in groups. Strong in one area and inexplicably struggling in another.
These patterns can be early clues of a neurological or neurodevelopmental disorder — a broad umbrella that includes ADHD, autism spectrum disorder (ASD), learning disorders, developmental coordination disorder, tic disorders, and more.
Dr. Robert Melillo has popularized a framework sometimes described as functional disconnection — the idea that many childhood challenges reflect timing and coordination problems in brain networks, including differences in maturation and integration between systems (and sometimes between hemispheres). In his peer-reviewed review on ASD as a “functional disconnection syndrome,” Melillo and Leisman argue that many symptoms can be understood as problems of desynchronization and ineffective coordination across regions³.
You don’t need to adopt any single theoretical model to benefit from the core insight: the brain develops from the bottom up. When early sensory-motor building blocks don’t integrate smoothly, higher-level skills — attention, language, emotional regulation, and learning — require significantly more effort.
One of the most visible of those building blocks involves early movement patterns known as primitive reflexes.
But before we get there, it’s important to understand something foundational.
When It’s More Than a Phase
Parents are often reassured that developmental quirks are temporary.
“They’ll grow out of it.”
“Boys develop later.”
“She’s just sensitive.”
And sometimes that reassurance is accurate.
Development is not linear. Children grow in bursts. Temporary unevenness is normal.
But sometimes what you’re observing is not a passing phase. It isn’t poor parenting. It isn’t a lack of discipline or motivation.
Sometimes it’s neurological timing.
Recognizing that possibility early is not about labeling a child. It is about understanding developmental patterns while the brain is still remarkably adaptable.
Development Is Not Linear — It’s Layered
Brain development happens in layers.
Lower brain systems that regulate movement, posture, balance, and sensory processing mature first. Higher brain systems responsible for executive function, emotional control, language, and complex reasoning build on that foundation.
When foundational systems are strong, higher-level skills emerge more naturally.
When foundational systems are underdeveloped or inefficient, higher-level skills may appear inconsistent, fragile, or delayed.
This layered model helps explain why children with attention challenges often have coordination issues. Why children with sensory sensitivities struggle with regulation. Why learning difficulties frequently coexist with posture, balance, or eye-tracking weaknesses.
The American Academy of Pediatrics emphasizes developmental surveillance at every well-child visit and standardized screening in early childhood¹. Early identification matters because early support changes developmental trajectories.
The Power of Patterns
Nearly every child shows distractibility at times. Nearly every child has emotional moments. Nearly every child avoids something difficult.
What suggests a neurological imbalance is not the presence of one difficulty — it’s the presence of multiple difficulties that cluster together and persist over time.
A child who struggles to sit still may also have weak core stability.
A child who is emotionally explosive may also be highly sensory sensitive.
A child who finds reading exhausting may also avoid crossing midline during movement tasks.
A child who appears inattentive may fatigue quickly during physical activity.
When multiple systems show strain simultaneously, it suggests that brain networks may not be communicating efficiently.
Melillo’s work describes this as reduced synchronization between regions³.
The goal is not to treat symptoms in isolation. It is to understand the developmental imbalance beneath them.
Movement: The Overlooked Foundation
At NeuroFiT Connections, movement is never “just exercise.” Movement is neurological input.
Motor development shapes brain organization. Research continues to demonstrate strong relationships between motor maturation and higher-level cognitive function⁴.
Early signs may include skipping crawling, avoiding tummy time, or delayed walking. But often the signs are subtle and appear later.
A child may appear clumsy. They may lean on furniture when standing. They may fatigue quickly during sports. Their handwriting may be laborious despite strong verbal reasoning.
Motor systems influence attention, visual tracking, spatial awareness, and emotional regulation. When these systems are inefficient, the ripple effects show up in classrooms and at home.
Motor coordination is not separate from academic success. It supports it.
Sensory Processing: When the World Feels Too Loud — or Too Quiet
Some children experience the world at full volume.
Bright lights overwhelm them. Background noise feels intrusive. Clothing textures irritate their skin. Busy environments trigger shutdown or meltdown.
Others seem under-responsive. They seek intense input — crashing into furniture, chewing objects, constantly moving. They may seem unaware of pain or personal space.
Both patterns reflect sensory processing differences.
When the brain struggles to filter and integrate sensory information efficiently, regulation becomes harder. An overloaded nervous system becomes reactive. An under-responsive nervous system seeks stimulation.
Understanding sensory patterns reframes behavior. Instead of asking, “Why are they acting like this?” we begin asking, “What is their nervous system experiencing?”
Emotional Regulation Is Neurological
Emotional regulation is not simply a behavioral skill. It is a neurological function dependent on communication between lower brain centers and higher cortical regions.
When that communication is inefficient, children may escalate quickly and struggle to recover. They may appear rigid, anxious, or oppositional when in reality they are overwhelmed.
Melillo’s functional disconnection model suggests that inconsistent synchronization between brain regions may underlie these patterns³.
When we approach regulation from a neurological perspective, the focus shifts from punishment to strengthening the systems that allow self-control to emerge.
Attention and Executive Function: The Inconsistency Clue
Many parents describe their child as “very smart but inconsistent.”
They hyperfocus on preferred tasks yet struggle to initiate non-preferred ones. They understand instructions but forget them minutes later. They procrastinate despite knowing consequences.
Executive functions depend heavily on frontal lobe networks. Research suggests uneven maturation within these networks may contribute to attention-related challenges⁴.
When frontal systems are underactive, initiation, organization, impulse control, and working memory are affected.
This is not a character flaw. It is developmental timing.
Hemispheric Underactivity: Uneven Brain Development
One of the central ideas in Melillo’s model involves hemispheric imbalance — where one cerebral hemisphere may be relatively underactive compared to the other.
Hemispheric specialization is normal. The left and right hemispheres support different functional domains. However, when one side remains significantly underactive, development can appear uneven.
Relative right hemisphere underactivity may contribute to challenges involving social awareness, emotional processing, tone of voice interpretation, spatial awareness, and nonverbal communication.
Relative left hemisphere underactivity may contribute to language-based learning difficulties, sequencing problems, reading fluency challenges, and certain executive function weaknesses.
Melillo describes autism spectrum disorders as potentially reflecting asymmetric cortical maturation and disrupted hemispheric connectivity³. His later research explores associations between retained primitive reflexes and hemispheric connectivity patterns⁵.
In daily life, hemispheric underactivity often presents as an uneven profile. A child may be verbally articulate but socially unaware. Mechanically gifted but struggle with reading comprehension. Emotionally sensitive yet impulsive.
The imbalance creates strengths and vulnerabilities side by side.
The hopeful reality is that underactive systems are not permanently fixed. Neural pathways strengthen with targeted activation. Development remains dynamic.
Primitive Reflexes: Clues from Early Development
Primitive reflexes are automatic movement patterns present at birth. They are designed to integrate as higher brain systems mature.
When reflexes persist, they may interfere with voluntary movement and higher-level skills.
Research has documented retained primitive reflexes in developmental disorders including ADHD and autism⁶. Persistent reflexes may impact motor coordination, learning, and emotional regulation⁷.
For example, a retained Moro reflex may contribute to exaggerated stress responses. A retained ATNR may interfere with reading and handwriting due to midline crossing difficulties. Reflexes such as STNR and TLR may influence posture and coordination.
Melillo’s work links retained reflexes to hemispheric connectivity differences⁵.
Primitive reflexes are not diagnoses. They are developmental timing indicators.
When to Seek Immediate Evaluation
Uneven development can be common. Regression is not.
Loss of previously acquired skills, seizure-like activity, sudden weakness, or major personality changes warrant immediate medical evaluation.
Early action protects long-term outcomes.
The Brain Is Plastic
The most hopeful message for families is this:
The brain changes.
Neural networks reorganize in response to targeted input. Underactive systems can strengthen. Connectivity can improve.
Melillo’s framework emphasizes activating underactive systems to promote synchronization³.
Children are not static labels. They are developing brains.
A Message from NeuroFiT Connections
If you have been reading this and quietly recognizing your child, trust that instinct.
You are not overreacting.
You are observing patterns.
And patterns deserve clarity.
At NeuroFiT Connections, we do not simply look at behavior. We assess the underlying systems: movement patterns, primitive reflex integration, sensory processing, hemispheric balance, executive function, and regulation networks.
We identify areas of underactivity.
We map strengths and vulnerabilities.
We build individualized, developmentally informed programs.
If you are concerned about your child — whether the signs are subtle or significant — the most important next step is a comprehensive assessment.
An assessment does not force a diagnosis. It provides insight. It gives you data. It shows you where your child’s brain is thriving and where it needs support.
Waiting rarely resolves neurological imbalance on its own. Targeted intervention changes trajectories.
Your child’s brain is developing right now.
If something feels off, schedule an assessment.
Get clarity.
Get answers.
And begin strengthening the systems that allow your child to thrive.
Neurodevelopment is not about labels. It’s about potential.
And potential grows with the right support.
Sources
- American Academy of Pediatrics. Developmental Surveillance and Screening.
https://www.aap.org/en/patient-care/developmental-surveillance-and-screening-patient-care/ - Centers for Disease Control and Prevention (CDC). Developmental Monitoring and Screening.
https://www.cdc.gov/act-early/about/developmental-monitoring-and-screening.html - Melillo, R., & Leisman, G. (2009). Autistic spectrum disorders as functional disconnection syndrome. Reviews in the Neurosciences, 20(2), 111–131.
- Melillo, R., et al. (2022). Retained Primitive Reflexes and Potential for Intervention in Autism Spectrum Disorders. Frontiers in Neurology.
- Melillo, R., et al. (2023). The Relationship between Retained Primitive Reflexes and Hemispheric Connectivity in Autism Spectrum Disorders. Brain Sciences, 13, 1147.
- Pecuch, A., et al. (2021). Persistence of primitive reflexes in developmental disorders. Current Developmental Disorders Reports.
- Martello, J. M. (2023). Persistent Primitive Reflex and Developmental Delay in the School-Aged Child. Journal for Nurse Practitioners.
