Sensory Integration Disorder

While once thought to be one in the same with autism, we now recognize sensory integration disorder as its own specific neurodevelopmental condition. Maybe you've noticed that your child seems overly sensitive to sound, touch, smell, taste or other sensory input. Maybe they become overwhelmed and act erratic or even aggressive when experiencing things that other kids tolerate well? Each of my children have had some level of sensory integration, with my oldest son having been the most significant.

Now at twenty-four years old, he is thriving in the military, but as a young child my son didn't eat - almost at all. He could go days without putting anything solid in his mouth and would simply say it felt weird. He was picky beyond belief with his clothing - never wore jeans, socks had to be a very specific brand and he could not tolerate tags. His clothing material had to be exceedingly soft, but more than even food and clothing - he couldn't walk on grass and would full panic if an ant crawled on him.

He wanted to do karate for years and I think truly believed he was the toughest superhero in the land, but we lived in a really small town, so when we moved to the big town of Lafayette and these classes became an option, I quickly signed him up with my own Tae Kwon Do teacher from college. He loved it. Those first few practices went exceedingly well; he was in awe, until his uniform came in and he was expected to wear it into class. He had a complete melt down in front of everyone.

This is when I knew we had a bigger issue on our hands than simply #picky preferences; my strong and proud son had a full-out-of-body-experience, crying and panicking in front of the instructors that he so admired, in front of his new friends. I recognized this was not #defiance, but something else entirely, although I still didn't quite know what. He quickly took off his new uniform and we just left, never to return. I was broken-hearted for him, but didn't question his decision because I knew it was beyond his control and for him to walk away from Tae-Kwon-Do was pretty profound.

For many years, this same response happened in the dressing room when out shopping but because he was so skinny, I had difficulty finding clothes he could wear so I kept trying new approaches. In time I recognized all his specific needs and memorized all his nuances. I had to go completely out of my way to assure he was comfortable, but this wasn't unlike what I had to do for his father. When my husband found a style of socks he could wear comfortably, he bought them in cases and stored them in our attic so he would always have a pair he could tolerate - for the rest of his life.

Each of our little ones followed suit, although never as significant as my oldest son. They could not handle their heads being touched, at all. While they were all the most cuddly children and nursed for years, soon after weaning they never wanted to be touched again. My oldest picky eater struggled so significantly that he suffered a smidge of liver damage. He was starving himself.

His pediatrician recommended occupational therapy, which was only marginally helpful. What it really offered was validation. My son was really struggling to find comfort within his environment and I was offering significant effort to understand and advocate for him, but so few saw this as anything more than a spoiled child. My subsequent children, not having the luxury of homeschool as my older children did, are typically seen as defiant when they communicate their unique needs. Our society is not very tolerant to adjusting to what seems like overly picky preferences.

Dr. Jean Ayers conceptualized sensory integration in the 1970s, and has said that "intersensory integration is foundational to function," and we understand today, after a few decades of research that dysfunction in sensory integration leads to difficulties in development, learning, and emotional regulation (Kilroy et al., 2019). Therefore, children with sensory processing deficits may find it challenging to regulate their responses to everyday situations such as dressing, playing, mealtime, and social interactions.

Sensory Integration Disorders are Neurodevelopmental Conditions that Manifest with Dysfunctional Processing of External Stimuli by the Brain

Sensory integration disorders, also known as sensory processing disorders (#SPDs) can be very challenging to live with - they can be isolating for both children and parents, even leading to long-term social difficulties (Section on Complementary & Integrative Medicine et al., 2012). I remember sharing the scenario at Tae Kwon Do with my ol' bestie and her response was, "Oh, I would never have tolerated that from one of my children." The thing is that knowing my son, I knew without question this wasn't a behavioral issue. This was a fight-or-flight response. I just didn't know why or what to do about it. Thank goodness we had an excellent pediatrician back then, now twenty years ago, who was informed and compassionate, and who empowered us.

Struggling with sensory processing can make virtually any everyday task difficult to perform. Coordination problems, behavioral issues, anxiety, depression, school failure, social challenges, and a host of other problems may actually be the result of sensory processing disorder (Section on Complementary & Integrative Medicine et al., 2012). Difficulty tolerating or processing sensory information is a characteristic that may be seen in many developmental behavioral disorders, including those on the spectrum, attention-deficit/hyperactivity disorder, developmental coordination disorders, and childhood anxiety disorders. Screening for these can be enlightening, while also sometimes heart-breaking because with my youngest son, I recognized that what I thought were his personality quirks, sometimes even laziness or defiance, were actually his inability to process information.

Sensory integration is about how the nervous system integrates sensory input and puts that into action (Guardado & Sergent, 2023). Both the limbic system and the vestibular and proprioceptive systems are involved. The vestibular system is in charge of the sensory information from body movement through space, and the proprioceptive system has a role in processing sensory input from joints and muscles. When impaired, this can lead to issues such as hand flapping (Schaaf & Blanche, 2011).

Ayres hypothesized that the vestibular system is in charge of deciding whether we will act on a stimulus or not, while the vestibular nuclei register visual stimuli and gives it meaning (Kilroy et al., 2019; Lane et al., 2019). The over or under reaction to tactile or vestibular input may then lead to gravitational insecurity or fear of movement, tactile defensiveness, or both. The amygdala, otherwise the manager of our stress, also plays an important role in sensory registration as it is also our reward center (Kilroy et al., 2019). For instance, hyperactivation in the amygdala due to eye contact may be why individuals with autism spectrum disorder (ASD) avoid eye contact.

Lack of sensory integration may be one of the underlying causes of the behavioral problems in children with autism. Between 90 and 95% of children with autism are estimated to have sensory processing difficulties.

Ayres has hypothesized that impairments in sensory processing leads to a motivation deficit and lack of attribution of meaning to a stimulus, or poor registration, which in turn inhibits motivation to engage. He has also stated that somatosensation is composed of touch and proprioception. For instance, visual information and motor signals integrate with tactile sensations at the posterior parietal cortex, and the integration of these sensory inputs is essential for self-motion, postural stability, and spatial orientation (Lane et al., 2019). Individuals with reduced sensory modulation may lack the capacity to filter out redundant stimuli leading them to feel overwhelmed due to poor modulation.

How Common are Sensory Integration Disorders?

The incidence of sensory integration disorder is hard to identify in that many practitioners are ignorant to it completely, and many times people don't recognize it as a condition worthy of diagnosis in themselves. There are studies that indicate this to be as common as five to 15 percent of school-aged children and within the general population, whether under or over response to stimulation, and then among those with neurodevelopmental disorders, its as high as 40 to 80 percent (Section on Complementary and Integrative Medicine et al., 2012).

What are the Symptoms of Sensory Integration Disorder?

Sensory input is certainly the underlying issue, but often what is recognized is the child becoming agitated or #hyperactive in specific forms of sensory input. One child may over-respond to touch and may find the sensation of clothing on their skin to be intolerable. Another child may over-respond to visual or auditory stimuli, and be prone to emotional meltdowns in complicated sensory environments. Another child still may suffer with under-response and show little or no reaction to even extreme stimulation from pain and temperature changes, yet this can easily go unrecognized by parents, and children end up exceedingly sick before anyone is aware.

Some children may have difficulty processing the input from muscles and joints known as #proprioception. These children will show hypotonia and will exhibit poor motor skills, yet again, this can be a bit subtle until it is fully recognized. My youngest son for example can't tie his shoes, perform jumping jacks, swing, and he never gets dizzy. He falls off swings, even falls out of his chair, but because he is so efficient in so many things, this was always believed to be him being goofy or not paying attention. Broke my heart when I learned this was a lack of connection between his brain and his core, or his ability to know where he is at in space, ultimately completely outside of his control. My oldest son was much like this too, but it seems as he aged this all improved, and today like I mentioned, he is active military - artillery. He couldn't kick a soccer ball just a decade ago; today he is an excellent marksman and proudly shows off his 6-pack.

Other children still may be sensory seekers, and will crave any and all forms of extreme sensation. These children often are misdiagnosed with #ADHD and medicated accordingly. What they may need to succeed is not Ritalin, but rather an #IEP that allows for airpods so they can play music while they study.

How do Sensory Integration Disorders Affect the Brain?

Researchers have used diffusion tensor imaging to measure the structural connectivity of children with and without sensory integration disorder (Section on Complementary & Integrative Medicine et al., 2012). This advanced form of imaging maps the structural connections between brain regions. The microstructure of the white matter tracts correlate with sensory functioning, in particular, in the posterior regions of the brain where tracts are responsible for relaying sensory information.

DTI studies have demonstrated abnormal white matter tracts in SPD subjects that serve as connections for the auditory, visual and somatosensory (tactile) systems involved in sensory processing, including their connections between the left and right hemispheres of the brain (Section on Complementary & Integrative Medicine et al., 2012). The abnormal microstructure of sensory white matter tracts shown with DTI in children with SPD likely alters the timing of sensory transmission, such that processing of sensory stimuli and integrating information across multiple senses becomes difficult or impossible.

How are Sensory Integration Disorders Usually Treated?

Struggles with sensory integration are seen in many different neurodevelopmental disorders. Primary treatment for SPD generally involves pharmacological management to reduce behavioral symptoms. While this can be somewhat effective, all medications come with a side effect profile. Some of these side effects are as significant as the disorder itself. As my own children have utilized, occupational therapists that specialize in neurodevelopmental disorders can offer treatment protocols involving some form of play-based activity geared towards gradual exposure to the sensory stimulation that is problematic.

Another approach to improving sensory processing is sensory integration therapy which involves activities that are believed to organize the sensory system by providing vestibular, proprioceptive, auditory, and tactile inputs (Kashefimehr et al., 2018 & Randell et al., 2019). This may involve implementing brushes, swings, trampolines, balls, and other equipment to elicit proprioceptive, tactile, and vestibular challenges. There may also be activities that elicit deeper pressure, joint compression, oral moral exercises, and body massage to enhance arousal states (Schaaf & Blanche, 2011).

Sensory integration therapy is aimed at the areas that give the child the greatest challenges during their day-to-day activities, so these therapies are then integrated into their play and usually tackle more than one sensory system at a time, and trigger proprioception of muscles and joints, receptors of the inner ear, as well as auditory, visual, and tactile receptors on the skin (Drobnyk et al., 2011). The ultimate goal is to improve the nervous system's sensory processing, organization, integration, and motor planning.

These interventions are founded on neuroplasticity, aiming to maleate the nervous system through experience. Just like we practice any other routine, such as dance or foul shots, we practice to gain familiarity, muscle memory, or nervous system organization. We can help our little ones create neural networks as a result of experience through therapy. The science is supportive that this is effective in better organizing our brains and demonstrates that the brain will make important connections as a result of an environment and from learning (Lane et al., 2019). Studies have found improved educational and social skills, as well as reduction in self-harm behaviors, and improved neural functioning specifically in language and reading (Devlin et al., 2011).

Many different types of occupational therapy and sensorimotor therapies have demonstrated improvement, but with mixed results. It seems the best success comes with using both sensory stimulus and movement of the body as this forces us to use our frontal lobe to generate movement at the same time as our parietal lobe processes sensory input (Section on Complementary & Integrative Medicine et al., 2012). The thought is that if we pair two functions at the same time, we increase the chances of integrating the two more effectively. A review of published evidence by May-Benson and Koomar (2010) found that the sensory integration approach may result in positive outcomes in the areas of sensorimotor skills and motor planning, socialization, attention, and behavioral regulation, reading and reading-related skills, and individualized goals for the study populations.

While the science is still new, there does seem to be viable strategies to improving sensory integration, developmental motor function, and social interaction. This begins with a thorough evaluation of every neurologic pathway and system involved in sensory processing. Specific diagnostic tests can measure dysfunction in the vestibular, proprioceptive, auditory, and tactile systems.

Deficits in body awareness is the hallmark of sensory processing disorders. This might present with some level of hearing challenges or challenges with body awareness, balance and motion may be impacted, or even planning and ideation. Touch and vision are also components of sensory processing disorders. Research has taught us that individuals with sensory processing disorder have deficits in brain processing of sensory feedback, which involves the cerebellum, parietal lobe, and the prefrontal cortex (Section on Complementary and Integrative Medicine et al., 2012). These deficits in somatosensory feedback promote increased dependence on visual and spatial processing as well as on attention and memory for motor learning.

The impairment in body awareness manifests as developmental coordination disorders, but also makes these individuals very visually dependent. They are forced to rely on vision to make sense of where they exist in space, and as such any impairment in eye movement or visual processing can lead to a marked increase in symptoms. My youngest son who struggles with jumping jacks, does so because he can't see where his appendages are when he is jumping and moving all of them at the same time. He is smart though so he brings them in front of his body so his arms have a bit more coordination, but he can't quite get his legs coordinated. Consider though that when visually dependent to regulate your sensory stimulation, visually complicated environments can be overwhelming and cause children to demonstrate meltdowns. Oculomotor rehabilitation has been shown to be very helpful for these children (Section on Complementary and Integrative Medicine et al., 2012).

As with all neurodevelopmental disorders, it is extremely common for us to see retained primitive reflexes in SPD children (Section on Complementary and Integrative Medicine et al., 2012). Primitive reflexes are a series of motor patterns we all have ingrained in our spinal cords and brainstems, also called fetal reflexes. These reflexes use sensory input to drive motor responses that help the brain develop. The parts of the brain that are stimulated by these reflexes function as integration nodes that facilitate proper connectivity within the developing brain. They are normal in infants, but they mature and extinguish by about ten months of age. If for whatever reason these don't fully integrate, sensory processing disorder is commonly the result. An evaluation of these reflexes should be part of every neurodevelopmental assessment. If found, specific repatterning exercises can help integrate any retained reflexes and restore appropriate connectivity between brain regions. These can be coupled with sensory stimulation to promote rapid neurodevelopmental gains.

The communication between the sensory and motor systems is impaired in sensory processing disorders (Section on Complementary and Integrative Medicine et al., 2012). Motor coordination is almost inevitably dysfunctional on some level in SPD. An essential component of motor coordination is motor timing, which is frequently compromised in these individuals. Rhythmic motor entrainment therapy has been shown to be very helpful for these children. An Interactive Metronome can be used to rehabilitate these pathways and coupling this with protocols such as the NeuroSenoriomotor Integrator system helps to restore motor timing, motor control, sensory integration, executive function, and behavioral control.

Other modalities utilized in the treatment of sensory integration disorder include eye movement strategies which improve attention and focus, and motor entrainment therapies for improving coordination and cognition (Section on Complementary and Integrative Medicine et al., 2012). Older individuals may utilize electrical stimulation or transcranial magnetic stimulation to facilitate improvement in motor learning and coordination. Dietary modulation and supplementation regimens can also be implemented into a sensory integration treatment plan, along with hyperbaric oxygen therapy to reduce repetitive, self-stimulatory and stereotypical behaviors and impairments in communications, sensory perception, and social interaction. They may involve photobiomodulation strategies to reduce irritability and other associated symptoms and behaviors and vestibular rehabilitation exercises to improve balance and postural control, or even exercises performed in a virtual reality environment to improve social interaction and cognition. Gut health is also an integral component of treatment, as many suffer inflammatory or dysbiotic conditions.

Living with a sensory integration disorder can be challenging for all, family included. Treatment can offer significant improvement.

References

Drobnyk, W., Rocco, K., Davidson, S., Bruce, S., Zhang, F., & Soumerai, S. B. (2019). Sensory integration and functional reaching in children with Rett Syndrome/Rett-Related disorders. Clinical Medical Insights Pediatrics, 13.

Guardado, K. E. & Sergent, S. R. (2023). Sensory integration. StatPearls.

Kashefimehr, B., Kayihan, H., & Huri, M. (2018). The effect of sensory integration therapy on occupational performance in children with autism. OTJR, 38(2), 75-83.

Kilroy, E., Aziz-Zadeh, L., & Cermak, S. (2019). Ayres theories of autism and sensory integration revisited: what contemporary neuroscience has to say. Brain Science, 9(3).

Lane, S. J., Mailloux, Z, Schoen, S., Bundy, A., May-Benson, T. A., Parham, L. D., Smith, R. S., & Schaaf, R. C. (2019). Neural Foundations of Ayres Sensory Integration. Brain Science, 9(7).

May-Benson, T. A. & Koomar, J. A. (2010). Systematic review of the research evidence examining the effectiveness of interventions using a sensory integrative approach for children. American Journal of Occupational Therapy, 64(3), 403-414.

Randell, E., McNamara, R., Delport, S., Busse, M., Hastings, R. P., Gillespie, D., Williams-Thomas, R., Brookes-Howell, L., Romeo, R., Boadu, J., Ahuja, A. S., McKigney, A. M., Knapp, M., Smith, K., Thornton, J., & Warren, G. (2019). Sensory integration therapy verses usual care for sensory processing difficulties in autism spectrum disorder in children: study protocol for a pragmatic randomised controlled trial. Trials, 20(1), 113.

Section on Complementary and Integrative Medicine, Council on Children with Disabilities, Zimmer, M., Desch, L., Rosen, L. D., Bailey, M. L., Becker, D., Culbert, T. P., McClafferty, H., Sahler, O. J. Z., Vohra, S., Liptak, G. S., Adams, R. C., Burke, R. T., Friedman, S. L., Houtrow, A. J., Kalichman, M. A., Kuo, D. Z., Levy, S. E., Norwood, K. W., Turchi, R. M. & Wiley, S. E. (2012). Sensory integration therapies for children with developmental and behavioral disorders. Pediatrics, 129(6), 1186-1189.

Schaaf, R. C. & Blanche, E. I. (2011). Comparison of behavioral intervention and sensory-integration therapy in the treatment of challenging behavior. Journal of Autism Development Disorders, 41(10), 1436-1438.