Sensory Processing Disorders in Children: 5 Hidden Causes, Risk Factors, and Early Warning Signs

Abstract

Sensory Processing Disorder (SPD) affects a child’s ability to receive, interpret, and respond appropriately to sensory information. While some causes and signs are well known, this paper focuses on the less discussed contributors, their risk factors, and early warning signs. With real-life cases from diverse regions, particularly African settings, this article seeks to humanise the experience, deepen understanding, and empower early intervention. The paper also examines the underlying biological mechanisms (pathophysiology) of SPD, presenting it in clear, accessible language.

Introduction

In many families across the world—from Lagos to London, from Nairobi to New York—parents watch their children struggle to interact with a world that often feels overwhelming or confusing. Sensory Processing Disorder (SPD) is a condition where the brain struggles to organise sensory information correctly. This disorder is not yet officially classified under major diagnostic manuals like DSM-5 (American Psychiatric Association, 2013), but it is widely recognised by occupational therapists and neuroscientists.

Early identification is key. Unfortunately, many little-known causes and early warning signs go unnoticed, especially in lower-resourced settings where awareness is low. This article aims to bridge that gap by presenting evidence-based information in a relatable way.

Understanding Sensory Processing Disorders: A Simple Overview

What is Sensory Processing?
Our brains are constantly flooded with information from our five main senses—sight, sound, touch, taste, and smell—as well as two “hidden” senses: the vestibular (balance) and proprioceptive (body position) systems. Sensory processing is how our brains organise this information to create appropriate responses.

What Happens in SPD?
In SPD, there is a “miswiring” somewhere along the sensory pathways. The brain may overreact (hypersensitivity) or underreact (hyposensitivity) to sensory input. This can lead to clumsiness, behavioural outbursts, poor coordination, anxiety, or even social withdrawal (Miller et al., 2017).

Pathophysiology of SPD
Research suggests that SPD involves dysfunctions in the thalamus, the parietal lobe, and the cerebellum (Chang et al., 2014). Neuroimaging studies using diffusion tensor imaging (DTI) reveal that children with SPD often have reduced white matter integrity, meaning that the “communication highways” between parts of the brain are weaker or less efficient (Owen et al., 2013).
Abnormalities in neurotransmitters like dopamine and serotonin are also suspected, which affects the way sensory information is filtered and interpreted.

Top 5 Little Known Causes and Risk Factors

While genetic predisposition and prematurity are well-known risk factors, let us explore five lesser-known causes:

1. Chronic Early Childhood Malnutrition

Explanation:
In many parts of Africa and developing nations, early childhood malnutrition remains a silent epidemic. Malnutrition deprives the growing brain of essential nutrients like omega-3 fatty acids, iron, and zinc—key building blocks for healthy neural connections (Grantham-McGregor et al., 2007).

Case Study (Kenya):
A three-year-old boy from a rural village showed extreme sensitivity to sounds and refused to walk barefoot on the grass. Nutritional assessments showed significant deficiencies. After six months of nutritional rehabilitation, combined with occupational therapy, his sensory symptoms dramatically improved.

Scientific Link:
Malnutrition during the critical “first 1,000 days” of life disrupts myelination, which is essential for fast and coordinated nerve signaling (Black et al., 2013).

2. Prenatal Maternal Stress and Trauma

Explanation:
When a pregnant woman experiences high levels of stress—due to violence, poverty, or natural disasters—the cortisol hormone can cross the placenta and affect the foetal brain’s sensory development (Charil et al., 2010).

Example (South Africa):
During community unrest, many pregnant women in Cape Town reported high stress levels. Later, higher rates of SPD-like symptoms were found in their children, especially with tactile defensiveness (hypersensitivity to touch).

Scientific Link:
Elevated maternal cortisol can alter the foetal hypothalamic-pituitary-adrenal (HPA) axis, affecting how the child’s brain processes sensory input (Sandman et al., 2012).

3. Untreated Middle Ear Infections (Otitis Media)

Explanation:
Frequent untreated ear infections disrupt auditory input during critical periods of brain development. This is common in areas with limited access to antibiotics.

Case Study (Nigeria):
A seven-year-old girl, who suffered repeated untreated ear infections in early childhood, later struggled with auditory processing, language delays, and showed classic signs of SPD.

Scientific Link:
Chronic otitis media leads to inconsistent auditory input, which can cause the auditory cortex to develop abnormally, resulting in difficulties integrating sounds properly (Roberts et al., 2004).

4. Environmental Toxin Exposure (e.g., Lead, Mercury)

Explanation:
Exposure to environmental toxins like lead or mercury—often from old paints, contaminated water, or mining activities—can impair sensory pathways.

Example (Ghana):
Children living near illegal gold mining sites, where mercury is used, showed a higher incidence of tactile defensiveness and balance issues.

Scientific Link:
Heavy metals interfere with synaptic transmission and can cause neuroinflammation, leading to sensory processing abnormalities (Grandjean & Landrigan, 2006).

5. Lack of “Messy Play” and Sensory Experiences in Early Childhood

Explanation:
Modern parenting styles—especially in urban and affluent areas—often over-sanitise children’s environments. Without diverse sensory experiences (like mud play, messy foods, rough-and-tumble play), sensory pathways remain underdeveloped.

Case Scenario (Botswana):
In a middle-class Gaborone suburb, preschoolers who spent most of their time indoors had more SPD symptoms compared to their rural peers who engaged freely with nature.

Scientific Link:
The brain needs “sensory challenges” to build strong neural networks. Lack of sensory variety can result in a disorganised sensory system (Bundy & Lane, 2020).

Early Warning Signs: What to Watch For

Catching SPD early can change a child’s life. Here are five early warning signs, often overlooked:

• Extreme Sensitivity or Insensitivity:
  Children may scream when touched lightly or seem to not feel pain from serious injuries.
• Avoidance of Certain Textures:
  Refusing to walk on sand, grass, or to wear certain fabrics.
• Motor Clumsiness:
  Frequent tripping, bumping into objects, or poor balance.
• Emotional Overreactions:
  Meltdowns in crowded places (markets, weddings, churches) due to sensory overload.
• Delayed Language and Social Skills:
  Difficulty making friends, trouble understanding instructions, or withdrawal in group settings.

Conclusion

Sensory Processing Disorder is real, widespread, and often hidden under other labels like “naughty child” or “slow learner.” Understanding lesser-known causes—from malnutrition to toxin exposure—can equip families, teachers, and healthcare providers to intervene early.
For many African communities, simple strategies like improving nutrition, reducing environmental toxin exposure, and encouraging sensory-rich play can make a world of difference.

Parents, teachers, and communities are the first line of defence. Let us arm them with knowledge, compassion, and practical support.

References

American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.).

Black, R. E., Victora, C. G., Walker, S. P., et al. (2013). Maternal and child undernutrition and overweight in low-income and middle-income countries. The Lancet, 382(9890), 427-451. https://doi.org/10.1016/S0140-6736(13)60937-X

Bundy, A. C., & Lane, S. J. (2020). Sensory integration: Theory and practice (3rd ed.). F.A. Davis Company.

Chang, Y. S., Owen, J. P., Pojman, N. J., Thieu, T., Bukshpun, P., Wakahiro, M. L., … & Mukherjee, P. (2014). White matter changes of neurite density and fiber orientation dispersion in sensory processing disorder. Frontiers in Neuroanatomy, 8, 53. https://doi.org/10.3389/fnana.2014.00053

Charil, A., Laplante, D. P., Vaillancourt, C., & King, S. (2010). Prenatal stress and brain development. Brain Research Reviews, 65(1), 56-79. https://doi.org/10.1016/j.brainresrev.2010.06.002

Grandjean, P., & Landrigan, P. J. (2006). Developmental neurotoxicity of industrial chemicals. The Lancet, 368(9553), 2167-2178. https://doi.org/10.1016/S0140-6736(06)69665-7

Grantham-McGregor, S., Cheung, Y. B., Cueto, S., Glewwe, P., Richter, L., & Strupp, B. (2007). Developmental potential in the first 5 years for children in developing countries. The Lancet, 369(9555), 60-70. https://doi.org/10.1016/S0140-6736(07)60032-4

Miller, L. J., Anzalone, M. E., Lane, S. J., Cermak, S. A., & Osten, E. T. (2017). Concept evolution in sensory integration: A proposed nosology for diagnosis. The American Journal of Occupational Therapy, 71(3), 7103260010p1-7103260010p10. https://doi.org/10.5014/ajot.2017.015800

Owen, J. P., Marco, E. J., Desai, S., Fourie, E., Harris, J., Hill, S. S., … & Mukherjee, P. (2013). Abnormal white matter microstructure in children with sensory processing disorders. NeuroImage: Clinical, 2, 844-853. https://doi.org/10.1016/j.nicl.2013.06.009

Roberts, J. E., Burchinal, M. R., Zeisel, S. A., et al. (2004). Otitis media in early childhood and cognitive, academic, and classroom performance of the school-aged child. Pediatrics, 113(3), e301-e308. https://doi.org/10.1542/peds.113.3.e301

Sandman, C. A., Davis, E. P., Buss, C., & Glynn, L. M. (2012). Exposure to prenatal psychobiological stress exerts programming influences on the mother and her fetus. Neuroendocrinology, 95(1), 7-21. https://doi.org/10.1159/000327017