Sensory Processing Disorder Part 1: Defining It

October is National Sensory Awareness Month. As part of this national education effort, Inside Bainbridge is publishing a series on Sensory Processing Disorder (SPD), citing the latest research, information from experts in the field, and personal stories from parents, caregivers, and kids affected by the condition. (Family names have been changed for privacy.) Read the other articles in the series:

The elegance of the animal brain and neurological system makes complex processes seem simple. Our sensory systems tell us where to place our feet, how to maneuver through space, which sounds to ignore and which to attend to, what to focus on in our visual field, how to chew and swallow without choking, when to speak and when to listen, and countless other actions each minute of each day.

All kids have different learning styles, and this teaching method apparently isn’t working.

A child in a classroom, for example, has to filter out noises from other classrooms, buzzing lights, shuffling feet, and a host of other extraneous sounds in order to focus on the most important sound—the teacher’s voice. This can be challenging at times for many children, but for kids with sensory processing disorder it can be downright exhausting, painful, or even at times impossible.

What SPD Is Not

Sensory Processing Disorder is not ADD or ADHD, although it is often misdiagnosed as such. It also is not a form of autism or Asberger’s, though sensory processing problems often accompany those spectrum conditions. SPD is not a “learning disability” per se, but it may lead to learning and emotional problems.

What SPD Is

Research on SPD began in earnest in the 1960s and 1970s with the work of neuroscientist and occupational therapist Dr. Anna Jean Ayres. She described SPD as a neurological “traffic jam” preventing parts of the brain from receiving the information needed to accurately interpret sensory information.

Some peoples’ fun is other peoples’ sensory nightmare.

Extensive research and practitioner work has followed Ayres’s pioneering studies, but a widespread lack of awareness and understanding of SPD still persist in the general population. Some remain skeptical, dismissive, or simply unaware of the condition. But for families, caregivers, and educators dealing with kids displaying SPD symptoms, the condition is very real.

A current goal of the Sensory Processing Disorder Foundation is to get recognition for SPD in the next edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM), due out in 2013. Difficulty getting recognition for “newly emerging” diagnostic conditions is old news. Before 1980, autism was labeled a form of childhood schizophrenia, and the full autism spectrum wasn’t included in the DSM until 1987.

A 2004 study conducted by the SPD Foundation found that “at least 1 in 20 children’s daily lives is affected by SPD.” A 2009 study suggested that “1 in 6 children experiences sensory challenges sufficient to disrupt their academic, social, and/or emotional development.”

Based on new research, the SPD Foundation, led by Director Lucy Jane Miller, Ph.D., OTR, identifies three major categories of SPD:

Sensory Modulation Disorder. This includes sensory overresponsivity, sensory underresponsivity, and sensory-seeking behaviors, or combinations thereof. People with this condition can alternate from one state to the other, sometimes seeking stimulation, for example with hand flapping or spinning, and at other times retreating from stimulation by hiding or going off alone.
Sensory Discrimination Disorder. This includes difficulty with accurate perception of all the five senses, plus proprioceptive awareness (knowing how much pressure to exert), vestibular awareness (knowing where you are in space), and interoceptive awareness (being aware of your bodily functions, like hunger and the need to go to the bathroom). People with sensory discrimination problems may have trouble reading because they can’t discriminate between letters, or they may have trouble identifying who is speaking to them because they can’t locate the sources of sounds.
Sensory-Based Motor Disorder. This includes postural disorders and/or dyspraxia (difficulty planning and carrying out motor tasks). People with sensory motor problems may have low muscle tone, difficulty holding utensils, poor posture, trouble with balance, and low stamina.

Terry and Jan in Seattle have a son, Eli, who slumps and has trouble holding his pencil firmly when he writes and draws. He has difficulty sitting up straight at school and at the dinner table, and his handwriting is poor. Sometimes he falls out of his chair. Eli’s Sensory Motor Disorder makes him unable to keep up with playground activities and leaves him feeling socially isolated and embarrassed, especially around the other boys in his class.

People with SPD may have problems in one, two, or all three areas, to varying degrees. The often very different manifestations of SPD make it a challenge to diagnose and treat. It can be bewildering to people unfamiliar with the condition, making it easy to mistake as the result of poor parenting or character flaws such as stubbornness, belligerence, laziness, or lack of intelligence.

Morgan and Jim, parents in Portland, have two kids with SPD, displaying two very different forms of Sensory Modulation Disorder. Their daughter is generally overresponsive to sensory input, screaming at mild pain and dissolving into long crying fits, even in public, over minor disappointments. Their son, on the other hand, is sensory-seeking, often hitting, biting, touching, and talking excessively in school and at home. Both children are highly intelligent, which is not uncommon for children with SPD.

SPD can feel insurmountable.

According to Paula Jarrard, MS, OTR, and doctoral candidate at Rocky Mountain University of Health Professions, there is a correlation between giftedness and SPD. She based her conclusions partly on two studies, one by the SPD Foundation that found that 35 percent of the children in one large sample (n=500) from a gifted and talented center exhibited symptoms of SPD. The second study showed that almost 17 percent of gifted children that were tested at a different center had SPD.

Although a significantly higher-than-average number of SPD kids may be gifted, they often suffer from low self-esteem, anxiety, and poor school performance, leading to underachievement in adulthood.

Bainbridge Island pyschotherapist Elizabeth Turner, who works with many SPD children, explains that their difficulty filtering and interpreting sensory information can create chronic stress: “Sensory-challenging situations, like chaotic classrooms, for example, can feel overwhelming and create an anxiety response that becomes physiologically wired into the nervous system. These kids develop a flight, fight, or freeze reaction that becomes involuntary without intervention.”

So what begins as a neurological difference in SPD kids often develops into a socially isolating and emotionally debilitating condition. In the next feature in this series, I will examine what it’s like living with SPD from the point of view of those who have it and their parents and caregivers.

[This article from the archives originally appeared on Inside Bainbridge October 19, 2011.]

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Images courtesy of Mike Baird, Reiner Kraft, and James Emery.