Playing with bubble wrap is a silly activity that delights most preschoolers. But for one

21 / 2 -year-old from Silver Spring, loud noises such as the pop of plastic bubbles were so upsetting that he would cover his ears and run away. Some days the sound of a vacuum cleaner would make him scream. The child so persistently avoided activities with too much noise and motion that his preschool’s administrators asked to meet with his family — and soon an assessment led to a diagnosis of sensory processing disorder, or SPD.

SPD is a clinical label for people who have abnormal behavioral responses to sensory input such as sound and touch. Some children with SPD seem oversensitive to ordinary stimuli such as a shirt label’s scratching their skin. Others can be underresponsive — seemingly unaffected by the prick of a needle. A third group have motor problems that make holding a pencil or riding a bike seem impossible. Whatever the difficulty, such kids are often described as “out-of-sync,” a term popularized by Carol Stock Kranowitz’s 1998 book “The Out-of-Sync Child,” which has sold nearly 700,000 copies.

As many as 16 percent of school-age kids in the United States may face sensory processing challenges. And yet there’s debate over whether these challenges constitute a discrete medical disorder. Some experts contend that SPD may be merely a symptom of some other ailment — autism, attention-deficit hyperactivity disorder, anxiety disorder or fragile X syndrome, for example — while others insist it is a separate condition that should be labeled a disorder when it interferes with daily life.

The debate over how to classify SPD is not merely matter of semantics. Such discussions can affect research funding and can guide whether insurers will reimburse therapy costs.

The mother of the Silver Spring child (who asked not to be identified to protect his privacy) said that since SPD is not recognized as a disorder by much of the medical establishment, she and her husband must pay out of pocket to send their son to a school that caters to his needs and for occupational therapy, which can cost more than $6,500 a year for weekly, hour-long sessions.

Laura Pittman, of Colorado Springs, whose son was diagnosed with SPD as a toddler, said the challenges families face are not understood.

“I feel like it’s an invisible disorder,” she said. Her son had trouble transitioning from indoors to outdoors and adjusting to changes in routine; he ran all the time. The first-time mother worried that the difficulties were her fault. She wept in relief when an occupational therapist told her that there was a label for his condition. (OTs are typically on the front lines in assessing these children.)

Pittman thinks that recognition of this disorder by established medicine would help parents. “I feel like it would give freedom to many parents across the country that didn’t have to work the system to get services for our children,” she said.

Just temperament?

In the past two years, the cause of increased recognition for SPD has been dealt a few setbacks. In a 2012 policy statement, the American Academy of Pediatrics advised pediatricians not to use sensory processing disorder as a diagnosis.

“We have no evidence that it is a separate disorder,” explained the statement’s co-author, Michelle Zimmer, a pediatrician in Cincinnati. “The pediatrician’s first thought needs to be: What else is going on here? What other disorder could this be a part of? It needs to be thought of more as a symptom rather than a disorder in and of itself.”

The AAP’s action was followed in 2013 by an expert committee’s decision not to include SPD as a diagnosis in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, or DSM-5, published by the American Psychiatric Association. This decision came despite a vigorous campaign to include SPD in the DSM for the first time.

“I do not doubt that the people that report this . . . are really experiencing something,” said Catherine Lord, a member of the DSM-5 committee. “But we don’t know very much about what it is that they are actually experiencing,”

A diagnosis of SPD may seem easier to accept than, say, the stigma-fraught label of autism. “SPD, I think, for many parents, sounds better, sounds like a more minor thing; it sounds like it’s easily treatable,” said Lord, a professor of psychiatry at Weill Cornell Medical College and the director of the Center for Autism and the Developing Brain at New York-Presbyterian Hospital. But Lord said a parent’s acceptance of an incorrect diagnosis can harm a child: “People focus on something like that and don’t deal with the fact that this child has multiple difficulties and many of those multiple difficulties are treatable.”

Part of the problem is that SPD manifests itself in varied ways. “There are different kinds of sensory processing challenges,” said Elysa Marco, a cognitive and behavioral child neurologist at the University of California at San Francisco. “And certainly no two kids with that label are going to be exactly the same.”

Zimmer noted that some unusual behaviors may not last and are not necessarily indicative of anything larger. “Maybe it doesn’t turn into anything,” she said. “Maybe it’s just certain kids’ temperament. . . . Maybe they’re just more oversensitive to things, and usually those kids honestly grow out of it.”

Research and a diagnosis

Sensory processing has been in the news and on the minds of parents for decades — ever since occupational therapist and psychologist A. Jean Ayres focused on what was called sensory integration dysfunction in the 1960s.

But getting to the bottom of SPD has never been easy. Since SPD is not recognized by the likes of the AAP and the DSM-5, researchers in the field face particular funding challenges. Marco, who is director of research for the autism and neurodevelopment program at UCSF, is considering using crowdfunding for an upcoming project.

To foster scientific inquiry into SPD, since 2002, the Sensory Processing Disorder Foundation has been convening a work group of leading researchers. One of them is John J. Foxe, a professor of pediatrics and neuroscience at the Albert Einstein College of Medicine in New York. “I’m interested in the underlying neuropathologies that give rise to these kind of symptoms,” Foxe said.

Foxe, who is also the director of research at the Children’s Evaluation and Rehabilitation Center at Einstein, said that he has indeed seen children with only sensory processing problems: “The kids are out there, they’re suffering, and we need to get to the bottom of it. That’s really what matters here.”

Although a biological basis for SPD has been assumed for decades by some, it was first demonstrated only last year in a small study by Marco and other scientists from UCSF. Their research, published in NeuroImage: Clinical, an online journal, used an advanced imaging technique to show differences in connectivity in the part of the brain that processes information from the senses between boys identified with SPD alone and a control group.

“That’s, I think, the first study that showed a concrete, measurable structural difference in brains of kids who carry that label,” Marco said. Her next study will compare children with SPD alone and those with autism.

Other challenges to understanding SPD include the variety of its presumed causes and the fact that it changes over time: What you see at age 2 is going to be very different from what you see at 8 and 18, Marco said. So far, researchers have studied possible causes ranging from genetics to structural brain problems to premature birth. Studies in animals have linked sensory issues to prenatal exposure to lead or alcohol.

Foxe said his research — recording children’s brain wave patterns — found evidence that children identified with SPD are processing sensory inputs in a somewhat different way from others. “For me,” he said, “this is a home run from a science perspective that it’s clear that their brains are somewhat different.” Foxe and his colleague Sophie Molholm posit that a typical child processes, for example, the sounds, sights and feel of an object or an event as a whole experience, whereas a child with SPD would not be able to integrate these parts as easily. As a result, Foxe said, the world could become overwhelming for the SPD child.

Treating SPD

The frustrations of these sensory challenges can lead to temper tantrums and meltdowns. Kids sometimes get expelled from preschool because of their intense behavior issues.

“Everybody thinks they’re ‘a bad kid,’ ” said Lucy Jane Miller, clinical director of the Sensory Therapies and Research Center in Greenwood Village, Colo., which works with about 400 families a year. “But they’re not a bad kid, they’re just misunderstood.”

Such children can be helped through a variety of therapies. Often, an occupational therapist and/or a psychologist provide the treatment. Miller, who is also research director of the Sensory Processing Disorder Foundation, explains that the big goals of therapy are “social participation, self-regulation and self-esteem.”

The occupational therapy usually takes place in a gym with multisensory challenges such as climbing, jumping, riding zip lines and diving into a container of bubble balls. Other techniques might include comforting a restless child by covering him with slightly weighted blankets or gently brushing a child who is underresponsive.

Most experts believe OT can help children with sensory processing issues, but some, such as Lord, caution that there’s little scientific evidence to prove it. With the lack of in-depth data on treatment comes the possibility that families may be taken advantage of by the false promise of cures — a situation that can happen with other puzzling conditions such as autism or Asperger syndrome.

Zimmer encourages families dealing with sensory issues to have their pediatricians help navigate the child’s treatment by occupational therapists. OT sessions, which can run roughly $125 to $200 an hour, are often conducted weekly, but some practices offer intensive programs over several weeks. Whereas insurance may not pay for treatment for SPD, these visits may be covered for a coexisting condition such as autism or for developmental delays or low muscle tone and/or coordination issues that interfere with daily life.

At age 5, the Silver Spring boy who avoided bubble wrap games is doing better, thanks, his mother said, to occupational and speech therapy, his special school and efforts at home by his parents. He seems much more comfortable in the world, and, his mother said, “He can function and look pretty normal most of the time.”

Levingston is a writer in Bethesda.