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Breakthrough Study Reveals Biological Basis for Sensory Processing Disorders in Kids


The image shows areas of the brain that can be affected by sensory processing disorders. Using an advanced form of MRI, researchers at UCSF have identified abnormalities in the brain structure of children with SPD primarily in the back of the brain.

By Juliana Bunim on July 09, 2013


Sensory processing disorders (SPD) are more prevalent in children than autism and as common as attention deficit hyperactivity disorder, yet the condition receives far less attention partly because it’s never been recognized as a distinct disease.


In a groundbreaking new study

from UC San Francisco, researchers have found that children affected with SPD have quantifiable differences in brain structure, for the first time showing a biological basis for the disease that sets it apart from other neurodevelopmental disorders.

One of the reasons SPD has been overlooked until now is that it often occurs in children who also have ADHD or autism, and the disorders have not been listed in the Diagnostic and Statistical Manual used by psychiatrists and psychologists.

“Until now, SPD hasn’t had a known biological underpinning,” said senior author Pratik Mukherjee, MD, PhD, a professor of radiology and biomedical imaging and bioengineering at UCSF. “Our findings point the way to establishing a biological basis for the disease that can be easily measured and used as a diagnostic tool,” Mukherjee said.

The work is published in the open access online journal NeuroImage:Clinical.

‘Out of Sync’ Kids

Sensory processing disorders affect 5 to 16 percent of school-aged children.


Children with SPD struggle with how to process stimulation, which can cause a wide range of symptoms including hypersensitivity to sound, sight and touch, poor fine motor skills and easy distractibility. Some SPD children cannot tolerate the sound of a vacuum, while others can’t hold a pencil or struggle with social interaction. Furthermore, a sound that one day is an irritant can the next day be sought out.  The disease can be baffling for parents and has been a source of much controversy for clinicians, according to the researchers.


Elysa Marco, MD



“Most people don’t know how to support these kids because they don’t fall into a traditional clinical group,” said Elysa Marco, MD, who led the study along with postdoctoral fellow Julia Owen, PhD. Marco is a cognitive and behavioral child neurologist at UCSF Benioff Children’s Hospital, ranked among the nation's best and one of California's top-ranked centers for neurology and other specialties, according to the 2013-2014 U.S. News & World Report Best Children's Hospitals survey.

“Sometimes they are called the ‘out of sync’ kids. Their language is good, but they seem to have trouble with just about everything else, especially emotional regulation and distraction. In the real world, they’re just less able to process information efficiently, and they get left out and bullied,” said Marco, who treats affected children in her cognitive and behavioral neurology clinic.

“If we can better understand these kids who are falling through the cracks, we will not only help a whole lot of families, but we will better understand sensory processing in general. This work is laying the foundation for expanding our research and clinical evaluation of children with a wide range of neurodevelopmental challenges – stretching beyond autism and ADHD,” she said.

Imaging the Brain’s White Matter

In the study, researchers used an advanced form of MRI called diffusion tensor imaging (DTI), which measures the microscopic movement of water molecules within the brain in order to give information about the brain’s white matter tracts. DTI shows the direction of the white matter fibers and the integrity of the white matter. The brain’s white matter is essential for perceiving, thinking and learning.


These brain images, taken with DTI, show water diffusion within the white matter

of children with sensory processing disorders.  Row FA: The blue areas show

white matter where water diffusion was less directional than in typical children,

ndicating impaired white matter microstructure.  Row MD: The red areas show

white matter where the overall rate of water diffusion was higher than in typical

children, also indicating abnormal white matter.  Row RD: The red areas show

white matter where SPD children have higher rates of water diffusion perpendicular

to the axonal fibers, indicating a loss of integrity of the fiber bundles comprising the

white matter tracts.

The study examined 16 boys, between the ages of eight and 11, with SPD but without a diagnosis of autism or prematurity, and compared the results with 24 typically developing boys who were matched for age, gender, right- or left-handedness and IQ. The patients’ and control subjects’ behaviors were first characterized using a parent report measure of sensory behavior called the Sensory Profile. 

The imaging detected abnormal white matter tracts in the SPD subjects, primarily involving areas in the back of the brain, that serve as connections for the auditory, visual and somatosensory (tactile) systems involved in sensory processing, including their connections between the left and right halves of the brain. 

“These are tracts that are emblematic of someone with problems with sensory processing,” said Mukherjee. “More frontal anterior white matter tracts are typically involved in children with only ADHD or autistic spectrum disorders. The abnormalities we found are focused in a different region of the brain, indicating SPD may be neuroanatomically distinct.” 

The researchers found a strong correlation between the micro-structural abnormalities in the white matter of the posterior cerebral tracts focused on sensory processing and the auditory, multisensory and inattention scores reported by parents in the Sensory Profile. The strongest correlation was for auditory processing, with other correlations observed for multi-sensory integration, vision, tactile and inattention.

The abnormal microstructure of sensory white matter tracts shown by DTI in kids with SPD likely alters the timing of sensory transmission so that processing of sensory stimuli and integrating information across multiple senses becomes difficult or impossible.

“We are just at the beginning, because people didn’t believe this existed,” said Marco. “This is absolutely the first structural imaging comparison of kids with research diagnosed sensory processing disorder and typically developing kids. It shows it is a brain-based disorder and gives us a way to evaluate them in clinic.”

We are just at the beginning, because people didn’t believe this existed. ... [This study] shows it is a brain-based disorder and gives us a way to evaluate them in clinic.

Elysa Marco, MD

Future studies need to be done, she said, to research the many children affected by sensory processing differences who have a known genetic disorder or brain injury related to prematurity.

The study’s co-authors are Shivani Desai, BS, Emily Fourie, BS, Julia Harris, BS, and Susanna Hill, BS, all of UCSF, and Anne Arnett, MA, of the University of Denver.

The research was supported by the Wallace Research Foundation. The authors have reported that they have no conflicts of interest relevant to the contents of this paper to disclose.

UCSF Benioff Children’s Hospital creates an environment where children and their families find compassionate care at the forefront of scientific discovery, with more than 150 experts in 50 medical specialties serving patients throughout Northern California and beyond. The hospital admits about 5,000 children each year, including 2,000 babies born in the hospital. For more information, visit

UCSF is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care.


Signs and Symptoms of Sensory Processing Disorder

Ask parents of kids with learning and behavioral disorders if their children experience problems with sensory processing, and many of them will answer with a resounding “yes”. While it is widely accepted that most children with Autism Spectrum Disordershave trouble integrating sensory input, the fact that children who aren’t on the spectrum also experience these issues to varying degrees is now being examined more closely by the special needs community.  While all children can seem quirky or particular about their likes and dislikes, children with Sensory Processing Disorder (also called Sensory Integration Dysfunction) will be so severely affected by their sensory preferences that it interferes with their normal, everyday functioning. Sensory issues are usually defined as either hypersensitivity (over-responsiveness) or hyposensitivity (under-responsiveness) to sensory stimuli. Below, find some common signs of Sensory Processing Disorder.

Hypersensitivities to sensory input may include:

  • Extreme response to or fear of sudden, high-pitched, loud, or metallic noises like flushing toilets, clanking silverware, or other noises that seem unoffensive to others

  • May notice and/or be distracted by background noises that others don’t seem to hear

  • Fearful of surprise touch, avoids hugs and cuddling even with familiar adults

  • Seems fearful of crowds or avoids standing in close proximity to others

  • Doesn’t enjoy a game of tag and/or is overly fearful of swings and playground equipment

  • Extremely fearful of climbing or falling, even when there is no real danger i.e. doesn’t like his or her feet to be off the ground

  • Has poor balance, may fall often

Hyposensitivities to sensory input may include:

  • A constant need to touch people or textures, even when it’s inappropriate to do so

  • Doesn’t understand personal space even when same-age peers are old enough to understand it

  • Clumsy and uncoordinated movements

  • An extremely high tolerance for or indifference to pain

  • Often harms other children and/or pets when playing, i.e. doesn’t understand his or her own strength

  • May be very fidgety and unable to sit still, enjoys movement-based play like spinning, jumping, etc.

  • Seems to be a “thrill seeker” and can be dangerous at times.

 Kids with sensory sensitivities ...

often have trouble enjoying everyday activities like play dates and school functions. Extreme sensitivity to noise, crowds, touch, textures, bright lights, bothersome clothing, and new experiences are often so overwhelming for kids with sensory problems that it can run their lives and the lives of their parents. When symptoms are severe enough to interfere with daily functioning, it is often referred to as Sensory Processing Disorder(SPD) and can be co-morbid with anxiety disorders and Autism Spectrum Disorders. Find below some tips and strategies to help parents keep sensory sensitivities in check so kids can focus on growing, playing, and learning:

1. Earn Their Trust
Children with severe sensory issues often feel out of control and seem to be in “fight or flight” mode most of the time. Let your child know that you understand his issues are real and that you are working on a concrete plan to help minimize his stress and sensory overload. It may sound simple, but parents should do what they say and say what they mean, particularly for kids with special needs. This will help your child feel confident that you are in charge, that he is safe, and that you will be his advocate.

2. Manage Sensory Exposure
If your child has sensory problems, it is critical to stay ahead of known triggers to minimize meltdowns. For kids with hypersensitivity to noise, try giving them a quiet place at home they can go to when they feel overwhelmed and need a break. For older kids, it may help to give them a watch or timer so they know exactly what time a bothersome activity or environment will end. If your child has extreme sensitivity to certain types of clothing, go through his wardrobe together to determine which pieces are tolerable and which ones aren’t. Be an advocate for your child by explaining to others what sensory problems are and how they can help minimize your child’s distress. If possible, create small kits for dealing with sensory problems on the go so you’re always prepared. Kits should include ear plugs for noise, sensory fidgets to keep hands busy, and sticky notes to cover sensors on automatic toilets and hand driers. You may also want to include some headphones and a music player with their favorite music or a book for older kids. Staying ahead of your child’s sensory sensitivities by being prepared can go a long way in minimizing distress.

3. Schedule Silence
If you have a child who is hypersensitive to sensory stimuli, particularly noise and touch, he may benefit from scheduled silent time. Wake your child 15 minutes earlier in the morning to enjoy a favorite activity before school. Whether it be reading, computer time, or a game, make sure your child is quiet and undisturbed. Give your child at least thirty minutes of quiet time after school to rest and reset before bombarding him with questions or commands. Before bed, allow another 30 minutes of quiet time to unwind. Swinging and rocking are beneficial for organizing the senses, so quiet time can include those activities as well.


Treatment for Sensory Processing Disorder

Many families with an affected child find that it is hard to get help. That's because sensory processing disorder isn't a recognized medical diagnosis.

Despite the lack of widely accepted diagnostic criteria, occupational therapists commonly see and treat children and adults with sensory processing problems.

Treatment depends on a child's individual needs. But in general, it involves helping children do better at things they're not good at and helping them get used to things they can't tolerate.

Treatment for sensory processing problems is called sensory integration. The goal of sensory integration is to challenge a child in a fun, playful way so he or she can learn to respond appropriately and function more normally.

One type of therapy is called the Developmental, Individual Difference, Relationship-based (DIR) model. The therapy was developed by Stanley Greenspan, MD, and Serena Wieder, PhD.

A major part of this therapy is the "floortime" method. The method involves multiple sessions of play with the child and parent. The play sessions last about 20 minutes.

During the sessions, parents are first asked to follow the child's lead, even if the playtime behavior isn't typical. For example, if a child is rubbing the same spot on the floor over and over, the parent does the same. These actions allow the parent to "enter" into the child's world.

This is followed by a second phase, where parents use the play sessions to create challenges for the child. The challenges help pull the child into what Greenspan calls a "shared" world with the parent. And the challenges create opportunities for the child to master important skills in areas such as:

  • Relating

  • Communicating

  • Thinking  

The sessions are tailored to the child's needs. For instance, if the child tends to under-react to touch and sound, the parent needs to be very energetic during the second phase of the play sessions. If the child tends to overreact to touch and sound, the parent will need to be more soothing.

These interactions will help the child move forward and, DIR therapists believe, help with sensory issues as well.

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