You notice that your child hates loud noises, is sensitive to certain food textures, likes to eat only certain foods and does not handle transitions well. You may be concerned that your child has Autism. Instead, the occupational therapist diagnoses your child with Sensory Processing Disorder (SPD)! What is Sensory Processing Disorder (SPD) and how does it differ from Autism Spectrum Disorder (ASD)?
The difference is in the White (and grey) Matter of the Brain!
As you know, the human brain is a massive sensory processor. Its core function is to perceive, integrate, interpret, and then respond to the visual, tactile, auditory, olfactory, vestibular and proprioceptive information it receives from the world around us. When the brain has difficulty with the perception and integration of sensory information it receives, the interpretation and responses to that sensory information are impaired. In effect, “faulty” sensory processing and sensory integration results in the condition called Sensory Processing Disorder, also called Sensory Integration Disorder or SPD.
Sensory information comes into the brain through nerves, sometimes called the grey matter of the brain. Various parts of the brain talk to each other to process the information the brain receives through the white matter of the brain. White matter is what enables various parts of the brain to communicate with one another, essential for perceiving, thinking and acting.
Using a method called diffusion tensor imaging, (DTI) researchers at UC San Francisco have found that children with SPD have differences in brain white matter tracts in the back of the brain as compared with the brains of typically developing children. These differences correlate with behavioral differences in the child’s responses to auditory and tactile processing.
Autism Spectrum Disorder, on the other hand, has been linked to abnormalities in the grey and white matter of the brain. Researchers have found differences in brain volume in children with ASD as compared with typically developing children. According to the DSM-5 diagnostic criteria, social communication impairments and restricted, repetitive patterns of behaviors, are key to a diagnosis of ASD. Studies have found differences in those brain areas related to social communication and interaction in persons with ASD. A number of studies using brain imaging techniques such as fMRI and diffusion tensor image (DTI) identified abnormal brain connectivity in individuals with ASD. The studies suggest white matter differences in the brains of children with ASD occur throughout the brain.
Both groups have white matter deficits in the brain regions that handle basic sensory information and this may be the reason that children with SPD can look like they may have ASD. However, research has identified that children with ASD are different than children with SPD based on differences in brain wiring (white matter) as well as behaviors.
In Summary
The DSM-5 uses some of the following criteria to diagnose ASD: persistent difficulty in the social use of verbal and non-verbal communication, and restricted, repetitive patterns of behavior, interests, or activities, including a hyper- or hypo-reactivity to sensory input or unusual interests in sensory aspects of the environment. It is this latter response to sensory information that makes children with SPD look like children with ASD. While many children with SPD have difficulty with sensory processing, all children with SPD do not have ASD.
Whether your child has a diagnosis of SPD or ASD, the right kind of occupational therapy utilizing sensory integration techniques can help. The therapists at Irvine Therapy Services would love to meet you and your child and know that we can assist you in meeting your child’s sensory processing needs. If you have questions or concerns about your child’s development, please feel free to contact our office. Come in for a free, no obligation consultation! Please refer to Behavioral Manifestations of Sensory Processing Disorder for information about some signs and symptoms to identify a SPD.