The term 'Sensory Integration" is be used to reflect the theory developed by A. Jean Ayres, an occupational therapist, as well as for the intervention strategy that was based on that original theory.
Sensory integration is the brain's ability to take in, process, and organize sensory input from the seven senses, (sight, sound, smell, touch, movement, body awareness, and the pull of gravity),but also to integrate them together. This is how we perceive our environment and the people and physical objects in it, how we relate our body to them, as well as how they relate to each other. Sensory Integration is a normal phenomenon of central nervous system functioning and provides a foundation for more complex learning and behavior. We are all sensory processors, every waking minute. Here are some examples:
Learning and remembering which direction to run on a ball playing field
Finding something in your book bag, purse, or pocket without having to look with your eyes
Perceiving a piece of fruit, such as an orange, by color, shape, texture, weight, smell & taste
Holding a pen or pencil correctly, writing on paper, and pressing down just the right amount
being able to write alphabet letters without necessarily looking
Walking through the mall and not running into people
knowing "how far away" things are
Sensory processing and the ability to organize sensations also affect our emotions and feelings as well. Here are some examples:
A comforting touch...versus a painful shot...versus being tickled
An exciting roller coaster ride...versus slow rocking on the front porch
The smell of our favorite dish cooking in the kitchen...versus the odor of gas in our home
A loud, sudden alarm ringing...versus the sound of a loved one's voice
The taste of something foul versus Mom's warm cookies and milk
2. What are sensory integrative (also called sensory processing) disorders?
Sensory integrative/processing disorders are a set of conditions caused by an insufficient ability of the central nervous system to take in, register, modulate, perceive, and/or combine sensory experiences (input) from the environment around us. It starts with the most basic senses in the "sensory food chain", and moves upward. The senses affected include any or all of:
Vestibular: our sense of movement, the pull of earth's gravity, and position in space; the first sensory organ to be completed during pre-natal development. This sense allows us to maintain our balance and upright posture. It is also closely involved with the visual system, allowing us to judge our motion in relation to the objects around us. This can sometimes play tricks on us (sitting in one of those movies where you feel like you are moving when you aren't). This sense allows us to feel secure with gravity and is a way of knowing where we are in relation to gravity (i.e.. if we are upside-down or sideways).
Tactile: our sense of touch, not just from the hands, but from all over the body, including the inside of the mouth
Proprioception: our internal sense from joints and muscles; the basis of muscle memory. This is the sense that allows us to know what position our body parts are in. For example, without looking at them, you can tell if your elbows or knees are bent or straight. This sense also tells us about the force of our movements. So if we see a cup and want to reach for it, we can judge how much force and speed we are reaching with so we can accurately get our hand to the cup without knocking it over or missing it. We can also tell how hard we need to hold on to lift the cup without squashing it or dropping it. It is primarily proprioception you are using when you walk a familiar flight of stairs in the dark and know exactly where to place your feet and how high the steps are by the feel of the movement of your legs. This sense is extremely important for body awareness and coordinated movements.
Auditory: not just "hearing", but perception of different sound wave frequencies, perceiving the correct bits and pieces of sound that make up words, and organizing them in the correct sequence. For example, perceiving the word "caterpiller" instead of "callerpitter."
Visual: not simply "seeing", but perceiving brightness of light, spatial orientation, form, vertical vs. horizontal, color, shape, direction, etc.
Olfactory & Gustatory: our sense of smells, odors, and tastes, but also our perception of the intensity of them. Under-reactive individuals seek excessive salt, sweetness, or hot spice, while overly-reactive people may tolerate only very bland, or just a handful of different flavors in their "repertoire" of foods.
In SI/P disorders, the person affected is not "blind" to sensory input. Rather, the neural messages become disorganized as they travel up towards the higher brain centers. The messages may also become overly-amplified or diminished, and are hence un-usable. Sensory inputs are the building blocks of learning and relating to our environment and the people in it.
3. Is there more than one type of S.I. disorder?
There are four major sub-types of sensory processing disorder:
Sensory modulation dysfunction
Postural-Bilateral Integration dysfunction
Generalized dysfunction (impairments in all areas)
This set of problems first began to be identified in the 1960's by Dr. A. Jean Ayres, an occupational therapist. Ayres initially noticed that people with primary motor disorders also had significant visual-spatial, tactile, and vestibular perceptual impairments. Later, she identified the movement disorders of apraxia (or developmental dyspraxia) in children, as well as postural-bilateral integration dysfunction. She also identified patterns of over-reactivity or under-reactivity to sensory experiences that we now call sensory modulation dysfunction.
Sensory Modulation Dysfunction: Just as you can control the volume on your radio or television from very faint, to quite loud, the brain has built-in systems that automatically "decide" how much sensory information they will allow to enter. This ability helps us to "filter" sensations, putting more emphasis on those that are important at the moment, while damping down those that are not---a process called "inhibition." However, children with SMD are not effective sensory modulators. Their brains may interpret a tickling feather as painful, a conversational tone of voice as "too loud", or a little bit of movement as "making me dizzy." The smell or taste of many foods may actually make them become nauseous and vomit.
At other times, the opposite can happen. The child may seem sluggish, or unaware of sensory stimuli. A bad fall that causes a bruise doesn't make them cry; or they can spin in circles repeatedly and not feel dizzy. They may even seem to crave certain sensory experiences, like engaging in a lot of falling-and-crashing play.
Developmental Dyspraxia is a type of coordination disorder where the child is unable to mentally visualize and "figure out", or plan, new or skilled movements. (People usually say the child is "clumsy.") These movements might involve large muscle actions, like learning how to roller skate or do a cartwheel; or fine hand/finger skills for handwriting or using tools like scissors, or eating utensils.
Children with milder impairment have a "mental picture" of what they wish to do (called ideation), but cannot execute the body positions and action sequences to accomplish it. More severely impaired children do not have a mental image of the possibilities of a given object.
Even more significantly, Ayres found that these dyspraxic children showed an underlying pattern of impairment in the detection, organization, and discrimination of sensory information from the skin (tactile), joints and muscles (proprioception), and/or vestibular system (inner ear "equilibrium"). Her hypothesis for successful intervention was to treat the underlying sensory processing issues---not an educational process to teach the child how to execute specific movements.
Postural-Bilateral Integration problems, children demonstrate:
immature developmental reflexes and core muscle patterns
poor ability to use the two sides of the body together
a tendency not to cross the body midline
poor lateral dominance development
poor conjugate eye movements
confusion about space, distances, and directionality
unusual fear/discomfort in certain positions (on tummy, moving backwards, going down stairs, riding on parent's shoulders)
This is the child who switches hands to write or draw on different sides of the page; confuses "b" and "d", or "m" and "w"; has difficulty with skills requiring alternating limb movements, such as riding a bike, roller skating, or two-handed skills like buttoning a shirt.
4. How do I know if my child has a sensory integration disorder?
As efficient organization of sensory information provides the foundation for the development of functional skills, there can be many potential outcomes that might cause a parent concern.
A disruption in sensory processing can result in sensory defensiveness (sensory seeking or sensory avoiding behaviors), problems in self-regulation (activity levels too high or too low, not matched for the task at hand), and difficulties with praxis (the ability to conceive, organize and execute skills of all kinds). Disruptions in processing sensory information can interfere with self-care skills, language skills, motor skills, academic skills, and social/emotional skills.
Some specific concerns might be:
Takes a long time to learn a new task/skill
Seems clumsy, has too many accidents
Not keeping up with peers
Presents as a behavior problem at school
Has trouble with handwriting
Demonstrates unpredictable behavior in social situations, especially new or highly stimulating ones
Acts restless/fussy when held
Displays short attention span
Seems overly dependent on routine or schedules and/or easily upset with minor changes
Acts impulsively or explosively
Angers easily or frequently accused of of fighting, acting out or "bullying" others
Appears overly colicky or fussy
Exhibits "picky" eating behavior
5. Can't they just practice?
We are sure that the family and teaching staff have tried to "teach" the child skills that appear difficult. Unfortunately, unless the child has the underlying ability to "be taught" the skill, it will not important to remember that not all types of learning, particularly motor learning, can be mastered by practicing. No matter how many times children practice a wrong pattern, it won't make it right. Until they have the internal ability to do it correctly, they will be unable to correct the problem.
6. Why is sensory integration disorder not listed in the ICD-9 diagnostic manual? My physician is unable to find it.
Most of the individual components of SPD can be identified within the ICD-9, but there is not yet a set of listings that encompass the family of sensory processing/integration disorders. (However, there is a procedural code for sensory integration treatment in the CPT manual.)
7. Who will pay for therapy?
Most insurance companies will pay for "medically necessary" therapy. Otherwise the family will assume financial responsibility. Our experience with this process is that the insurance company will cover the cost of the evaluation, and then determine funding the services from the results of the evaluation.