Crash Course in Sensory Processing Disorder

This is even more interesting. I'm going to try to simplify it...

There are external senses, sight, smell, hearing, taste, and touch. There are also internal senses, interoception (feedback from internal organs), vestibular sense (balance from the inner ear), and proprioception, feedback from muscles and joints. The brain takes in feedback and input from each of these senses, and responds appropriately. In kids with SPD, there is a disconnect somewhere that prevents them from responding appropriately. Problems can be as follows:

The brain may not receive or detect sensory input
The brain may not organize and integrate sensory messages correctly
The brain may send out inaccurate messages to direct the child's actions- he may have problems "looking, listening, paying attention, interacting with people and objects, processing new information, remembering, and learning".


Put simply, some kids overrespond, some underrespond, and some crave sensory stimulation. Some kids have a combination of problems depending on what they eat and what the circumstances are that day- what kind of sensory input they are getting. All of these problems can have profound effects on behavior, and may fluctuate depending on what specific sense is affected.

Justin has tactile overresponsivity, for example. Light touch can drive him nuts, especially on the top of the head. Tousling his hair can make him "duck and run", and rub his head to get rid of the light touch. He prefers hugs to light kisses. His behavior can be stubborn, rigid, inflexible, willful, pushy, and difficult for no reason, which can be an adversive responses to touch stimulation. Sometimes tickling him on the back of the neck can send him over the edge. Kids with tactile overresponsivity prefer deep touches, like tight squeezing hugs.

He is however sensory seeking when it comes to touch. He frequently crams his mouth with food, to the point that he can choke and vomit. He gets too close to other kids, bumping them, tackling them, and poking them in the eye. He likes messy activities and can do them for hours. He wants his shoes off so that he can feel the ground. He tolerates very hot and very cold weather without an issue. He likes movement that provides "strong sensory feedback", like swinging forever and being held upside down. All of these are characteristics of the sensory seeking child.

He also has a tactile discrimination problem, which simply put means that he has problems with motor tasks related to touch. He doesn't know how tightly to squeeze the doorknob to get it open. He has trouble pedaling a bike, because he can't figure out where his feet are supposed to go and how much pressure to exert. He has problems figuring out with his feet where the sidewalk ends and the grass begins, without looking. He has trouble pointing things out. He has problems with sorting and turning things around to fit them in tight spaces, like inserting a play piece of mail into the mailbox.

He may have oral apraxia, which means that he has poor tactile or touch awareness of his mouth, lips, tongue, and jaw, which would make it difficult for him to make certain sounds. The tactile system governs motor control and motor planning for using those muscles to produce intelligible speech. So along with the physical problem of fluid in the ear that has now been solved with the tubes, he has a tactile issue with speech.

Justin has auditory overresponsivity. In normal children, when loud noises come at them, a muscle in the middle ear contracts to stifle the vibrations. When a child feels threatened, and the sympathetic nervous system (SNS) goes into fight/flight mode, the little muscle does not contract, because attention to all sounds is imperative. Children with overresponsivity are constantly alerted by the SNS, and must listen to every sound, because the muscle does not clamp down in response to loud noises. This would explain why he empties everything out of containers and puts them on his head, to muffle loud sounds.

A child with auditory overresponsivity frequently displays avoidant behavior when it comes to crowds, birthday parties, large gatherings of people, and loud people. If they can't get away, they frequently raise their own voice, yelling over the hubbub to try to counteract the noise. Their state of constant alertness can use up energy, interfere with learning, slow language development and hamper social interactions.

Justin also has some problems with the vestibular sense, which is governed by the inner ear. He is sensory seeking in this area, which would explain why he enjoys intense movement experiences, like climbing on the couch, rocking the recliner feverishly, loving the sit and spin, being held upside down, swinging for a long period of time, and putting his head of the floor to look between his legs. In order to help these kids with speech, it is helpful sometimes to give them intense motor experiences first. Sometimes the vestibular stimulation helps a child speak once he gets moving. For example Justin is a chatterbox after the stimulation of swimming in a big pool, and he is more intelligible.

His problems with the vestibular sense can also explain why he has trouble going down stairs, but not up. It may be that he feels like he is losing his balance when he looks down the stairs. He is also overwhelmed by too many toys around him, and will start throwing them to try to regain order (I guess through disorder because he prefers them on the floor). He used to do the same thing with food, throw it on the floor or push some of it off if there was too much on his plate.

He can't discriminate pointing, can't get his brain to figure out how to follow when someone points, although when asked can point to an object himself. That is a sign of autism, and is also a sign of tactile dysfunction. He can't point to ask for something, or indicate interest in something, or follow when someone points at something across the room. He also doesn't follow your gaze when looking at something- I forget the name for it but it is a skill most toddlers master by now. If you ask him where something is, he'll say "right dere" instead of pointing to it. It may seem like something little, but pointing is a big deal in the world of autism diagnosis.


To be continued...