090: Sensory processing disorder

This episode comes to us courtesy of my friend Jess, whose daughter has Sensory Processing Disorder (SPD) and who is on a mission to make sure that as many parents as possible learn about it. She says that every time she describes it to a parent they realize that they know someone who exhibits behavior that looks like SPD that warrants following up. I have to say that I was highly ambivalent about doing this episode, because I don’t usually deal with topics that result in medical diagnoses as I’m (obviously) not a doctor. But the more I looked into this the more I realized that helping parents to understand the mess of research on this topic is exactly the kind of thing that I usually do on this show, and that an episode on this topic could probably be useful to a number of you. And here’s the love letter to John McPhee that I mention in the episode     Read Full Transcript Hello and welcome to the Your Parenting Mojo podcast. Today’s episode on Sensory Processing Disorder comes to you courtesy of my friend Jess, and I’m going to tell you a little about Jess and her daughter as a way to introduce the topic. Jess told me that her daughter likely had a mini-stroke either in utero or during birth that affected the left side of her body, and Jess figured this out around the time her daughter was 10 months old. So her daughter started physical therapy for that, but Jess still felt as though something wasn’t quite right, and while she already had a pediatrician, physical therapist, and neurologist, six months or so of Jess being (in her words) “a crazy parent,” along with the support of her mother who happens to be a pediatric physical therapist, to convince her daughter’s support team that something wasn’t right, and finally her daughter was evaluated for sensory processing disorder. Her daughter received occupational therapy treatment and is now doing very well. Jess realized that if she hadn’t been especially vocal, and if she hadn’t had her own mother’s expert support, then it’s possible that her daughter’s issues would have gone undiagnosed. Jess told me she has started talking with anyone who will listen about this topic and whenever she mentions it a lightbulb goes off with whomever she is talking with about either a child in their lie or a friend of a friend who is having similar issues, so she asked me to do an episode on it so more people could learn about it. Now I have to say that as much as I love Jess I did hesitate before taking this on. I don’t usually deal with topics that result in medical diagnoses because I’m obviously not a doctor or a psychiatrist. But the more I looked into this the more I realized that helping parents to understand the mess of research on this topic is exactly the kind of thing that I usually do on this show, and that an episode on this topic could probably be useful to a number of you. So, to reiterate, I am not a doctor or a psychiatrist, and this episode is not intended to diagnose, treat, cure, or prevent any disease. In fact, for reasons we’ll get into in the episode, it’s actually kind of difficult for a doctor to diagnose as well. So we’ll talk about diagnoses, and about the efficacy of treatment for SPD, and finally about how to chart a path forward if you suspect that your child may have difficulties processing sensory information. So let’s get into it! For those of you who haven’t heard of it before, what is sensory processing disorder, and where did it come from? The research in this field was pioneered by Dr. A. Jean Ayres, who was an occupational therapist active from the 1960s to the 1980s. Dr. Ayres’ classic book is called Sensory Integration and the Child, and was re-released in 2005 in a 25th anniversary edition. In the book, Dr. Ayres describes sensory integration, which is the organization of our senses, which give us information about the physical conditions of our body and the environment around us. She says that the brain has to organize all of these sensations if a person is to move and learn and behave in a productive way – for example, by making your eyes, nose, mouth, skin, muscles, and joints work together to peel and eat an orange, and that an adaptive response to a sensory experience is a purposeful and goal-directed one. When we have an adaptive response we master a challenge and learn something new. Until the child is about 7, they are primarily a sensory processing machine – they sense things and respond, without having many abstract thoughts and ideas. Dr. Ayres says that the brain’s mental and social functions in the later years are based on this foundation of sensorimotor processes, and if sensorimotor processes are well organized in the first 7 years, the child will have an easier time learning mental and social skills later on. Dr. Ayres died in 1989, and Dr. Lucy Jane Miller has carried the flag on this work. Dr. Miller is the director of the Sensory Therapies and Research Center in Denver, Colorado, and has written her own book called Sensational Kids: Hope and Help for Children with Sensory Processing Disorder. In Dr. Miller’s book she shifts Dr. Ayres’ original six syndromes of sensory integration dysfunction into three main “pattern types” with a number of subtypes. Pattern Type 1 is Sensory Modulation Disorder (SMD), and results when a person has difficulty responding to sensory input with behavior that is appropriate to the degree, nature, or intensity of the sensory information. Dr. Miller’s book describes SMD as having three main subtypes, although her own peer-reviewed research has only found support for two of these – sensory seeking, and sensory underresponsivity. In Subtype 1, Sensory Overresponsivity (so the one that doesn’t have peer-reviewed research support), people respond faster, with more intensity, or for a longer duration than people with typical sensory responsivity. It may occur in only one sensory system (like not wanting to be touched) or in multiple systems. Difficulties are most often seen in new situations and during transitions, and the responses may appear as willful behavior, seemingly logical, and inconsistent. For example, a child with this subtype may not be able to tolerate being jostled as coats are being put on at preschool for the transition to outdoor play, and may lash out at another child in response. Behavior may also result from cumulative stresses, so the jostle while putting coats on might just trigger the response that has built up as a result of a whole morning of being jostled and touched through normal interactions. People with Subtype 2, Sensory Underresponsivity, disregard or do not respond to sensory stimuli. A child may seem apathetic, lethargic, and lacking an inner drive to socialize and explore. They might not notice bumps, falls, or cuts, or extreme eat or cold, and may be labeled ‘lazy’ or ‘unmotivated.’ As an infant, the child might have been considered a ‘good baby’ or an ‘easy child’ but when they become older they may not be able to maintain enough arousal to participate in family or school life. People with Subtype 3, Sensory Seeking/Craving, crave an unusual amount or type of sensory input, possibly including spicy food, loud noises, visual stimulation, and constant spinning, which can lead to socially unacceptable or unsafe behavior and can be perceived as demanding or attention-seeking. They may become explosive or aggressive when they are unable to meet their sensory needs – for example, when they are asked to sit still and be quiet at school. This subtype can be confused with, and even co-occur with, attention deficit hyperactivity disorder, or ADHD. People with Pattern 2, Sensory Discrimination Disorder, have trouble interpreting qualities of sensory stimuli and tell how they are similar and different; this characteristic may be present in just one or more than one sense. SDD in the tactile, vestibular, and proprioceptive systems, which tell you where your body is in the world, results in awkward motor abilities. SDD in the visual or auditory systems can lead to learning or language disabilities. There are two sub-types to Pattern 3, which is Sensory-Based Motor Disorder. In Subtype 1, Postural Disorder, the person has difficulty stabilizing the body during movement or at rest. The child may have low muscle tone, inadequate control of muscles and movement, and poor balance. In Subtype 2, Dyspraxia, the person has difficulty conceiving of, planning, sequencing, and executing actions. They may appear awkward and poorly coordinated in their gross motor skills like running and jumping, fine motor skills like drawing and painting, or oral-motor skills like chewing and swallowing. They seem unsure where their body is in space, have trouble with ball sports, and any actions involving coordinated timing. Where does SPD come from? Dr. Ayres herself acknowledged that we don’t really know what causes SPD, but she goes on to make quite a variety of speculations. She says “Many people think that the increase in environmental toxins, such as air contaminants, destructive viruses, and other chemicals that we take into our bodies may contribute to the dysfunction,” without offering a shred of supportive evidence from these “many people.” She hypothesizes that hereditary and chemical factors may be combined in some children, and that genetic factors in certain children may allow environmental toxins to interfere with sensory integrative development. Some babies do not get enough oxygen at birth, which may affect brain function, and that children who lead very deprived lives – like the children in the Romanian orphanages from the 1980s who had very little human contact – don’t develop adequate sensory, motor, or intellectual functions. But lest you start blaming yourself for your child’s problems, she goes on to say that most of the children with minor irregularities in brain function have had normal sensory experiences, and their parents or guardians did do a good enough job of raising them to allow for good brain development so the parents did not deliberately or accidentally produce the dysfunction. When I was researching this episode I got a question in the Your Parenting Mojo Facebook group about whether there’s any evidence about how children’s diets impact their sensory processing, and I have to say that this view is VERY popular in the online community groups related to SPD but I’m afraid there is zero evidence whatsoever in the peer-reviewed research, or even in the books by Dr. Ayres and Dr. Miller, that implicates children’s diets in causing or worsening SPD. The only potential connection I could see is that a child may be unwilling to eat if they find the textures of some foods to be difficult to deal with, but there is zero evidence that SPD is caused by gluten intolerance or eggs or sugar or food coloring or any other kind of food. I want to put a couple of side notes in at this point. Firstly, I’m also looking at doing an episode on Dr. Elaine Aron’s work on Highly Sensitive People, and in one of her papers Dr. Aron actually expressly makes the distinction that being a Highly Sensitive Person is different from Sensory Processing Disorder. In her book The Highly Sensitive Child, Dr. Aron says that many parents have told her they have found sensory integration to be helpful for their highly sensitive children, but she doesn’t think that being sensitive as she defines it is a problem to be treated, much less cured. Secondly, a couple of listeners have been in touch about unintegrated reflexes, and since the topic has a bit of an overlap with this one I’d like to address that here too. All babies have reflexes – one of the more famous ones is the Moro reflex which is when the infant spreads their arms and hands out and then pulls them in, usually while crying, when they feel they’re falling. In most infants this reflex goes away, which we call becoming “integrated,” by around four or five months of age but in some children this reflex doesn’t become integrated and the child will still produce it when they feel like they’re falling. There is quite a bit of evidence showing that unintegrated reflexes are *correlated* with a variety of developmental disabilities, but I’m afraid that’s pretty much where the evidence ends on this topic. It’s a bit hard to get your head around because nobody seems to have done any kind of meta-analysis to synthesize the results except the Wisconsin Department of Health Services which briefly reports that this therapy remains an “untested treatment, as there are no studies that have tested its effectiveness. There is no evidence to suggest that it is harmful.” Also, the main figure doing the research is Dr. Svetlana Masgutova is the creator of the Masgutova Neurosensorimotor Integration Method® and she’s also done a good chunk of the research on the effectiveness of the eponymous method. Unfortunately, methodological problems abound in the paper she’s done that’s most relevant to us, which is on the use of the Nurosensorimotor Integration Method in treating symptoms of Autism Spectrum Disorder. In that study she trated 484 children with autism, but the control groups were only 72 children with Autism who weren’t treated, and 483 children with neurotypical development. A more robust methodology would have compared the treated children with a much larger group of children who received comparable attention from a therapist and traditionally accepted treatment to compare the reflex integration treatment with traditional treatment, rather than with no treatment. It’s well-known that just attention from a therapist can produce a therapeutic effect even when the treatment itself doesn’t have any effect at all. And the results produced changes in reflex patterns, which were correlated with improvements in cognitive abilities, but since there’s no mention in the study of the children being randomly assigned to treatment or control groups, we can’t say with any certainty that the treatment *caused* these improvements. So that’s that. And while we’re on the topic of co-morbidity, which is two or more chronic diagnoses in the same individual, some authors estimate that the majority of children with autism spectrum disorders have SPD, although not all children with SPD have autism. SPD is also very difficult to diagnose, and this topic brings me to the part of the episode where I’m not going to just recite what Dr. Miller and Dr. Ayres say but bring a bit more of a critical perspective. SPD is actually not included in the Fifth Edition of the Diagnostic and Statistical Manual of Mental Disorders, which is abbreviated as DSM-V, which is the standard diagnostic guide for psychological diagnoses, although I should acknowledge that what makes it into the DSM is as much a political issue as a diagnostic one – the first and second editions of the DSM included homosexuality as a mental disorder and it wasn’t removed until 1973. Dr. Ayres developed a Sensory Integration and Praxis test which has been described as “the most comprehensive and statistically sound means for assessing some important aspects of sensory integration, most notably praxis and tactile discrimination,” but apparently five of the 17 subtests are unstable, which means that the same child is likely to get different results each time they are tested. Dr. Ayres reported that scores on the test were different for children with and without learning disabilities, although subsequent analyses of her work showed there were actually no reliable differences between the scores of children with and without learning disabilities, which is a pretty big problem. The American Academy of Pediatrics published a position paper in 2012 stating “it remains unclear whether children who present with findings described as sensory processing difficulties have an actual “disorder” of the sensory pathways of the brain (and I will note, Dr. Ayres says they do), or whether these deficits represent differences associated with other developmental and behavioral disorders. Specifically, the behavioral differences seen in children with autism spectrum disorders, attention-deficit/hyperactivity disorder, and developmental coordination disorders overlap symptoms described in children with sensory processing disorders. Studies to date have not demonstrated that sensory integration dysfunction exists as a separate disorder distinct from these other developmental disabilities. Furthermore, numerous challenges exist for evaluating the effectiveness of sensory integration therapy, including the wide spectrum of symptom severity and presentation, lack of consistent outcome measures, and family factors, which make response to therapy variable.” The APA officially recommends that “At this time, pediatricians should not use sensory processing disorder as a diagnosis.” Dr. Miller’s team published a paper in 2014 describing the development of a new scale to diagnose SPD, but it focused on only some of the sub-types and the study was conducted on only 20 children, and only 10 of those actually had a developmental disorder, with the other 10 being typically developing children in a comparison group. Dr. Miller does acknowledge that “the standardization of a reliable and valid scale to assess SPD is essential for the field to move forward” but at the moment, we don’t have one. So I want to set this issue of diagnosis aside for a bit and talk about prevalence and treatment, because that is, after all, how we got here in the first place – after occupational therapy was successful for my friend Jess’ daughter. The most widely cited study on the prevalence of SPD was conducted by Dr. Miller and her colleagues, where the researchers sent surveys out to the parents of one suburban public school asking about whether their children exhibit symptoms of SPD. Only 39% of the parents responded, and the researchers were conservative in assuming that none of the parents who didn’t respond who had children who had these symptoms, and based on this they came up with a prevalence rate of 5.3%. If you assume that the children of the non-responding parents had symptoms at the same rate as the responding parents then the prevalence rate goes up to 13.7%. Of course, there are a variety of problems with this – firstly, that this is a suburban school district of mostly white, middle class parents who may be more likely to look for symptoms in their children and report these to a set of researchers. The second problem is that 39% of parents from one school really is a pretty low response rate to base this kind of determination on, even if you are going to assess the results conservatively. Thirdly, the researchers didn’t make any attempt to study comorbidity, which is the concept of having more than one infliction at once, and as we already know SPD has a LOT of symptoms in common with other potential diagnoses. And, finally, there’s the predictable issue we see with so much other research on this show – we see a heavily caveated result in a paper that gets grasped by other researchers and reported as if it were fact: for example, a 2013 paper reports that “Mental health practitioners, however, may have limited information or understanding of [SPD]. This is concerning, as [the disorder] is estimated to occur in 5% of the general population (Ahn et al. 2004), equating to three million children in the United States (United States Census Bureau 2008).” Another set of researchers report that “In fact, Ahn, Miller, Milberger, and McIntosh found that 5-15% of children in the general population of kindergarten-age children demonstrate difficulties with sensory modulation” when in fact it would be irresponsible to generalize from...