|
George T. Capone, M.D. Director of the Down Syndrome Clinic and Attending Physician on the Neurobehavioral Unit at Kennedy Krieger Institute, Baltimore, MD Disability Solutions, September/October, 1999 Volume 3, Special Issue 5 & 6, p. 8-15. |
 |
Printed with the permission of Joan E. Medlen, R.D., Editor
9220 S.W. Barbur Boulevard, #119-179 Portland OR 97219-5428 (503) 244-7662 Fax: (503) 246-3869 |
During the past 10 years, I've evaluated hundreds of children with Down syndrome, each one with their own strengths and weaknesses, and certainly their own personality. I don't think I've met a parent who does not care deeply for their child at the clinic; their love and dedication is obvious. But some of the families stand out in my mind. Sometimes parents bring their child with Down syndrome to the clinic—not always for the first time—and they are deeply distraught about a change in their child's behavior or development. Sometimes they describe situations and isolated concerns that worry them such as their child has stopped learning new signs or using speech. He is happy playing by himself, seeming to need no one else to make the odd game (shaking a toy, lining things up) he is playing fun. When they call to him, he doesn't look at them. Maybe he isn't hearing well? He will only eat 3 or 4 foods. The suggestion of a new food, or even an old favorite, brings about a tantrum like no other. He is constantly staring at the lights and ceiling fans. Not just while they pass by, but obsessively. Getting him to stop staring at the lights is sometimes difficult and may result in a scene. He requires a certain order to things. Moving a chair to another spot in the room upsets him until it is returned to its usual spot.
Some families do their own research and mention they think their child may have autistic spectrum disorder (ASD) along with Down syndrome. Others have no idea what may be happening. They do know it isn't good and they want answers now. This article is for families in situations like this and other, similar ones. If your child has been dually-diagnosed with Down syndrome and autistic spectrum disorder (DS-ASD) or if you believe your child may have ASD, you will learn a little more about what that means, what we are learning through data collection, and insights to the evaluation process.
There is little written in the form of research or commentary about DS-ASD. In fact, until recently, it was commonly believed that the two conditions could not exist together. Parents were told their child had Down syndrome with a severe to profound cognitive impairment without further investigation or intervention into a diagnostic cause. Today, the medical profession recognizes that people with Down syndrome may also have a psychiatric-related diagnosis such as ASD or Obsessive Compulsive Disorder (OCD). Because this philosophy is relatively new to medical and educational professionals, there is little known about children and adults with DS-ASD medically or educationally.
Over the past six years we have gathered data and studied DS-ASD at Kennedy Krieger Institute. We have collected and analyzed data from clinical medical evaluations, psychological and behavioral testing, and MRI scans of the brain. We now follow a cohort of approximately 30 children with DS-ASD through the Down syndrome Clinic, possibly the largest group of children with DS-ASD that has been gathered.
Along with these behaviors, other medical conditions may also be present including seizures, dysfunctional swallow, nystagmus (a constant movement of the eyes), or severe hypotonia (low muscle tone) with a delay in motor skills.
If your child with Down syndrome is young, you may see only one or a few of the behaviors listed above. This does not mean your child will necessarily progress to have autistic spectrum disorder. It does mean that they should be monitored closely and may benefit from receiving different intervention services (such as sensory integration) and teaching strategies (such as visual communication strategies or discrete trial teaching) to promote learning.
A second group of children are usually older. This group of children experience a dramatic loss (or plateauing) in their acquisition and use of language and social-attending skills. This developmental regression may be followed by excessive irritability, anxiety, and the onset of repetitive behaviors. This situation is most often reported by parents to occur following an otherwise "typical" course of early development for a child with Down syndrome. According to parents, this regression most often occurs between ages three to seven years.
The medical concerns and strategies for these two groups may be different. There is not enough information available to know at this time. However, regardless of how or when ASD is first discovered, children with DS-ASD have similar educational and behavioral needs once they are identified.
 |
| Madison Duffey shows off her new hair ties |
Although we are documenting some similarities in the way DS-ASD presents, autism is what is considered a spectrum disorder. This means every child with DSASD will be different in one way or another. Some will have speech, some will not. Some will rely heavily on routine and order, and others will be more easy-going. Combined with the wide range of abilities seen in Down syndrome alone, it can feel mystifying. It is easier if you have an understanding of ASD disorders separate from Down syndrome.
Autism, autistic-like condition, autistic spectrum disorder (ASD), and pervasive developmental disorder (PDD) are terms that mean the same thing, more or less. They all refer to a neurobehavioral syndrome diagnosed by the appearance of specific symptoms and developmental delays early in life. These symptoms result from an underlying disorder of the brain, which may have multiple causes, including Down syndrome. At this time, there is some disagreement in the medical community regarding the specific evaluations necessary to identify the syndrome or the degree to which certain "core-features" must be present to establish the diagnosis of ASD in a child with Down syndrome. Unfortunately, the lack of specific diagnostic tests creates considerable confusion for professionals, parents, and others trying to understand the child and develop an optimal medical care and effective educational program.
There is general agreement that:
The most commonly described areas of concern for children with ASD include:
Of course there is inconsistency in any of these areas in all children, especially during early childhood. Children who have ASD may or may not exhibit all of these characteristics at any one time nor will they consistently demonstrate their abilities across similar circumstances. Some of the variable characteristics of ASD we have commonly observed in children with DS-ASD include:
 |
| Ryan Drape of Wilts, England |
Sometimes these characteristics are seen in other childhood disorders such as attention deficit hyperactivity disorder or obsessive compulsive disorder. Sometimes ASD is overlooked or considered inappropriate for a child with Down syndrome due to cognitive impairment. For instance, if a child has a high degree of hyperactivity and impulsivity only the diagnosis of ADHD may be considered. Children with many repetitive behaviors may only be regarded as having stereotypy movement disorder (SMD), which is common in individuals with severe cognitive impairments.
Most parents agree that severe behavior problems are usually not easily fixed. Finding solutions for behavioral concerns is one reason families seek help from physicians and behavior specialists. Compared to other groups of children with cognitive impairment, those with Down syndrome, as a group, are less likely to have behavioral or psychiatric disorders. When they do, it is sometimes referred to as having a "dual-diagnosis." It is important for professionals to consider the possibility of a dual diagnosis (Down syndrome with a psychiatric condition such as ASD or OCD) because:
If you think your child may have ASD disorder, share this before or during your evaluation. Don't wait to see what might happen.
Estimating the prevalence or occurrence of ASD disorder among children and adults with Down syndrome is difficult. This is partly due to disagreement about diagnostic criteria and incomplete documentation of cases over the years. Currently, estimates vary between 1 and 10%. I believe that 5-7% is a more accurate estimate. This is substantially higher than is seen in the general population (.04%) and less than other groups of children with mental retardation (20%). Apparently, the occurrence of trisomy 21 lowers the threshold for the emergence of ASD in some children. This may be due to other genetic or other biological influences on brain development.
A review of the literature on this subject since 1979 reveals 36 reports of DS-ASD (24 children and 12 adults). Of the 31 cases that include gender, an astonishing 28 individuals were males. The male-tofemale ratio is much higher than the ratio seen for autism in the general population. Additionally, in reports that include cognitive level, most children tested were in the severe range of cognitive impairment.
Generally, the cause of ASD is poorly understood, whether or not it is associated with Down syndrome. There are some medical conditions in which ASD is more common such as Fragile-X syndrome, other chromosome anomalies, seizure disorder, and prenatal or perinatal viral infections. Down syndrome should be included in this list of conditions. The impact of a pre-existing medical condition such as Down syndrome on the developing brain is probably a critical factor in the emergence of ASD disorder in a child.
The development of the brain and how it functions is different in some way in children with DS-ASD than their peers with Down syndrome. Characterizing and recording these differences in brain development through detailed evaluation of both groups of children will provide a better understanding of the situation and possible treatments for children with DS-ASD.
A detailed analysis of the brain performed at autopsy or with magnetic resonance imaging (MRI) in children with autism shows involvement of several different regions of the brain:
At Kennedy Krieger Institute, we have conducted MRI studies of 25 children with DS-ASD. The preliminary results support the notion that the cerebellum and corpus callosum is different in appearance in these children compared to those with Down syndrome alone. We are presently evaluating other areas of the brain, including the limbic system and all major cortical subregions, to look for additional markers that will distinguish children with DS-ASD from their peers with Down syndrome alone.
The neurochemistry (chemistry of the brain) of autism is far from clear and very likely involves several different chemical systems of the brain. This information provides the basis for medication trials to impact the way the brain works in order to elicit a change in behavior. An analysis of neurochemistry in children with ASD alone has consistently identified involvement of at least two systems.
Additionally, opiates, which regulate mood, reward, responses to stress, and perception of pain, may also be involved in some children.
Detailed studies of brain chemistry in children with DS-ASD have not yet been done. However, our clinical experience in using medications that modulate dopamine, serotonin or both systems has been favorable in some children with DS-ASD.
If you suspect that your child with Down syndrome has some of the characteristics of ASD or any other condition qualifying as a dual-diagnosis, it is important for him to be seen by someone with sufficient experience evaluating children with cognitive impairment—ideally Down syndrome in particular. Some of the same symptoms which occur in DS-ASD are also seen in stereotypy movement disorder, major depression, post-traumatic stress disorder, acute adjustment reactions, obsessive-compulsive disorder, anxiety disorder, or when children are exposed to extremely stressful and chaotic events or environments.
Sometimes when children with Down syndrome are experiencing medical problems that are hidden— such as earache, headache, toothache, sinusitis, gastritis, ulcer, pelvic pain, glaucoma, and so on—the situation results in behaviors that may appear "autistic-like" such as self-injury, irritability, or aggressive behaviors. A comprehensive medical history and physical examination is mandatory to rule out other reasons for the behavior. When cooperation is elusive, sedation or anesthesia may be required. If so, use this "anesthesia time" effectively by scheduling as many specialty examinations as are feasible at one session.
In addition to the medical assessment, you will be asked to help complete a checklist to determine whether or not your child has ASD. I use the Autism Behavior Checklist (ABC), but there are others that are also used such as the Childhood Autism Rating Scale (CARS) and the Gilliam Autism Rating Scale (GARS). Each of these is completed either in an interview with parents or done by parents before coming to the appointment. They are then scored and considered along with clinical observation to determine if your child has ASD.
"If it looks like a duck, and it quacks like a duck... guess what?"
Parents sometimes face unnecessary obstacles in seeking help for their children. Parents have shared several reasons demonstrating this. Some of the more common include:
Obtaining a diagnosis of DS-ASD is rarely helpful in understanding how ASD effects your child. It is complicated by the lack of information available, making it difficult to discern appropriate medical and educational options. To determine what behaviors are most common in DS-ASD we are conducting case-control studies which randomly match (for gender and age) a child with DS-ASD with a child who has Down syndrome without ASD. These comparisons are based on the information obtained from the ABC together with a detailed developmental history and behavioral observation. Through this process we have been able to determine the following:
Children with DS-ASD were more likely to have:
Other observations include:
The conclusion I draw from this data is children DSASD are clearly distinguishable from both "typical" children with Down syndrome and those with severe cognitive impairment (including children with Down syndrome). Thus, it is probably incorrect to suggest autistic-like behaviors are entirely due to lower cognitive function. However, the fact that autistic features and lower cognition are associated indicates there is some shared determinant(s) that are common to both features (ASD and lower cognition) of the condition.
There are questions about the possibility of similarities in the variety of medical conditions associated with Down syndrome in general in children with DSASD. To determine this we used the same matching scheme as described above. It is important to point out the number of matched pairs currently in our study is quite small and, as a result, some of these findings may not hold up as we examine more children. DS/ASD children were more likely to have:
If your child has DS-ASD, obtaining the diagnosis or label may be a relief of sorts. The addition of ASD brings new questions. From a medical perspective it is important to consider use of medication, particularly in older children, for specific behaviors. This is especially true if these behaviors interfere with learning or socialization. While there is no cure or remarkably effective treatment for Down syndrome and autistic spectrum, certain "target behaviors" may be responsive to medication. Some of these behaviors include:
As you continue to take care of your child, make a point to take care of yourself and your family—in that order. You have a life and a family to consider. Recognize that there is only so much time, energy and resources that you can put into this "project." Of course there will be cycles, of good times and bad, but if you can't find some way to renew your emotional spirit, then "burn-out" is inevitable. There is a higher rate of anxiety, sleep problems, lack of energy, depression, and failed or struggling marriages under these circumstances. Learn to recognize your own difficulties and be honest with yourself and your spouse about the need for help. Counseling and medication may go a long way in helping you to be at your best, for everyone's sake.
Clearly there is a great deal to be learned about children with Down syndrome who are dually diagnosed with autism spectrum disorder. In the meantime, it is essential for parents to educate themselves and others about this condition. Families must work on building a team of health-care professionals, therapists, and educators who are interested in working with their child to promote the best possible outcome. Research efforts must move beyond mere description to address causation, early identification, and natural history. Specific markers in the development of the brain which can distinguish DS-ASD from "typical" Down syndrome and "typical" autism need to be sought; and the possible benefits of various treatments need to be more carefully documented. Realizing these goals will take a very long time to accomplish and must be approached with a spirit of support, cooperation, and caring both for individual children and the larger community of children with DS-ASD.