Chapter III (Continued) Health Evaluations for Young Children With Possible Autism
This section provides recommendations about both general and specific evaluations of health status for children with autism. In contrast to the behavioral assessment methods, health assessment methods are not used to identify or diagnose autism.
The diagnosis of autism is made based on historical information about and direct observation of a child's behavior (in terms of communication, social interactions, and maladaptive behaviors). Most experts on autism agree that there are currently no specific laboratory, imaging, electrophysiological or other medical tests that can be used to establish the diagnosis of autism.
However, there are several well-accepted reasons why it is important to perform general and specific health evaluations of young children with possible autism. There are also controversial methods that have been proposed for assessing children with autism. Both well-accepted health assessment methods and those that are more controversial are discussed in this section.
Primary reasons for health evaluations of children with possible autism
There are three primary reasons generally accepted by the professional community for doing health evaluations of children with autism. These are:
- to provide a general assessment of the child's health status (as is recommended for all children with possible developmental delays or disorders)
- to identify other conditions (such as hearing loss) that are sometimes confused with autism, in a child who does not have autism
- to identify and assess medical conditions or genetic syndromes that are sometimes associated with autism
Aspects of health evaluations reviewed in this section
It would be an extremely large task to evaluate the efficacy of all possible methods for assessing health status in children with possible autism. Therefore, the scope of this section is limited to the following:
- the general health evaluation process for children with possible autism
- a few specific assessment methods used to identify some of the more common associated health conditions seen in children with autism
- some controversial assessment methods for children with autism that are of current concern to parents and professionals
Providing a general health evaluation
Children with autism are susceptible to all the same health problems as children without autism. While there is an extensive scientific literature on the general health evaluation of young children, a systematic literature evaluation was not done for this topic since it was considered to be outside the scope of the guideline. The recommendations in this section are primarily general recommendations based on the consensus opinion of the guideline panel about general health care for children with autism. In some cases, these recommendations were derived from evidence reviewed in other parts of the guideline.
Assessing associated health conditions sometimes seen in children with autism
An important purpose of a comprehensive health evaluations for children with suspected autism is to identify possible associated medical conditions that are seen more commonly in children with autism than in the general population. These associated medical conditions include a variety of neurological problems (such as seizure disorders), genetic syndromes (such as Fragile X syndrome, a specific genetic disorder that is sometimes associated with the clinical picture of autism) and metabolic disorders. Table III-8 provides a list of medical conditions and syndromes that are more common in children with autism than in the general population.
Some of the health conditions associated with autism may benefit from early identification and appropriate treatment. For example, seizure disorders, hypothyroidism and some metabolic disorders are important to diagnose and treat as early as possible. In other cases, there may be no specific treatment for a condition, but identifying the condition may still be beneficial. For example, for some genetic conditions associated with autism (such as Fragile X syndrome), the primary benefit of early identification may be to provide appropriate genetic counseling to the parents.
This section of the guideline includes recommendations about specific methods for assessing hearing problems, seizures and Fragile X syndrome, which are three of the more common associated health conditions seen in children with autism. While there is an extensive scientific literature on each of these three topics, the relevant literature was not systematically reviewed because:
- the methods for assessing these associated conditions are well established
- these topics are not particularly controversial
- detailed information on these topics is considered to be readily available to interested professionals
Controversial methods of health assessment for children with possible autism
Another more controversial use of health assessment methods that has been proposed is the use of specific immune, allergic, or metabolic tests to identify subgroups of children with autism who may respond to specific medication or dietary interventions.
The justifications for such testing are based on various controversial theories about the causation of autism. The proponents of these medical tests maintain that in some children autism may be caused by certain immune, allergic, or metabolic processes related to diet, yeast infections, prior viral infections, or other causes. These theories are not generally accepted in the scientific community. Although it is generally accepted that autism is a biologically based condition affecting the central nervous system, extensive biological research has not yet identified any specific anatomical or biochemical findings considered to cause autism.
Systematic literature evaluations were done for the specific health assessment methods that are considered to be areas of current controversy. While some of these assessment methods, such as allergy testing, are well established as general diagnostic tools for specific health conditions, the use of these assessment methods in children with autism can be controversial. For some of these assessment methods an extensive scientific literature exists. For other topics, very little published scientific research is available, but the methods are discussed extensively by parents and others in the community.
Evaluating the use of MRI scans
One of the specific medical assessment methods evaluated in this chapter is the use of magnetic resonance imaging (MRI) scans to evaluate children with autism. There are many studies in the literature on the use of MRI scans in persons with autism to identify associated neurological conditions, such as tumors. These articles were not included in the literature review because evaluation of the efficacy of MRI scans for identifying tumors and neuropathology is well established and is beyond the scope of the guideline. However, the guideline panel did review studies that evaluated the structural anatomy of the brain seen on MRI scans in children with autism compared to children without autism. These studies were reviewed to assess if MRI scans offered any information that would be useful for either estimating prognosis or guiding treatment decisions in persons with autism. In addition, the panel also evaluated the use of single photon emission computerized tomography (SPECT) scans, which are another type of imaging test sometimes proposed for assessing children with autism.
Evaluating the use of other medical assessments
Topics included in this section include:
- immune status
- food allergies
- lab tests to look for yeast overgrowth
The remaining parts of this section evaluate certain medical assessment methods purporting to identify subgroups of children with autism who may respond to specific interventions. Identifying such subgroups is the usual rationale given by proponents of assessing immune status, food allergies, and urinary organic acid metabolites to look for yeast overgrowth in individuals with autism. Proponents of these testing methods also maintain that individuals with autism who have positive results on these tests may respond to special immunological, diet, or anti-yeast therapies.
These assessment methods and associated treatments, as well as the theories they are based on, are all controversial. However, these controversial assessment methods are included in order to provide evidence-based recommendations to parents and professionals who may be considering the use of these methods.
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Table III-8:
Medical Conditions and Syndromes Seen More Frequently in Children with Autism than in the General Population
Cytomegalovirus
infection
Duchenne muscular
dystrophy
Encephalitis
Fragile X syndrome
Haemophilus influenzae
meningitis
Herpes simplex
encephalitis
Hypomelanosis of Ito
Hypothyroidism
Lactic acidosis
Maternal rubella
Multiple congenital abnormalities
/
Mental retardation syndrome
Moebius syndrome
Mucopolysaccharidosis
Neurofibromatosis
Other autosomal chromosome
abnormalities
Other sex chromosome
abnormalities
Partial tetrasomy 15
syndrome
Phenylketonuria
Purine disorders
Rett's disorder
Seizures
Sotos syndrome
Tuberous sclerosis
West syndrome
Williams syndrome
Adapted from Gilberg and Coleman, 1996
General Strategies for the Health Evaluation
| Evidence Ratings: [A] = Strong [B] = Moderate [C] = Limited [D1] = Opinion/No evidence meeting criteria [D2] = Literature not reviewed |
Recommendations
Importance of the general health evaluation for children with possible autism
- It is important that all children with suspected developmental problems have a comprehensive health evaluation. [D2]
- It is important to carry out a comprehensive health evaluation for children with possible autism in order to:
- screen for disease and assess suspected health problems
- look for associated medical conditions or genetic syndromes that are not part of autism but are seen more frequently in children with autism
- look for evidence of other developmental problems, since these are more frequently seen in children with autism than in typically developing children
- aid in assessing the child's level of development
- aid in planning of interventions and assessing health outcomes from interventions [D2]
Components of the health examination
- It is important to recognize that children with autism are susceptible to all the same health and medical problems as children without autism. [D2]
- It is important to recognize that health care for children with autism may present special challenges for health care providers and parents. [D2]
- It is important that a general health evaluation for children with possible autism include at least the following components:
- assessment of hearing and vision
- a neurological evaluation
- a skin exam (for signs of tuberous sclerosis or neurofibromatosis)
- a search for medical conditions, genetic syndromes, or other developmental problems that are sometimes associated with autism
- elements of routine developmental surveillance and general health screening appropriate for the child's age
- assessment of other current health problems
- addressing any other health concerns expressed by the parents [D2]
Role of the health evaluation in diagnosing autism
- In assessing a child where autism is suspected but has not yet been diagnosed, it is important to recognize that:
- The diagnosis of autism is made based on historical information about and direct observation of a child's behavior (in terms of communication, social interactions and maladaptive behaviors).
- Most experts on autism agree that there are no specific laboratory, imaging, electrophysiological or other medical tests that can be used to establish the diagnosis of autism.
- There are currently no laboratory tests or clinical assessment methods that are useful for identifying subgroups of children with autism that respond to specific medications, immune, or dietary interventions. [D1]
- As part of the process of diagnosing autism, it is important to:
- help identify and adequately assess any associated medical conditions or genetic syndromes that are not part of autism but are seen more frequently in children with autism than in the general population
- help identify other medical conditions and developmental problems that are sometimes mistaken for autism in children who do not have autism [D1]
Explaining the health assessment to parents and obtaining informed consent
- It is important that professionals carrying out the health evaluation of children with possible autism discuss the findings of the evaluation with the child's parents. [D2]
- In cases where a health assessment procedure is associated with some potential physical harm, it is important that professionals obtain appropriate informed consent from the child's parents prior to performing the test. [D2]
Tests to Identify Health Conditions Associated with Autism
Recommendations
Looking for associated health conditions
- It is recommended that professionals assessing health status of children with autism actively look for associated health conditions (listed in Table III-8 ) seen more commonly in children with autism than in typically developing children. [D2]
Evaluation of hearing status
- It is extremely important to establish the hearing status in a child with suspected or diagnosed autism to rule out hearing impairment as a contributing factor for the child's communication problems. [D2]
- If there is any indication that a child with suspected or diagnosed autism has a hearing problem, it is important to refer the child for a hearing evaluation by an audiologist (including brain stem evoked response testing if appropriate). [D2]
Testing for Fragile X syndrome
- In most children with suspected or diagnosed autism, it is useful to do an appropriate laboratory test for Fragile X syndrome in order to determine:
- possible appropriate interventions
- if genetic counseling is appropriate for the parents [D2]
- It is useful to recognize that Fragile X syndrome is less likely to be found in children with autism who have average or above average intelligence. [D2]
- In doing laboratory testing for Fragile X syndrome, it is recommended that a test be used which has established clinical validity and reliability (such as, a specific DNA probe test). [D2]
- In children with suspected or diagnosed autism, electro-encephalograms (EEGs), including possibly a sleep EEG, may be useful when there is an increased likelihood or clinical suspicion of possible seizures, including::
- a clinical history suggesting seizures
- an associated neurological abnormality
- a clinical picture of Landau-Kleffner syndrome (a specific condition in which the child has a form of epilepsy and also does not talk)
- in the clinical judgment of the physician it is important to rule out seizures [D1]
- An EEG is not useful for making the diagnosis of autism. [D1]
Magnetic Resonance Imaging (MRI)
Magnetic resonance imaging (MRI) scans of the head use strong electromagnetic fields to produce cross-sectional images of the head and brain. MRI scans do not involve ionizing radiation (such as x-rays or radioactive isotopes). Computer-generated cross-sectional images of the head and brain are produced in three geometric planes (coronal, frontal and sagittal). MRI scans provide information about the structural anatomy of the brain that can be used to detect abnormal anatomical structures, tumors, infections, traumatic injuries, and other pathological changes in the brain.
When a MRI scan is being done, the individual must remain still for about 45 minutes while lying on a table with the head inside a circular electromagnetic coil. The procedure almost always requires sedation for children under 3 years old. MRI scans are associated with minimal risks except for those related to sedation for the procedure.
| Evidence Ratings: [A] = Strong [B] = Moderate [C] = Limited [D1] = Opinion/No evidence meeting criteria [D2] = Literature not reviewed |
Recommendations
- Magnetic resonance imaging (MRI) scans may be useful in certain clinical situations in assessing children with autism when there is heightened concern about focal neurological problems, such as seizures. [D2]
- MRI scans may be useful in assessing some children at risk for neurological problems, such as children with a history of perinatal problems (medical problems that occurred around the time of birth). [D2]
- The use of MRI scans is not recommended in the routine assessment of children with possible autism. [C]
Single photon emission computerized tomography (SPECT) is a nuclear medicine technique that has been used to assess regional blood flow within the brain. SPECT involves either injecting the subject or having the subject inhale a small amount of radioactive tracer materials (radioisotopes). Two radioisotopes often used in SPECT scans of the brain are Technicium-99 (Tc99) and Xenon 133.
The radioisotopes travel via the blood stream to the brain and images of cerebral blood flow are obtained using a special camera that measures photon emissions from the radioisotopes. Subjects must remain still for 4-5 minutes while images are being recorded, so sedation is often needed to perform SPECT in younger children and uncooperative subjects.
Recommendations
- The use of single photon emission computerized tomography (SPECT) scan is not recommended in the assessment of autism in children. [D1]
The main function of the immune system is to differentiate between the self and foreign elements. A breakdown of self-recognition mechanisms, or autoimmunity, is characterized by cellular and/or humoral immunological reactions against the self. All of the studies of immune status in individuals with autism have been done to investigate if the immune status in these individuals is different than in individuals without autism. None of the studies found in the literature was designed specifically to see if evaluating immune status was useful for identifying young children with possible autism. However, since this was the question of interest to the panel, relevant information from these studies was used to evaluate the usefulness of evaluating immune status in assessing children with autism.
Studies in autistic subjects have focused on measuring cellular elements of the immune system (particularly T-cells and NK-cells) or measuring humoral immunity (particularly immunoglobulin levels or specific autoantibodies).
| Evidence Ratings: [A] = Strong [B] = Moderate [C] = Limited [D1] = Opinion/No evidence meeting criteria [D2] = Literature not reviewed |
Recommendations
- Evaluating immune status is not recommended in the routine assessment of children with autism. [C]
An allergy is an immunological sensitization to a specific foreign material that originates outside the person. Allergies are not inherited but must be acquired. Upon exposure to certain foreign materials, a person can become sensitized and then later develop allergic reactions when re-exposed to that substance. The majority of individuals are not allergic to any specific substance, and it is unclear why some persons develop an allergy after exposure to a material while others with the same type of exposure do not develop an allergy.
The most common types of allergic conditions are allergic rhinitis (hay fever) and allergic asthma. Allergic reactions can also occur to a variety of foods. However, in young children food allergies are much less common than allergic rhinitis or allergic asthma. The most common types of reactions from food allergies are nasal congestion and hives. Some individuals with severe food allergies do sometimes develop systemic allergic reactions and anaphylaxis. There are also other types of digestive or malabsorption problems that are not allergic conditions (such as lactose intolerance, an inability to digest milk products based on an enzyme deficiency rather than an allergy to milk).
The usual method to test for food allergies is to do skin prick or scratch testing. This involves placing a drop of sterile solution containing a very small amount of the allergen on the subject's skin, and then scratching or pricking the skin with a needle to introduce some of the solution under the skin. An alternative method of testing for allergies is to inject a small amount of the solution just below the surface of the skin (intradermal injection). This technique is used both for airborne allergens and food allergens.
Another method of testing for allergies is to check the person's blood for antibodies to the particular foreign substance. This method is considered by many experts to have lower accuracy, resulting in both more false positive and more false negative tests. Moreover, the validity (sensitivity and specificity) and reliability of these antibody tests appears to vary greatly depending on the individual allergen and test method being evaluated.
Elimination diets are also sometimes proposed as a method for detecting food allergies. These involve having a subject eliminate certain foods from the diet that are suspected of possibly causing allergic problems. After these foods have been eliminated for several weeks, each suspect food is then added back into the diet one at a time (this is referred to as a food challenge). Proponents of this approach suggest that if a subject's symptoms of concern improve during the food elimination stage, and then worsen again after a food is reintroduced, this suggests the individual is allergic to that particular food. Many allergy experts consider the use of elimination diets and food challenges to be controversial, and question the validity of these procedures for diagnosing food allergies.
| Evidence Ratings: [A] = Strong [B] = Moderate [C] = Limited [D1] = Opinion/No evidence meeting criteria [D2] = Literature not reviewed |
Recommendations
- Testing for food allergies is not recommended in the routine assessment of children with possible autism. [C]
- It is recommended that children with possible autism be treated no differently than other children in the assessment of food allergies. Testing for food allergies may be useful in some children if there is a heightened concern about allergies. [D1]
This assessment method involves laboratory analysis of a urine specimen for specific organic acid metabolites. The proposed rationale for such testing is based on the controversial theory that in some persons an overgrowth of yeast in the intestinal tract can cause or aggravate autism. Proponents of this theory suggest that an overgrowth of yeast in the intestinal tract can occur after the use of antibiotics or in certain susceptible individuals. They further maintain that this overgrowth of yeast leads to the systemic absorption of yeast metabolites, which then causes or aggravates manifestations of autism. These yeast metabolites are then said to be excreted in the urine as specific organic acids.
Proponents of this theory maintain that for a person with autism, high levels of specific organic acids in the urine suggest that an overgrowth of yeast in the intestinal tract may have caused or aggravated the autism. Proponents also suggest that in these individuals anti-yeast therapy may bring about an improvement in autism.
A further discussion of this theory is given in Chapter IV, Intervention Methods , which evaluates the use of anti-yeast therapies for children with autism.
| Evidence Ratings : [A] = Strong [B] = Moderate [C] = Limited [D1] = Opinion/No evidence meeting criteria [D2] = Literature not reviewed |
Recommendations
- Testing for specific organic acids in the urine as a means to identify an overgrowth of yeast in the intestinal tract is not recommended in the assessment of children with possible autism. [D1]
