Chapter 9: Autism Spectrum Disorder Flashcards
Prevalence of Autism Spectrum Disorder
- Steadily increasing, mostly from increases in milder cases
- About 2% of the US population
- People thought DSM-V would ameliorate some of the increase by making the criteria less subjective (putting mmroe emphasis on repetitive & restrictive behaviors as a criteria), but this has not affected the ttrajectory in prevalence.
- Genetic cause identified in only 20% of cases. Mostly epigenetics (genetic predisposition + environment).
General Use of CAM in Autisom Spectrum Disorder
- 28% of patients with autism use CIH
- Higher parental education and families using > 20 hrs per week of conventional services more likely to use CIH
- Likely to use more than one kind of CIH - monitor for interactions
Guideline for parents interested in CIH:
* research safety and effficacy
* isolate behavior you hope to improve
* start one new treatment at a time
* know that all kids with autism will improve in development over time
* kids may naturally have good vs bad weeks regardless of Rx
* observe other confounding life factors (new baby, vacation)
* work on sleep first!
Epigenetic theory of Autism
Autism is caused by **multiple genes **acting over time in a progressive, longitudinal disorder of brain development that likely starts in prenatal life and has a cascading effect that may be uniquely different in each child.
Brain imaging shows differences in brain structural development and altered functioning.
Risk factors for development of Autism
- prematurity and other pregnancy or birth complications
- twins or multiple pregnancies
- maternal immune activation
- maternal obesity and diabetes
- advanced maternal and paternal age at conception
- infection and immune abnormalities in the child
- Protective factors: folic acid supplementation.
What is the MOST important aspect of interventional therapy for autism?
Early diagnosis!
Earlier interventions = better outcomes.
What is the ONLY conventional therapy proven through evidence to marginally treat the core disorder of autism?
Intensive behavioral therapy, or applied behavioral analysis (ABA)
- designed to increase socially appropriate behavior and decrease the severity and/or emergence of challenging behaviors.
- focuses on teaching specific behaviors in a systematic manner in the context of repeated trials.
- improves language, communication, social relatedness, and decreasing repetitive behaviors
There are NO medications known to treat the core symptoms of autism. (Comorbid medical conditions can be treated)
Potential reasons for GI problems in Autism
- Co-occurring conditions, medications, and restrictive diets may cause GI symptoms.
- individuals with autism who have GI symptoms may manifest their discomfort as agitation, irritability, or repetitive behaviors (ie the behaviors ascribed to ASD)
- the gut may play a causal role in ASD (microbiome, leaky gut, maternal immune system interactions)
Leaky Gut / Dysbiosis theory of Autism
- Altered intestinal permeability (“leaky gut”), possibly in response to allergy or inflammatory response, may play a pathogenic role
- several studies report impaired intestinal barrier function in autism.
- elevated levels of a bacterial product (p-cresol) in the urine of kids with ASD
- higher concentrations of Clostridia, Bacteroidetes, and Firmicutes in kids with ASD.
- Intestinal permeability issues: impaired nutrient absorption AND neuropeptides can get into bloodstream affecting the brain
Probiotics in Autism
- probiotics decreased the levels of plasma myeloperoxidase (MPO) in kids with autism and improved GI absorption in general
- Not enough studies to inform standard recommendations
- Most common Lactobacillus rhamnosus GG and Saccharomyces boulardii.
- Fecal transplant may improve GI sx and core ASD sx!
Gluten / Casein elimination in ASD
- Theory: increased intestinal permeability allows gluten and casein peptides to leak from the gut and promote opioid activity resulting in ASD behaviors.
- No convincing evidence of any benefit
- Risks: low calcium, vitamin D, aminoa acids, decreased bone density
- High dropout rates
Suggestions if parents wish to try it:
1. work with dietician
2. list the behavior / diet problems they wish to monitor
3. clear start and stop date (60-90 days)
Exercise in ASD
- Can improve behaviors & academic performance
- Can improve metabolic indicators and lower cholesterol
- Recommend aerobic exercises that can be performed in groups but dont require strict rules (running, swimming, treadmill, bicycling)
Stimulants in Autism
- ADHD may be apparent in up to half of patinets with Autism
- Very few RCTs published, limited evidence to support treating with stimulants
- kids with autism are more sensitive to stimulants and experience more side effects
- Dosse: half tab of, short trial of methylphenidate or amphetamine
- If intolerant (tics, hyperemotional) consider guanfacine or clonidine (limited evience)
- Nonstimulant atomoxetine (a norepi reuptake inhibitor) can help with hyperactiity and stereotypic behaviors. Takes 6-8 weeks to see full effects!
Antipsychotics in autism
- Risperidone and aripiprazole
- For irritability and explosive behavior
- similar side effects for both: rapid weight gain (big appetite –> elevated TGLs, diabetes)
- Monitor for extrapyramidal symptoms for both
- Aripiprazole can cause hypothyroidism, QT prolongation, neutropenia, HLD, DM, suicidal ideation
SRIs and SSRIs in autisim
- treat anxiety, phobias, and compulsions
- Mixed efficacy in trials –> limited use is supported
- Fluoxetine preferred. Low dose better for depression and compulsions. High dose better for anxiety.
- Side effects: agitation, poor sleep, increased energy
Unproven or disproven meds for autism
- antifungals
- antibiotics
- chelation. One small study suggesting benefit, but side effect unaccpetably high (renal and hepatic toxicity, fatal hypocalcemia)
- secretin
- immune therapy (IVIG or oral IGs)
