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Chapter 10: Childhood Disorders

In This Chapter…

  • Autism

  • Attention Deficit Hyperactivity Disorder

  • Down Syndrome

  • Dyslexia

Autism

  • ASD (Autism Spectrum Disorders) are characterized by

    • impaired social skills

    • verbal & nonverbal communication difficulties

    • narrow obsessive interests or repetitive behaviors

  • Symptoms of ASD include:

    • intellectual disabilities

    • seizures

    • gastrointestinal problems

      • Increase due to the detection of subtler autism and an actual increase

  • ASD is thought to be highly genetic

    • 100+ genes are linked to an increased risk for autism

    • There is no single genetic or biochemical marker for autism

  • ASD is typically diagnosed based on behavior in children around 3 years old

  • ASD-affected children at 1-2 years old show abnormal growth of the brain

    • This indicates that brain development has gone awry

    • Also a potential marker for early evaluation

    • These brain alterations are subtle

  • Speculation: abnormal development in regions of the brain involved with language, cognition, and social communication leads to abnormal connections with other parts of the brain

  • No cure or drugs for the major symptoms of ASD

  • Good response to specialized behavioral therapies based on learning theory

    • Therapy is guided by an increased understanding of how the brain normally reacts to learning, bonding, and social challenge as it develops

Attention Deficit Hyperactivity Disorder

  • Attention deficit hyperactivity disorder (ADHD): Characterized by excessively inattentive, hyperactive, or impulsive behaviors

    • described 100+ years ago

  • Children with ADHD are more likely to have problems in

    • school

    • graduating high school

    • maintaining a job

    • abusing drugs

    • having healthy relationships

  • Symptoms appear by mid-childhood and last for 6+ months

  • ADHD impairs normal function to a significant degree in different settings:

    • Children: among friends, at school and home

    • Adults: at work and home

  • Diagnosis needs a comprehensive evaluation:

    • Clinical interview, parent & teacher ratings in children

    • self ratings in adults

  • Problems with attention may also be triggered by other conditions

  • ADHD has a strong genetic influence

    • Genes for dopamine and norepinephrine transmission may be affected

  • Altered activity is present in

    • Cerebral cortex

      • Delay in cortical development

    • Striatum- a part of the midbrain

    • Cerebellum (especially the right hemisphere)

  • Symptoms often change as growing older

    • Less hyperactivity

  • There is reduced catecholamine transmission in some individuals with ADHD

    • Prefrontal circuits need an optimal level of catecholamine stimulation

      • Reduced transmission could lead to weakened prefrontal cortex regulation of attention and behavior (symptoms of ADHD)

  • Treated with parent education, school-based intervention

    • Medications: stimulants (methylphenidate) and non-stimulant drugs

    • Meds all act by enhancing catecholamine stimulation

  • There is no cure to ADHD

Down Syndrome (DS)

  • Occurs at the time of conception (when egg is fertilized)

  • Down syndrome: caused by an extra copy of chromosome 21

    • Usually present in the egg but can also sometimes be in the sperm

  • Not linked to environmental or behavioral factors before or during pregnancy

    • The risk for down syndrome increases as the mother gets older

      • If the mother is 25 years of age, the risk is 1 in 1250

      • If the mother is 40 years of age, the risk is 1 in 100

  • Down syndrome can be diagnosed by prenatal screening tests

    • They accurately detect DS in around 70% of babies

    • Prenatal diagnoses can be obtained with either chorionic villus sampling or amniocentesis

      • Chorionic villus sampling (CVS): obtaining a sample of the chorionic villi in the placenta to get the fetus’s DNA

        • CVS can be done in 2 forms:

          • transcervical- through the cervix

            • miscarriage rates slightly higher if done this way

            • performed by inserting a thin plastic tube through the vagina and cervix to reach the placenta

          • transabdominal- through the belly

      • Amniocentesis: a prenatal test in which a small amount of amniotic fluid is removed from the sac surrounding the fetus for testing

        • The sample of amniotic fluid is removed through a fine needle inserted into the uterus through the abdomen, under ultrasound guidance.

        • Less than 1 ounce is collected

  • DS is associated with around 50 physical/developmental characteristics

  • Individuals with DS are likely to possess:

    • Mild to moderate intellectual disabilities

    • Low muscle tone

    • Upward slant of the eyes

    • Flat facial profile

    • Enlarged tongue

    • Increased risk of congenital heart defects

    • Respiratory problems

    • Digestive tract obstruction

  • Individuals with down syndrome show neurological changes similar to Alzheimer’s by 40 years of age

    • Experience cognitive decline by 60 years of age

  • DS babies develop as much as typical children but at a slower rate

  • There is currently no cure for DS

Dyslexia

  • Around 8-10 % of children in the US have a form of learning disability involving difficulties in the acquisition and use of listening, speaking, reading, writing reasoning, and mathematical abilities

  • Dyslexia: unexpected difficulty in speaking & reading in children & adults who otherwise possess the intelligence, motivation, and schooling necessary for accurate fluent reading

    • Dyslexia affected 80% of learning disabled

      • 15-20% of Americans

    • It is a persistent, chronic condition though improvements can occur

    • Most forms reflect a deficit in the language system

      • specifically in a component called phonology

    • Dyslexia results in difficulty in oral language and reading

      • Mispronunciations of words

      • lack of fluency in speech

      • hesitations before responding

      • word retrieval difficulties

  • One manifestation of dyslexia is a slow reading rate

    • An individual may learn to read words accurately but their reading is not fluent or automatic

    • This may be the only manifestation of dyslexia in languages that are consistent in the relationship between letters and sounds

  • Sometimes dyslexic adolescents or young adults are assumed to have “outgrown” dyslexia

    • This is due to their accurate albeit slow reading of words

  • The differences between dyslexic and non-dyslexic readers involve 3 important left hemisphere neural systems:

    • Parieto-temporal system

    • Occipito-temporal system

    • Broca’s area (left inferior frontal region)

  • Dyslexic readers have functional inefficiency in an extensive neural system in the posterior portion of the brain

    • This was determined from brain images from studies called “neural signature of dyslexia”

  • Dyslexia tends to run in families

    • GWAS (Genome wide association studies) in dyslexia have identified genetic variants that only account for <1% of risk

  • Dyslexia is conceptualized within a model that is dependent on many factors (genetic and environmental)

  • Treatments are focused on teaching the child that words can be broken up into smaller units of sound and that the sounds are linked with specific letter patterns

    • Requires practice in reading stories

Chapter 10: Childhood Disorders

In This Chapter…

  • Autism

  • Attention Deficit Hyperactivity Disorder

  • Down Syndrome

  • Dyslexia

Autism

  • ASD (Autism Spectrum Disorders) are characterized by

    • impaired social skills

    • verbal & nonverbal communication difficulties

    • narrow obsessive interests or repetitive behaviors

  • Symptoms of ASD include:

    • intellectual disabilities

    • seizures

    • gastrointestinal problems

      • Increase due to the detection of subtler autism and an actual increase

  • ASD is thought to be highly genetic

    • 100+ genes are linked to an increased risk for autism

    • There is no single genetic or biochemical marker for autism

  • ASD is typically diagnosed based on behavior in children around 3 years old

  • ASD-affected children at 1-2 years old show abnormal growth of the brain

    • This indicates that brain development has gone awry

    • Also a potential marker for early evaluation

    • These brain alterations are subtle

  • Speculation: abnormal development in regions of the brain involved with language, cognition, and social communication leads to abnormal connections with other parts of the brain

  • No cure or drugs for the major symptoms of ASD

  • Good response to specialized behavioral therapies based on learning theory

    • Therapy is guided by an increased understanding of how the brain normally reacts to learning, bonding, and social challenge as it develops

Attention Deficit Hyperactivity Disorder

  • Attention deficit hyperactivity disorder (ADHD): Characterized by excessively inattentive, hyperactive, or impulsive behaviors

    • described 100+ years ago

  • Children with ADHD are more likely to have problems in

    • school

    • graduating high school

    • maintaining a job

    • abusing drugs

    • having healthy relationships

  • Symptoms appear by mid-childhood and last for 6+ months

  • ADHD impairs normal function to a significant degree in different settings:

    • Children: among friends, at school and home

    • Adults: at work and home

  • Diagnosis needs a comprehensive evaluation:

    • Clinical interview, parent & teacher ratings in children

    • self ratings in adults

  • Problems with attention may also be triggered by other conditions

  • ADHD has a strong genetic influence

    • Genes for dopamine and norepinephrine transmission may be affected

  • Altered activity is present in

    • Cerebral cortex

      • Delay in cortical development

    • Striatum- a part of the midbrain

    • Cerebellum (especially the right hemisphere)

  • Symptoms often change as growing older

    • Less hyperactivity

  • There is reduced catecholamine transmission in some individuals with ADHD

    • Prefrontal circuits need an optimal level of catecholamine stimulation

      • Reduced transmission could lead to weakened prefrontal cortex regulation of attention and behavior (symptoms of ADHD)

  • Treated with parent education, school-based intervention

    • Medications: stimulants (methylphenidate) and non-stimulant drugs

    • Meds all act by enhancing catecholamine stimulation

  • There is no cure to ADHD

Down Syndrome (DS)

  • Occurs at the time of conception (when egg is fertilized)

  • Down syndrome: caused by an extra copy of chromosome 21

    • Usually present in the egg but can also sometimes be in the sperm

  • Not linked to environmental or behavioral factors before or during pregnancy

    • The risk for down syndrome increases as the mother gets older

      • If the mother is 25 years of age, the risk is 1 in 1250

      • If the mother is 40 years of age, the risk is 1 in 100

  • Down syndrome can be diagnosed by prenatal screening tests

    • They accurately detect DS in around 70% of babies

    • Prenatal diagnoses can be obtained with either chorionic villus sampling or amniocentesis

      • Chorionic villus sampling (CVS): obtaining a sample of the chorionic villi in the placenta to get the fetus’s DNA

        • CVS can be done in 2 forms:

          • transcervical- through the cervix

            • miscarriage rates slightly higher if done this way

            • performed by inserting a thin plastic tube through the vagina and cervix to reach the placenta

          • transabdominal- through the belly

      • Amniocentesis: a prenatal test in which a small amount of amniotic fluid is removed from the sac surrounding the fetus for testing

        • The sample of amniotic fluid is removed through a fine needle inserted into the uterus through the abdomen, under ultrasound guidance.

        • Less than 1 ounce is collected

  • DS is associated with around 50 physical/developmental characteristics

  • Individuals with DS are likely to possess:

    • Mild to moderate intellectual disabilities

    • Low muscle tone

    • Upward slant of the eyes

    • Flat facial profile

    • Enlarged tongue

    • Increased risk of congenital heart defects

    • Respiratory problems

    • Digestive tract obstruction

  • Individuals with down syndrome show neurological changes similar to Alzheimer’s by 40 years of age

    • Experience cognitive decline by 60 years of age

  • DS babies develop as much as typical children but at a slower rate

  • There is currently no cure for DS

Dyslexia

  • Around 8-10 % of children in the US have a form of learning disability involving difficulties in the acquisition and use of listening, speaking, reading, writing reasoning, and mathematical abilities

  • Dyslexia: unexpected difficulty in speaking & reading in children & adults who otherwise possess the intelligence, motivation, and schooling necessary for accurate fluent reading

    • Dyslexia affected 80% of learning disabled

      • 15-20% of Americans

    • It is a persistent, chronic condition though improvements can occur

    • Most forms reflect a deficit in the language system

      • specifically in a component called phonology

    • Dyslexia results in difficulty in oral language and reading

      • Mispronunciations of words

      • lack of fluency in speech

      • hesitations before responding

      • word retrieval difficulties

  • One manifestation of dyslexia is a slow reading rate

    • An individual may learn to read words accurately but their reading is not fluent or automatic

    • This may be the only manifestation of dyslexia in languages that are consistent in the relationship between letters and sounds

  • Sometimes dyslexic adolescents or young adults are assumed to have “outgrown” dyslexia

    • This is due to their accurate albeit slow reading of words

  • The differences between dyslexic and non-dyslexic readers involve 3 important left hemisphere neural systems:

    • Parieto-temporal system

    • Occipito-temporal system

    • Broca’s area (left inferior frontal region)

  • Dyslexic readers have functional inefficiency in an extensive neural system in the posterior portion of the brain

    • This was determined from brain images from studies called “neural signature of dyslexia”

  • Dyslexia tends to run in families

    • GWAS (Genome wide association studies) in dyslexia have identified genetic variants that only account for <1% of risk

  • Dyslexia is conceptualized within a model that is dependent on many factors (genetic and environmental)

  • Treatments are focused on teaching the child that words can be broken up into smaller units of sound and that the sounds are linked with specific letter patterns

    • Requires practice in reading stories