CHILDHOOD DISORDERSNeuroscience: Disorders

DISEASE VS. DISORDER Disease: a definite pathological process

having a characteristic set of signs and symptoms.  It may affect the whole body or any of its parts, and its etiology, pathology, and prognosis may be known or unknown. 

Disorder: a derangement or abnormality of function; a morbid physical or mental state.

Not really a difference?

Dorland’s medical dictionary

AUTISM

characterized by communication difficulties, delayed development of language, impaired social skills, and narrow, obsessive interests.

AUTISM• 1 in every 150 babies born• More than childhood cancer,

juvenille diabetes, and pediatric AIDS combined.

• 3-4x more boys diagnosed with Autism

• Increasing numbers of children diagnosed with autism

• Changes in diagnostic criteria, environment

ASD (AUTISM SPECTRUM DISORDER)CHARACTERISTICS

• Communication difficulty• Absent, delayed, abnormal

language• Impaired social skills• Narrow, obsessive interests or

repetitive behaviors• Associated symptoms: mental

retardation, seizure, behavioral abnormalities.

DIAGNOSING AUTISM IDIOPATHIC – no discernable cause, only

speculation. Based on behavioral symptoms http://www.youtube.com/watch?v=FuWWie1

DlJY Can treat SYMPTOMS with medication Earlier intervention = better outcome

WHAT DO YOU THINK CAUSES AUTISM? Developmental processes before and

after birth-Abnormal brain growth Neural cell proliferation, migration, survival,

axon and dendrite extensions, synapse formation

Specific language areas seem involved May involve dysregulation of the

immune system Genetics

Determining genetics v. environment (twin studies)100’s of genes seem linked to increased risk

TEMPLE GRANDIN“THE WOMAN WHO THINKS LIKE A COW”

http://www.youtube.com/watch?v=46ycu3JFRrA&feature=rellist&playnext=1&list=PL6F7275739B1BB023

REVIEW1. Disorder characterized by communication

difficulties, delayed development of language, impaired social skills, and narrow, obsessive interests.

2. Which gender is more likely to be diagnosed with autism?

3. What has happened to the number of diagnosed autism cases since the 1970’s? Why?

4. What are classic symptoms of autism?•Communication difficulty•Absent, delayed, abnormal language•Impaired social skills•Narrow, obsessive interests or repetitive behaviors

•Increased,•Diagnostic criteria, awareness, and…

•Males

•autism

ATTENTION DEFICIT HYPERACTIVITY DISORDER

Childhood Disorders section 2: ADHD

What would happen if your prefrontal cortex (frontal lobe)

were underdeveloped, or understimulated?

ATTENTION DEFICIT HYPERACTIVITY DISORDER (ADHD)

Characterized by inattentiveness, hyperactivity, and impulsive behaviors.

Affects 5-8% of American children Treatment: behavioral therapy and

stimulants (methylphenidate-Ritalyn)

http://www.youtube.com/watch?v=u82nzTzL7To

POTENTIAL PROBLEMS WITH ADHD

Children with ADHD are more likely to have:problems in school, graduating from high school, Maintaining a job, abusing drugs, or having healthy relationships.

DIAGNOSTIC CRITERIA FROM DIAGNOSTIC AND STATISTICAL MANUAL OF MENTAL DISORDERS, FIFTH EDITION (DSM-5) Is easily distracted Is forgetful, even in daily activities Fails to give close attention to

details in school work or other activities, including making careless mistakes

Has trouble keeping attention on tasks or activities

Ignores a speaker, even when spoken to directly

Does not follow instructions, fails to finish schoolwork or chores, and loses focus or is easily side-tracked.

Has trouble with organization Dislikes and avoids tasks that

require long periods of mental effort, such as homework

Loses vital things needed for tasks and activities, such as books, keys, wallet, phones, etc.

Appears to be “driven by a motor” and always “on the go”

Excessively talks Has trouble waiting his or

her turn Squirms in his seat, taps his

hands or feet, or fidgets Gets up from a seat when

remaining seated is expected

Runs around or climbs in inappropriate situations

Unable to quietly play or take part in leisure activities

Blurts out an answer before a question has been finished

Intrudes on and interrupts others

Trouble paying attention Hyperactivity Impulsive behaviors 

SYMPTOMS OF ADHD

DIAGNOSIS

• Many healthy kids show these behaviors, so it is important to have a thorough evaluation• Clinical interview• Parent and teacher ratings• Learning disorder testing• Psychological testing

CAUSES & TREATMENTS OF ADHD

• Genetic component• Genes encoding components of

dopamine and norepinephrine transmission seem involved.

• Differences in brain volume and functiono Decreased volume and activity in

prefrontal circuits Altered activity is often observed in circuits

connecting the cortex, the striatum, and the cerebellum, particularly in the right hemisphere.

Delay in cortical development Most individuals with ADHD do not

outgrowSymptoms often change as ADHD

individuals grow older, with less hyperactivity as adults.

Problems with attention tend to continue

CAUSES & TREATMENTS OF ADHD

• Decreased catecholamine transmission -> Decreased regulation of attention and behavior

• Because of this, ADHD can be treated with drugs that increase catecholamine (dopamine) transmission. 

• Also must have behavioral treatments

HTTP://WWW.YOUTUBE.COM/WATCH?V=UU6O2_UFSEY TED TALK FOR LAB DAY

TRISOMY 21

Childhood Disorders section 3: Down Syndrome

DOWN SYNDROME Trisomy 21

Trisomy 21 involves the inheritance of three copies of chromosome 21

– Trisomy 21 is the most common human chromosome abnormality

– An imbalance in chromosome number causes Down syndrome, which is characterized by

– Characteristic facial features– Susceptibility to disease– Shortened life span– Mental retardation– Variation in characteristics

– The incidence increases with the age of the mother

AN EXTRA COPY OF CHROMOSOME 21 CAUSES DOWN SYNDROME

DOWN SYNDROME

1 of every 691 babies, or about 6,000 babies annually in the United States

more common with older motherscharacterized by:

mental retardation, low muscle tone, upward slant of eyes,flat face, enlarged tongue, congenital heart defects, respiratory problems, digestive tract obstruction

Infa

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Age of mother

90

70

60

50

40

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20

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80

20 40353025 5045

At age 25, the risk is about 1 in 1,250 births; at age 40, it is 1 in 100 births.

Because of higher fertility rates in younger women, 80 percent of children with Down syndrome are born to women under 35 years of age.

Nondisjunction is the failure of chromosomes or chromatids to separate during meiosis

– During Meiosis I – Both members of a homologous pair

go to one pole– During Meiosis II

– Both sister chromatids go to one pole Fertilization after nondisjunction yields

zygotes with altered numbers of chromosomes

ACCIDENTS DURING MEIOSIS CAN ALTER CHROMOSOME NUMBER

Nondisjunctionin meiosis I

Nondisjunctionin meiosis I

Normalmeiosis II

Nondisjunctionin meiosis I

Normalmeiosis II

n + 1

Gametes

Number of chromosomes

n + 1 n – 1 n – 1

Normalmeiosis I

Nondisjunctionin meiosis II

Normalmeiosis I

Nondisjunctionin meiosis II

Normalmeiosis I

Gametes

Number of chromosomes

n + 1 n – 1 n n

TESTING FOR DOWN SYNDROME

Prenatal screening tests, such as the triple and quadruple screen blood tests, can accurately detect Down syndrome in about 70 percent of fetuses.

Definitive prenatal diagnoses can be obtained with either chorionic villus sampling or amniocentesis.

AGING WITH DOWN SYNDROME

By age 40, nearly all people with Down syndrome show some neurological changes similar to those seen in Alzheimer’s disease, and most show cognitive decline by age 60.

No cure for Down syndrome or means of preventing it

Scientists focused on understanding the genes on chromosome 21 to find treatments

DYSLEXIA

Childhood Disorders section 4: Learning Disabilities

LEARNING DISORDERS: DYSLEXIA

8-10% of US children have some form of learning disability.Not associated with intelligence

Dyslexia: Most common (80%) of all learning disabilitiesChronic reading disorderDifficulty in speaking and readingDeficiency in converting letters to soundTends to run in familiesTreatment: practice with reading and

taught different reading strategies

WHAT CAUSES DYSLEXIA• A problem with the "phonology"

component of the language systemo Difficulty translating letters into sounds

• NOT a problem of accuracy• Can still read the words correctly, • takes a longer time • May not be fluent or automatico Adolescents or young adults with

dyslexia who can read accurately may be mistakenly thought to have "grown out of it"

WHAT CAUSES DYSLEXIA (CONTD)• Brain imaging studies have shown differences in three neural systems in the left hemisphere in dyslexic people:o 2 posteriorly (parieto-occipital and

occipito-temporal)o 1 anteriorly (Broca's area)

Brain-imaging studies show differences in the dyslexic brain during reading tasks. [Credit: Guinevere Eden, DPhil, Georgetown university.]

WHAT CAUSES DYSLEXIA (CONTD)o These differences in brain function

are thought to cause disruptions in the system that links visual pictures of the letters to the sounds they make

•Dyselxia runs in familieso 6 "risk alleles" have been potentially

found and are thought to play roles in fetal brain development

Risk alleles increase your total risk of developing a disease

DYSLEXIA? IS IT IN THE GENES? Genome-wide association studies

(GWAS) in dyslexia have so far identified genetic variants that account for only a very small percentage of the risk — less than 1 percent — making it unlikely that a single gene or even a few genes will identify people with dyslexia.

Likely multiple genetic and environmental risk and protective factors leading to dyslexia.