Neurodevelopmental Disorders

What is specific learning disorder and what are the DSM-5 criteria for diagnosis?

Specific learning disorder is characterized by difficulties learning and using academic skills for ≥6 months despite targeted interventions. The DSM-5 criteria include: A) At least one symptom for ≥6 months; B) Skills substantially below age/expected level, interfering with academics or daily living; C) Onset during school-age years; D) Not better explained by other disorders or conditions.

What causes dyslexia and what is its definition?

Dyslexia is a specific learning disorder that affects word recognition, reading, and spelling, among school-age children, and is more common in boys (60-80%). Causes include genetic factors, cognitive deficits (specifically phonological deficits), and specific brain activation abnormalities.

What is dyscalculia and what are its three forms?

Dyscalculia is characterized by mathematical ability significantly below expected levels for age and education. The three forms include: 1) Deficit in memorizing/retrieving arithmetic facts; 2) Immature problem-solving strategies; 3) Impaired visuo-spatial skills.

What are the three types of communication disorders under specific learning disorder?

The three communication disorders include: 1) Language disorder - difficulties with language acquisition and use; 2) Speech sound disorder - difficulty with speech sound production; 3) Childhood onset fluency disorder (stuttering) - issues with fluency and time-patterning of speech.

What are the causes of stuttering and communication disorders, and how are they treated?

Aetiology includes developmental abnormalities, genetic factors, and emotional triggers, though emotional factors do not cause stuttering. Treatment options range from specialized educational interventions to auditory feedback and prolonged speech training.

Define intellectual disability and what are the DSM-5 criteria for it?

Intellectual disability is a disorder with impairments in both intellectual functioning and adaptive functioning with onset during developmental periods (before age 18).

The three DSM-5 criteria include:

1) in intellectual functioning (IQ <70);

2) Deficits in adaptive functioning;

3) Onset during the developmental period.

How common is intellectual disability and what are alternative approaches to its definition?

Intellectual disability has a prevalence of around 1%, with severe ID at ~0.6%. Alternative definitions, such as those proposed by AAIDD, focus on individualized assessments of strengths and limitations.

What are two chromosomal causes of intellectual disability?

1) Down syndrome (trisomy 21) - an extra chromosome 21 leading to various developmental issues; 2) Fragile X syndrome - a mutation in the X chromosome resulting in mild to moderate ID and associated behavioral issues.

Describe PKU and Tay-Sachs syndrome as causes of intellectual disability.

PKU is a metabolic disorder caused by a deficiency in an enzyme, leading to severe ID if untreated. Tay-Sachs is a degenerative condition caused by the absence of a specific enzyme, common in certain ethnicities, with severe outcomes in infancy.

What perinatal and childhood factors contribute to intellectual disability?

Perinatal factors include congenital disorders, maternal infections and substance use (e.g., fetal alcohol syndrome). Childhood factors encompass accidents, exposure to toxins like lead, and socioeconomic deprivation.

How is intellectual disability managed including prevention and training?

Management includes prevention through predictive testing and counseling, training through methods like applied behavior analysis (ABA), and inclusive practices in education and employment settings.

Define autism spectrum disorder and list the DSM-5 criteria.

Autism spectrum disorder is a neurodevelopmental disorder marked by deficits in social communication and restricted, repetitive behaviors. DSM-5 criteria include: A) Persistent deficits in social communication; B) Restricted, repetitive patterns of behavior; C) Symptoms present in early development; D) Clinically significant impairment.

What are the three classic impairments in autism spectrum disorder?

The classic impairments include: 1) Impairments in social interaction (lack of nonverbal behaviors and difficulty understanding others); 2) Impairments in communication (delayed speech and inability to maintain conversations); 3) Impairments in imagination and flexibility (restricted behaviors and resistance to change).

How common is autism spectrum disorder and what demographic patterns exist?

The prevalence of autism spectrum disorder has increased, now estimated at ~1.1%. Approximately 80% of those diagnosed are boys, with no significant socioeconomic or racial disparities.

What genetic evidence supports the existence of autism spectrum disorder?

Evidence includes strong familial aggregation, with sibling recurrence risks between 2-14%, and high concordance rates among identical twins indicating a polygenic nature.

What brain and biochemical factors are associated with autism spectrum disorder?

Brain abnormalities may include atypical development of the limbic system and cerebellum, and biochemical research has inconclusive findings; perinatal factors show only weak evidence.

Explain the Theory of Mind deficit in autism spectrum disorder. How is it tested?

Theory of Mind is the ability to infer others' mental states, which is often lacking in ASD. It can be tested using the Sally-Anne false belief task, where ASD children struggle to predict others' actions based on their beliefs.

What are executive dysfunction and Baron-Cohen's empathizing-systematizing theory in ASD?

Executive dysfunction involves difficulties in cognitive processes essential for problem-solving and planning. Baron-Cohen's empathizing-systematizing theory posits that individuals with ASD excel in systematizing but struggle with empathizing.

What difficulties arise in treating autism spectrum disorder and what medications are used?

Treatment challenges include resistance to change and selective attention; medications like antipsychotics and naltrexone may help manage problem behaviors.

What behavioral and inclusion strategies are applied for autism spectrum disorder?

Strategies include behavioral training like ABA and social skills development, as well as inclusion practices such as supported employment and mainstream education adaptations.