2024 Neurodevelopmental Disorders PDF

Intellectual Disability, Learning Disorders, and Autism Spectrum Disorder ž Most ¡ disorders originate in childhood Manifestation changes over time ž Disorders ¡ persist over time “Childhood disorder” is a misnomer ž Childhood ¡ ¡ Significant brain changes first few years after birth Sensitive perio...

Intellectual Disability, Learning Disorders, and Autism Spectrum Disorder ž Most ¡ disorders originate in childhood Manifestation changes over time ž Disorders ¡ persist over time “Childhood disorder” is a misnomer ž Childhood ¡ ¡ Significant brain changes first few years after birth Sensitive periods ¢ E.g., language ž Patterns ¡ important developmental time of development Disruption of early parts of the pattern interfere with later development ž Name changes to reduce stigma, inappropriate use ž DSM-IV-TR Criteria A. Significantly subaverage intellectual functioning: an IQ of approximately 70 or below on an individually administered IQ test (for infants, a clinical judgment of significantly subaverage intellectual functioning) ¡ B. Concurrent deficits or impairments in present adaptive functioning (i.e., the person’s effectiveness in meeting the standards expected for his or her age by his or her cultural group) in at least two of the following areas: communication, self-care, home living, social/interpersonal skills, use of community resources, self-direction, functional academic skills, work, leisure, health, and safety ¡ ¡ C. The onset is before age 18 years ¡ Code based on degree of severity reflecting level of intellectual impairment: ¢ ¢ ¢ ¢ ¢ Mild: 50-55 to approximately 70 Moderate: 35-40 to 50-55 Severe: 20-25 to 35-40 Profound: below 20-25 Severity Unspecified: person’s IQ is untestable by standard tests ž DSM-5 ¡ Intellectual disability is a disorder with onset during the developmental period that includes both intellectual and adaptive functioning deficits in conceptual, social, and practical domains. The following three criteria must be met: ¢ A. Deficits in intellectual functions, such as reasoning, problem solving, planning, abstract thinking, judgement, academic learning, and learning from experience, confirmed by both clinical assessment and individualized, standardized intelligence testing. ¢ ¢ ¡ B. Deficits in adaptive functioning that result in failure to meet developmental and sociocultural standards for personal independence and social responsibility. Without ongoing support, the adaptive deficits limit functioning in one or more activities of daily life, such as communication, social participation, and independent living, across multiple environments, such as home, school, work, and community C. Onset of intellectual and adaptive deficits during the developmental period Specifiers are based on adaptive functioning, not IQ scores ž Prevalence: ~1-2% of general population ž Male to female ration 1.5:1 ¡ Due to number of X-linked syndromes ž DSM-5 has attempted to de-emphasize the importance of IQ scores ¡ WHY?? ž How does one quantify adaptive functioning? Using both clinical evaluation and individualized, culturally appropriate, psychometrically sound measures Used with knowledgeable informants Used with the individual (to the extent possible) ž Standardized ¡ ABAS-II, Vineland-II ¢ ¡ Observer completed — Problem?? ILS ¢ ¡ instruments Individual answers questions — Problem?? Performance based assessments ¢ New area; lack of norms, standardization — Problems?? Intellectual capacity Education Motivation Socialization Personality features Vocational opportunity Cultural experience Coexisting general medical conditions or mental disorders DSM-5 At least one domain of adaptive functioning is sufficiently impaired that ongoing support is needed in order for the person to perform adequately in one or more life settings at school, at work, at home, or in the community DSM-5 Defined on the basis of adaptive functioning, and not IQ scores Mild Moderate Severe Profound It is adaptive functioning that determines the levels of supports required. IQ measures are less valid in the lower range DSM-5 § § § § § § § § Formerly “educable” 85% Typically develop social and communication skills during the preschool years (0-5 years) § Hard to distinguish from others until a later age § Can acquire academic skills up to approximately sixth grade Minimal impairment in sensorimotor areas Can live successfully in community Immature in social interactions Can obtain competitive employment May need support for complex decision-making § § § § § § § § § Formerly “trainable” 10% Most acquire functional communication skills during early childhood Can attend to their personal care and household tasks § With supervision/training/reminders Achieve second-grade level in academic subjects May learn to travel independently in familiar places Peer relationship difficulties in adolescence § Have capacity for meaningful relationships but have difficulty perceiving social cues Profit from vocational training In adult years § Able to perform unskilled or semiskilled work under supervision in sheltered workshops or in the general workforce Adapt well to life in the community, usually in supervised settings § § § § § § 3%-4% Acquire little or no communicative speech Can be trained in elementary self care skills Limited benefit from instruction in pre-academic subjects § can master skills such as learning sight reading of some “survival” words In adult years, may be able to perform simple tasks in closely supervised settings § Dependent on others for decisions § Work and recreation skills require ongoing supervision and support Most adapt well to life in the community, in group homes or with their families § Maladaptive behaviour is present in a significant minority § Can include self-injury 1-2% Most have an identified neurological condition In early childhood years, display considerable impairments in sensorimotor functioning Optimal development may occur in a highly structured environment Constant aid/supervision Acquire no academic skills Motor development and self care and communication skills may improve if appropriate training is provided May learn single words and understand simple instructions or gestures Some can perform tasks in closely supervised and sheltered settings Simple actions with objects ž Can be primarily biological, psychosocial, or both ¡ 30-40% have no clear etiology ¢ ž Specific etiology more likely with Severe and Profound Multiple Predisposing Factors Pregnancy and Perinatal Problems (e.g.,toxins, malnutrition, prematurity, hypoxia, infections) ¡ General medical conditions acquired in infancy/childhood (e.g., infection, trauma, heavy metal poisoning) ¡ Heredity/Genetics ¡ Environmental Influences (e.g., deprivation/neglect vs highly stimulating environments) ¡ o At both ends of age spectrum: o Adolescent mothers o After the age of 35 ž Maternal ¡ Iodine deficiency (causes thyroid hormone deficiency during pregnancy) ž Infection ¡ in the mother Can damage fetus ¢ E.g., toxoplasmosis, rubella, herpes simplex ž Maternal ¡ Malnutrition Trauma Physical injury, suffocation, carbon monoxide poisoning ¢ Can result in premature detachment of placenta, secondary anoxia, premature delivery, etc. ž Mother’s ¡ Both illicit and prescribed ¢ ¡ E.g., valproate for seizures Use during first trimester causes more gross abnormalities ¢ ¡ alcohol/drug use Affects neural tube development Drugs and other toxic substances can result in other complications which can affect cognitive functions ¢ E.g., prematurity ž CNS dysfunction ¡ Intellectual disability ¢ ¡ ¡ ¡ ¡ ¡ ž Poor prognosis if severe ID, but most fall within borderline to moderate ID range Developmental delays Impaired coordination Hypotonia Irritability in infants ADHD Growth deficiency Microcephaly ¡ Small stature ¡ ž Dysmorphic features ž Continuum ¡ ¡ of severity Depends on exposure FAS is most severe ¢ ¢ Symptoms include: — Hyperactivity — Poor impulse control — Social/emotional difficulties — Learning problems — Executive dysfunction Alterations in brain structure include — Reductions in gray matter volume throughout — Altered development of white matter ¤ Especially tracts connects frontal lobes with other regions Numerous possibilities for injury – resulting in cognitive and behavioral disorders – exist Premature separation of placenta Placenta previa Narrow birth canal Use of forceps Breech birth Cord around neck Rh incompatibility § Risk factors: § Maternal age younger than age 16 § Maternal age older than 35 years § Short spacing between pregnancy § Multiple birth pregnancy § Maternal health problems § Diabetes § Obesity § High blood pressure § Kidney/heart disease § Infections § Stress § Low SES § Lack of prenatal care § Premature babies have higher rate of various types of disabilities when compared to controls § E.g., blindness, deafness, cerebral palsy, and intellectual disabilities § Only 1/3 babies born at