Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
41 Cards in this Set
- Front
- Back
|
genetic disorders |
- variation or a mutation in a gene - neural tube defects - neural migration disorders - white matter myelin disorders |
|
|
neural tube defects |
- most common birth defect - brain and/or spinal cord exposed at birth - can be due to folic acid deficiency |
|
|
anencephaly |
without brain: - do not survive more than a few hours after birth |
|
|
encephaloceles |
protrusion of brain through skull in a sac like membrane - surgery can help but intellectual disability will be a high risk |
|
|
hydraencephaly |
- missing cerebral hemispheres, replaced by sacs of fluid - can happen in varying degrees - poor outcome |
|
|
spin bifida |
- opening of the spinal cord - meninges or spinal cord herniation |
|
|
heterotopias |
failure of normal neuroblast migration often causes neurons to accumulate in unusual areas |
|
|
nodular hetertopias |
focal: 'clumps' of neurons located in the wrong part of the brain |
|
|
diffuse band hetertopias |
band of neurons formed in the WM beneath the cortex - migrated wrong direction |
|
|
lissencephaly |
'smooth brain' - absent (agyria) or decreased (pachygyria) cortical folding |
|
|
example of lissencephaly: Type I LIS |
- migratory defect occurs 12-16 weeks gestation - very thick 4-layered cortex (missing layers 5-6) - hypotonia at birth - develop progressive spasticity - seizures start within first few months of life |
|
|
what is the main cuase of lissencephaly? |
- result from LISI gene disruption which normally encoded B-acetylhydrolase, it degrades the platelet activating factor. |
|
|
subcorticalband hetertopia |
- bands of neurons are located in the white matter between the cortex and the lateral ventricles - majority of cases due to mutations of the DCX gene |
|
|
focal cortical dysplasia |
- spectrum of abnormalities of the laminar structure of the corte - dont seem to form axons or dendritees/ connections as they should - intractable epilepsy in children - development delays |
|
|
leukodystrophies |
group of disorders characterised by progressive white matter degeneration - mutations in genes that produce or maintain myelin - manifests during childhood |
|
|
vanishing white matter disease |
due to oligodendrocyte cell death - causes a diffuse disappearance of white matter, loss of myelin - mutation in the eIH2BI-5 genes - rapid cognitive decline - bulk of the WM around venticle dies |
|
|
Phenylketonuria (PKU) |
metabolic disorder (1:10,000) - mutation in phenylalanine hydroxylase - Phenylalanine accumulates in brain 0 inhibits HMG-COA reductase to decrease cholesterole synthesis - hypomyleination/demylenation - strict diet |
|
|
infectious disease |
- some can be transmitted congenitally or in early childhoo, and can cause serious neurodevelopment disorders including schizophrenia |
|
|
congenital taxoplasmosis |
- can cause cyst formation in the brain, seizures, intellectual disability - most damaging in first trimester |
|
|
congenital syphilis |
can progress to neurosyphilis - most damaging in 3rd trimester |
|
|
measles |
can cause oligodendrocyte and neuronal cell death - mental deterioration and death within 3 years |
|
|
congenital rubella syndrome |
- linked with schizophrenia - also hearing and visual impairment - critical during first few weeks of gestation |
|
|
immune dysfunction |
- immune reactions during pregnancy and infancy can produce neurodevelopmental disorders |
|
|
sydenham's chorea and PANDAs |
- autoimmune reactions against brain tissue following streptococcus (group A) infection - kills neurons in the corpus striatum of the basal ganglia - causes abnormal movements of body, emotional disturbances, altered cognition, tics and OCD behaviours |
|
|
perinatal systemic infection |
- chorioamnionitis (maternal infection): inflammation of fetal membrane due to bacterial infection: neurocogntiive deficits - neonatal sepsis: very severe |
|
|
Fetal inflammatory response syndrome |
chorioamnionitis associated with elevated levels of inflammatory molecules in fetus/neonate |
|
|
metabolic disorders |
fetal metabolism altered by: - maternal nutrition - maternal neurotoxins/teratogens |
|
|
in-born erros of metabolism (IEM) |
single gene deficits in biochemical pathways |
|
|
lysosomal storage disorders |
intracellular structures responsible for breakdown of metabolic waste products - about 50 different disorders |
|
|
diabetes mellitus |
metabolic disorder involving high blood sugar sue to failure to produce insulin (type 1) or cell-insensitivity to insulin (type-2) - in children - can produce impaired neurodevelopment/cognition |
|
|
toxin and environmental factors (teratogens) |
- exposure to teratogens can alter organ development - each organ system is most vulnerable to disruption at the time when it is developing most rapidly - such as alcohol, drugs, nicotine, heavy metals |
|
|
retinoic acid |
- retinoids include alcohol, aldehyde and acid forms of vitamin A - Accutance: treatment for acne lead to high rats of birth defects in children |
|
|
fetal alcohol spectrum disorders |
1-2/1000 infants fetal damage occurs at regular doses of 1-2oz/day (2-4 drinks) |
|
|
FASD in infants |
- problems with sleep, feeding, milestones, muscle tone, sensory information processing and irritability |
|
|
FASD in children |
- hyperactivity, poorly coordinated, learing delays |
|
|
FASD in adolescents and adults |
- poor judgment, attention, problems with arithmetic, memory, abstraction, frustration/anger |
|
|
when is alcohol exposure most dangerous? |
- alcohol inhibits all stages of brain development, ecept neuronal death, which it promotes |
|
|
maternal smoking - nicotine |
- increases risk of infants being born with low brith weight (20-30%) - nicotine is a fetal neuroteratogen - targets the ACh receptors and impairs its processing - impairs cell proliferation and differentiation, synaptogenesis and induced neuronal apoptosis - constricts placental blood vessels, to reduced blood flow/nutrients to retus |
|
|
risk of ADHD by prenatal tobacco exsosure |
- about 2.5 fold risk of ADHD |
|
|
heavy metal poisoning - mercury |
- developmental mercury poisoning - from working in the industry etc - can lead to behavioural disorders, visual impairment, impaired coordination, hallucinations, intellectual disability |
|
|
cord blood lead and mental development index |
- lead accumulates and stored in bones for decades - woemn exposed to lead can cause elevated fetal leav poisoning even well after exposure - neuronal, astrocyte and oligodendrocyte apoptosis - altered neurotransmitter storage/release - impairment in cognition |
