Toxic Exposure in Utero Flashcards
What is fetal alcohol spectrum disorder (FASD)?
An umberlla term that describes the craniofacial, cardiovascular, skeletal, and neurologic effects that can occur when alcohol is consumed during pregnancy.
What are the diagnostic classifications that comprise FASD?
- Fetal alcohol syndrome (FAS)
- Partial FAS
- Fetal alcohol effects (FAE)
- Alcohol related birth defects (ARBD)
- Alcohol related neurodevelopmental disorder (ARND)
What are the leading cause of preventable ID in the Western hemisphere?
Fetal alcohol spectrum disorders
What is the neuropathology of fetal alcohol exposure?
- Alterations in size and structure w/in frontal, temporal, and parietal brain regions
- During 1st and 2nd trimester: interferes w/ migration, proliferation, and organization of brain cells which results in craniofacial and brain malformations
- During 3rd trimester damages the cerebellum, hippocampus, and prefrontal cortext
What are the neurochemical effects of alcohol?
- Increased turnover of NE and DA
- Decreased transmission in acetylcholine systems
- Increased transmission in GABA systems
- Increased production of beta-endorphin in the hypothalamus
What is observed on structural neuroimaging studies in those with prenatal alcohol exposure?
- Microcephaly
- Migrational anomalies
- Relative increases in gray matter but decreases in gray matter in perisylvian cortices
- Thinning or agenesis of corpus collosum
- Reduced brain growth in the ventral portions of the frontal lobes (L>R)
- Reduced cerebellar size
- Reduced basal ganglia (CN and LN)
- L hippocampus < R hippocampus
- Reduced parietal volumes
- WM hypoplasia
What are typical EEG findings in those w/ prenatal alcohol exposure?
50% w/ FAS exhibit reductions in alpha frequencies (when individuals are relaxed)
What are typical PET findings in those w/ prenatal alcohol exposure?
Reduced metabolic activity in the caudatenucleus and thalamus in children w/ FAS
What are typical SPECT findings in those w/ prenatal alcohol exposure?
Those w/ FAS show similar metabloic activity in both hemispheres
Typically developing children show > resting activity in L hemisphere
What are typical fMRI findings in those w/ prenatal alcohol exposure?
Disproportionate reductions in WM (parietal and temporal lobes)
Increased gray matter density in the parietal cortex
What are the diagnostic classifications for FASD?
FAS w/ confirmed maternal alcohol exposure
A. Confirmed maternal alcohol exposure
B. Evidence of characteristic facial abnormalities
C. Evidence of growth retardation
D. Evidence of CNS abnomralities
FAS w/out confirmed maternal alcohol exposure= C and D above
Partial FAS w/ confirmed maternal alcohol exposure- A, C, D above, plus some components of facial characteristics and behavior/cognitive abnormalities
What are the diagnostic classifications for alcohol related effects?
Alcohol Related Birth Defects
- Congenital anomalies, including malformations & dysplasias
- Includes various cardiac, skeletal, renal, ocular, and auditory defects
Alcohol-related neurodevelopmental disorder
-Evidence of CNS abnormalities
OR
-Evidence of behavioral/cognitive abnormalities
What 4 criteria must be met for a diagnosis of FAS?
1) Growth deficiency
2) Craniofacial features
3) CNS dysfunction: microcephaly (2 or more SD below the mean), callosal agenesis, cerebellar hypoplasia, seizures, motor problems, cognitive deficits
4) Prenatal alcohol exposure: confirmed or unknown
What are the characteristic craniofacial features of FAS?
- Short palpebral fissures
- Flat midface
- Short upturned nose
- Smooth or long philtrum
- This vermilion
Is the incidence of FAS higher in the US or Europe?
-It is more than 2X higher in the US compared to Europe
What are risk factors associated with FAS?
- In the US: low SES and race are confounded
- In Europe: low SES rather than race
What level of alcohol exposure is considered high risk, some risk, and an unknown risk?
- High risk: BAC greater than 100 mg/dL weekly early in pregnancy (121 lb woman drinking 6-8 beers at a time)
- Some risk: confirmed use of alcohol during pregnancy
- Unknown risk: unknown use of alcohol during pregnancy
Is chronic consumption (4-5 drinks daily) or binge drinking (5 or more standard drinks in a sitting or >9 a week) associated with FAS?
Both. Lesser quantities are associated with ARBD and ARND
During what trimester are the most significant risks associated with consumption?
First and second
What are additional risk factors associated with FAS besides SES and race?
- Polydrug use
- Higher maternal age
- Maternal mental health issues
- Lower educational attainment
- Reduced pre/postnatal care
- Inadequate nutirtion
- Stress, abuse, neglect
What is the typical disease course for children and adolescents/adults with FAS?
Children: CNS damage that leads to lifelong neurocog and behavioral problems
Adolescents/Adults: School failure, unemployment, mental health issues, and delinquency
What are the typical neuropsychological findings from those with FASD?
- Average IQ from 65-72 with great variability
- Those w/ more dysmorphic features have lower IQ scores
- 60-95% qualify for ADHD
- Pervasive deficits in visual sustained attention
- Deficits in complex reaction time
- Poor naming, and expressive and receptive language disorders
- Reduced oral motor function and speech production d/t craniofacial abnormalities
- Deficits in local analysis of visual stimuli
- Difficulties acquiring verbal information rather than retention deficit
- EF deficits
- Delayed motor development and fine motor deficits
- Poor balance
- Restless, impulsive, inattentive, disruptive, and aggressive
- Elevated levels of internalizing/externalizing disorders
Why is early diagnosis essential for those with FASD?
Because early interventions and resources may
1) Mitigate the development of secondary disabilities
2) Allow intervention and counseling to the mother to prevent the birth of additional affected children
3) Seek diagnosis and support for siblings who may be affected