Toxic Exposure Flashcards
Fetal Alcohol Spectrum Disorder - Definition and primary criteria
Umbrella term (not a diagnostic term) that describes the craniofacial, cardiovascular, skeletal, and neurological deficits that can occur when alcohol is consumed during pregnancy.
Criteria:
-Pattern of facial abnormalities that includes features such as short palpebral fissures (space between eyelids) and abnormal premaxillary zone (e.g., flat upper lip, flattened philtrum, and flat midface)
-growth retardation
-CNS abnormalities such as structural brain or hard/soft neurologic signs
Fetal Alcohol Spectrum Disorder - Structural Brain Abnormalities
Include (but are not limited to)
-microcephaly (i.e., smaller head)
-Migrational anomalies (e.g., heteropias/things ‘out of place’)
-Disproportionate reductions in gray and white matter volumes (mostly in frontal, parietal, and temporal lobes)
-White matter hypoplasia (underdevelopment) > gray matter hypoplasia
Fetal Alcohol Spectrum Disorder - Determinants of Severity
-Dose of alcohol consumed (‘high risk’ = e.g., 6-8 beers in one sitting from a 121 lb female in early pregnancy)
-Pattern of exposure - chronic and binge use associated with FAS
-Timing of exposure - First trimester increased likelihood of FAS is 12x, first and second 61x, and all three trimesters is 65x
-Other risk factors (e.g., polysubstance use, higher maternal age, maternal mental health issues, lower education level, reduced access to services, inadequate nutrition, and environmental stress)
Fetal Alcohol Spectrum Disorder - Neuropsychological Assessment Results
IQ = scores range from 65 to 72 (25% of FASD have <70)
Att/Conc = deficits in visual sustained attention; 60-95% qualify for ADHD
Proc Speed = Poor reaction time and cognitive efficiency
Speech/Lang = Oral-motor production (2/2 craniofacial abnormalities); deficits in naming, comprehension, abstract reasoning, and social aspects
Visuo = Construction deficits possibly 2/2 motor deficits
Memory = Poor learning and recall with adequate retention; mixed findings for visual
ExFn = deficits across aspects, including fluency, response inhibition, planning and organization, flexibility, and concept formation
Cocaine use - neuropathology
Exposure affects the CNS via its effects on the monoamine system (especially dopamine).
Early gestation exposure affect neural proliferation and migration, whereas late exposure may affect neuronal maturation and synaptogenesis
Exposure may lead to abnormalities in the frontocingulate cortex, including the anterior cingulate gyrus
Cocaine use - Presentation, Course, Recovery
Infants may display neurobehavioral during neonatal period, including poor sleep cycles, abnormal startled response, abnormal brainstem evokes potentials, and other evidence of immature neurological functioning.
Toddlers/preschoolers often show impulsivity and emotional lability in response to frustration
Cocaine use - Neuropsychological Assessment Results
IQ = generally lower overall
Att/Conc = deficits in sustained and selected
Proc Speed = slower reaction times on CPT, though may be function of poor attention regulation
Speech/Lang = delays in expressive lang
Visuo = deficits in visual perceptual organization
Memory = deficits in working memory
ExFn = deficits in preservation, disinhibition, and poor task orientation
Marijuana use - Definition
Delta-9 THC (the main psychoactive compound) produces changes in mood, perception, motor coordination, short-term and working memory, and concentration
THC readily crosses the placenta during gestation and is secreted in maternal milk during lactation (8x more concentration in milk compared to plasma concentrations)
Marijuana use - Neuropathology
Multiple points of vulnerability throughout gestation. Exposure is associated with fetal growth restriction and lower birthweight
Heavy use causes heightened tremors, exaggerated startle and visual responses, and poor habituation to novel stimuli
Marijuana use - Epidemiology
-3rd most used substance during pregnancy
-rising increase of use (2/2 legalization)
-Women with nausea/vomiting more likely to use
-Heavy use associated with use of other substances
-Use of 6 or more times per week associated with shorter gestation (1.1 weeks)
-Boys are more vulnerable when tested for performance in attention, learning, and memory
Marijuana use - Neuropsychological Assessment Results
IQ = None
Att/Conc = increased problems with hyperactivity, inattention, and impulsivity
ExFn = Deficits in working memory, focused attention, behavioral disinhibition, self-regulation and monitoring, and flexibility
Mercury Exposure - Neuropathology
May be ingested, inhaled, or absorbed through skin. Neurologic, gastrointestinal, and renal systems are most commonly affected organs
Methylmercury destroys neurons and causes cerebral atrophy bilaterally. Dimethylmercury is the deadliest form, with easy permeation of skin, blood stream, then brain/other organs
Acute exposure includes paresthesia, deterioration in fine motor coordination, restriction of visual fields (and eventually… severe ataxia, dementia, and death)
Mercury Exposure - Pre- and Post-natal exposure
Pregnant women with a diet high in fish and shellfish are at greatest risk of methylmercury exposure
Fetal exposure can result in atrophy and hypoplasia of the cortex and corpus callosum, abnormal cytoarchitecture, and dsymyelination of the pyramidal tract
- includes brain damage, intellectual disability, poor motor coordination, blindness, seizures, and inability to speak
Exposure may also occur through breastmilk
Mercury Exposure - Neuropsychological Assessment Results
Based on 3 large scale studies:
- no neurodevelopmental problems (Seychelles)
- deficits in motor skills, attention, language, visuospatial skills, and memory (Faroe Islands)
- deficts in expressive language and visuospatial deficits with overall lower IQ (New Zealand)
Polychlorinated Biphenyls (PCBs) Exposure - Definition and Neuropathology
PCBs - part of man-made organic chemicals known as chlorinated hydrocarbons; Humans are primarily exposed through the food change (e.g., fish and sea animals)
PCBs are noted to be endocrine disruptors and associated with changes in thyroid hormone levels in infants and decreased size of the splenium of the corpus callosum
