Fetal Alchohol Syndrome CONT....psychology notes

 Fetal Alcohol Syndrome  (FAS)  continued     Psychology notes

 Brain anomalies

. neuroglial heterotopias (3/4 cases) [migration problem, when migrated up didn’t stop at the right place.

. underdeveloped cerebellum (4/4 cases)

. ectopic neurons in white matter (lost on way)

. agenesis of corpus callosum (also seen in imaging studies)[split brain – usually cognitive problems

This was in severe alcoholics – gallon of wine or case of beer.

Central Nervous System effects of ethanol (has quite wide spread effects in the brain)

.GABA system

.Dopamine system

.Opioid mechanisms

Alcohol Facts

.absorption of Ethanol:

-thru stomache wall (30%)

-thru small intestine (70%)

                  Breakdown of Ethanol (thru liver)

Ethanol …….>   acetaldehyde…………..>

        Breaks down to acetate

    Probably more toxic than Ethanol

Absorb alcohol -  crosses placenta if more on mom’s side will cross to fetus and is there longer and not broken down as efficiently.

Blood  alcohol level (BAL)

0.5 oz absolute alcohol (AA) in 130 lb person.

.043 g/100 ml

Legal limit for driving 0.08 – 0.10

0.5 oz AA= 1 beer, 4 oz of wine, 1 oz liquor

Question about fetal alcohol exposure -  Are there behavioral consequences?

Is there a threshold?   A line above which is effect and below no effect.  Low dose no effect and more as increase an amount or has an effect and gets smaller and smaller.

Does the pattern of drinking matter? Eg. 3 ½ of alcohol – 1 drink a day or no drinks until Saturday night and have 7 drinks - Same effect?

      Is there a critical period for FAS- Yes, multiple critical periods face early embryological growth, later gestation

Is there a genetic component?  Not everyone who drinks in pregnancy or alcohol produced a child with FAS.  Why some yes and why not?

What is the role of nutrition?  Mothers drinking to access and most calories from alchohol—note don’t see face amolities in malnutrition.   Can’t absolutely rule out nutrition.  Is alcohol really the culprit?  Some anti-convulsives also cause facial dysmorphology.  fore Also, alcohol goes with other things eg. alcohol/cigarettes/drugs/prescription or illicit and might not volunteer information.  Less likely to admit therefore need animal studies so can control exposure.

Is rehabilitation possible?  Maybe not in extreme cases.  Children from early study environment did not reverse it or cause it.

Genetic, Individual differences

4 % of alcohol – dependent women have affected (FAS/FAE) children.

Study of  twins (Streissguth):

-monozygotic twins : both affected 5/5

-dizygotic twins: bothaffected 7/11

Critical Periods?

-Facial features

-growth retardation

-CNS effects (mid gestational to second half, maybe even later.

(early embryonic period 4 ½ to 7, 8, wks, may go longer.  All the way through gestation there is a risk.

To be continued with Animal Models