Brain Development: Normal Processes and the Effects of Alcohol ...

126 ETHANOL-AFFECTE D DEVELOPMENT
ing organogenesi s (U S Departmen t o f Healt h an d
Human Services , 2000; see Chapter 17) . In practice,
assessment of these anomalies is complicated b y variance
associate d wit h ag e an d ethnicity . Whe n af -
fected individual s are followe d ove r childhoo d int o
early adulthood, som e o f the individua l features tha t
are salien t durin g infanc y and earl y childhoo d be -
come harde r t o identify , particularl y afte r pubert y
(Streissguth, 1997) .
Several different "systems " of diagnosis are use d i n
clinical diagnosi s an d researc h o n FAS . Astle y an d
Clarren (2001 ) have propose d a syste m tha t focuse s
on "sentine l features, " whic h the y hav e identifie d
through analysi s of a large sample o f children wh o applied
for diagnostic services. In this large clinical sample,
severa l facia l feature s hav e bee n foun d t o b e
associated with the diagnosi s at each stag e of development.
Thes e feature s ar e (1 ) a n absen t o r indistinc t
philthrum, (2 ) a thinne d uppe r vermillion , an d
(3) shortene d palpebra i fissures . I n thei r four-digi t
code metho d for diagnosis, these facia l features constitute
on e dimensio n necessar y fo r diagnosi s (Astley ,
2004). Othe r dimension s ar e growt h (les s than thir d
percentile), materna l alcoho l use , an d evidenc e o f
CNS involvement.
The Collaborativ e Initiativ e o n Feta l Alcoho l
Spectrum Disorders , sponsored b y the Nationa l Insti -
tute o n Alcoholis m an d Alcoho l Abuse , ha s devel -
oped a Dysmorphia Core Physica l Exam that i s used
in international studies to diagnosis participants of all
ages and ethnicities (Ma y et al, 2000; Hoyme e t al,
2005). Thi s method , develope d b y Jone s an d col -
leagues (1973) , i s based o n th e origina l description s
of FAS and i s a modification o f the criteri a offered b y
the Institute of Medicine (Stratto n et al, 1996) . As in
other systems , th e chil d i s measured an d examine d
for physica l an d facia l anomalies , a s well a s height ,
weight, head circumference , and heart and neurolog -
ical problems . The n a determinatio n i s made a s t o
whether th e chil d ca n b e rate d a s (1 ) havin g FAS ,
(2) not having FAS, or (3) deferred. The classification
"deferred" indicate s tha t som e characteristic s ar e
present bu t tha t the diagnosi s cannot b e mad e with -
out mor e information (e.g., neurodevelopmental tes t
results). Thi s methodolog y ha s bee n use d i n Russi a
and Sout h Afric a as well as the Unite d State s (Hoym e
et al, 2005).
Coles an d colleague s (Fernhoff e t al., 1980 ; Black -
ston e t al , 2004 ; Lync h e t al. , 2004 ) hav e use d a
slightly differen t methodology . I n a longitudinall y
followed exposur e sample report , a dose-response pattern
between alcohol exposur e and physical characteristics
can be identified both in the neonatal perio d and
later i n development. Th e sam e dysmorphi c features,
however, ar e no t alway s salien t ove r development .
Rather, it is the total "dysmorphia score" that is reliable
from infanc y through middle adolescence. Mor e longitudinal
research is needed t o determine th e continuity
of physica l characteristics , particularl y facia l anom -
alies, to provide guidelines for making the diagnosis in
older childre n and adults . This kind of research i s important
als o because there may be ethnic differences in
facial characteristics that can affect diagnosis. Finally, it
is necessar y t o us e a longitudina l approac h becaus e
use o f clinical sample s in a cohort desig n exaggerates
the salienc e o f feature s tha t ar e expecte d t o b e par t
of th e criteri a an d ignore s individuals whose features
are not consistent with these expectations .
Effect of Alcohol Exposur e
on Growt h
Growth retardatio n is useful fo r the identificatio n of
FAS during infanc y an d th e preschoo l period , but i t
is les s consistentl y eviden t i n olde r childre n an d
youth (Streissguth , 1997 ; Cole s et al, 2002). It is difficult
t o evaluat e thi s facto r i n clinica l sample s
because th e argumen t i s necessaril y circular . Thi s
criterion i s use d i n makin g a clinica l diagnosis ,
hence suc h individual s ar e necessaril y growt h re -
tarded. Expose d individual s who presen t fo r diagno -
sis do no t receiv e i t i f they ar e no t growt h retarded .
Long-term follow-u p o f childre n identifie d earl y i n
life i s necessary to confirm persistent growth deficits .
For thi s reason , exposur e studie s provid e a bette r
method fo r evaluatio n o f thi s outcome . Generally ,
children expose d t o alcohol appea r to be statistically
smaller tha n control s o r tha n nationa l norm s (Da y
et al, 1999 , 2002) . Ofte n mean s ar e within norma l
ranges, however , s o althoug h thi s characteristi c i s
statistically "real, " i t ma y o r ma y no t b e o f clinical
significance, and i t is not necessaril y helpful in iden -
tification o f specifi c individual s if prenatal alcoho l
exposure i s no t known . I t i s no t ye t establishe d
whether lowe r birt h weight , height , an d hea d cir -
cumference associate d wit h prenata l alcoho l expo -
sure (and, perhaps, associate d polydrug use) are ris k
factors for other conditions occurring later in life .