ACC
Research Report
Presented at the annual meeting of
CORPAL (United Kingdom organization for the support of families of
children with agenesis of the corpus callosum and Aicardi Syndrome) May
2001, Great Ormond Street Hospital, London, England.
- Minding the Gap: A Large
Scale Survey of
- Agenesis of the Corpus
Callosum
- and Other Callosal
Anamolies
By
Gary Schilmoeller & Kathy Schilmoeller
Introduction
Existing information about agenesis of
the corpus callosum (ACC) comes mostly from the medical field and the
studies usually are based on very small numbers of participants (e.g.,
O'Brien, 1994; Wisniewski & Jeret, 1994). Noting that some professionals
suggest that people who have only ACC may be asymptomatic - that is,
they will develop normally and without delays, O'Brien argues that more
comprehensive studies need to be conducted in order to test this
hypothesis. He conducted a study of 47 children with ACC with the intent
of beginning to describe the behavioral and developmental consequences
of ACC (O'Brien, 1994). Our intent in this study was to expand upon
O'Brien's work with a more comprehensive survey of a much larger group
of people with ACC.
Sample
In March, 2000, we mailed a
comprehensive survey to 1,900 families who had a member with ACC. Six
hundred and seventy eight (36%) of the surveys were returned. Most of
the respondents were birth mothers (89.2%) with a small number of birth
fathers (4.9%) and mothers of adopted children (3.0%). The mean age of
the mothers of the person with ACC was 37 years old; the youngest mother
was 19 and the oldest was 68. The mean age of the fathers was 40; the
youngest father was 20 and the oldest was 75. Respondents had completed
an mean of 14.9 years of school (ranging from completing ninth grade
through more than 18 years of education). Their spouses had completed a
mean of 14.7 years of school (ranging from completing sixth grade
through more than 18 years of education).
The mean age of the persons with ACC
was 7.6 years (ranging from 4 months to 45.5 years). Nearly fifty-eight
percent (57.9%) were males and 42.1% were females. Most of the persons
with ACC (91.3%) were white. A small number were Hispanic (3.9%) and
Asian (2.0%). The rest were either Black, Native American, or listed
their race or ethnicity as some other category.
Survey
The survey was constructed based on
descriptive information published in earlier survey studies of people
with ACC (e.g., O'Brien, 1994; Schilmoeller & Schilmoeller, 2000;
Schilmoeller, Schilmoeller, & Baranowski, 1999) as well as from reports
of parents who had shared information about their child with ACC through
phone calls, emails, and regular mail correspondence with us at The ACC
Network or through themes that appeared in discussions on the ACC-L
listserv, an electronic discussion group focused on issues pertaining to
ACC. Categories of questions focused on general diagnostic information
as well as the physical, social, and communication skills of the persons
with ACC. Types of learning style, settings where these children
received education, and therapies received also were described.
Results
Diagnostic History. The most
frequent method of diagnosis was magnetic resonance imaging [MRI]
(82.7%). Fifty percent of the parents reported that a CT scan was the
method diagnosis. Ultrasound (26.9%) and EEG (21.0%) were also used to
diagnose the ACC. The percentages add up to more than 100% because many
children had more than one method used to determine and then corroborate
the diagnosis.
Concurrent Conditions. The ten
most frequently reported concurrent conditions were developmental delays
(78.0%), learning disability (32.8%), seizures (29.9%), mental
retardation (26.8%), cerebral palsy (16.1%), microcephaly (14.1%),
hydrocephaly (12.8%), autism or autistic-like behaviors (9.9%),
obsessive compulsive disorder (7.0%), and attention deficit
hyperactivity disorder (6.7%).
Physical characteristics. Nearly
half (46.7%) of the children were described as having a body size that
was small or slightly smaller than average compared to others of the
same age and gender. On the other hand, the number of children who were
described as having smaller than average head size was nearly equal to
the number described as having larger than average head size (31.6% v.
30.8%) with the remaining 37.6% described as being comparable in head
size to others of the same age and gender. Asked about head and facial
anomalies, 17.8% reported the person with ACC had eyes set wide apart,
19.6% had low-set ears, and 23.3% had unusual head shape. The incidence
of cleft lip or cleft palate was very low (0.7% and 4.3% respectively).
Over half of the respondents (53.9%) reported that their children were
either slightly floppy or very floppy (hypotonic) in terms of muscle
tone.
One physical characteristic often
reported anecdotally by parents is that their children have a high
tolerance for pain. For example, parents have reported a child putting a
hand on a hot stove burner and not withdrawing the hand nor showing any
sign of registering pain, a child getting a hand caught in a car door
without protest, and a child with a broken collarbone that was not
detected until several days after the injury. While this characteristic
is not reported in the research literature about ACC, the anecdotal
reports occur frequently enough that we included several questions about
sensitivity to pain, touch, and cold. Respondents reported that over
half (56.1%) of the children showed either little or no pain perception
(19.8%) or less pain perception than average (36.3%). On the other hand,
over 40% of the children were more sensitive to being touched by others
(30.5%) or much more sensitive to being touched by others (10.0%). There
was no discernible pattern of children being either more or less
sensitive to cold than average.
Developmental milestones. Since
78% of the children experienced developmental delays, we asked whether
or not children had met several milestones and at what age.
| Milestone |
Percentage
Met |
Mean Age
in Months When Met |
| Lifted head |
62% |
5.6 |
| Rolled over |
67% |
9.9 |
| Sit alone |
66% |
12.3 |
| Crawled |
56% |
19.2 |
| Stood alone |
47% |
21.7 |
| Walked alone |
55% |
25.3 |
| Talked single words
|
42% |
23.4 |
| Toilet trained |
34% |
49.9 |
| Rode a bicycle
|
13% |
84.9 |
Eating and Elimination problems.
Parents reported their children had multiple problems with eating. For
example, 55% had an inadequate sucking reflex at birth, and 16% had or
have a gastric feeding tube. Parents also reported that their children
either “occasionally,” “often,” or “in the past” had difficulty
swallowing (41.3%), experienced reflux (43.9%), did not know when the
child had enough food or fluid (36.9%), tried to eat things other than
food (24.9%), or had chewing difficulty (51.9%). Many children had
trouble with bladder control (57.2%), constipation (61.4%), or diarrhea
(38.8%).
Social Behavior. Parents rated
their children's social behavior on a five point scale - much less,
slightly less, about the same, slightly more, much more than others.
These children with ACC were slightly or much more likely to enjoy
social interaction (44.0%) and be friendly with strangers (42.5%). They
also were less likely to be reserved or shy (47.5%) than others. On the
other hand, only 21.8% were more likely to enjoy interacting with a peer
group. This corroborates parental reports that their children often get
along well with adults and younger children, but not as well with age
peers. Forty percent of the children also had difficulty using
appropriate physical space. This corresponds to the 40% who were more
sensitive to touch by others, raising the question of whether
sensitivity to touch migh play a role in the less frequent social
interaction with peers.
Parents rated disruptive behavior on a
three point scale - rare/not true, occasional, or very frequent. Some
parents reported their children occasionally or frequently physically
attacked other people (21.5%), suddenly lashed out for no apparent
reason (25.4%), or deliberately destroyed things (16.6%).
Children were rated as often or almost
always happy and cheerful (91.0%), content (87.0%), and relaxed (72.5%).
By contrast, only 6.4% were sad or unhappy and only 10.6% were angry.
Some children showed fearfulness or anxiousness (17.4%), experienced
quick mood shifts (22.0%), or showed moods out of place (11.7%).
In summary, children with ACC tended to
be rated as very happy, socially-engaging children though they tended to
be less social with age peers and to occasionally have problems with
anger control.
Communication Skills. Parents
reported that the vast majority of children with ACC (81.6%) showed at
least some ability to understand from communication, ranging from
understanding single words to understanding most messages that are at
the person's age level. Indeed, 60.3% were able to understand either
most long sentences or understand most age-level messages. In terms of
expressive communication, though, 33.9% were not able to communicate
verbally at all. And, in contrast to the 60.3% who could understand long
sentences or age-level messages, only 40.9% could express such verbally.
Communications by these children were
sometimes challenging. For example, children occasionally or frequently
engaged in meaningless conversation (38.1%), shouted or screamed
unexpectedly (39.9%), engaged in out-of-place conversations (45.2%), or
repeated words or phrases apparently without understanding them (30.5%).
Learning Variables. According to
their parents, children with ACC “often” or “almost always” learn by
repetition (84.1%) and by imitation (66.3%). They also have good
memories (58.2%). And many enjoy learning and working on computers
(57.5%).
On the other hand, these children have
difficulty with abstract reasoning (67.6%), have difficulty staying on
task when learning (54.0%), and perseverate on some details when
learning something (42.0%).
Parents report a variety of settings in
which learning can occur for their children with ACC including play
groups (40.1%), preschools (56.3%), self-contained special education
classrooms (46.1%), regular education classrooms (32.4%), resource room
(sometimes called “pull-out” programs) (19.4%), and other types of
special education programs (20.0%). A small percentage of children
attend Headstart programs (8.0%) or are home-schooled (7.9%). Often a
single child experiences a variety of these programs, sometimes at the
same time and at other times sequentially as the child gets older.
Nearly one-fifth (18.3%) of the children were too young to begin any
form of schooling.
Therapies and Intervention Services.
More than half of the children with ACC received three therapies -
speech therapy (65.1%), occupational therapy (64.1%), and physical
therapy (60.5%). Other therapies commonly reported were early
intervention (36.9%), sensori-integration (36.3%), academic counseling
(23.9%), and vision therapy (18.0%). Early intervention also was
reported to have been received “only in the past” by 45.1% of the
families. Thus, speech therapy, occupational therapy, physical therapy,
and early intervention are the therapies most frequently provided for
these children.
Summary Comments
These data represent only a very
preliminary analysis. In subsequent analyses, we will look at these
variables for different age groups of the children with ACC. We will
compare those with complete ACC and those with partial ACC to see
whether there will be differences between groups on some of the
categories we reported here. We also will try to distinguish between
children who have ACC and many other concurrent conditions with those
who have only ACC and no other or only a few other concurrent
conditions. Results of these and other subsequent analyses will be
published in later newsletters.
References
O'Brien, G. (1994) The behavioral and
developmental consequences of corpus callosal agenesis and Aicardi
syndrome. In M. Lassonde & M.A. Jeeves. (Eds.), Callosal Agenesis: A
Natural Split Brain? (Pp. 235 - 246). New York: Plenum Press.
Schilmoeller, G.L. & Schilmoeller, K.
(2000). Filling a void: Facilitating family support through networking
for children with a rare disorder. Family Science Review,
13, 224 - 233.
Schilmoeller, G.L., Schilmoeller, K.J.,
& Baranowski, M.D. (1999, November). Creating community for families
with a rare disorder: The case of agenesis of the corpus callosum.
Presented at the annual meeting of the National Council on Family
Relations, Irvine, CA.
Wisniewski, K.E. & Jeret, J.S. (1994).
Callosal Agenesis: Review of clinical, pathological and cytogenetic
features. In M. Lassonde & M.A. Jeeves. (Eds.), Callosal Agenesis: A
Natural Split Brain? (Pp. 1 - 6). New York: Plenum Press.
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