What is Agenesis of the Corpus Callosum?
Agenesis of the corpus callosum (ACC) is a rare congenital abnormality in which
there is a partial or complete absence (agenesis) of the corpus callosum. The
corpus callosum is the area of the brain which connects the two cerebral
hemispheres. In most patients, ACC is diagnosed within the first two years of
life. It may occur as a severe syndrome in infancy or childhood, as a milder
condition in young adults, or as an asymptomatic incidental finding. The first
symptoms of ACC are usually seizures, which may be followed by feeding problems
and delays in holding the head erect, sitting, standing, and walking. The
seizures may be caused by a very common disorder called infantile spasms, which
is associated with ACC. There may be impairments in mental and physical
development, hand-eye coordination, and visual and auditory memory. Hydrocephaly
may also occur. In mild cases, symptoms such as seizures, repetitive speech, or
headaches may not appear for years. Female children may also have a specific
syndrome, Aicardi's syndrome, in addition to ACC and infantile spasms, in which
there is severe mental retardation and chorioretinal lacunae (lesions of the
retina of the eye). ACC may occur as an isolated condition or in combination
with other cerebral anomalies including Arnold-Chiari malformation and
Dandy-Walker syndrome, Andermann syndrome (with progressive neuropathy),
schizencephaly, holoprosencephaly, and migrational anomalies. ACC is also
sometimes associated with complex multi-system malformations and with several
chromosomal anomalies, including trisomy 13 and 18. There are non-nervous system
malformations that may occur both with and without chromosomal aberrations such
as midline facial defects.
Is there any treatment?
There is no standard course of treatment for ACC. Treatment usually involves
management of symptoms such as hydrocephaly and seizures if they occur.
What is the prognosis?
ACC does not cause death in the majority of patients. Although many children
with the disorder will lead normal lives and have average intelligence, careful
neuropsychological testing reveals subtle differences in higher cortical
function compared to individuals of the same age and education without ACC.
Children with ACC accompanied by developmental delay and/or seizure disorders
should be screened for metabolic disorders. Mental retardation is nonprogressive.
What research is being done?
The NINDS conducts and supports a wide range of studies that explore the complex
mechanisms of normal brain development. The knowledge gained from these
fundamental studies provides the foundation for understanding how this process
can go awry and, thus, offers hope for new means to treat and prevent
developmental brain disorders, including ACC.
Organizations
March of Dimes Birth Defects Foundation
1275 Mamaroneck Avenue
White Plains, NY 10605
resourcecenter@modimes.org
http://www.modimes.org/
Tel: 914-428-7100 888-MODIMES (663-4637)
Fax: 914-428-8203
National Organization for Rare Disorders (NORD)
P.O. Box 8923
(100 Route 37)
New Fairfield, CT 06812-8923
orphan@rarediseases.org
http://www.rarediseases.org/
Tel: 203-746-6518 800-999-NORD (6673)
Fax: 203-746-6481
Source: National Institutes of Health; National Institute of
Neurological Disorders and Stroke
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