Can ACC be cured?
Structural diagnosis vs. behavioral syndromes
Who can diagnose ACC?
What causes ACC?
Will ACC get worse?
Why does my child have ACC?
Can ACC be cured?
Stem-cell research has raised expectations and hopes that we may find “cures” for some forms of nervous system damage and developmental abnormalities. At this time, it does not seem likely that DCC will be impacted by such interventions. This is due to the large number of steps in the process of development of the corpus callosum that would need to be re-instituted. Another factor is that the brain already has organized without the corpus callosum.
Overall, disorders of the corpus callosum are conditions one must “learn to live with” rather than “hope to recover from.” Long-term challenges are associated with absence of the corpus callosum, but this in no way suggests that individuals with DCC cannot lead productive and meaningful lives
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Structural diagnosis vs. behavioral syndromes
DCC are physical diagnoses based solely on an anatomical reality, the absence of the corpus callosum. This does not mean that DCC do not have behavioral characteristics, they clearly do. However, DCC is not a “behavioral” diagnosis such as Attention Deficit Hyperactivity Disorder (ADHD), Non-Verbal Learning Disability, Autism, or Asperger’s Syndrome. In contrast to DCC, these syndromes are diagnosed strictly based on unusual or abnormal behaviors.
Although much research has been done, it is not clear what, if anything, is structurally wrong with the brain in most of these disorders. On the other hand, the diagnosis of DCC is clear and unambiguous. Once an embryo passes the 16th week, if the corpus callosum isn’t there, the diagnosis is permanent. At this point, the absence of the corpus callosum is visibly evident on brain scans.
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Who can diagnose ACC?
ACC/DCC must be diagnosed by viewing the brain, either with MRI, Computerized Axial Tomography (CT-scan or CAT scan), or pre/post-natal sonogram (ultrasound). Among these, MRI is clearly best to see DCC and any other brain abnormalities. Absence of the corpus callosum can be seen at any age after the critical period of prenatal development. A neurologist or other physician may request an MRI or CT scan of the brain. An obstetrician or neonatal specialist may request an extensive pre-natal or post-natal sonogram or MRI. The pictures typically will be examined by a neuroradiologist or pediatric neuroradiologist, who will write a report describing any unusual findings. A neurologist or other physician also may examine the scan and diagnose DCC. If that is the case, it is always wise to have a neuroradiologist re-examine the pictures to verify the diagnosis and carefully assess for any other possible abnormalities. DCC itself cannot be detected by amniocentesis.
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What causes ACC?
ACC/DCC does not have a single cause. In fact, there are multiple factors that may be involved in disrupting the formation of the corpus callosum. Among the suggested causal factors are genetics, metabolic disorders, and structural interruptions. Brain cells may not get the chemical guidance needed to grow in the right direction, possibly because of a faulty gene. Similarly, the nerve cells may not reach their destination due to lack of oxygen, poor nutrition, toxic chemicals (for example, alcohol or drugs), infections, or metabolic disturbance. Finally, the development of the corpus callosum may be stopped by some other developmental process that interrupts the initial crossing-point of callosal fibers. In these individuals, DCC may be accompanied by cysts or lipomas. There are no known medical conditions in which DCC is always present.
Some of the conditions in which DCC is usually present are: Aicardi Syndrome, Shapiro Syndrome, Acrocallosal Syndrome, Mowat-Wilson Syndrome, and Toriello Carey Syndrome.
Some of the conditions in which DCC is sometimes present are: Fetal Alcohol Syndrome, intra-uterine infections, maternal riboflavin/ folate/ or niacin deficiency, Dandy-Walker Syndrome, Andermann Syndrome, Arnold-Chiari II Malformation, Holoprosencephaly, Hirschsprung Disease, Occulo-Cerebro-Cutaneous Syndrome, Menkes Disease, Hydrocephalus, and others.
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Will ACC get worse?
Physically, complete ACC is a condition that does not change. It will not get worse. Since the corpus callosum is already absent, it cannot regenerate or degenerate. Likewise, in partial ACC and hypoplasia, once the infant’s brain is developed, no new callosal fibers will emerge.
Behaviorally, however, individuals with ACC/DCC may fall behind their peers in social and problem solving skills in elementary school or as they approach adolescence. In typical development, the fibers of the corpus callosum become more efficient as children approach adolescence. At that point children with an intact corpus callosum show rapid gains in abstract reasoning, problem solving, and social comprehension. Although a child with DCC may have kept up with his or her peers until this age, as the peer-group begins to make use of an increasingly efficient corpus callosum, the child with DCC falls behind in mental and social functioning. In this way, the behavioral challenges for individuals with DCC may become more evident as they grow older.
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Why does my child have ACC?
Many parents worry that they may have caused their child to have brain damage or may fear that it is a condition that will recur in future children. In addressing those questions, it is important to remember that it is usually impossible to establish the reason a particular child has DCC.
Genetic testing may reveal a genetic abnormality or syndrome that is the underlying cause of the DCC. In these cases, the parents or the individual with DCC will want to consult a genetic counselor prior to becoming pregnant with another child.
In the absence of an identified genetic abnormality, it is extremely difficult to find a specific cause of DCC. Multiple possible causes appear to exist, and genetic testing does not always reveal what that cause might be. If it is not genetic, it was caused by something that happened during the first trimester of pregnancy. While it is understandable that parents will want to know “why this happened,” in many cases they may never know. Therefore it may be important to shift the focus from asking “why?” to asking “what can we do to cope with the diagnosis?” and “how can we best help our child?”
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