ACC -- AGENESIS OF THE CORPUS CALLOSUM-- refers to the congential absence of the brain's corpus callosum -- the massive formation of nerve fibers bridging the two cerebral hemispheres. (When partial or incomplete, the term dysgenesis is sometimes used.) Once thought to be a rare condition, ACC has been turning up with increasing frequency ever since the widespread clinical use of MRI to examine the living brain.
Human embryology textbooks* tell us that fibers of the future corpus callosum start growing off the embryonic nerve cells (neuroblasts) when the fetus is about about 3 1/2 months old. At five months, the fetus typically has a corpus callosum with the general shape and the anatomical features typically seen in the adult. In some ACC brains, there's an extra tract, the Probst bundle, believed by some investigators to be made up of fibers that ordinarily would have formed the corpus callosum, fibers that grew in the wrong direction during development.
In and of itself, the corpus callosum is not necessary for life or health -- or even for a productive intellectual life, as split-brain operations revealed many years ago. But conditions that precipitate ACC can also lead to other serious medical problems. The latter tend to dominate the scientific literature. Thus a compilation of works on ACC tells us much about the discouraging side of the subject but provides comparatively little encouraging news. Keep that in mind If you're a parent or friend looking for information on ACC,as you consult the papers in the Abstract Sets listed below.
Help Groups for ACC exist and these organizations often provide assistance with related conditions as well. The most extensive information source on ACC is the University of Maine's ACC NETWORK whose e-mail address is um-acc@maine.edu and whose ground mail and phones are:ACC ABSTRACT SETS :
- The ACC Network
- 5749 Merrill Hall, Room 18, University of Maine Orono, Maine, USA 04469-5749
- (207) 581-3119
- Fax: (207) 581-3120
- Click here for web site.
Use the "find" key of your computer to locate specific topics within a given set.
FOR SEARCHING THE WEB: