Steven William Hetts MD, Presenter: Nothing to Disclose

Elliott H Sherr MD, Abstract Co-Author: Nothing to Disclose

Stephanie D Chao BS, Abstract Co-Author: Nothing to Disclose

Mari Wakahiro, Abstract Co-Author: Nothing to Disclose

A. James Barkovich MD, Abstract Co-Author: Nothing to Disclose

Anomalies of the cerebral commissures (ACC, including the corpus callosum, anterior commissure, and hippocampal commissure) are associated with a variable spectrum of neurological, behavioral and cognitive deficits. We have initiated a project to establish phenotypic groupings of patients with ACC based on clinical MR scans.

Our hospital's radiology database (1985 to 2003) was queried to identify likely cases of ACC; this yielded 167 cases. An additional 25 cases were drawn from MR examinations of members of a national support organization for patients with callosal anomalies. The scans of included patients were evaluated for type and severity of commissural anomalies, presence and type of interhemispheric cyst (if present), presence and type of malformations of cortical development, distortions of the cerebral ventricles, anomalies of white matter (normal or reduced volume, location of reduced volume), presence or absence of Probst bundles, and anomalies of the cerebellum, brainstem, orbits, and olfactory apparatus.

Of 167 patients from our institution, 82 MR studies were available; all 25 ACC network patients had available MR exams. Forty-four patients had callosal agenesis, 40 had dysgenesis/hypogenesis, 1 had either agenesis or dysgenesis, and 22 were excluded from further review. Fourteen patients had interhemispheric cysts (7 type I and 7 type II) and 3 had interhemispheric lipomas. An anterior commissure was absent in 36 patients and abnormal in size in 21. No hippocampal commisure was present in 58 patients and abnormal in size in 3. Cortical malformations were present in 52 patients. Cerebral ventricles were dilated or dysplastic in 74. Reduced white matter volume was present in 80 patients, with abnormal myelination in 24.

Callosal anomalies were by far the most common commissural anomalies. Isolated commissural anomalies are rare among the population of patients examined. White matter abnormalities are the most frequent MR finding, seen in greater than 80%, while malformations of cortical development are seen in more than half of patients, suggesting that most commissural anomalies are only one part of an overall cortical and white matter dysgenesis.

Hetts, S, Sherr, E, Chao, S, Wakahiro, M, Barkovich, A, MR Analysis of Cerebral Commissural Anomalies and Associated Malformations.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4410359.html