White-matter alterations and callosal abnormalities in syndromic patients with mental retardation.

The aim of this study was to evaluate the frequency of callosal abnormalities and white matter alterations in syndromic patients. The authors report on the cerebral magnetic resonance imaging (MRI) morphologic analysis of the corpus callosum and white matter in 73 normal subjects and 61 syndromic patients. The study of the corpus callosum was carried out by MRI using different morphometric methods: measurement of the dimensions of length and thickness of genu, body, and splenium; measurement of angles obtained using the sagittal plane; and application of the proportional grid of Talairach. The evaluation of the white matter was carried out by applying a subjective grading scale. Abnormalities of the corpus callosum were found in about 50% of the syndromic subjects; in half of these cases, the abnormalities were associated with white matter alterations. In five syndromic patients (8.2%), the white matter alterations were not associated with corpus callosum abnormalities. This study shows that corpus callosum abnormalities are frequent in syndromology regardless of the syndrome type.