A longitudinal study of the corpus callosum in chronic XXXX .

@entity1 @entity161
BACKGROUND: Decreased callosal size and anisotropy have been described in @entity161 @entity1 but their longitudinal progression remains poorly understood. METHODS: We performed diffusion-tensor and structural magnetic resonance imaging at baseline and at follow-up four years later in 49 chronic @entity161 @entity1 and 16 healthy comparison subjects. @entity161 @entity1 were subdivided into good-outcome (n=23) and poor-outcome (n=26) groups. Baseline-to-follow-up changes in size, shape, position and fractional anisotropy of the corpus callosum, divided into five sagittal sections and five rostro-caudal segments, were assessed. RESULTS: At baseline scan and in comparison to healthy subjects, @entity161 @entity1 displayed 1) smaller callosal size, 2) lower average anisotropy in all sagittal sections except the midline, and 3) more dorsal average coordinate position. During the four years after the baseline scan, @entity1 with @entity161 exhibited a more pronounced decline in absolute size of the corpus callosum than healthy comparison subjects. As compared with the good-outcome group, the corpus callosum in poor-outcome @entity1 at baseline was of smaller size and lower average anisotropy, more elongated and posteriorly positioned. During the follow-up interval, poor-outcome @entity1 displayed a more pronounced decline in size but less pronounced decline in anisotropy of the corpus callosum than @entity1 with good outcomes. CONCLUSIONS: Differences in callosal size between @entity161 @entity1 and healthy subjects seen at baseline continue to widen in the chronic phase of the illness, especially in @entity1 with poor functional outcome. Baseline differences in callosal anisotropy among @entity1 with different outcomes, however, diminish over time.
