Frontal horn coarctation: CT demonstration. A report of two cases.

The CT aspects of frontal horn coarctation by ependymal fusion in two cases are described with post-mortem verification. These ependymal fusions in the lateral ventricles are seen frequently on air ventriculograms, especially in the occipital horns. Ependymal fusions in the frontal horns are rare and not very well known. These fusions are clearly seen on CT and post-mortem examinations. The frontal horns appear asymmetrical on CT and this asymmetry evokes frontal horn compression (by an isodense tumour for instance), or contralateral frontal horn dilatation. Some CT details of ventricular coaractation makes it easy to differentiate tumoural compression from controlateral subcortical atrophy.