This is a discussion of the clinical condition of a 49-year-old patient who had been presenting intermittent episodes of intracranial hypertension since the age of 9, at which time she suddenly began a serious psychic deterioration which impaired her normal intellectual development. A new episode of intracranial hypertension led to the emergency admittance to the medical center, and was the cause of death. The cerebral post mortem study showed a large ventricular dilatation and the existence of a translucent cysticercus of a lobular shape which was adhered by a fine filament ot the internal wall of the right ventricle, very near to Monro's foramen; the possibility, therefore, was attributed to it of having had the effect of a valve mechanism which might have been causing the crises and the intracranial hypertension. At the same time, it was also observed that there existed an angiomatosis at the level of the temporal lobe, which does not seem to be related to the process, especially because of its small area and the integrity of the blood vessels.