Pathologic anatomy of the thalamoperforating arteries in lesions of the third ventricle: Part II.

A review of vertebral and carotid angiograms in 59 cases of third ventricular pathology demonstrated that the anterior thalamoperforating arteries are affected primarily by obstructive dilatation of the third ventricle, dilatation of the third ventricle secondary to atrophy, intra third ventricular tumors, anterior and para third ventricular tumors, and hypothalamic and thalamic tumors. The posterior thalamoperforating arteries are affected primarily by midbrain atrophy, midbrain tumors, and thalamic tumors. The primary and secondary effects have been outlined. Understanding of the anatomy of the thalamoperforating arteries facilitates localization of the site of obstruction in hydrocephalus, helps differentiate obstructive hydrocephalus from ventricular dilatation secondary to atrophy, permits differentiation between tumoral and non-tumoral dilatation of the third ventricle, aids in the diagnosis and differential diagnosis of intra third and para third ventricular masses including their posterior extent, and facilitates the diagnosis of thalamic, hypothalamic, and midbrain tumors.