The anatomy of the arterial supply of the human thalamus and its use for the interpretation of the thalamic vascular pathology

The importance given to-day to the thalamus and the lack of sufficient knowledge about its arterial supply have led to a succession of new studies; the present one is based on macroscopical examinations and restricted injections of 50 hémispheres. This account is only a summary of the results. It is divided in three parts. I. Concerning the macroscopic anatomy of some arterial segment giving rise to thalamic branches, three points have been emphazised. a) There seems to be a present agreement to isolate as a special entity the arterial portion extended from the ending of the basilar artery to the junction with the posterior communicating artery. It is proposed here to call it the “communicating basilar artery”. The posterior cerebral artery begins at the level of the circle of Willis. b) The ending point of anterior choroideal artery is variable but most often it appears to be ventral to the thalamus. c) The anatomy of the so-called posterior choroideal arteries is extremely complex and so still poorly known. Rather than speaking of simple arteries it appears more convenient to speak of arterial system admitting various types of organization. The mesencephalo-thalamo-choroideal postero-medial system often appears as an unique postero-medial choroideal artery, but other types have been observed. The hippocampo-thalamo-choroideal postero-lateral system is the most complex. Several components can vary separatly or together and realize various dispositions. An unique postero-lateral choroideal artery is only one of these possible dispositions. Finally, the systematisation is very difficult. II. Thalamic arteries and arterial territories: III. The use of these datas for the interpretation of thalamic vascular pathology is, then, approached.