ARTERIES FROM BASAL BRAIN TO INNER EAR OBSERVATION OF 20 JAPANESE

Abstract

The author reported morphological study of arteries from basal brain to inner ear of 20 Japanese. Results are as follows: 1) Basilar arteries were found to be very variable.A.cerebelli inferior anterior and posterior were especially observed, since they have important relation with internal auditory artery.Anastomosis was also observed between the two inferior cerebellar arteries. 2) In 34 out of 40 internal auditory arteries, A.cerebelli inferior anterior gave rise to A.labyrinths.Other A.labyrinthi originated in A.cerebelli inferior posterior or A.cerebelli accessoria. 3) Only 25% out of 40 temporal bones showed typical arterial system of internal auditory meatus, described by Siebenmann, etc.Many types of individual variations were observed.The author showed pictures of reconstruction of internal auditory meatus by method of temporal bone serial section. 4) Outside diameter(inside diameter) of A. labyrinthi was 155(76) micron in average.The maximum 245(140) micron, though the minimum 100(68) micron.The average outside diameters (inside diameters) of A.cochleae propria, A.vestibulo-cochlearis and A.vestibuli anterior were 84 (42), 101(47) and 82(37) micron respectively. 5) Variations were not always found in both sides.They happened to appear at random.Even if a kind of variation was seen in basilar arteries of a case, it is not always expected that the arteries of internal auditory meatus of that case had a variating pattern. Only 4 out of 20 cases had regular pattern of arteries from basal brain to inner ear.Other 16 cases had a certain variating pattern in arterial system from basal brain to inner ear.The author concluded that inner ear disease of vascular origin is expected to be influenced on by the individual variations of arteries from basal brain to inner ear.