Anomalous Capillary Plexus in the Scala Tympani

Abstract

A case in which there was an anomalous capillary plexus in the scala tympani of the human cochlea is here reported. The plexus was found in the right ear of a Negro man aged 62. It was located in the basal coil 8.9 mm. within the round window. The condition apparently was unilateral.In the scali tympani, about half way between the basilar membrane and the lower border of the scala, there occurred a union of two capillaries. These capillaries were the vessel under the labium spirale (inner spiral vessel) illustrated in figure 1, and the vessel under the tunnel of Corti (outer spiral vessel) seen in figures 2 and 3. The caliber of the vessel formed was not appreciably altered after the union of the two component vessels. At the point of union the vessel made an angular turn and proceeded toward the lower border of the spiral ligament. Near the lower border of the spiral ligament it again divided ( fig. 4), one branch proceeding into the meshes of the ligament and the other joining the vein in the periosteum of the scala tympani, where the vessel proceeds toward the modiolus.The entire simple network was complete within six microscopic sections (cut at 20 microns) which were 120 microns, or 0.12 mm., in length. The vessel as seen in figure 1 was included in only one section. This was to be expected when it is recalled that its caliber was only that of a red blood cell, or 7.5 microns, and that the sections were 20 microns thick. There was no evidence of previous labyrinthitis. The organ of Corti was in excellent condition in the apical and middle coils. The basal coil showed atrophy of the organ, which might be expected in a person of this decade of life with a 4 + Wassermann reaction of the blood. CLINICAL NOTEThe patient was in the hospital for only seven days. Death was due to carcinoma of the esophagus and trachea. A large semicystic tumor (the size of an orange) was found in the thymus. The Wassermann test of the blood was 4 + on two occasions; the Kahn test was 3 +. On the day of admission the examining internist elicited the information that the patient had had a ringing in the ears for two or three days. Five days before the patient's death the audiogram here From the

Vascular Variations of the Inner Ear

“…Developmental anomalies of the vasculature of the inner ear have been reported previously (5,9,13,16). Wolff (11) reported a case in which there was an anomalous capillary plexus in the scala tympani of the basal turn. Polvogt and Crowe (10) described 2 cases.…”

“…Wolff (11), in an attempt to explain the etiology of inner ear vascular anomalies in fetuses, found that, in a three-month-old fetus, the resorption of mesenchyme, which results in the formation of the peri- plexus (18) while Harris et al (19) noted that macrophages accumulated in the spiral modiolar veins following an infection with the cytomegalovirus. We propose the possibility that selected regions of the inner ear with freely¯oating fenestrated vessels within the scalae could be loci minoris resistentiae that might be selectively more susceptible to infections.…”