Parahy C, Linthicum F H
Laryngoscope. 1983 Jun;93(6):717-20. doi: 10.1288/00005537-198306000-00003.
The sensorineural component of a mixed hearing loss due to otosclerosis is generally accepted as due to the otosclerotic lesion. The existence of pure cochlear otosclerosis without stapes fixation has been questioned. However, we are documenting 7 such cases in a separate publication. Results of this study, which evaluates 46 temporal bones with clinical or cochlear otosclerosis, demonstrate that the degree of sensorineural loss is directly related to the amount of hyalinization of the spiral ligament. The hyalinization occurs adjacent to active otospongiotic lesions but not next to inactive otosclerotic lesions. Both types of lesions may involve the cochlear endosteum. Small channels through the endosteal bone from the lesion to the spiral ligament have been found. The hyalinization spreads laterally from these channels. The hyalinization is presumably a result of the passage of toxic substances (proteolytic enzymes) from the lesion to the ligament. Strial atrophy is most pronounced on ligaments with the greatest degree of hyalinization. Hyalinization in only one ear produces decreased hearing compared to the other ear.
耳硬化症所致混合性听力损失的感音神经性成分通常被认为是由耳硬化性病变引起的。无镫骨固定的单纯耳蜗耳硬化症的存在一直受到质疑。然而，我们将在另一篇论文中记录7例此类病例。本研究评估了46块有临床或耳蜗耳硬化症的颞骨，结果表明感音神经性听力损失的程度与螺旋韧带透明样变的程度直接相关。透明样变发生在活跃的耳海绵化病变附近，而非不活跃的耳硬化性病变附近。两种类型的病变均可累及耳蜗骨内膜。已发现从病变至螺旋韧带穿过骨内膜骨的小通道。透明样变从这些通道向外侧扩散。透明样变可能是有毒物质（蛋白水解酶）从病变至韧带传递的结果。在透明样变程度最高的韧带处，血管纹萎缩最为明显。仅一只耳朵出现透明样变会导致与另一只耳朵相比听力下降。
