嵴帽结石症

1969年Schuknecht提出了嵴帽结石学说。

嵴帽结石学说缺乏科学的描述和定义。Schuknecht描述结石是作用于壶腹嵴，可以在内淋巴液自由浮动，并试图用耳石理论解释BPPV的典型临床症状。

原文描述：

Recent pathological studies support the concept that the disorder is caused by a deposit,presumably composed of mineral, on the cupula of the posterior semicircular canal which renders this organ sensitive to gravitational force and, therefore, subject to stimulation with changes in head position.

The evidence from all sources appeared to support the idea that positional vertigo of the benign paroxysmal type, as it was then termed, is caused by substances of high specific gravity, possibly otoconia, acting upon the cupula of the posterior semicir-cular canal.

direction of flow is ampullofugal in the posterior canal being stimulated.

"support the hypothesis that 'benign paroxysmal positional nystagmus' results from displacement of otoconia into the canal ampullae."

It assumes that substances having a specific gravity greater than endolymph and thus subject to movement with changes in the direction of gravitational force come into contact with the cupula of the posterior semicircular canal.Presumably these particles may exist free in the endolymph or may become attached to the cupula.

The change in position from erect to supine-head hanging-ear down apparently results in a severe ampullofugal displacement of the cupula of the posterior canal.

the limited duration of the vertiginous attack may be due to the return of the cupula to a normal position after the particles have left it;

the fatigability may be due to dispersement of particles in the endolymph of the pars superior occurring during repeated head positionings; and the repeatability after rest may be due to the time required for the gravity sensitive particles to again settle into the posterior canal ampulla so that they can again act en masse when the pars superior is turned over.

实验室依据： 3例人颞骨解剖。 动物实验。

case1： Attached to the posterior surface of the cupula of the left posterior semicircular canal is a basophilic staining homogenous deposit measuring 300/u in its greatest dimension。

case2: Attached to the cupula of the left posterior semicircular canal is a granular, basophilic staining mass measuring 350/i in its greatest dimension. A thin layer of this material also is located on the membranous wall of the posterior semicircular canal in its most inferior location.

参考文献：

[1] Schuknecht H F. Cupulolithiasis.[J]. Archives of Otolaryngology-head & Neck Surgery, 1969, 90(6):434-443.