ABSTRACT
Objective:
To investigate the frequency characteristics and the pathological characteristics of the horizontal
crista ampullaris in
patients with
Meniere's disease,and to analyse its structural basis.
Methods:
Between March, 2019 and November, 2019, seventy-two
patients diagnosed as
Meniere's disease (27
males and 45
females,
aged from 13 to 74 years, with a
course of
disease ranging from 4 months to 32 years)in Shandong Provincial ENT
Hospital were included.
Caloric test, sinusoidal harmonic
acceleration test (SHA), video-
head impulse test (v-HIT),
Gadolinium-enhanced inner-
ear 3D-FLAIR MRI and pure tone
audiometry were conducted in the
patients. The function of the horizontal
semicircular canal in these
patients were analysed as well as its relationship with the degree of
endolymphatic hydrops,clinical stage and duration.
Light microscopy and
transmission electron microscopy were used to observe the
ultrastructure of horizontal
semicircular canal crista ampullaris from six
patients with refractory
Meniere's disease who underwent labyrinthectomy. The number of type Ⅰ and type Ⅱ
vestibular hair cells, the common pathophysiological changes of horizontal
semicircular canal crista ampullaris were investigated in these
patients.
Statistical analysis was performed using SPSS 19.0.
Results:
With the increase of
detection frequency, the abnormal rate decreased gradually. The abnormal rate of
caloric test was 69.4% (50/72), SHA 51.4% (37/72), V-HIT 36.1% (26/72), comparation of the positive rate among the three tests showed statistically significant differences(P<0.05).Neither
caloric test nor SHA had correlation with the degree of
hydrops(P>0.05), but v-HIT(r=0.434,P<0.01).There was correlation with clinical stage to SHA and v-HIT(r=0.338,0.462,P<0.01), except
caloric test(P>0.05).No significant relation was found with
caloric test, SHA, v-HIT and
course of
disease(P>0.05).Morphological
observation found abnormal monolayer epithelialization of the horizontal
semicircular canal crista ampullaris significantly decreased number of type Ⅱ
hair cells compared with type Ⅰ
hair cells.
Hair cells showed perinuclear vacuolization, cytoplasmic
vacuoles, mitochondrial
electron density increasement and loss of
stereocilia.
Conclusions:
The horizontal
semicircular canal damage in the
patients with
Meniere's disease has a frequency-dependent characteristic, mainly occurres in low frequency area. With progress of the
disease, the high frequency area of ampulla
will be impaired gradually, and it is related to the degree of
endolymphatic hydrops and
hearing level.
Hair cell injury would be observed,the frequency characteristics may be more associated with the disorder of type Ⅱ
hair cells.