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 Ⅰhair 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.
Caloric Tests ; Endolymphatic Hydrops ; Female ; Humans ; Male ; Meniere Disease ; Semicircular Canals ; Semicircular Ducts

BACKGROUND AND OBJECTIVES: Vestibular toxicity can be usually monitored by a caloric test, but measuring eye movements including nystagmus is also helpful in the evaluation of vestibulotoxic process. To understand the vestibular signs during bilateral vestibulotoxic process, we observed three dimensional serial changes of eye movements and the results of caloric test in cats using a magnetic search coil system. MATERIALS AND METHODS: Three-dimensional (3-D) eye movement responses to ice water caloric stimulus and spontaneous, positional, positioning, and post head shaking nystagmus in five cats were serially evaluated at 3, 7, 10, 14, 21, 28 days, 2, 3, 4, 5, 6 months after inducing bilateral vesitibulotoxicity by subcutaneous injection of streptomycin. Histologic changes of vestibular system were also observed. RESULTS: Bilateral vestibulotixicity which showed no response to ice water caloric stimulus was induced within 2 weeks with streptomycin injection. Positional, positioning and post head shaking nystagmus were present during vestibulotoxic process. Caloric nystagmus did not reappear within 6 months and histologic finding in crista ampullaris of lateral semicircular canal showed marked degeneration of the hair cells and nerves. CONCLUSION: Observation of positional, positioning and post head shaking nystagmus as well as ice water caloric test will be helpful to monitor vestibulotoxic process.
Animals ; Caloric Tests ; Cats* ; Eye Movements ; Hair ; Head* ; Ice ; Injections, Subcutaneous ; Nystagmus, Physiologic ; Semicircular Canals ; Semicircular Ducts ; Streptomycin ; Water

BACKGROUND AND OBJECTIVES: At the beginning of the Dix-Hallpike maneuver, one of the two functional pair planes of the vertical canals is presumed to lie in the sagittal plane. However, this presumption is not correct. This paper aims to describe this problem more clearly and speculate on clinical implications. Mathematical and theoretical reasoning will be discussed. MATERIALS AND METHODS: Two sets, each composed of three perpendicular planes, were modeled for simplified semicircular canals in the anatomical position with a 3D modeler. After a yaw rotation of 45 degrees, the surface normal of the vertical canal plane is compared with that of the true sagittal plane. RESULTS: The angle between the two normals was approximately 21.1 degrees. The theoretical vertical canal plane did not lie in the sagittal plane at the beginning position of Dix-Hallpike maneuver. CONCLUSIONS: More exact Dix-Hallpike maneuvers may require a roll tilting about 20 degrees toward the affected side.
Semicircular Canals ; Vertigo

Humans ; Semicircular Canals ; abnormalities

A 31-year-old woman presented with the very unusual symptom of being able to hear the movement of her eyeballs in her left ear: “I can hear my eyeballs move!” She initially described hearing a recurrent “swishing” sound that would occur intermittently. She eventually realized that its occurrence coincided with eyeball movement. In the eight months’ duration of her symptom, she had been unable to obtain a diagnosis from physicians whom she consulted and had even been referred for psychiatric evaluation and treatment. An otolaryngologist whom she consulted had a standard pure tone audiometric examination done, and this showed normal hearing acuity in both ears. A Magnetic Resonance Imaging (MRI) of the inner ear and brain likewise showed no abnormalities. Due to the peculiarity of the patient’s complaint, the otolaryngologist consulted with a neurotologist who suspected the presence of a semicircular canal dehiscence. A computerized tomographic imaging study of the temporal bone confirmed the presence of a left superior semicircular canal dehiscence syndrome.
Semicircular Canal Dehiscence ; Semicircular Canals ; Eye Movements

Even though benign paroxysmal positional vertigo (BPPV) mostly affects a single semicircular canal (SCC), BPPV simultaneously involving more than one SCC is not rare. This multi-canal BPPV may either involve the same canals on both sides or simultaneously affect different canals on the same or on both sides. Since the SCCs can be involved in various combinations in one or both ears, multi-canal BPPVs pose diagnostic and therapeutic challenges. The different patterns of nystagmus induced during each positional maneuver should be differentiated from positional vertigo and nystagmus due to central lesions. It remains unknown which canal should be treated first and which maneuver should be adopted for multi-canal BPPVs. Furthermore, the optimal interval from treatment of a canal to another should be determined. The response to canalith repositioning maneuvers and recurrences do not differ between multi- and single canal BPPVs in spite of more frequent involvement of multiple canals in traumatic cases.
Ear ; Recurrence ; Semicircular Canals ; Vertigo

BACKGROUND AND OBJECTIVES: The Na+-K+-2Cl- cotransporter-1 (NKCC1) is a member of the cation-coupled chloride transporter that participates in salt transport and cell volume regulation in diverse tissues. NKCC1 deficient mice exhibit deafness, and have structural alterations in the cochlea. In addition to hearing loss, NKCC1-deficient mice show a shaker-waltzer behavior, which suggests a vestibular system defect. This study investigated the morphology of the vestibular system of NKCC1-deficient mice. In addition, this study evaluated whether NKCC1 mRNA and its protein are expressed in human vestibular end organs. MATERIALS AND METHOD: NKCC1-deficient and wild type mice aged 4~5 weeks were sacrificed. Their heads were cut in the midsagittal plane, fixed and decalcified. For light microscopy, 5 m sections were cut, and stained with hematoxylin and eosin. Human vestibular end organs were harvested during acoustic tumor surgery via translabyrinthine approach. Some of these end organs were used for the total mRNA extraction and the remainder was used for immunostaining. RT-PCR was performed for NKCC1. RESULTS: The scala media of the cochlear of the NKCC1-deficient mice were collapsed but the bony labyrinth of the cochlea appeared unaffected. However, the semicircular canals (SCCs) were much smaller than those in the wild type. Furthermore, the SCCs were completely missing in some NKCC1-deficient mice. NKCC1 mRNA was expressed in both human macula and crista ampullaris and its protein was expressed mainly in the transitional and dark cell area of the human crista ampullaris. CONCLUSION: NKCC1 may be essential for maintaining the vestibular morphology and its function in mice and NKCC1 is well expressed in human vestibular end organs.
Animals ; Cell Size ; Cochlea ; Cochlear Duct ; Deafness ; Ear, Inner ; Eosine Yellowish-(YS) ; Head ; Hearing Loss ; Hematoxylin ; Humans ; Ion Transport ; Mice* ; Mice, Knockout ; Microscopy ; Neuroma, Acoustic ; RNA, Messenger ; Semicircular Canals ; Semicircular Ducts

BACKGROUND AND OBJECTIVES: The Na+-K+-2Cl- cotransporter-1 (NKCC1) is a member of the cation-coupled chloride transporter that participates in salt transport and cell volume regulation in diverse tissues. NKCC1 deficient mice exhibit deafness, and have structural alterations in the cochlea. In addition to hearing loss, NKCC1-deficient mice show a shaker-waltzer behavior, which suggests a vestibular system defect. This study investigated the morphology of the vestibular system of NKCC1-deficient mice. In addition, this study evaluated whether NKCC1 mRNA and its protein are expressed in human vestibular end organs. MATERIALS AND METHOD: NKCC1-deficient and wild type mice aged 4~5 weeks were sacrificed. Their heads were cut in the midsagittal plane, fixed and decalcified. For light microscopy, 5 m sections were cut, and stained with hematoxylin and eosin. Human vestibular end organs were harvested during acoustic tumor surgery via translabyrinthine approach. Some of these end organs were used for the total mRNA extraction and the remainder was used for immunostaining. RT-PCR was performed for NKCC1. RESULTS: The scala media of the cochlear of the NKCC1-deficient mice were collapsed but the bony labyrinth of the cochlea appeared unaffected. However, the semicircular canals (SCCs) were much smaller than those in the wild type. Furthermore, the SCCs were completely missing in some NKCC1-deficient mice. NKCC1 mRNA was expressed in both human macula and crista ampullaris and its protein was expressed mainly in the transitional and dark cell area of the human crista ampullaris. CONCLUSION: NKCC1 may be essential for maintaining the vestibular morphology and its function in mice and NKCC1 is well expressed in human vestibular end organs.
Animals ; Cell Size ; Cochlea ; Cochlear Duct ; Deafness ; Ear, Inner ; Eosine Yellowish-(YS) ; Head ; Hearing Loss ; Hematoxylin ; Humans ; Ion Transport ; Mice* ; Mice, Knockout ; Microscopy ; Neuroma, Acoustic ; RNA, Messenger ; Semicircular Canals ; Semicircular Ducts

OBJECTIVETo assess the characteristics of the dysfunction of semicircular canal in benign paroxysmal positional vertigo and the relationship with the ectopic otoconia.

METHODSThere were 214 patients with benign paroxysmal positional vertigo (BPPV), including 107 cases of posterior semicircular canal canalithiasis (PSC-Can) 80 cases of horizontal semicircular canal canalithiasis (HSC-Can), 27 cases of horizontal semicircular canal cupulolithiasis (HSC-Cup). One hundred and ninety (88.8%) patients were accompany with relevant diseases while 24 (11.2%) cases were not. They accepted low, middle and high frequency vestibular function tests, including caloric test (CT), head shaking test (HST) and video head impulse test (vHIT) respectively. The parameters of the unilateral weakness (UW), head shaking nystagmus (HSN) and video head impulse test gain (vHIT-G) were observed. Patients classified into three groups (PSC-Can, HSC-Can, HSC-Cup) according to the involvement semicircular canal. The results of the three tests were analyzed with SPSS16.0 software.

RESULTSThe positive cases of the three tests were vHIT: 15 (7.0%), HST: 52 (24.3%), CT: 152 (71.0%), a statistically significant difference (P < 0.05) was found between the three tests. When compared the Caloric Test, HST and vHIT between the BPPV patients with and without relevant diseases, there were no significant differences (P > 0.05). The variance without statistical significance (P > 0.05) was showed between three tests' results in each groups, it was also showed that the variance between the three groups in each tests reached no statistical significance (P > 0.05). The test of affected side UW between PSC-Can, HSC-Can and HSC-Cup showed the variance without statistical significance (F = 0.970, P = 0.383).

CONCLUSIONSThe lesion of semicircular canals has the same etiological factors with the utricle pathological change in benign paroxysmal positional vertigo, and the dysfunction mostly happens in low frequency range of semicircular canal frequency band. The ectopic otoconia is not the main etiological factors for that. HST and vHIT of middle and high frequency can not be ultimately used for the screening test evaluating due to the semicircular canal function in BPPV.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Benign Paroxysmal Positional Vertigo ; Female ; Humans ; Male ; Middle Aged ; Otolithic Membrane ; physiopathology ; Semicircular Canals ; physiopathology ; Semicircular Ducts ; physiopathology ; Vertigo ; physiopathology ; Vestibular Function Tests ; Young Adult

The authors report jerky seesaw nystagmus, extorsional downbeating in the right eye and intorsional upbeating in the left eye, in a patient with right internuclear ophthalmoplegia (INO). This pattern of nystagmus may occur by disrupting pathways from contralateral posterior and anterior semicircular canals by a lesion in the medial longitudinal fasciculus. Depending on damage to the pathways from contralateral vertical canals, various patterns of dissociated torsional-vertical nystagmus may accompany INO.
Humans ; Ocular Motility Disorders* ; Semicircular Canals