[Frequency characteristics of horizontal semicircular canals damage and the ultrastructure analysis of crista ampullaris in patients with Meniere's disease].

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.

[Ultrastructural study of ampulla of mouse inner ear].

Objective: To observe the ultrastructure of the ampulla, and analyze its physiological and pathological significance. Methods: In this study, 20 Kunming mice were used, and scanning electron microscopy was used to observe the ultrastructure of the ampulla of inner ear. Results: Otoconia was found among the cilia bundles of different haircell(intercilla otoconia of ampulla). The cupula was attached to the lateral wall of the ampulla, and easily to be separated; after separated, a kind of slender crystal(surface otoconia of ampulla) could be seen between the cupula and lateral wall of the ampulla, both sides of ampullary crest were covered with slender crystals too. On the canal side of the ampulla wall, there was more particulate matter attached to the wall near the bottom of ampullary crest, partially embedded in the wall, and less on the utricle side of the ampulla wall. Conclusions: The observation of the ultrastructure of the ampulla is helpful for better understanding the physiological functions of the semicircular canals and the ampulla, and better understanding the pathogenesis and solution of some vertigo diseases.

[The exploration on optimization of two alternatives between roll test and Dix-Hallpike test in benign paroxysmal positional vertigo].

Objective: To analyze the objective characteristics of roll test and Dix-Hallpike test in benign paroxysmal positional vertigo(BPPV)patients, discussing the premier solution of positional test. Methods: A total of 230 patients with BPPV, whereas 170 posterior semicircular canal canalithiasis (PSC-Can) BPPV and 60 horizontal semicircular canal canalithiasis (HSC-Can) BPPV were involved respectively. The induced nystagmus in roll test and Dix-Hallpike test was recorded by video nystagmuo graph (VNG), and the direction, intensity and time characteristics of nystagmus were compared in various BPPV.SPSS19.0 software was used for statistical analysis. Results: Vertically upward nystagmus was induced by hanging in 170 PSC-Can Dix-Hallpike test, and the nystagmus reversed and turned weaker when the subjects came to sit. The intensity of nystagmus at turning to lesion side by hanging and sitting were (30.3±14.1)°/s and (12.6±7.5)°/s respectively, the difference was statistically significant (t=20.153, P<0.05). However, no nystagmus was induced in PSC-Can roll test. Horizontal nystagmus in the same direction with turning was induced in 60 HSC-Can roll test. The intensity of nystagmus at turning to lesion side and normal side was (42.0±18.0)°/s and (20.3±8.7)°/s respectively, the difference was statistically significant (t=12.731, P<0.05). Furthermore, horizontal nystagmus in the same direction with turning was induced in 57 HSC-Can Dix-Hallpike. The coherence was 95% with the results of roll test. Conclusions: Dix-Hallpike test can not only be used to diagnose PSC-Can, but also induce nystagmus in HSC-Can effectively. Whereas the roll test only show significance in diagnosing HSC-Can. To avoid uncomfortable stimulation to patients as much as possible, we suggest to use Dix-Hallpike test at first, and to judge whether using roll test based on the result of the horizontal nystagmus.

Compliance and outcomes of concurrent Chemo-radiation in patients with peri-ampullary cancer undergoing curative resections.

OBJECTIVES: We aimed to study the compliance and treatment outcome of patients who received adjuvant treatment following curative resection for periampullary cancers periampullary cancers. MATERIALS AND METHODS: Institute medical records of PAC treated during 2007-2014 were retrieved. Demographics, treatment, and outcome in patients who were intended to receive adjuvant chemoradiation after curative resection were analyzed. Patients received first cycle chemotherapy with 5-fluorouracil folinic acid/capecitabine, followed by external radiotherapy 45 Gy/25 fractions/5 weeks and second and third cycle concurrent chemotherapy. Fourth and fifth cycle chemotherapy were administered after radiotherapy). Various prognostic factors, disease-free survival (DFS), and overall survival (OS) were evaluated. RESULTS: Sixty-five patients were evaluated. Median age was 50 years. 96.9% patients completed the intended course of radiation and overall adherence to chemotherapy was 86.2%. Median follow-up and DFS were 20 and 29.64 months, respectively (range: 1.9-97.3 months). Estimated 1-, 2-, 5-year DFS was 77.8%, 59.3%, and 37.6%, respectively. One-year estimated OS was 92.7%. Median DFS for node-negative and node-positive patients was 88.6 and 24.33 months (P = 0.06). Grade ≥III hematological toxicity was 20%. CONCLUSION: Positive node indicated a trend toward poor survival. The study highlights high compliance to multimodal management of PAC with acceptable toxicity in and out of clinical trial setting in a tertiary cancer center in India.

Refractory Positional Vertigo With Apogeotropic Horizontal Nystagmus After Labyrinthitis: Surgical Treatment and Identification of Dysmorphic Ampullae.

OBJECTIVES: To describe the rationale, intraoperative details, and histopathologic findings discovered when treating an unusual case of apogeotropic horizontal canal positional vertigo with a transmastoid labyrinthectomy. PATIENT: A single case report. INTERVENTION: Therapeutic. MAIN OUTCOME MEASURES: Resolution of apogeotropic nystagmus and improvement of positional vertigo. RESULTS: The apogeotropic variant of horizontal canal positional vertigo can be a difficult entity to treat. This report describes a patient who developed profound sensorineural hearing loss and vertigo after an acute left labyrinthitis. Ten months later, she developed vertigo with apogeotropic positional nystagmus involving the left horizontal semicircular canal. Particle repositioning maneuvers and vestibular physical therapy were unsuccessful. In addition, she developed intermittent positional vertigo affecting the ipsilateral vertical semicircular canals. Given the persistence of her vertigo, multiple canal involvement, and patient preference for definitive treatment, a transmastoid labyrinthectomy was performed. Intraoperatively, the ampulla of the horizontal canal as well as that of the other canals was grossly abnormal as later confirmed on histology. After surgery, her apogeotropic nystagmus and vertigo resolved, and her balance ability gradually improved to a highly functional level. CONCLUSION: This case illustrates a unique form of positional vertigo that developed and persisted after acute labyrinthitis. Conservative measures were unsuccessful and a transmastoid labyrinthectomy documented dense inflammatory tissue involving all three ampullae. We postulate that the post-labyrinthitic inflammatory changes resulted in mass loading of the membranous ampullae, causing abnormal nystagmus patterns and positional vertigo, which resolved after the labyrinthectomy.

[Investigation of the reverse phase nystagmus in positioning test for benign paroxysmal positional vertigo].

OBJECTIVE: To investigate the clinical significances and formation mechanism by analyzing the characteristics of the reverse phase nystagmus parameters from benign paroxysmal positional vertigo (BPPV) positioning test. METHODS: There were 183 cases with BPPV, including 108 cases (59.0%) of posterior semicircular canal canalithiasis, 55 cases (30.1%) of horizontal semicircular canal canalithiasis, and 15 cases (8.2%) of horizontal and posterior semicircular canal cupulolithiasis and 5 cases (2.7%) of anterior semicircular canalithiasis . The video-nystagmography was utilized in positioning tests to induce nystagmus. The direction, intensity, time parameters characteristic of vertical nystagmus in Dix-Hallpike test and horizontal nystagmus in roll test were analyzed and compared. RESULTS: There were no reversal phase nystagmus in 15 cases of semicircular canal cupulolithiasis and 5 cases of anterior semicircular canalithiasis. After the disappearance of vertical nystagmus which induced by hanging position (the first phase nystagmus) in 108 cases of posterior semicircular canalithiasis of Dix-Hallpike test, there was 54 cases(50.0%) of posterior semicircular canal canalithiasis displayed downward vertical nystagmus (reverse phase nystagmus) . The latency, duration time and intensity of the first phase nystagmus and reverse phase nystagmus were [(2.00 ± 1.10) s, (3.54 ± 1.42) s], [ (16.27 ± 4.95) s, (61.65 ± 33.69)s] and [ (51.80 ± 25.25) °/s, (10.65 ± 6.29)°/s] respectively; 43 cases(78.2%) of horizontal semicircular canal canalithiasis displayed the opposite to turning head (reverse phase nystagmus) after the horizontal nystagmus, similar with turning head disappeared in Roll test. The latency, duration time and intensity of the first phase of nystagmus and reverse phase nystagmus were [ (1.67 ± 1.07) s, (3.57 ± 1.89)s], [ (25.19 ± 9.74) s, (70.48 ± 40.26)s] and [ (68.47 ± 30.18) °/s, (11.22 ± 8.78)°/s] respectively. Comparing with the latency, duration time, intensity of first phase nystagmus and reverse phase nystagmus of posterior and horizontal semicircular canal canalithiasis, the differences had statistical significances (P < 0.05). Comparing with the first phase nystagmus of reverse phase and no reverse phase nystagmus canalithiasis, the difference of nystagmus intensity had statistical significances (P < 0.05); but the differences of latency and duration of nystagmus had no significant difference (P > 0.05). CONCLUSIONS: It is common in PSC-Can and HSC-Can patients that reverse phase nystagmus is one of the clinical features of canalithiasis. It appears in side head position of Rolling test or the hanging of Dix- Hallpike test. More power of the first phase nystagmus has, reverse phase nystagmus will be induced much easier. In comparison of the reverse phase nystagmus, the first phase nystagmus has the shorter incubation and duration, but it has more power. It is helpful to avoid interruptions of clinical statolith positioning and reset since we recognize the reverse phase nystagmus. The mechanism might be similar to the vestibular mirror image nystagmus. It is another form of the vestibular mirror image nystagmus in BPPV patients.

Radiologic examinations in human temporal bone specimens using digital volume tomography and high-resolution computed tomography after implantation of middle ear prosthesis and cochlear implant electrode array.

INTRODUCTION: Adequate imaging of the middle ear and its surrounding structures is an essential preoperative part in ear surgery. In the past, the main disadvantage of computed tomography (CT) scanners was the decreased diagnostic quality due to metallic artifacts. Furthermore, these scanners showed mostly an inferior image quality compared to digital volume tomography (DVT) in the temporal bone. It was the aim of this experimental study to compare the image quality of a state-of-the-art dual-source 2 × 128-slice CT scanner to DVT in temporal bone specimen. MATERIALS AND METHODS: Metallic prosthesis (PORP, TORP, stapes piston, cochlear implant electrode array) and an autologous incus were implanted in temporal bone specimen to analyze the diagnostic quality concerning the characterization of anatomic structures. Three further temporal bones were scanned without any preparation. Independently, 2 otologists and 2 radiologists scored the image quality of defined anatomic structures, using a range from 4 (excellent) to 0 (no diagnostic value). RESULTS: The general score for DVT was 2.67, whereas CT reached a score of 2.76. The diagnostic value for hard contrast objects was 3.0 for DVT and 2.9 for CT, whereas the score for soft tissue was 1.1 for DVT and 2.3 for CT. Almost no quality reduction of the display of anatomic structures caused by metallic artifacts could be detected in both diagnostic modalities. DISCUSSION: Both DVT and high-resolution CT allow good overall image quality in temporal bones, with discrete advantages for digital volume tomographic scans in terms of the image quality of hard contrast objects like bony structures or metallic implants.

Temporal and spatial distribution of gentamicin in the peripheral vestibular system after transtympanic administration in guinea pigs.

BACKGROUND AND OBJECTIVE: Transtympanic administration of gentamicin is effective for treating patients with intractable vertigo. This study explored the spatial and temporal distribution of gentamicin in vestibular end-organs after transtympanic administration. METHODS: Thirty guinea pigs were transtympanically injected with gentamicin conjugated to Texas Red (GTTR) and their vestibular end-organs examined after various survival periods. Another 9 guinea pigs received GTTR at different doses. Nine animals received Texas Red only and served as controls. We used confocal microscopy to determine the cellular distribution of GTTR in semicircular canal cristae, as well as the utricular and saccular maculae. RESULTS: The most intense GTTR labeling was present in the saccule compared to other vestibular end-organs. GTTR fluorescence was detected predominantly in type I hair cells, type II hair cells and transitional cells after a single transtympanic dose of GTTR (0.1 mg/ml, 0.05 ml), while only weak fluorescence was observed in non-sensory cells such as supporting cells, dark cells and lumenal epithelial cells. Transitional cells displayed intense GTTR fluorescence in the supra-nuclear regions 24 h after transtympanic injection that was retained for at least 4 weeks. A decreasing spatial gradient of GTTR fluorescence was observed sensory epithelial regions containing central type I to peripheral type I and then type II hair cells in the crista ampullaris, and from striolar to extra-striolar hair cells within the vestibular macula. GTTR fluorescence extended from being restricted to the apical cytoplasm at lower doses to the entire cell body of type I hair cells with increasing dose. GTTR fluorescence reached peak intensities for individual regions of interest within the cristae and maculae between 3 and 7 days after transtympanic injection. CONCLUSION: The saccular uptake of GTTR is greater than other vestibular end-organs after transtympanic injection in the semicircular canals.

[Analysis of the dysfunction frequency and characteristics of semicircular canal in benign paroxysmal positional vertigo].

OBJECTIVE: To assess the characteristics of the dysfunction of semicircular canal in benign paroxysmal positional vertigo and the relationship with the ectopic otoconia. METHODS: There 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. RESULTS: The 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). CONCLUSIONS: The 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.

Infrared photostimulation of the crista ampullaris.

The present results show that the semicircular canal crista ampullaris of the toadfish, Opsanus tau, is sensitive to infrared radiation (IR) applied in vivo. IR pulse trains (∼1862 nm, ∼200 µs pulse⁻¹) delivered to the sensory epithelium by an optical fibre evoked profound changes in phasic and tonic discharge rates of postsynaptic afferent neurons. Phasic afferent responses to pulsed IR occurred with a latency of <8 ms while tonic responses developed with a time constant (τ) of 7 ms to 10 s following the onset or cessation of the radiation. Afferents responded to direct optical radiation of the sensory epithelium but did not respond to thermal stimuli that generated nearly equivalent temperature increases of the whole organ. A subset of afferent neurons fired an action potential in response to each IR pulse delivered to the sensory epithelium, at phase-locked rates up to 96 pulses per second. The latency between IR pulses and afferent nerve action potentials was much greater than synaptic delay and spike generation, demonstrating the presence of a signalling delay interposed between the IR pulse and the action potential. The same IR stimulus applied to afferent nerve axons failed to evoke responses of similar magnitude and failed to phase-lock afferent nerve action potentials. The present data support the hypothesis that pulsed IR activates sensory hair cells, thus leading to modulation of synaptic transmission and afferent nerve discharge reported here.

Transcrusal approach to the retrochiasmatic region with special reference to temporal lobe retraction: an anatomical study.

BACKGROUND: The retrochiasmatic region is one of the most challenging areas to surgically expose. The authors evaluated the transcrusal approach, which involves removal of the superior and posterior semicircular canal from the ampulla to the common crus, to expose the retrochiasmatic region and compared it with the retrolabyrinthine approach, both of which are a variation of the posterior petrosal approach with hearing preservation, with a special emphasis on the influence of temporal lobe retraction. METHODS: Six sides of silicone-injected cadaveric heads were dissected using two approaches: the transcrusal approach and the retrolabyrinthine approach. For each craniotomy, 3 exposure parameters in the retrochiasmatic region were measured: (1) horizontal distance, (2) vertical distance, and (3) triangular area of exposure, at three different levels of temporal lobe retractions: 0, 5, and 10 mm of retraction from the level of the tentorial incisura. RESULTS: Without temporal lobe retraction, only the transcrusal and not the retrolabyrinthine approach provided a direct exposure of the retrochiasmatic region, especially in the horizontal distance (p < 0.001). At all levels of temporal lobe retraction, the transcrusal approach provided greater exposure in the horizontal and vertical distances and in the area of exposure. Nonetheless, in the horizontal distance, the difference between the transcrusal and retrolabyrinthine approaches decreased along with increased temporal lobe retraction, and almost no difference was obtained at 10 mm of retraction. CONCLUSIONS: Posterior petrosal approaches can provide an excellent exposure of the retrochiasmatic region. Of these two approaches, namely, transcrusal and retrolabyrinthine with hearing preservation, the transcrusal approach offers greater exposure than the retrolabyrinthine approach. The beneficial effect of partial labyrinthectomy of the transcrusal approach to the retrochiasmatic region is accentuated in the exposure of the horizontal distance with less temporal lobe retraction.

Frequency perception and cell injury in the semicircular canal caused by gentamicin.

OBJECTIVE: The frequency characteristics of the vestibular organ have gained notice in recent years, but the morphologic basis was unknown. This study investigated the gentamicin-induced damage of frequency-selective perception of the horizontal semicircular canal and its morphologic basis. METHODS: Eighty guinea pigs were randomly divided into four groups, one control group and three experimental groups. The experimental animals received gentamicin subcutaneously for 1 to 3 weeks. Short-latency vestibular evoked potentials evoked by 0.5 and 10 Hz step rotation stimuli following drug administration were recorded, and then the crista ampullaris of the horizontal semicircular canals was investigated by scanning and transmission electron microscopy. RESULTS: Damage to hair cells of the crista ampullaris is concentrated at the apex area first and then extends to the peripheral area of the vestibular crista ampullaris when the gentamicin administration time increased. When only the hair cells at the apex area are damaged, the high-frequency (10 Hz) rotation perception of the crista ampullaris of the horizontal semicircular canal was injured, but perceptions to 0.5 Hz step rotation stimulation remained normal. CONCLUSION: Gentamicin mainly affects the high-frequency perception function of the crista ampullaris of the horizontal semicircular canal. The hair cells at the central apex area of the crista ampullaris might be responsible for high-frequency rotation perception function.

Benign paroxysmal positional vertigo: a series of eight singular neurectomies.

CONCLUSION: The singular neurectomy as described by Gacek in 1974 is an efficient procedure to control symptoms in case of intractable benign paroxysmal positional vertigo (BPPV), with an acceptable risk of postoperative sensorineural hearing loss (SNHL). We postulate that this complication may not be a direct consequence of the surgical procedure but rather may be consecutive to the reactivation of the biological phenomenon that caused the BPPV. We also observed in one patient that BPPV may exist although no nystagmus can be elicited by provocative manoeuvres. OBJECTIVE: To report our experience of the surgery, and to analyse the rate and causes of complications. PATIENTS AND METHODS: The eight patients operated in the department between August 1997 and April 2006 were evaluated in June 2006. One had been operated because he had a typical history of BPPV, but no nystagmus could be elicited by the Hallpike's manoeuvre. RESULTS: All patients were free of vertigo and considered their quality of life improved. The Hallpike's manoeuvre was negative in all cases. A SNHL occurred in two patients, immediately after surgery in one and several months later in the second. The patient with a negative Hallpike's manoeuvre before surgery went back to work 3 weeks after surgery.

Transcanal approach to the singular nerve.

OBJECTIVES/HYPOTHESIS: Intractable benign paroxysmal positional vertigo is rare, and surgery is indicated in only a very small number of cases. Transcanal singular neurectomy is considered a difficult and risky procedure possibly leading to hearing loss and vertigo. The objective of this study was to evaluate the feasibility of the singular neurectomy through the external ear canal in an attempt to explain the contradictory results of previous reports of anatomists and of surgeons who abandoned the technique, considering that the singular neurectomy could not be reached via the external auditory canal without damaging the labyrinth. MATERIALS AND METHODS: Anatomical study on 100 halves of human heads in which the canal of the singular nerve (SN) was identified and opened at its extremities, the internal auditory canal and the ampulla of the posterior semicircular canal, via a posterior fossa approach. Next, the canal of the SN was dissected via the external auditory canal, at the floor of the round window (RW) niche. The relation of the SN canal to the ampulla of the posterior semicircular canal was evaluated. RESULTS: In 90 cases, the canal was transected medially to and away from the ampulla of the posterior semicircular canal, and in 8, at its emergence from the posterior ampullary recess. In these 98 cases, the RW membrane and the bony labyrinth were kept intact. In two cases, the canal of the SN could not be reached at the floor of the RW niche. CONCLUSION: Singular neurectomy is feasible via the external auditory canal, without damaging the RW membrane or the labyrinth in 98% of the cases. Because singular neurectomy is indicated in a very small number of cases, it is difficult to master this particular surgical procedure. This may explain why most surgeons abandoned the technique after a few attempts, followed by an unacceptable rate of sensorineural hearing loss.