posterior semicircular canal
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2022 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Daibo Li ◽  
Danni Cheng ◽  
Wenjie Yang ◽  
Ting Chen ◽  
Di Zhang ◽  
...  

Author(s):  
Rimjhim Sharma

<p class="abstract"><strong>Background:</strong> Benign paroxysmal positional vertigo (BPPV) is the most common reason for vertigo. Most common site of BPPV is posterior semicircular canal. The commonest symptom is episodic vertigo. This study aimed at the treatment response of Epley’s manoeuvre for posterior semicircular canal BPPV.</p><p class="abstract"><strong>Methods:</strong> 87 patients out of 114 were enrolled for the study from 2020 to 2021. After proper history and examination, Dix-Hallpike test (DHT) was done for diagnosis. Epley’s manoeuvre was done at first visit and was repeated at subsequent visits.</p><p class="abstract"><strong>Results:</strong> The mean age of the patients was 54 years. In this study, out of total 87 patients, there were 59 females (67.82%) and 28 males (32.18%). The male to female ratio was 1:2.11. Out of 87 patients, 53 patients (60.92%) recovered in the first visit, 18 patients (20.69%) recovered in second visit, 11 patients (12.64%) recovered in the third visit and remaining 5 patients (5.75%) recovered in fourth visit. In 3 out of 87 cases, that is, in 3.45%, recurrence was seen with return of the BPPV symptoms.</p><p class="abstract"><strong>Conclusions:</strong> Treatment response of Epley’s manoeuvre in posterior semicircular canal BPPV is good. Maximum number of patients’ recovered in the first visit.</p>


2021 ◽  
Vol 9 (3) ◽  
pp. 75-80
Author(s):  
Mustafa Caner Kesimli

OBJECTIVE: This study aimed to compare the effectiveness of the Epley maneuver with the Semont maneuver in the treatment of posterior semicircular canal benign paroxysmal positional vertigo and observe differences in the resolution time of symptoms in the short-term follow-up. METHODS: Sixty patients with posterior semicircular canal benign paroxysmal positional vertigo (23 males, 37 females; median age: 44.9 years; range, 14 to 80 years) were included in the prospective randomized comparative study conducted in our clinic between April 2019 and October 2019. Diagnosis and treatment maneuvers were performed under videonystagmography examination. Participants were randomly selected after the diagnostic tests for the Epley maneuver and the Semont maneuver treatment groups. RESULTS: In the evaluation of vertigo with videonystagmography, 25 (83.3%) patients in the Epley maneuver group and 20 (66.6%) patients in the Semont maneuver group recovered in the one-week follow-up, and 28 (93.3%) patients in the Epley maneuver group and 24 (80%) patients in the Semont maneuver group recovered in the two-week follow-up. All patients in the Epley maneuver group recovered at the end of one month; four patients in the Semont maneuver group still had vertiginous symptoms (100% vs. 86.6%, p=0.04). There was a statistically significant difference between the Epley and Semont groups regarding visual analog scores at the one-week, two-week, and one-month follow-ups (p=0.002, p<0.001, p=0.001, respectively). CONCLUSION: The Epley maneuver was significantly more effective than the Semont maneuver in resolving vertigo in the short-term treatment of posterior semicircular canal benign paroxysmal positional vertigo.


Author(s):  
Ajay Kumar Vats

AbstractVestibular lithiasis (canalolithiasis as well as cupulolithiasis) commonly exists in monocanalicular forms involving one of the three semicircular canals, frequent posterior, less frequent horizontal, and very rarely anterior. It is treated with canal clearing maneuvers intended to reposition the otoconia from the semicircular canal (where they have inappropriately entered) through the utricular exit in the nonampullary arm of the semicircular canal to the utricle (where they normally remain as a part of utricular gelatinous matrix). The cases of multicanalicular vestibular lithiasis with the involvement of more than one semicircular canal require meticulous identification of the involved canals and multiple different canal-clearing maneuvers for effective treatment. A 70-year-old male patient with no significant history of previous medical or otologic illnesses or head trauma presented with a 1-day history of vertigo with positional aggravation. A one-time performed diagnostic supine head roll test elicited three different patterns of positional nystagmus, each with an accurate localizing and lateralizing value. Diagnosis of unilateral multicanalicular vestibular lithiasis of right horizontal and posterior semicircular canals was entertained based on the pattern of the elicited positional nystagmi on the supine roll test. The upbeating torsional nystagmus that localizes the involvement to the posterior semicircular canal was paradoxically elicited by supine head roll test and not by the Dix–Hallpike test. As horizontal semicircular canalolithiasis causes severe symptoms, its treatment preceded that of concurrent posterior semicircular canalolithiasis. The patient was successfully treated with multiple sessions of canalith repositioning maneuvers (CRMs) spread over 24 hours. It is important to perform both positional tests, namely Dix–Hallpike maneuver, and supine head roll test, in cases suspected to have multicanalicular vestibular lithiasis. The positionings may need to be repeated several times to unveil multiple nystagmi, each with different localizing and lateralizing values. Identifying treatment priorities with CRM for the individual semicircular canals is crucial, and the canal that is liable to cause severe symptoms needs early clearance of the otoconial debris. If a CRM fails to clear a semicircular canal, an alternative maneuver may need to be executed. Clinicians involved in the care of cases with multicanalicular vestibular lithiasis should be well versed with all possible backup maneuvers for clearing each of the three semicircular canals.


2021 ◽  
Vol 12 ◽  
Author(s):  
Shuzhi Wu ◽  
Ping Lin ◽  
Yanyan Zheng ◽  
Yifei Zhou ◽  
Zhaobang Liu ◽  
...  

Located deep in the temporal bone, the semicircular canal is a subtle structure that requires a spatial coordinate system for measurement and observation. In this study, 55 semicircular canal and eyeball models were obtained by segmentation of MRI data. The spatial coordinate system was established by taking the top of the common crus and the bottom of the eyeball as the horizontal plane. First, the plane equation was established according to the centerline of the semicircular canals. Then, according to the parameters of the plane equation, the plane normal vectors were obtained. Finally, the average unit normal vector of each semicircular canal plane was obtained by calculating the average value of the vectors. The standard normal vectors of the and left posterior semicircular canal, superior semicircular canal and lateral semicircular canal were [−0.651, 0.702, 0.287], [0.749, 0.577, 0.324], [−0.017, −0.299, 0.954], [0.660, 0.702, 0.266], [−0.739, 0.588, 0.329], [0.025, −0.279, 0.960]. The different angles for the different ways of calculating the standard normal vectors of the right and left posterior semicircular canal, superior semicircular canal and lateral semicircular canal were 0.011, 0.028, 0.008, 0.011, 0.024, and 0.006 degrees. The technology for measuring the semicircular canal spatial attitudes in this study are reliable, and the measurement results can guide vestibular function examinations and help with guiding the diagnosis and treatment of BPPV.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jianliang Zhu ◽  
Jin Woong Choi ◽  
Yasuko Ishibashi ◽  
Kevin Isgrig ◽  
Mhamed Grati ◽  
...  

AbstractHearing loss is a common disability affecting the world’s population today. While several studies have shown that inner ear gene therapy can be successfully applied to mouse models of hereditary hearing loss to improve hearing, most of these studies rely on inner ear gene delivery in the neonatal age, when mouse inner ear has not fully developed. However, the human inner ear is fully developed at birth. Therefore, in order for inner ear gene therapy to be successfully applied in patients with hearing loss, one must demonstrate that gene delivery can be safely and reliably performed in the mature mammalian inner ear. In this study, we examine the steps involved in posterior semicircular canal gene delivery in the adult mouse inner ear. We find that the duration of perilymphatic leakage and injection rate have a significant effect on the post-surgical hearing outcome. Our results show that although AAV2.7m8 has a lower hair cell transduction rate in adult mice compared to neonatal mice at equivalent viral load, AAV2.7m8 is capable of transducing the adult mouse inner and outer hair cells with high efficiency in a dose-dependent manner.


2021 ◽  
Author(s):  
Xiaokai Yang ◽  
Qiancheng Yang ◽  
Zhaobang Liu

Abstract To discusses and analyzes how to realize the design of posterior semicircular canal BPPV diagnostic maneuver. First, measure the spatial attitude of the human semicircular canal, establish a BPPV virtual simulation platform, then analyze the key positions of the maneuver, and finally design a new diagnostic maneuver according to the demand, and perform physical simulation verification. The average value of the unit normal vector of the right posterior semicircular plane is [ 0.660, 0.702, 0.266], after rotate -46.8 ° around Z axis and 15.4 ° around Y axis, it parallel to the X axis. After that, when the tilt back angle reaches 70 °, the free otoconia in the left utricle will fall into the common crus; when bend forward 53.3°, the unit normal vector of the crista ampullaris plane of the posterior semicircular canal to the XY plane; when bend forward angle reaches 30°, the otoconia slides to the opening of the ampulla; when bend forward angle reaches 70°, the otoconia slides to the bottom of the crista ampullaris. The shallow pitching Yang maneuver is designed as turn head 45° to the one side, bend forward 45°, tilt back 90°, and bend forward 90°. The deep pitching Yang maneuver is designed as bend forward 90°, turn head 45° to one side, tilt back 135°, and bend forward 90°. A new posterior semicircular BPPV diagnostic test is designed to make the induced nystagmus have the characteristics of long latency, reversal, and repeatability, will not cause the inhibitory stimulation of the contralateral superior semicircular canal, and has good operation fault tolerance, which is of great value for clinical and scientific research.


2021 ◽  
Author(s):  
Sarah Baxendale ◽  
Esther C. Maier ◽  
Nikolaus D. Obholzer ◽  
Sarah Burbridge ◽  
Joseph Zinski ◽  
...  

BMP signalling is known to have a conserved function in development of the semicircular canal system of the vertebrate inner ear, but its regulation, target genes and effects on cell behaviour during otic morphogenesis are not fully understood. We have characterised the effects of mutations in the zebrafish gene bmper, which codes for a regulator of BMP signalling with both pro- and anti-BMP roles in different developmental contexts. The inner ears of bmper mutant embryos develop with truncations of the anterior and posterior semicircular canal ducts. To image the developing ear in live embryos, we have exploited a new transgenic line, Tg(smad6b:EGFP), which exhibits strong GFP expression in the otic epithelium. Morphometric analysis indicates defects in the bmper mutant ear from early stages of semicircular canal formation, correlating with a specific reduction in BMP signalling activity and specific loss of dlx5a expression in dorsal otic epithelium. Subsequent changes to cell shape occur at the truncation site and the dorsolateral septum. The bmper mutations that we describe are adult viable; truncation of the anterior and posterior semicircular canal ducts persists into adulthood. Our results argue against a major role for Bmper in specification of the pre-placodal region, induction of the otic placode, or development of the neural crest, processes in which Bmper function has previously been implicated. Instead, we conclude that a key requirement for Bmper function in the zebrafish is to promote BMP signalling during patterning and morphogenesis of the semicircular canal system.


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