Tsukushi is essential for the formation of the posterior semicircular canal that detects gait performance.
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ABSTRACT:
SUBMITTER: Miwa T
PROVIDER: S-EPMC8642578 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Spontaneous canalith jam is an uncommon form of benign paroxysmal positional vertigo mimicking acute vestibular neuritis. We described for the first time a spontaneous horizontal semicircular canalith jam associated with a typical canalolithiasis involving contralateral posterior semicircular canal (PSC), illustrating how the latter condition modified direction-fixed nystagmus during head movements. An 81-year-old woman with persistent vertigo referred to our center. Video-Frenzel examination showed horizontal direction-fixed right-beating nystagmus in primary gaze position, inhibited by visual fixation. She exhibited corrective saccades after leftward head impulses. Chin-to-chest positioning at the head-pitch test did not modify spontaneous nystagmus, whereas slight torsional components with the top pole of the eye beating toward the right ear appeared in backward head-bending, resulting in mixed horizontal-torsional nystagmus. At supine positioning tests, direction-fixed nystagmus turned into direction-changing geotropic horizontal nystagmus, which was stronger on the left side, while overlapping upbeat nystagmus with torsional right-beating components appeared on the right. Primary clinical findings were consistent with a left horizontal semicircular canalith jam, inducing a persistent utriculofugal cupular displacement, combined with a typical right-sided PSC-canalolithiasis. Once canalith jam crumbled, resulting in a non-ampullary arm canalolithiasis of the horizontal semicircular canal, both involved canals were freed by debris with appropriate repositioning procedures.
| S-EPMC8755438 | biostudies-literature
Project description:BackgroundVestibular symptoms on sitting-up are frequent on patients seen by vestibular specialists. Recently, a benign paroxysmal positional vertigo (BPPV) variant which elicits vestibular symptoms with oculomotor evidence of posterior semicircular canal (P-SCC) cupula stimulation on sitting-up was described and named sitting-up vertigo BPPV. A periampullar restricted P-SCC canalolithiasis was proposed as a causal mechanism.ObjectiveTo describe new mechanisms of action for the sitting-up vertigo BPPV variant.MethodsEighteen patients with sitting-up vertigo BPPV were examined with a pre-established set of positional maneuvers and follow-up until they resolved their symptoms and clinical findings.ResultsAll patients showed up-beating torsional nystagmus (UBTN) and vestibular symptoms on coming up from either Dix-Hallpike (DHM) or straight head-hanging maneuver. Sixteen out of 18 patients presented a sustained UBTN with an ipsitorsional component to the tested side on half-Hallpike maneuver (HH). A slower persistent contratorsional down-beating nystagmus was found in eleven out 18 patients tested on nose down position (ND).ConclusionsPersistent direction changing positional nystagmus on HH and ND positions indicative of P-SCC heavy cupula was found in 11 patients. A sustained UBTN on HH with the absence of findings on ND, which is suggestive of the presence of P-SCC short arm canalolithiasis, was found on 5 patients. All patients were treated with canalith repositioning maneuvers without success, but they resolved their findings by means of Brandt-Daroff exercises. We propose P-SCC heavy cupula and P-SCC short arm canalolithiasis as two new putative mechanisms for the sitting-up vertigo BPPV variant.
| S-EPMC9349016 | biostudies-literature
Project description:BackgroundThe video head impulse test (vHIT) is a useful clinical tool to detect semicircular canal dysfunction. However vHIT has hitherto been limited to measurement of horizontal canals, while scleral search coils have been the only accepted method to measure head impulses in vertical canals. The goal of this study was to determine whether vHIT can detect vertical semicircular canal dysfunction as identified by scleral search coil recordings.MethodsSmall unpredictable head rotations were delivered by hand diagonally in the plane of the vertical semicircular canals while gaze was directed along the same plane. The planes were oriented along the left-anterior-right-posterior (LARP) canals and right-anterior-left-posterior (RALP) canals. Eye movements were recorded simultaneously in 2D with vHIT (250 Hz) and in 3D with search coils (1000 Hz). Twelve patients with unilateral, bilateral and individual semicircular canal dysfunction were tested and compared to seven normal subjects.ResultsSimultaneous video and search coil recordings were closely comparable. Mean VOR gain difference measured with vHIT and search coils was 0.05 (SD?=?0.14) for the LARP plane and -0.04 (SD?=?0.14) for the RALP plane. The coefficient of determination R(2) was 0.98 for the LARP plane and 0.98 for the RALP plane and the results of the two methods were not significantly different. vHIT and search coil measures displayed comparable patterns of covert and overt catch-up saccades.ConclusionsvHIT detects dysfunction of individual vertical semicircular canals in vestibular patients as accurately as scleral search coils. Unlike search coils, vHIT is non-invasive, easy to use and hence practical in clinics.
| S-EPMC3632590 | biostudies-literature
Project description:We describe the clinical evaluation and operative management of posterior semicircular canal dehiscence caused by a high jugular bulb.We performed a retrospective case report.The patient had clinical and audiometric findings consistent with semicircular canal dehiscence and imaging findings that demonstrated erosion of the posterior semicircular canal by a high jugular bulb. Resurfacing of the eroded canal provided resolution of the vestibular symptoms without damage to the inner ear.Dehiscence of the posterior semicircular canal can cause clinical and audiometric findings similar to those of superior semicircular canal dehiscence syndrome. Resurfacing of the area of dehiscence can successfully relieve the vestibular symptoms. In the case of dehiscence of the posterior canal from a high jugular bulb, resurfacing may offer advantages over canal plugging for definitive management.
| S-EPMC3972486 | biostudies-literature
Project description:A 16-year-old boy with rotatory positional vertigo and nausea, particularly when lying down, visited our clinic. Initially, we observed vertical/torsional (downward/leftward) nystagmus in the supine position, and it did not diminish. In the sitting position, nystagmus was not provoked. Neurological examinations were normal. We speculated that persistent torsional down-beating nystagmus was caused by the light cupula of the posterior semicircular canal. This case provides novel insights into the light cupula pathophysiology.
| S-EPMC5030422 | biostudies-literature
Project description:Vestibular neuritis (VN) mostly involves the superior vestibular nerve. Isolated inferior vestibular neuritis (IVN) has been more rarely described. The diagnosis of IVN is based on an abnormal head impulse test (HIT) for the posterior semicircular canal (PSC), pathological cervical vestibular-evoked myogenic potentials (C-VEMPs), and spontaneous downbeat nystagmus consistent with acute functional loss of inner ear sensors lying within the inferior part of the labyrinth. HIT for both lateral and superior semicircular canals is normal, as are ocular VEMPs and bithermal caloric irrigations. The etiology of IVN is debated since peripheral acute vestibular loss with a similar lesion pattern can often be associated with ipsilesional sudden hearing loss (HL). Viral inflammation of vestibular nerves is considered the most likely cause, although reports suggest that VN usually spares the inferior division. On the other hand, an ischemic lesion involving the terminal branches of the common cochlear artery has been hypothesized in cases with concurrent HL. Debated is also the lesion site in the case of IVN without HL since different instrumental patterns have been documented. Either isolated posterior ampullary nerve involvement presenting with selective PSC functional loss on video-HIT, or only saccular lesion with isolated ipsilesional C-VEMPs impairment, or inferior vestibular nerve damage (including both saccular and posterior ampullary afferents) exhibiting an impairment of both C-VEMPs and PSC-HIT. We report an interesting case of a patient with an acute vestibular loss consistent with IVN without HL who developed a PSC ossification on follow-up, questioning the viral origin of the lesion and rather orienting toward an occlusion of the posterior vestibular artery. To the best of our knowledge, this is the first report of PSC ossification after a clinical picture consistent with IVN.
| S-EPMC9621331 | biostudies-literature
Project description:ObjectiveThe transmastoid plugging of a superior semicircular canal is considered a safe and effective technique for the management of superior semicircular canal dehiscence (SSCD). The aim of this meta-analysis is to assess the postoperative hearing outcomes after the transmastoid plugging of the superior semicircular canal. Search method and data sources: A systematic database search was performed on the following databases until 30 January 2023: MEDLINE, Embase, Cochrane Library, Web of Science, CINAHL, ICTRP, and clinicaltrials.gov. A systematic literature review and meta-analysis of the pooled data were conducted. We also included a consecutive case series with SCDS for those who underwent transmastoid plugging treatment at our clinic.ResultsWe identified 643 citations and examined 358 full abstracts and 88 full manuscripts. A total of 16 studies were eligible for the systematic review and 11 studies for the meta-analysis. Furthermore, 159 ears (152 patients) were included. The postoperative mean air conduction threshold remained unchanged (mean difference, 2.89 dB; 95% CI: -0.05, 5.84 dB, p = 0.58), while the mean bone conduction threshold was significantly worse (mean difference, -3.53 dB; 95% CI, -6.1, -0.95 dB, p = 0.9).ConclusionThe transmastoid plugging technique for superior semicircular canal dehiscence syndrome, although minimally worsening the inner ear threshold, is a safe procedure in terms of hearing preservation and satisfactory symptom relief.
| S-EPMC10604912 | biostudies-literature
Project description:To determine the use of multi-detector computed tomography (MDCT) in the diagnostic interpretation of superior semicircular canal dehiscence (SSCD) or thinning and its association with ear pathologies and to find whether it is an acquired condition and its association with increase in age.study was performed in a tertiary care institute present in a village, following approval of the institutional ethical committee. Retrospective review of temporal bone CT examinations performed between September 2016 and March 2017 was done. 1 mm interval axial images with sagittal and coronal reformatted images were reviewed for the presence of canal dehiscence and thinning by investigators. We characterised the Superior semicircular canal status as normal, frank dehiscence or thinning. Frank dehiscence was further classified anatomically as anterior limb, apex and posterior limb dehiscence.The patient list was then subcategorized into 5 age groups, and the prevalence of SSCD was calculated for each group.Retrospective review yielded 80 positive cases which included SSC dehiscence (N = 39) and thinning (N = 41). 80 normal scans were selected as control group retrospectively. Statistical analysis was performed to assess for differences between the groups studied. Pearson chi-square test applied. there was a significant association of SSC pathologies prevalence with increasing age (p = < 0.001). No significant relationship was found between SSCD and presence of either CSOM or Cholesteatoma (p = 0.285). Vertigo rather than Tullio phenomenon was the statistically significant complaint (p = <0.001). which brought the patient to the hospital.The SSCD and thinning belong to the same spectrum and are acquired conditions. Increasing prevalence in old age suggests it to be an acquired condition rather than a congenital one. No significant association of these condition was seen with CSOM and cholesteatoma. Vertigo is the predominat symptom bringing the patient to hospital along with Tullio phenomenon.
| S-EPMC5717502 | biostudies-literature
Project description: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.
| S-EPMC8498035 | biostudies-literature
Project description:The semicircular canal system of vertebrates helps coordinate body movements, including stabilization of gaze during locomotion. Quantitative phylogenetically informed analysis of the radius of curvature of the three semicircular canals in 91 extant and recently extinct primate species and 119 other mammalian taxa provide support for the hypothesis that canal size varies in relation to the jerkiness of head motion during locomotion. Primate and other mammalian species studied here that are agile and have fast, jerky locomotion have significantly larger canals relative to body mass than those that move more cautiously.
| S-EPMC1892787 | biostudies-literature