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167 result(s) for "Semicircular Canals - pathology"
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The importance of bone density and anatomical structure in superior semicircular canal dehiscence
Objective This study investigates the importance of bone density, surface area, and diameter of anatomical structures of the superior semicircular canal (SSC), lateral semicircular canal (LSC), posterior semicircular canal (PSC), utricle, and saccule in patients diagnosed with superior semicircular canal dehiscence (SSCD). Materials and methods The bone density, surface area, and diameter of SSC, LSC, PSC, utricle, and saccule were measured and compared between the SSCD group and control group. Fifteen ears in the SSCD group and 60 ears in the control group were evaluated. Additionally, within the SSCD group, the dehiscent and healthy sides were evaluated independently. Results SSC’s bone density was significantly lower in the SSCD group compared to the control group ( p  = 0.008). No significant differences were found in surface area and diameter between the groups ( p  > 0.05). While most of the anatomical structures showed no significant difference in bone density between dehiscent and healthy ears ( p  > 0.05), SSC bone density was significantly lower in affected ears ( p  = 0.000) in SSCD group. Conclusion Based on the data obtained in this study, bone density and anatomical structure may be useful in patients diagnosed with SSCD.
Horizontal Semicircular Canal Benign Paroxysmal Positional Vertigo: Effectiveness of Two Different Methods of Treatment
The aim of this study is to compare the results obtained using 2 methods of treatment for horizontal semicircular canal benign paroxysmal positional vertigo (HSC-BPPV): the barbecue maneuver + forced prolonged position (FPP) versus the Gufoni maneuver. In a randomized prospective clinical trial, we recruited 147 patients affected by HSC-BPPV. The primary outcome was the absence of vertigo and nystagmus upon application of the supine roll test during the follow-up examination. A statistical evaluation was performed in order to assess whether any parameters (e.g. age, duration of nystagmus and symptoms) could influence in any way the results obtained with the 2 methods of treatment. One hundred and three of the 147 patients affected by HSC-BPPV had the geotropic form and 44 had the apogeotropic type. We were able to transform 29 cases of HSC-BPPV from apogeotropic to geotropic. Finally, we obtained a group of 112 patients who were randomized either to the barbecue + FPP procedure (54 patients) or to the Gufoni maneuver (58 patients). The most evident result is the higher percentage of success (statistically significant) with the Gufoni maneuver at the first session of treatment (86 vs. 61%). The final control showed that 44 out of 54 (81%) patients treated with the barbecue maneuver + FPP were symptom free compared to 54 out of 58 (93%) treated with the Gufoni maneuver. Both the barbecue maneuver + FPP and the Gufoni maneuver are valid methods for treating HSC-BPPV (geotropic forms). However, our results also indicate that the Gufoni maneuver has a significant advantage: the success rate shown at the follow-up, although without statistical significance, is undoubtedly higher (93 vs. 81%). This result, together with the fact that it is very easy to perform and that patient compliance is better, make the Gufoni maneuver the method of choice in HSC-BPPV treatment.
Short-term efficacy of Epley’s manoeuvre: a double-blind randomised trial
Background: Benign paroxysmal positional vertigo of the posterior canal (PC-BPPV) is a common vestibular disorder and can be easily treated with Epley’s manoeuvre. Thus far, the short-term efficacy of Epley’s manoeuvre for treatment of PC-BPPV is unknown. Objectives: To evaluate the efficacy of Epley’s manoeuvre for treatment of PC-BPPV 24 h after applying the manoeuvre. Methods: The short-term efficacy of Epley’s manoeuvre was compared with a sham procedure in 66 patients with PC-BPPV by using a double-blind randomised study design. Results: 24 h after treatment, 28 of 35 (80%) patients in the Epley’s manoeuvre group had neither vertigo nor nystagmus on positional testing compared with 3 of 31 (10%) patients in the sham group (p<0.001). Conclusion: Epley’s manoeuvre is shown to resolve PC-BPPV both effectively and rapidly.
Superior semicircular canal dehiscence in relation with the superior petrosal sinus: our experience, surgical management and systematic review of literature
Purpose Most of Superior Semicircular Canal Dehiscence (SSCD) are located in the apical region of the SSC. However, in a small number of cases, it may be situated in the medial wall, causing the SSC to contact with the superior petrosal sinus (SPS). The aim of this study is to describe four patients with SSCD involving the superior petrosal sinus (SSCD-SPS) and to perform a review of the literature. Methods Observational retrospective study of patients diagnosed of SSCD-SPS in a tertiary referral center. A systematic review was made, identifying 7 articles in the literature. Clinical presentation, complementary test (pure-tone audiometry, PTA; vestibular evoked myogenic potential, VEMP; computed tomography, CT), therapeutic management and outcomes were reported. Results Four new cases of SSCD-SPS are reported, in three of them a transmastoid plugging was performed. 54 patients with SSCD-SPS (57 dehiscences) were reported in the literature. The most frequent symptoms were aural pressure (57.41%) and vertigo provoked by pressure/Valsalva (55.55%). Conductive hearing loss was the most common finding in PTA (47.37%). Abnormally low thresholds were observed in 59.46% of reported VEMP. Transmastoid approach was used in ten cases, middle fossa approach in four, round window reinforcement in one, and occlusion of the SPS using coils in two. Conclusions Within SSCD, we have encountered a rare subtype characterized by its medial wall location in close proximity to the SPS. This subgroup needs special consideration as it has shown its own distinct characteristics. Regarding therapeutic management, we advocate a transmastoid approach.
Lateral semi-circular canal asymmetry in females with idiopathic scoliosis
Adolescent idiopathic scoliosis (AIS) is a three-dimensional spinal structural deformity that occurs in otherwise normal individuals. Although curve progression and severity vary amongst individuals, AIS can lead to significant cosmetic and functional deformity. AIS etiology has been determined to be genetic, however, exact genetic and biological processes underlying this disorder remain unknown. Vestibular structure and function have potentially been related to the etiopathogenesis of AIS. Here, we aimed to characterize the anatomy of the semicircular canals (SCC) within the vestibular system through a novel approach utilizing T2-weighted magnetic resonance images (MRI). Three dimensional, MRI-based models of the SCCs were generated from AIS subjects (n = 20) and healthy control subjects (n = 19). Linear mixed models were used to compare SCC morphological measurements in the two groups. We compared side-to-side differences in the SCC measurements between groups (group*side interaction). Side-to-side differences in the lateral SCC were different between the two groups [false discovery rate adjusted p-value: 0.0107]. Orientation of right versus left lateral SCC was significantly different in the AIS group compared to the control group [mean side-to-side difference: -4.1°, 95% CI: -6.4° to -1.7°]. Overall, among subjects in the AIS group, the left lateral SCC tended to be oriented in a more horizontal position than subjects in the control group. Asymmetry within the SCCs of the vestibular system of individuals with AIS potentially results in abnormal efferent activity to postural muscles. Consequences of this muscular activity during periods of rapid growth, which often coincides with AIS onset and progression, warrant consideration.
Diagnosis strategy and Yacovino maneuver for anterior canal-benign paroxysmal positional vertigo
ObjectiveTo investigate the diagnosis strategy of anterior canal-benign paroxysmal positional vertigo (AC-BPPV) and the therapeutic effects of the Yacovino maneuver.MethodsThe clinical data of 40 AC-BPPV patients were collected. The nystagmus characteristics induced by the Dix–Hallpike (D–H) and straight head-hanging (SHH) tests, the diagnostic methods used, and the effectiveness of the Yacovino maneuver for the treatment of AC-BPPV were all retrospectively analyzed.ResultsAmong the 40 cases analyzed, 19 patients had simple AC-BPPV, 11 patients had AC-posterior canal BPPV, and 10 patients had AC-horizontal canal BPPV. D–H and SHH tests showed down-beating nystagmus in 26 and 33 patients, respectively, and showed down-beating and torsional nystagmus in 14 and 7 patients, respectively. AC-BPPV was diagnosed in 15 patients based on the presence of typical BPPV in other canals, in 9 patients based on typical disease history and the results of position tests, in 6 patients based on effectiveness of the treatment with the Yacovino maneuver, in 4 patients based on the treatment effectiveness and the presence of typical BPPV in other canals, in 3 patients based on the treatment effectiveness and the follow-up outcome, in 2 patients based on the typical BPPV in other canals and occurrence of canal conversion, and in 1 patient based on the treatment effectiveness and occurrence of canal conversion. Thirteen patients with canalolithiasis and four patients with cupulolithiasis were cured after the initial Yacovino maneuver treatment. Twenty-one patients with canalolithiasis and seven patients with cupulolithiasis were cured following 1 week of treatment.ConclusionsThe effectiveness of the Yacovino maneuver, the follow-up outcome, the presence of typical BPPV in other canals, and the occurrence of canal conversions contribute to AC-BPPV diagnosis. The Yacovino maneuver was found to be more effective in AC-BPPV patients with canalolithiasis than in those with cupulolithiasis.
Novel Method of Measuring Canal Dehiscence and Evaluation of its Potential as a Predictor of Symptom Outcomes After Middle Fossa Craniotomy
Abstract BACKGROUND Superior semicircular canal dehiscence (SSCD) is an osseous defect of the arcuate eminence of the petrous temporal bone. Strategies for measuring dehiscence size are variable, and the usefulness of such parameters remains in clinical equipoise. OBJECTIVE To present a novel method of measuring dehiscence volume and to evaluate its potential as a predictor of symptom outcomes after surgical repair of SSCD. METHODS High-resolution computed tomographic temporal bone images were imported into a freely available segmentation software. Dehiscence lengths and volumes were ascertained by independent authors. Inter-rater observer reliability was assessed using Cronbach's alpha. Correlation and regression analyses were performed to evaluate for relationships between dehiscence size and symptoms (pre- and post-operative). RESULTS Thirty-seven dehiscences were segmented using the novel volumetric assessment. Cronbach's alpha for dehiscence lengths and volumes were 0.97 and 0.95, respectively. Dehiscence lengths were more variable as compared to dehiscence volumes (σ2 8.92 vs σ2 0.55, F = 1.74). The mean dehiscence volume was 2.22 mm3 (0.74, 0.64-0.53 mm3). Dehiscence volume and headache at presentation were positively correlated (Rpb = 0.67, P = .03). Dehiscence volume and vertigo improvement after surgery were positively correlated, although this did not reach statistical significance (Rpb = 0.46, P = .21). CONCLUSION SSCD volumetry is a novel method of measuring dehiscence size that has excellent inter-rater reliability and is less variable compared to dehiscence length, but its potential as a predictor of symptom outcomes is not substantiated. However, the study is limited by low power.
Lateral Semicircular Canal Asymmetry in Idiopathic Scoliosis: An Early Link between Biomechanical, Hormonal and Neurosensory Theories?
Despite its high incidence and severe morbidity, the physiopathogenesis of adolescent idiopathic scoliosis (AIS) is still unknown. Here, we looked for early anomalies in AIS which are likely to be the cause of spinal deformity and could also be targeted by early treatments. We focused on the vestibular system, which is suspected of acting in AIS pathogenesis and which exhibits an end organ with size and shape fixed before birth. We hypothesize that, in adolescents with idiopathic scoliosis, vestibular morphological anomalies were already present at birth and could possibly have caused other abnormalities. The vestibular organ of 18 adolescents with AIS and 9 controls were evaluated with MRI in a prospective case controlled study. We studied lateral semicircular canal orientation and the three semicircular canal positions relative to the midline. Lateral semicircular canal function was also evaluated by vestibulonystagmography after bithermal caloric stimulation. The left lateral semicircular canal was more vertical and further from the midline in AIS (p = 0.01) and these two parameters were highly correlated (r = -0.6; p = 0.02). These morphological anomalies were associated with functional anomalies in AIS (lower excitability, higher canal paresis), but were not significantly different from controls (p>0.05). Adolescents with idiopathic scoliosis exhibit morphological vestibular asymmetry, probably determined well before birth. Since the vestibular system influences the vestibulospinal pathway, the hypothalamus, and the cerebellum, this indicates that the vestibular system is a possible cause of later morphological, hormonal and neurosensory anomalies observed in AIS. Moreover, the simple lateral SCC MRI measurement demonstrated here could be used for early detection of AIS, selection of children for close follow-up, and initiation of preventive treatment before spinal deformity occurs.
Assessment of the Effects of Superior Canal Dehiscence Location and Size on Intracochlear Sound Pressures
Superior canal dehiscence (SCD) is a defect in the bony covering of the superior semicircular canal. Patients with SCD present with a wide range of symptoms, including hearing loss, yet it is unknown whether hearing is affected by parameters such as the location of the SCD. Our previous human cadaveric temporal bone study, utilizing intracochlear pressure measurements, generally showed that an increase in dehiscence size caused a low-frequency monotonic decrease in the cochlear drive across the partition, consistent with increased hearing loss. This previous study was limited to SCD sizes including and smaller than 2 mm long and 0.7 mm wide. However, the effects of larger SCDs (>2 mm long) were not studied, although larger SCDs are seen in many patients. Therefore, to answer the effect of parameters that have not been studied, this present study assessed the effect of SCD location and the effect of large-sized SCDs (>2 mm long) on intracochlear pressures. We used simultaneous measurements of sound pressures in the scala vestibuli and scala tympani at the base of the cochlea to determine the sound pressure difference across the cochlear partition - a measure of the cochlear drive in a temporal bone preparation - allowing for assessment of hearing loss. We measured the cochlear drive before and after SCDs were made at different locations (e.g. closer to the ampulla of the superior semicircular canal or closer to the common crus) and for different dehiscence sizes (including larger than 2 mm long and 0.7 mm wide). Our measurements suggest the following: (1) different SCD locations result in similar cochlear drive and (2) larger SCDs produce larger decreases in cochlear drive at low frequencies. However, the effect of SCD size seems to saturate as the size increases above 2-3 mm long and 0.7 mm wide. Although the monotonic effect was generally consistent across ears, the quantitative amount of change in cochlear drive due to dehiscence size varied across ears. Additionally, the size of the dehiscence above which the effect on hearing saturated varied across ears. These findings show that the location of the SCD does not generally influence the amount of hearing loss and that SCD size can help explain some of the variability of hearing loss in patients. i 2014 S. Karger AG, Basel
Benign Paroxysmal Positional Vertigo: Is It Really an Otolith Disease?
The current theory in physiopathology of benign paroxysmal positional vertigo is the mechanical theory, namely the cupulolithiasis-canalolithiasis theory. Repositioning maneuvers based on this theory has now taken place in therapy. However, mechanical theory is insufficient to explain some clinical situations and cannot fully enlighten the physiopathology. Mechanical theory is based on very few histological studies. Currently, these few articles are still used for reference. Anatomically, there are uncertainties that need to be explained in this theory. In this literature review, the histological and anatomical evidence is reviewed and the value of mechanical theory in benign paroxysmal positional vertigo physiopathology has been questioned. Studies suggest that the debris in the semicircular canals is caused by degeneration due to aging and may not be responsible for the symptoms in benign paroxysmal positional vertigo. Some patients with debris in semicircular canals do not have benign paroxysmal positional vertigo symptomatology, while some patients without debris may have benign paroxysmal positional vertigo symptomatology. Experimental and histological findings suggest that vestibulopathy due to inflammation caused by neurotropic viruses may lead to benign paroxysmal positional vertigo picture. For all these reasons, in benign paroxysmal positional vertigo physiopathology, there must be other factors besides particle debris in semicircular canals.