Investigation of serum calcium and vitamin D levels in superior semicircular canal dehiscence syndrome: A case control study

Objective: It remains unknown whether calcium metabolism has any effect on the clinical presentation of superior semicircular canal dehiscence(SSCD). Our aim was to analyse the adjusted calcium and vitamin D levels in SSCD patients compared to a control group.Methods: This was a prospective case-control study performed in a tertiary referral center, university teaching hospital in the UK. It included all new patients with SSCD seen in a dedicated skull base clinic over a 5-year period(2015-2019) compared to a gender and age matched control group. The main outcome of the study was adjusted calcium and Vitamin D levels between the two groups.Results: A total of 31 SSCD patients were recruited with a matched number of control patients. The mean Vitamin D level on the SSCD group was 44.8 nmoL/l(SD: 20.8) compared to 47.5 nmoL/l(SD: 27.4) on the control group(p = 0.702). Mean Adjusted calcium level was 2.34 mmoL/l(SD: 0.7) for SSCD compared to2.41 mmoL/l(SD: 0.11) for controls(p = 0.01), being within normal limits for both the SSCD and the control group.Conclusion: Our study did not identify a link between Vitamin D levels and presence of SSCD. Normal adjusted calcium values were found in both groups. Despite that a statistically significant lower calcium level was found in the SSCD group which could indicate that suboptimal levels of calcium may affect the micro-environment of the otic capsule at the SSC region.

An evidenced-based diagnostic tool for superior semicircular canal dehiscence syndrome

Purpose:To construct a symptoms-based prediction tool to assess the likelihood of superior canal dehiscence(SSCD)on high-resolution CT.Materials and methods:Mathematical modeling was employed to predict radiologic evidence of SSCD at a tertiary neurotology referral center.Results:A total of 168 patients were included,of which 118 had imaging-confirmed SSCD.On univariate analysis significant predictors of SSCD presence were:sound/pressure-induced vertigo(p?0.006),disequilibrium(p?0.008),hyperacusis(p?0.008),and autophony(p?0.034).Multivariate analysis enabled a 14-point symptom-weighted tool to be developed,wherein a score of6 raised the suspicion of SSCD(70%likelihood of being present),R2?0.853.Conclusions:The likelihood of SSCD on CT scan can be determined with a high degree of certainty based on symptoms recorded at presentation.Using the evidenced-based diagnostic tool validated herein,a score6 with any symptom combination justifies ordering a CT scan.

Quick repositioning maneuver for horizontal semicircular canal benign paroxysmal positional vertigo

Objective:To investigate the efficacy of quick repositioning maneuver for horizontal semicircular canal benign paroxysmal positional vertigo (H-BPPV). Methods:Clinical data of 67 patients with H-BPPV who underwent quick repositioning maneuver in our hospital from July 2009 to November 2014 were retrospectively analyzed. The maneuver involved rotating the patient in the axial plane for 180? from the involved side towards contralateral side as quickly as possible. Results:Complete symptom resolution was achieved in 61 patients (91.0%) at one week and in 64 patients (95.5%) at 3 months post-treatment. During the repositioning maneuver process, there were no obvious untoward responses except transient nausea with or without vomiting in a few patients. Conclusion:The results indicate that the quick repositioning maneuver is an easy and effective alternative treatment in the management of H-BPPV. Copyright ? 2015 The Authors. Production & hosting by Elsevier (Singapore) Pte Ltd On behalf of PLA General Hospital Department of Otolaryngology Head and Neck Surgery. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Bilateral Superior Semicircular Canal Dehiscence without Signs of Vestibular Involvement about a Case

Superior semicircular canal dehiscence (SSCD) is a rare entity recently described whose typical clinical symptomatology is represented by dizziness triggered by a variation of pressure. We reported a case of SSCD which was diagnosed thanks to computed tomography (CT) scan of the petrous bone conducted systematically in front of mixed deafness with normal eardrum. The SSCD was bilateral and was revealed by mixed deafness on the left side and perception deafness on the right with a normal eardrum without the notion of vertigo. The cervical vestibular evoked myogenic potential (cVEMP) and an ultra-high resolution CT scan of the petrous bones in coronal and sagittal sections allowed the diagnosis. The SSCD should be considered in the presence of any conductive or mixed hearing loss with a normal eardrum. The CT scan in coronal and sagittal submillimetric sections allows the diagnosis.

Subtemporal Extradural Approach for Dehiscence of the Superior Semicircular Canal: Surgical Technique and Results in Three Consecutive Patients

We describe three patients with severe disabling symptoms of unilateral dehiscence of the superior semicircular canal (DSSC) who had surgical treatment. Each patient underwent a unilateral subtemporal extradural approach with resurfacing the DCCS. In all 3 patients, all symptoms were completely resolved and remained symptom free on the long term. There were no postoperative complications. Only one patient experienced a temporary CSF hypotension syndrome and some dizziness. The pseudo-conductive hearing loss improved or resolved in all patients. Surgical treatment should be considered in patients with severe, disabling DSSC symptoms. Surgical resurfacing of the DSSC is a safe and rewarding surgical technique. The long term success rate regarding the elimination of the pseudo-conductive hearing loss and resolution of vestibular symptoms outweigh the potential surgical risks of this technique in these patients.

Affected-Ear-Up 90°Maneuver Proves That Nystagmus Does Not Occur by the Stimulation to the Macula of the Utricle

Background: The utricular macula is located on the floor of the utricle, approximately in the plane of the lateral semicircular canal, and is oriented to respond best to lateral tilts and side-to-side or fore-and-aft translations of the head. However, the details of the otolith ocular reflex are unknown. Pathophysiology of transient direction-changing geotropic positional nystagmus is a canalolithiasis in the lateral semicircular canal. The principle of affected-ear-up 90° maneuver is moving debris from a long arm to the utricle, therefore debris stimulates the utricular macula in the sitting position after the treatment. Objective: To clarify whether nystagmus occurs by the stimulation to the macula of the utricle. Methods: The subjects were 10 patients with lateral semicircular canal canalolithiasis. After the diagnosis, we performed affected-ear-up 90° maneuver immediately. We observed eye movements in the sitting position (chin-down 30°) just after the treatment. Results: No one showed nystagmus in the sitting position after the treatment. In all patients, positional nystagmus disappeared within 7 days after the treatment. Conclusion: Nystagmus does not occur by the stimulation to the macula of the utricle. Hence, we cannot assess the function of the utricle by the analysis of eye movements, and ocular counter-rolling is considered to be a semicircular canal ocular reflex.

Light Cupula:To Be Or Not to Be?

Benign paroxysmal positional vertigo(BPPV)represents the most common form of positional vertigo.It is caused by dislodged otoconia that freely float in the semicircular canals(canalolithiasis)or attach to the cupula(cupulolithiasis).A cupulolithiasis-type(or a heavy cupula-type)of BPPV implicating the lateral semicircular canal(LSCC)exhibits persistent ageotropic direction-changing positional nystagmus(DCPN)in a head-roll test.However,in some cases,unlike any type of BPPV,persistent geotropic DCPN cannot be explained by any mechanisms of BPPV,and don’t fit the current classifications.Recently,the notion of light cupula has been introduced to refer to the persistent geotropic DCPN.In this study,we looked at the clinical features of light cuplula and discussed the possible mechanisms and therapeutic strategies of the condition.The notion of light cupula is a helpful addition to the theory of peripheral positional vertigo and nystagmus.

Transmastoid Approach for Resurfacing the Superior Semicircular Canal Dehiscence with a Dumpling Structure

Background： Superior semicircular canal dehiscence （SSCD） is gradually recognized by otologists in recent years. The patients with SSCD have a syndrome comprising a series of vestibular symptoms and hearing function disorders which can be cured by the operation. In this study, we evaluated the characteristics of patients with SSCD and determined the effectiveness of treating this syndrome by resurfacing the canal via the transmastoid approach using a dumpling structure. Methods： Patients with SSCD, confirmed by high-resolution computed tomography and hospitalized at Beijing Tongren Hospital between November 2009 and October 2012, were included in the study. All of the patients underwent the unilateral transmastoid approach for resurfacing the canal, and received regular follow-up after surgery. Data from preoperative medical records and postoperative follow-up were comparatively analyzed to evaluate the effect of surgery. Results： In total, 10 patients and 13 ears （three left ears, four right ears, three bilateral ears） were evaluated in the study, which included 7 men and 3 women. Different symptoms and distinctive manifestations of vestibular evoked myogenic potential were found in these patients. Alter surgery, 4 patients had complete resolution, 5 had partial resolution, and 1 patient, with bilateral SSCD, had aggravation. None of the patients suffered from serious complications such as sensorineural hearing loss, facial paralysis, cerebrospinal fluid leakage, or intracranial hypertension. Conclusions： In patients with unilateral SSCD, resurfacing the canal via the transmastoid approach using a dumpling structure is an effective and sate technique. However, more consideration is needed for patients with bilateral SSCD.

BPPV Viewer: A downloadable 3D BPPV model for study of otolith disease

Objective:To develop a downloadable three-dimensional(3D)study tool of the membranous labyrinth in order to facilitate the study of benign paroxysmal positional vertigo(BPPV).Background:The diagnosis and treatment of BPPV depend on an understanding of the anatomy of the vestibular labyrinth and its position relative to the head.To date,many illustrations have been made to explain principles of diagnosis and treatment of BPPV,but few have been based on anatomical studies of the membranous labyrinth.Methods:A previously reported 3D model of a human labyrinth was transposed to a 3D development software to allow the creation of markers along the semicircular ducts and utricle.These markers represent otoliths at different positions during movement of the model within the 3D environment.User-friendly tools were created to navigate the model,to allow clear documentation and communication of studied problems,and to study the model across relevant planes.The final model can be downloaded and is available for general useat https://bppvviewer.com/download/.Results:The model allows visualization of true membranous labyrinth anatomy in both ears simultaneously.The dependent portion of each semicircular duct,the planes of the cristae,and the position of the utricle can easily be visualized in any head position.Moveable markers can mark the expected progress of otolith debris with changes in head position and images can be captured to document simulations in various draw styles.Conclusion:This simple model could offer insights that lead to more accurate diagnosis and treatment of BPPV.It may also be useful as a tool to teach BPPV.