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History Stations
Published in Peter Kullar, Joseph Manjaly, Livy Kenyon, Joseph Manjaly, Peter Kullar, Joseph Manjaly, Peter Kullar, ENT OSCEs, 2023
Peter Kullar, Joseph Manjaly, Livy Kenyon, Joseph Manjaly, Peter Kullar, Joseph Manjaly, Peter Kullar
Is there anything you have noticed that brings on the vertigo? (Ask about characteristic head positions for BPPV or the occurrence of vertigo with loud sounds [Tullio's phenomenon] that may indicate an underlying superior canal dehiscence.)
Middle Fossa Surgery
Published in John C Watkinson, Raymond W Clarke, Christopher P Aldren, Doris-Eva Bamiou, Raymond W Clarke, Richard M Irving, Haytham Kubba, Shakeel R Saeed, Paediatrics, The Ear, Skull Base, 2018
Raghu N.S. Kumar, Sunil N. Dutt, Richard M. Irving
A series with 43 cases of superior canal dehiscence syndrome (SCDS) who underwent surgical plugging by the MCF approach has been reported by Ward et al. 38 Plugging of the canal was performed using fascia strips, bone dust and bone chips, which are gently but securely placed inside the dehiscent canal to obliterate the canal lumen for 2–3 mm beyond either end of the dehiscence. Careful avoidance of unnecessary force on or suction near the membranous labyrinth was observed throughout the procedure. The repair was then covered with hydroxyapatite cement, followed by a layer of fascia and fibrin glue. The authors concluded that low frequency air–bone gap decreases following surgical plugging and appears to be due to both increased bone-conduction (BC) thresholds and decreased air-conduction (AC) thresholds. Surgical plugging via a middle cranial fossa approach in SCDS is associated with mild high frequency sensorineural hearing loss that persists in 25% but no change in speech discrimination.38–39
Eustachian Tube Dysfunction
Published in James R. Tysome, Rahul G. Kanegaonkar, Hearing, 2015
A large variety of methods have been employed to assess ET function, with more than 40 tests described in the literature. However, no single test is able to give detailed insights into all aspects of ET physiology and pathology. Otoscopy, endosocopy, Politzer test, Valsalva manoeuvre and Toynbee manoeuvre provide preliminary information. Manometric testing such as tympanometry and reflex decay tympanometry are in widespread clinical use. The nine-step inflation/ deflation test, modified inflation/deflation test, forced response test and tubomanometry (TMM) have some additional value. TMM is a valuable tool to measure the opening of the ET tube and the transportation of gas into the middle ear by applying pressure changes in the nasopharynx and measuring the pressure in the external ear canal (EAC). Sonotubometry applies sound via a probe in the nose and records sound in the EAC during swallowing. Imaging using CT, cone beam CT and MRI are employed to access anatomical and functional deficiencies as well as to rule out pathology in the nasopharynx or superior canal dehiscence syndrome. Recent developments include a patientrated ETD questionnaire (ETDQ-7) and an ET score (ETS7) that combine subjective and objective outcome measures. Despite extensive research, evidence guiding assessment and treatment of ETD patients is poor.
Is routine preoperative computed tomography imaging justified in otosclerosis? A retrospective single-centre analysis
Published in Hearing, Balance and Communication, 2022
Mohamed Bassiouni, Hans-Christian Bauknecht, Katharina Stölzel, Steffen Dommerich, Heidi Olze
Nevertheless, it is undeniable that preoperative CT scanning is useful for surgical planning, which explains its increasingly widespread use even in straightforward cases. CT imaging may help to avoid complications, since it can detect rare anatomical variants preoperatively (such as persistent stapedial artery, enlarged vestibular aqueduct, or dehiscent jugular bulb) [15]. This is especially relevant in cases of superior canal dehiscence or enlarged vestibular aqueduct, since the history may not always provide clues of the underlying diagnosis, but a preoperative scan may greatly influence the decision to operate. However, the main question here is whether its value in those rare cases justifies routine preoperative imaging in every case, especially when taking into account the associated risks of radiation exposure. We propose that preoperative CT imaging should not be routinely recommended for all cases, but rather selectively performed. We suggest that preoperative imaging should still be offered to patients, even in straightforward cases, to provide them with the best preoperative counselling. For instance, the surgical treatment of otosclerosis is markedly different from that of epitympanic incus ankylosis, and some patients would understandably wish to know the underlying diagnosis before surgery, because of the considerably different counselling and consent details regarding the audiological outcomes and complication rates of those two surgical procedures. Such patients should be offered a preoperative CT scan, but should be made aware of the added risks of ionising radiation exposure.
Possible pathomechanisms accounting for both sound/pressure-induced eye movements and video head impulse test data in superior canal dehiscence
Published in Acta Oto-Laryngologica, 2021
Andrea Castellucci, Salvatore Martellucci, Pasquale Malara, Cecilia Botti, Valeria Del Vecchio, Cristina Brandolini, Gian Gaetano Ferri, Angelo Ghidini, Enrico Armato
Since the first descriptions of superior canal dehiscence (SCD) syndrome, it has been widely demonstrated how a bony defect overlying the superior semicircular canal (SSC) can result in a low-impedance pathway for sound and pressure stimuli, resulting in a variety of audio-vestibular symptoms and signs consistent with a third window mechanism [1–3]. Although physiologists and clinicians have clearly explained the mechanisms accounting for both low-frequencies conductive hearing loss on audiometry and enhanced amplitudes of vestibular-evoked myogenic potentials (VEMPs), mismatching results have been achieved in the interpretation of the vestibulo-ocular reflex (VOR) data for the affected SSC. In fact, whilst it has been reported how sound and/or pressure stimuli can result in eye movements aligning with the plane of the dehiscent SSC [1,2,4], studies performed either with magnetic-scleral search coils [2,5] or with the video-head impulse test (vHIT) [6,7] observed that VOR-gain values for the affected SSC could be impaired. These questions have strongly arisen thanks to the growing accessibility of canal VOR-gain measurements in the high-frequency domain promoted by the recent introduction of the vHIT in clinical practice. Our aim is to point out some aspects resulting from our clinical experience in this field, and to offer further possible interpretations for some apparently mismatching data with a common theory accounting for overall measurements of SSC activity in case of SCD.
Video-head impulse test in superior canal dehiscence
Published in Acta Oto-Laryngologica, 2021
Payal Mukherjee, Elodie Chiarovano, Kai Cheng, Leonardo Manzari, Leigh A. McGarvie, Hamish G. MacDougall
First described by Minor et al. [1], superior canal dehiscence (SCD) induces hypersensitivity of inner ear receptors to sound, vibration and increased intracranial (Valsalva manoeuvre) and external ear pressure (Hennebert sign) [2,3]. The incidence of SCD varies greatly between countries but has been reported to be 0.7% [4]. Patients may present with non-specific symptoms such as autophony, dizziness, positional vertigo, pulsatile tinnitus or unilateral conductive hearing loss [5]. In order to be more specific it is important to correlate radiological findings [6] on Computed Tomography (CT) scans with cervical and ocular Vestibular Evoked Myogenic Potentials (cVEMPs and oVEMPs). In case of SCD, VEMPs result would show evidence of physiological hyperfunction of the labyrinth typically demonstrate by a low threshold of response to air conducted sounds (ACS) [7–9] and increased amplitude [10,11]. A diagnosis based on CT scan alone, may result in a false positive diagnosis. With the development of the video Head Impulse Test (vHIT), physiological tests of the semicircular canals are increasingly being used by more clinicians including physiotherapists, nursing staff as well as neuro-otologists and audiologists. However, the role of vHIT in the diagnosis of SCD has not been specifically studied. This study focuses on the findings on vHIT in Superior Canal Dehiscence.