Common Features in Patients With Superior Canal Dehiscence Declining Surgical Treatment

Abstract

BackgroundSuperior canal dehiscence (SCD) is a benign condition in which a surgical treatment may be considered depending on the patients’ tolerance of their symptoms. In this study, we aim to identify driving factors behind the patients’ choice of a surgical management over watchful waiting.MethodsSixty-two patients with cochlear and/or vestibular symptoms and a temporal bone high-resolution CT (HRCT) scan showing SCD were included in the study. All patients have been offered either surgical management or watchful waiting.ResultsOf these, 28 elected surgery and 34 declined it. The operated group showed more cochlear (6.6 vs. 2.4) symptoms than the non-operated group (P < 0.001) except for hypoacousis, but no significant difference (P = 0.059) was found for the number of vestibular symptoms between both groups (3.4 vs. 1.1). Footstep and eating hyperacousis were both present in 57.1% of operated vs. 3% of non-operated patients (P < 0.001). Oscillopsia with effort and with walking was found in 50% and 35.7% of operated patients, respectively, but none in the non-operated group (P < 0.001). Hearing tuning fork at malleolus and Valsalva and pneumatic speculum induced vertigo showed a statistically significant difference between the two groups (P = 0.003, P < 0.001, P = 0.010 respectively). Cervical vestibular-evoked myogenic potential (cVEMP) thresholds, air and bone conduction thresholds, and mean air-bone gap (ABG) were similar in the two populations (P > 0.05). The average dehiscence size was 4.7 mm (2.0 - 8.0 mm) and 3.8 mm (1.3 - 7.7 mm) in the operated and non-operated patients, respectively (P = 0.421).ConclusionsThe natures of cochleovestibular signs and symptoms were shown to be key factors in patients’ choice of a surgical management whereas paraclinical tests seem to be less significant in the patients’ decision for a surgical treatment.

Enhanced Auditory Sensitivity to Body Vibrations in Superior Canal Dehiscence Syndrome

“…The present results from Minishaker ankle stimulation suggested an intensity level of 98 dB FL to separate patients with SCD syndrome from controls with some diagnostic accuracy (89% sensitivity and 89% specificity). Thus, the present data lend support to the idea that a tuning fork placed at the ankle will be heard in the affected ear in many SCD patients [Halmagyi et al, 2003;Benamira et al, 2015]. In contrast, the stimulus intensity from such a tuning fork placed at the vertex or C7 would probably be outside the difference gap between SCD and controls, i.e., it would be heard not only by SCD patients but also by many other patients and healthy subjects.…”

“…The findings suggest that hearing thresholds in response to low-frequency body vibration at disturbed by their footsteps at walking. It has also been pointed out that a tuning fork placed at the ankle will be heard in the affected ear in many SCD patients [Halmagyi et al, 2003;Benamira et al, 2015].…”

The Effects of Vestibular Rehabilitation after Bilateral Superior Semicircular Canal Dehiscence: A Case Report

“…The most commonly noted symptoms in patients with SSCD are vertigo, oscillopsia, imbalance, hearing loss, and disequilibrium [1] [2]. Smaller dehiscence's (<2.5 mm) often present with either cochlear or vestibular symptoms, whereas larger dehiscence's (>2.5 mm) often present with a combination of both cochlear and vestibular symptoms but this is not always the case [4]. The most common symptoms of SSCD are Tullio's phenomenon (nystagmus induced by loud noises) and Hennebert's sign (nystagmus induced by excessive pressure in the auditory canal) [2].…”

“…Surgical repair of SSCD via a middle fossa approach has been shown to resolve symptoms in 90% of patients but the bone used to repair the dehiscence can get reabsorbed [6]. There are also complications associated with the middle fossa approach including facial paralysis, cerebrospinal fluid leak, seizures, epidural hematoma, and intracranial bleeding [4]. Using cortical bone from the mastoid is the preferred surgical method because it is less likely to get reabsorbed [2].…”

“…Using cortical bone from the mastoid is the preferred surgical method because it is less likely to get reabsorbed [2]. Transcanal round window obliteration is another (less invasive) surgical intervention for SSCD that has been highly successful in short-term reduction of symptoms, but there is lacking research regarding the long-term effectiveness of this technique [4]. Given the fact that these surgeries are performed near sensitive, life-sustaining structures, it is crucial to differentially diagnose SSCD and be sure of the diagnosis before surgical intervention [8].…”