Audiovestibular Findings in Patients with Concurrent Superior Canal Dehiscence and Vestibular Schwannoma.

OBJECTIVE: To describe the clinical-instrumental findings in case of concurrent superior canal dehiscence (SCD) and ipsilateral vestibular schwannoma (VS), aiming to highlight the importance of an extensive instrumental assessment to achieve a correct diagnosis. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Five patients with concurrent SCD and VS. INTERVENTION: Clinical-instrumental assessment and imaging. MAIN OUTCOME MEASURE: Clinical presentation, audiovestibular findings, and imaging. RESULTS: The chief complaints were hearing loss (HL) and unsteadiness (80%). Other main symptoms included tinnitus (60%) and pressure-induced vertigo (40%). Mixed-HL was identified in three patients and pure sensorineural-HL in 1, including a roll-over curve in speech-audiometry in two cases. Vibration-induced nystagmus was elicited in all cases, whereas vestibular-evoked myogenic potentials showed reduced thresholds and enhanced amplitudes on the affected side in three patients. Ipsilesional weakness on caloric testing was detected in three patients and a bilateral hyporeflexia in one. A global canal impairment was detected by the video-head impulse test in one case, whereas the rest of the cohort exhibited a reduced function for the affected superior canal, together with ipsilateral posterior canal impairment in two cases. All patients performed both temporal bones HRCT scan and brain-MRI showing unilateral SCD and ipsilateral VS, respectively. All patients were submitted to a wait-and-scan approach, requiring VS removal only in one case. CONCLUSION: Simultaneous SCD and VS might result in subtle clinical presentation with puzzling lesion patterns. When unclear symptoms and signs occur, a complete audiovestibular assessment plays a key role to address imaging and diagnosis.

Low-Frequency Air-Bone Gap and Pulsatile Tinnitus Due to a Dural Arteriovenous Fistula: Considerations upon Possible Pathomechanisms and Literature Review.

Low-frequency air-bone gap (ABG) associated with pulsatile tinnitus (PT) and normal impedance audiometry represents a common finding in patients with third window syndromes. Other inner disorders, including Meniere's disease (MD), perilymphatic fistula and intralabyrinthine schwannoma, might sometimes result in a similar scenario. On the other hand, PT is frequently associated with dural arteriovenous fistula (DAVF), while conductive hearing loss (CHL) is extremely rare in this clinical setting. A 47-year-old patient was referred to our center with progressive left-sided PT alongside ipsilateral fullness and hearing loss. She also experienced headache and dizziness. Otoscopy and video-oculographic examination were unremarkable. Conversely, a detailed instrumental audio-vestibular assessment revealed low-frequency CHL with normal impedance audiometry, slight left-sided caloric weakness, slightly impaired vestibular-evoked myogenic potentials on the left and normal results on the video-head impulse test, consistent with an MD-like instrumental profile. Gadolinium-enhanced brain MRI revealed an early enhancement of the left transverse sinus, consistent with a left DAVF between the left occipital artery and the transverse sinus, which was then confirmed by angiography. A trans-arterial embolization with Onyx glue was performed, resulting in a complete recession of the symptoms. Post-operatively, the low-frequency ABG disappeared, supporting the possible role of venous intracranial hypertension and abnormal pressure of inner ear fluids in the onset of symptoms and offering new insights into the pathomechanism of inner ear CHL.

Impaired Vestibulo-Ocular Reflex on Video Head Impulse Test in Superior Canal Dehiscence: "Spontaneous Plugging" or Endolymphatic Flow Dissipation?

Surgical plugging of the superior semicircular canal (SSC) represents an effective procedure to treat disabling symptoms in superior canal dehiscence (SCD), despite resulting in an impaired vestibulo-ocular reflex (VOR) gain for the SSC. On the other hand, SSC hypofunction on video head impulse test (vHIT) represents a common finding in patients with SCD exhibiting sound/pressure-induced vertigo, a low-frequency air-bone gap (ABG), and enhanced vestibular-evoked myogenic potentials (VEMPs). "Spontaneous canal plugging" has been assumed as the underlying process. Nevertheless, missing/mitigated symptoms and/or near-normal instrumental findings would be expected. An endolymphatic flow dissipation has been recently proposed as an alternative pathomechanism for SSC VOR gain reduction in SCD. We aimed to shed light on this debate by comparing instrumental findings from 46 ears of 44 patients with SCD exhibiting SSC hypofunction with post-operative data from 10 ears of 10 patients with SCD who underwent surgical plugging. While no difference in SSC VOR gain values was found between the two groups (p = 0.199), operated ears developed a posterior canal hypofunction (p = 0.002). Moreover, both ABG values (p = 0.012) and cervical/ocular VEMP amplitudes (p < 0.001) were significantly higher and VEMP thresholds were significantly lower (p < 0.001) in ears with SCD compared to operated ears. According to our data, canal VOR gain reduction in SCD should be considered as an additional sign of a third window mechanism, likely due to an endolymphatic flow dissipation.

Infants Born Following SARS-CoV-2 Infection in Pregnancy.

OBJECTIVES: To evaluate outcomes of neonates born to mothers with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy, the dynamics of placental transfer of maternal antibodies, and its persistence during infancy. METHODS: Cohort study enrolling neonates born to mothers with SARS-CoV-2 infection in pregnancy. All infants were evaluated at birth. Those born to women with infection onset within 2 weeks before delivery were excluded from further analyses. Remaining infants underwent cerebral and abdominal ultrasound, fundoscopy evaluation, and were enrolled in a 12 month follow-up. Qualitative immunoglobulin G (IgG)/immunoglobulin M and quantitative IgG to S1/S2 subunits of spike protein were assessed in mother-neonate dyads within 48 hours postdelivery and during follow-up. RESULTS: Between April 2020 and April 2021, 130 of 2745 (4.7%) neonates were born to mothers with SARS-CoV-2 infection in pregnancy, with 106 of 130 infections diagnosed before 2 weeks before delivery. Rates of preterm and cesarean delivery were comparable between women with and without infection (6% vs 8%, P = .57; 22% vs 32%, P = .06). No clinical or instrumental abnormalities were detected at birth or during follow-up. There was a positive correlation between maternal and neonatal SARS-CoV-2 IgG levels (r = 0.81, P < .001). Transplacental transfer ratio was higher after second-trimester maternal infections as compared with first and third trimester (P = .03). SARS-CoV-2 IgG level progressively decreased in all infants, with 89 of 92 (97%) infants seronegative at 6 months of age. CONCLUSIONS: Clinical outcomes were favorable in all infants. Matching peak IgG level after infection and higher IgG transplacental transfer might result in the most durable neonatal passive immunity.

Which Inner Ear Disorders Lie Behind a Selective Posterior Semicircular Canal Hypofunction on Video Head Impulse Test?

OBJECTIVE: To assess all different patterns of associated abnormalities on audiometry, bithermal caloric test (BCT) and cervical/ocular vestibular-evoked myogenic potentials (VEMPs) to air/bone-conduction in patients with selective posterior semicircular canal (PSC) hypofunction and to correlate them with underlying disorders. STUDY DESIGN: Retrospective review. SETTING: Tertiary referral center. PATIENTS: 51 patients (23 men, 28 women, mean age 57.5 yr) with isolated PSC deficit (one bilateral). INTERVENTIONS: Correlation with instrumental data and underlying diagnoses. MAIN OUTCOME MEASURES: Video-oculographic findings, objective measurements on audiometry, BCT, VEMPs and video-head impulse test (vHIT). RESULTS: Ongoing or previous acute vestibular loss (AVL) was diagnosed in 13 patients (25.5%, 3 inferior vestibular neuritis, 10 AVL with sudden sensorineural hearing loss [SSNHL]), Meniere's disease (MD) in 12 (23.5%), cerebellopontine angle (CPA) lesion in 9 (17.6%), various causes in 7 (13.7%), benign paroxysmal positional vertigo (BPPV) involving the non-ampullary arm of PSC in 5 cases (9.8%) whereas unknown pathology in 5 (9.8%). Involvement of at least one additional receptor besides PSC was seen in 89.8% of cases. Cochlear involvement was diagnosed in 74.5% with pure-tone average significantly greater in patients with AVL+SSNHL (p < 0.05). Overall involvement of labyrinthine receptors or afferents was highest in patients with AVL+SSNHL (p < 0.01), MD and CPA lesions (p < 0.05). CONCLUSIONS: Isolated loss of PSC function on vHIT is mostly accompanied by additional labyrinthine deficits that could only be identified through an accurate instrumental evaluation. Assessment of all receptors and afferents should be always pursued to identify the lesion site and better understand the underlying pathophysiological mechanisms.

The effect of superior canal dehiscence size and location on audiometric measurements, vestibular-evoked myogenic potentials and video-head impulse testing.

PURPOSE: To correlate objective measures of audio-vestibular function with superior canal dehiscence (SCD) size and location in ears with SCD and compare results with literature. METHODS: We retrospectively evaluated 242 patients exhibiting SCD and/or extremely thinned bone overlying superior canals (SC) on CT scans and selected 73 SCD patients (95 ears with SCD). Data concerning audiometry, impedance audiometry, video-head impulse test (vHIT), cervical vestibular-evoked myogenic potentials (cVEMPs) and ocular VEMPs (oVEMPs) to air- (AC) and bone-conducted (BC) stimuli were collected for each pathologic ear and correlated with dehiscence size and location. RESULTS: AC pure-tone average (PTA) (p = 0.013), low-frequency air-bone gap (ABG) (p < 0.001), AC cVEMPs amplitude (p = 0.002), BC cVEMPs amplitude (p < 0.001) and both AC and BC oVEMPs amplitude (p < 0.001) positively correlated with increasing SCD size. An inverse relationship between dehiscence length and both AC cVEMPs and oVEMPs thresholds (p < 0.001) and SC vestibulo-ocular reflex (VOR) gain (p < 0.001) was observed. Dehiscences at the arcuate eminence (AE) exhibited lower SC VOR gains compared to SCD along the ampullary arm (p = 0.008) and less impaired BC thresholds than dehiscences at the superior petrosal sinus (p = 0.04). CONCLUSION: We confirmed that SCD size affects AC PTA, ABG and both amplitudes and thresholds of cVEMPs and oVEMPs. We also described a tendency for SC function to impair with increasing SCD size and when dehiscence is located at the AE. The latter data may be explained either by a spontaneous canal plugging exerted by middle fossa dura or by a dissipation through the dehiscence of mechanical energy conveyed to the endolymph during high-frequency impulses.

Isolated horizontal canal hypofunction differentiating a canalith jam from an acute peripheral vestibular loss.

OBJECTIVES: To describe a unique case of acute vertigo presenting with spontaneous horizontal nystagmus (SHN) and a clinical picture consistent with right acute peripheral vestibular loss (APVL) in which an isolated hypofunction of a horizontal semicircular canal (HSC) permitted to detect a spontaneous canalith jam and treat the patient accordingly. METHODS: Case report and literature review. RESULTS: A 74-year old woman presented with acute vertigo, left-beating SHN and a clinical picture consistent with right APVL. Nevertheless, vestibular evoked myogenic potentials were normal with symmetrical amplitudes and the video head impulse test (vHIT) revealed an isolated hypofunction of the right HSC. After repeated head shakings, the supine roll test evoked bilaterally a positioning paroxysmal geotropic horizontal nystagmus suggesting benign paroxysmal positional vertigo involving the non-ampullated arm of the right HSC. vHIT and caloric testing confirmed restitution of HSC function after repositioning maneuvers. CONCLUSIONS: In case of acute vertigo with SHN, a complete functional assessment of vestibular receptors and afferents should always be given in order to avoid misdiagnosis. Canalith jam should be considered in case of spontaneous nystagmus and isolated canal hypofunction.

Superior canal dehiscence with tegmen defect revealed by otoscopy: Video clip demonstration of pulsatile tympanic membrane.

Superior canal dehiscence is a pathologic condition of the otic capsule acting as aberrant window of the inner ear. It results in reduction of inner ear impedance and in abnormal exposure of the labyrinthine neuroepithelium to the action of the surrounding structures. The sum of these phenomena leads to the onset of typical cochleo-vestibular symptoms and signs. Among them, pulsatile tinnitus has been attributed to a direct transmission of intracranial vascular activities to labyrinthine fluids. We present the first video-otoscopic documentation of spontaneous pulse-synchronous movements of the tympanic membrane in two patients with superior canal dehiscence. Pulsating eardrum may represent an additional sign of third-mobile window lesion.

The influence of systemic circulation on hearing: The reliability of a different impact of microcirculatory defects and atherosclerosis.

The extension of the dependence of hearing acuity from circulatory factors has been widely evaluated in the literature, without reaching an univocal conclusion. In our opinion, a precise distinction between acute/fluctuating disorders and progressive hearing loss must be made in order to identify the possible circulatory causes. Actually, it is conceivable to hypothesize that an acute lack of perfusion plays a major role in the inner ear microcirculation, and may be responsible for acute hearing damages; on the other hand, systemic atherosclerosis may coexist with good hearing provided that a sufficient local perfusion is maintained. This distinction, supported by our findings over the year, appears logical considering the autoregulatory properties of the cochlea and the differences between large/middle vessels and microvasculature; moreover, it can explain the finding of both people with no cardiovascular risk factors and (usually) unilateral inner ear affections and people with diffuse atherosclerosis and well preserved hearing, not exceptionally occurring in daily practice.

Primary vascular dysregulation syndrome: Possible implications for inner ear acute diseases?

Primary vascular dysregulation syndrome has been reported as a possible cause for different eye diseases. Signs or symptoms of this syndrome not only may consist in a series of ocular disorders, as they possibly concern or are associated to various systemic conditions; even the damage of another terminal sensory organ as the inner ear is reported among the possible associations. Herein, the analogies between eye and inner ear are outlined, analyzing the PVD profile that well corresponds to our widely described model of subject without organic cardiovascular impairment but prone to inner ear acute disturbances. Actually, in absence of a recognized cause the latter can be due to a systemic dysregulation like the described one concerning ocular disorders.

Inner ear symptoms: can we use them to approach cardiovascular diseases?

Sensory organs are programmed to detect external stimuli, and inform about possible threats. In general, they are characterized by a complex architecture, a highly energy-requiring function, a peripheral location and a vascular supply depending on a terminal circulation usually under systemic control. Their function may be highly sensitive to more general disorders primarily involving other organs or physiological systems. Consequently, the onset of transient or persistent symptoms of impairment of sensory organs might be the expression of abnormalities in the integrity of more general systems, especially in the elderly population. In the otologic area, despite the availability of evidence supporting the negative impact of some systemic conditions negatively affecting the local blood supply at the labyrinth level, the possibility that the inner ear can reveal the presence of sub-clinical, non-otologic disorders has never been the topic of a constructive investigation. The present review summarizes the preliminary available evidence suggesting a possible negative impact of early systemic hemodynamic changes on the function of the inner ear, as well as the possibility that some audiological symptoms may play some role in the early detection of cardiovascular diseases. In particular, we hypothesize that some cardiovascular diseases may cause an impairment in correct labyrinthine function as a result of a negative interaction between systemic hemodynamic changes, a reflex activation of the autonomic nervous system, and a local vascular response. A multidisciplinary approach to the interpretation of inner ear disorders may increase the possibility of an earlier recognition and understanding of systemic dysfunctions in clinical practice.

Dehiscence of the superior semicircular canal: a review of the literature on its possible pathogenic explanations.

The dehiscence of superior semicircular canal is a well-known affection which is able to explain some cases of hearing loss, tinnitus and/or vertigo unexpectedly presenting in adults without previous otologic affections. Although a diagnostic algorithm has been assessed and a surgical therapy has been indicated, the review of the literature shows that a completely satisfactory explanation for the reason why symptoms of a supposed congenital condition only occur in adulthood is still lacking. A pathogenic hypothesis based on the slow metabolism of the bony labyrinth, which could in time result in a prevalence of bone re-absorption on new bone formation leading to a dehiscence, despite some controversial findings could represent a the most reliable explanation for the question.

Ocular vestibular evoked myogenic potentials in patients with acoustic neuroma.

To assess the usefulness of vestibular testing in patients with acoustic neuroma, considering two main aspects: to compare diagnostic sensitivity of the current vestibular tests, especially considering ocular vestibular evoked myogenic potentials (OVEMPs) and to identify pre-operative localization of the tumor (inferior vestibular nerve vs. superior vestibular nerve) only with the help of vestibular electrophysiological data. Twenty-six patients with unilateral acoustic neuroma (mainly intracanalicular type) were studied with a full audio-vestibular test battery (pure tone and speech audiometry, caloric bithermal test, vibration-induced nystagmus test (VIN), cervical and OVEMPs). 18 patients (69 %) showed abnormal caloric responses. 12 patients (46.2 %) showed a pattern of VIN test suggestive of vestibular asymmetry. 16 patients (61.5 %) showed abnormal OVEMPs (12 only to AC, 4 both to AC and BC). 10 patients (38.5 %) showed abnormal cervical vestibular evoked myogenic potentials (5 both to AC and BC, 5 only to AC). In one case, results of vestibular evoked potentials and caloric test were confirmed by intra-operative and post-operative findings. Results of electrophysiological tests in AN patients could be helpful for planning the proper surgical approach, considering that sensitivity of every exam is quite low in intracanalicular lesion; clinical data allow a better interpretation of vestibular evoked myogenic potentials.

Do signs of natural plugging of superior semicircular canal dehiscence exist?

Our experience with 102 patients having superior semicircular canal dehiscence confirm that the clinical manifestations of the disease are very diverse; we also identified 3 patients who showed Meniere-like symptoms. Clinical examination during an acute vertigo attack of a patient with Meniere disease for several years and whom we subsequently diagnosed as having large superior semicircular canal dehiscence on the affected side allowed us to hypothesize that a natural plugging of the superior semicircular canal by the overhanging dura mater could be responsible for the recurrence of symptoms. Clinical and instrumental data were very similar to those recorded in 7 of 9 patients immediately after surgical plugging. The aim of the study was to understand which semiological and instrumental elements could be clinically useful, first in distinguishing Meniere disease from superior semicircular canal dehiscence and, secondly, in understanding if signs of natural plugging are present.

Tinnitus in elderly patients and prognosis of mild-to-moderate congestive heart failure: a cross-sectional study with a long-term extension of the clinical follow-up.

BACKGROUND: The complex mechanism responsible for tinnitus, a symptom highly prevalent in elderly patients, could involve an impaired control of the microcirculation of the inner ear, particularly in patients with poor blood pressure control and impaired left ventricular (LV) function. METHODS: In order to define the relationship between the presence of tinnitus and the severity and clinical prognosis of mild-to-moderate chronic heart failure (CHF) in a large population of elderly patients (N = 958), a cross-sectional study was conducted with a long-term extension of the clinical follow-up. Blood pressure, echocardiographic parameters, brain natriuretic peptide (BNP), hospitalization, and mortality for CHF were measured. Multivariate logistic regression analysis was used to assess the association between the presence of tinnitus and some of the prognostic determinants of heart failure. RESULTS: The presence of tinnitus was ascertained in 233 patients (24.3%; mean age 74.9 ± 6 years) and was associated with reduced systolic and diastolic blood pressure (123.1 ± 16/67.8 ± 9 vs 125.9 ± 15/69.7 ± 9; P = .027/P = .006), reduced LV ejection fraction (LVEF%; 43.6 ± 15 vs 47.9 ± 14%, P = .001), and increased BNP plasma levels (413.1 ± 480 vs 286.2 ± 357, P = .013) in comparison to patients without symptoms. The distribution of CHF functional class was shifted toward a greater severity of the disease in patients with tinnitus. Combined one-year mortality and hospitalization for CHF (events/year) was 1.43 ± 0.2 in patients with tinnitus and 0.83 ± 0.1 in patients without tinnitus, with an adjusted hazard ratio (HR) of 0.61 (95% confidence interval (CI): 0.37 to 0.93, P <.002). CONCLUSIONS: Our preliminary data indirectly support the hypothesis that tinnitus is associated with a worse CHF control in elderly patients and can have some important clinical implications for the early identification of patients who deserve a more aggressive management of CHF.