Non-functioning posterior communicating arteries of circle of Willis in idiopathic sudden hearing loss

The Correlation of Clinical Features and Endolymphatic Hydrops Visualized by 3D-Real IR MRI in Children With Sudden Sensorineural Hearing Loss

OBJECTIVES

To investigate the correlation between clinical features and endolymphatic hydrops (EH) in children with sudden sensorineural hearing loss (SSNHL).

METHODS

We collected 30 SSNHL children aged ≤17 years old, all of whom underwent intravenous gadolinium injection. After 4 hours, inner ear 3-dimensional inversion recovery sequence with real reconstruction (3D-real IR) magnetic resonance imaging was performed. Combined with their medical history such as gender, age, disease course, hearing loss, and so on, the results were analyzed.

RESULTS

Different degrees of EH were shown in the vestibule or different turns of cochlea in the affected ears of SSNHL children, and 12 (40%) of 30 children showed positive EH. Age, low and middle frequency hearing loss, and other clinical symptoms such as dizziness and ear fullness have been shown to be related to a certain degree of EH in vestibule or cochlea, whereas no relationship was found between EH and other clinical features such as high-frequency hearing loss, gender, affected side, and tinnitus.

CONCLUSIONS

Endolymphatic hydrops may not reflect the trend of disease progression over time in children with SSNHL, but the age of onset may be an important factor in the presence or absence of EH. Endolymphatic hydrops may be one of the causes of dizziness and ear fullness but has no obvious connection with the occurrence of tinnitus. Older SSNHL children with dizziness and ear fullness should maintain long-term follow-up to dynamically monitor the changes in EH.

The prognostic and predictive value of platelet parameters in diabetic and nondiabetic patients with sudden sensorineural hearing loss

BACKGROUND

We aimed to evaluate the association between mean platelet volume, platelet distribution width (PDW), platelet count (PC) and plateletcrit (PCT), and the presence of sudden sensorineural hearing loss (SSNHL) and treatment response. In the literature, there is no study that investigates the platelet functions in diabetic patients with SSNHL.

METHODS

The patients were retrospectively assigned into Group 1 (68 diabetic patients with SSNHL), Group 2 (63 nondiabetic patients with SSNHL) and Group 3 (64 healthy controls).

RESULTS

PC was not significantly different between the groups (p > 0.05). MPV, PDW and PCT values were significantly higher in Group 1 as compared to Groups 2 and 3 (p < 0.05). Platelet parameters were not significantly different between the patients who were responsive and nonresponsive to the treatment. Therefore, the platelet parameters did not affect prognosis significantly in this study samples (p > 0.05).

CONCLUSIONS

This study showed that platelet parameters did not have a significant effect as a prognostic and predictive value in diabetic and nondiabetic patients with SSNHL. Further studies with more homogenous and larger study groups investigating the platelet parameters are needed to demonstrate microvascular damage and vascular alterations induced by diabetes mellitus.

Serum Bilirubin Level as a Potential Marker for the Hearing Outcome in Severe-Profound Bilateral Sudden Deafness

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Objective:

To investigate the association of serum bilirubin level with hearing outcomes in bilateral sudden sensorineural hearing loss (BSSHL) patients.

Participants:

One hundred thirteen in-patient BSSHL patients were consecutively enrolled between July 2008 and December 2015 in a tertiary center.

Main Outcome Measures:

Multivariable linear regression, generalized estimating equations (GEE), and stratified analyses were applied to examine the association between serum bilirubin level and hearing outcome measures such as final hearing threshold and absolute and relative hearing gains in BSSHL.

Results:

After full adjustment for potential confounders, total bilirubin levels (TBIL) were observed to be positively and independently associated with hearing outcomes as measured by final hearing (β [95% confidence interval {CI}]: −1.5 [−2.7, −0.2] dB HL per 1 μmol/L increase in TBIL) and absolute and relative hearing gains (β [95% CI]: 1.4 [0.2, 2.7] dB and 1.6 [0.2, 3.1] dB, respectively) in the severe to profound hearing loss subpopulation.

Conclusions:

Higher TBIL levels, within the normal or mildly elevated ranges, were independently and significantly associated with better hearing outcome in BSSHL patients with severe to profound hearing loss. Given bilirubin elevation treatments exist, our finding suggests a novel pharmacological strategy for this specific subpopulation.

Predicting the hearing outcome in sudden sensorineural hearing loss via machine learning models

OBJECTIVE

Sudden sensorineural hearing loss (SSHL) is a multifactorial disorder with high heterogeneity, thus the outcomes vary widely. This study aimed to develop predictive models based on four machine learning methods for SSHL, identifying the best performer for clinical application.

DESIGN

Single-centre retrospective study.

SETTING

Chinese People's liberation army (PLA) hospital, Beijing, China.

PARTICIPANTS

A total of 1220 in-patient SSHL patients were enrolled between June 2008 and December 2015.

MAIN OUTCOME MEASURES

An advanced deep learning technique, deep belief network (DBN), together with the conventional logistic regression (LR), support vector machine (SVM) and multilayer perceptron (MLP) were developed to predict the dichotomised hearing outcome of SSHL by inputting six feature collections derived from 149 potential predictors. Accuracy, precision, recall, F-score and the area under the receiver operator characteristic curves (ROC-AUC) were exploited to compare the prediction performance of different models.

RESULTS

Overall the best predictive ability was provided by the DBN model when tested in the raw data set with 149 variables, achieving an accuracy of 77.58% and AUC of 0.84. Nevertheless, DBN yielded inferior performance after feature pruning. In contrast, the LR, SVM and MLP models demonstrated opposite trend as the greatest individual prediction powers were obtained when included merely three variables, with the ROC-AUC ranging from 0.79 to 0.81, and then decreased with the increasing size of input features combinations.

CONCLUSIONS

With the input of enough features, DBN can be a robust prediction tool for SSHL. But LR is more practical for early prediction in routine clinical application using three readily available variables, that is time elapse between symptom onset and study entry, initial hearing level and audiogram.

Bow hunter's syndrome in a patient with vertebral artery atresia, an arcuate foramen, and unilateral deafness: a case report

Bow hunter's syndrome (BHS) is a rare cause of vertebrobasilar insufficiency that occurs when the vertebral artery (VA) is occluded on rotation of the head and neck. This dynamic occlusion of the VA can occur anywhere along its course after it arises from the subclavian artery. Although most cases are associated with compression by osteophytes, cervical spondylosis, or lateral disc herniation, BHS has a highly variable clinical course that depends on the patient's specific anatomy. Therefore, it may be important for clinicians to be aware of anatomical variants that predispose individuals to BHS. Here, we report on a patient with BHS who was found to have two uncommon anatomical anomalies: an atretic right VA and a left-sided arcuate foramen.

Role of Platelet Parameters on Sudden Sensorineural Hearing Loss: A Case-Control Study in Iran

Sudden sensorineural hearing loss (SSNHL) is a common otological disorder characterized by a hearing loss greater than 30 dB over three consecutive frequencies, in less than 72 hours. It has been established that platelet parameters, such as mean platelet volume, are associated with ischemic heart events, whose clinical manifestations are similar to those of SSNHL. Hence, we aimed to determine if the platelet count, mean platelet volume and platelet distribution width are related to the occurrence and severity of sudden sensorineural hearing loss. A case-control prospective study was conducted in a teaching hospital in Iran. One hundred-eight patients with SSNHL and an equal number of healthy, age- and sex-matched controls were enrolled in the study. Peripheral venous blood samples were collected from the subjects, and the platelet count, mean platelet volume and platelet distribution width were measured with an automated blood cell counter. Analysis of the audiometry and hematological test results using SPSS22 software showed no statistical correlation between the platelet parameters and the occurrence of SSNHL, but correlation coefficients showed a significant correlation between PDW and hearing loss severity in patients group. However, further investigation is required to unequivocally establish the absence of correlation between the platelet parameters and occurrence of SSNHL.

Volumetric in vivo imaging of microvascular perfusion within the intact cochlea in mice using ultra-high sensitive optical microangiography

Studying the inner ear microvascular dynamics is extremely important to understand the cochlear function and to further advance the diagnosis, prevention, and treatment of many otologic disorders. However, there is currently no effective imaging tool available that is able to access the blood flow within the intact cochlea. In this paper, we report the use of an ultrahigh sensitive optical micro-angiography (UHS-OMAG) imaging system to image 3-D microvascular perfusion within the intact cochlea in living mice. The UHS-OMAG image system used in this study is based on spectral domain optical coherence tomography, which uses a broadband light source centered at 1300 nm with an imaging rate of 47[Formula: see text] 000 A-scans/s, capable of acquiring high-resolution B scans at 300 frames/s. The technique is sensitive enough to image very slow blood flow velocities, such as those found in capillary networks. The 3-D imaging acquisition time for a whole cochlea is  ∼ 4.1 s. We demonstrate that volumetric reconstruction of microvascular flow obtained by UHS-OMAG provides a comprehensive perfusion map of several regions of the cochlea, including the otic capsule, the stria vascularis of the apical and middle turns and the radiating arterioles that emanate from the modiolus.

Sudden sensorineural hearing loss and vertigo associated with arterial occlusive disease: three case reports and literature review

Sudden sensorineural hearing loss and vertigo (SSNHLV) has multifactorial causes, of which viral, autoimmune and vascular insufficiency are the most common. The therapeutic management for SSNHLV includes antiviral drugs, corticosteroids, vasodilators, normovolemic hemodilution therapy and hyperbaric oxygen therapy. Vertebrobasilar occlusive disease and carotid occlusive disease are seldom related to SSNHLV. Discussions concerning SSNHLV caused by occlusive vascular disease are important and necessary for both neurologists and otolaryngologists, since their therapeutic management and prognosis are very different from other causes of hearing loss and vertigo. Here, we present our experience with three cases managed with interventional treatment and conduct a review and discussion on the relevant literature. We conclude that investigation of vertebrobasilar and carotid occlusive diseases is necessary in patients over 50 years of age who present SSNHLV, mild neurological symptoms and a history of arteriosclerosis, high blood pressure or thrombosis.

A new phenotypical variant of intrauterine growth restriction?

OBJECTIVES

A link between intrauterine growth restriction and major adult-onset diseases has been reported. In this study we observed a series of hitherto-unrecognized clinical features in a population of children with intrauterine growth restriction.

PATIENTS AND METHODS

A total of 77 Italian children (aged 9.45 +/- 2.08 years) with antenatally diagnosed intrauterine growth restriction and small-for-gestational-age birth, along with their parents, were examined. The children with intrauterine growth restriction and were small for gestational age were subdivided into 2 groups ("variant" versus control subjects) according to evidence of auricle morphology deviation from normal. The following variables were determined: (1) external ear auricle geometry; (2) function of the posterior communicating arteries of the circle of Willis, as assessed by transcranial Doppler ultrasonography; (3) articular mobility, as assessed by Beighton's 9-point scale; (4) skin softness; and (5) distortion product-evoked otoacoustic emissions.

RESULTS

Intrauterine growth restriction-variant children (n = 27) showed a significant female predominance, a lower proportion of maternal pregnancy-induced hypertension/preeclampsia, and a higher head circumference as compared with intrauterine growth restriction control subjects. Mothers of small-for-gestational-age-variant children showed significantly different auricular geometry parameters as compared with the intrauterine growth restriction controls mothers. An excess of bilaterally nonfunctioning posterior communicating arteries was observed both in the children with the intrauterine growth restriction-variant phenotype and their mothers as compared with the control groups. Significantly increased proportions of joint hypermobility and skin softness were observed in the intrauterine growth restriction-variant children as compared with controls subjects. Children with the intrauterine growth restriction-variant phenotype and their mothers showed bilateral distortion product-evoked otoacoustic emissions notches versus none in the control subjects, with an associated reduction of the area under the curve in both the intrauterine growth restriction-variant children and their mothers. No significant differences between the variant and control groups regarding the fathers were observed.

CONCLUSIONS

We propose that the observed phenotypical constellation may represent an unrecognized variant of intrauterine growth restriction.

In vivo imaging of mammalian cochlear blood flow using fluorescence microendoscopy

AIMS

We sought to develop techniques for visualizing cochlear blood flow in live mammalian subjects using fluorescence microendoscopy.

BACKGROUND

Inner ear microcirculation appears to be intimately involved in cochlear function. Blood velocity measurements suggest that intense sounds can alter cochlear blood flow. Disruption of cochlear blood flow may be a significant cause of hearing impairment, including sudden sensorineural hearing loss. However, inability to image cochlear blood flow in a nondestructive manner has limited investigation of the role of inner ear microcirculation in hearing function. Present techniques for imaging cochlear microcirculation using intravital light microscopy involve extensive perturbations to cochlear structure, precluding application in human patients. The few previous endoscopy studies of the cochlea have suffered from optical resolution insufficient for visualizing cochlear microvasculature. Fluorescence microendoscopy is an emerging minimally invasive imaging modality that provides micron-scale resolution in tissues inaccessible to light microscopy. In this article, we describe the use of fluorescence microendoscopy in live guinea pigs to image capillary blood flow and movements of individual red blood cells within the basal turn of the cochlea.

METHODS

We anesthetized eight adult guinea pigs and accessed the inner ear through the mastoid bulla. After intravenous injection of fluorescein dye, we made a limited cochleostomy and introduced a compound doublet gradient refractive index endoscope probe 1 mm in diameter into the inner ear. We then imaged cochlear blood flow within individual vessels in an epifluorescence configuration using one-photon fluorescence microendoscopy.

RESULTS

We observed single red blood cells passing through individual capillaries in several cochlear structures, including the round window membrane, spiral ligament, osseous spiral lamina, and basilar membrane. Blood flow velocities within inner ear capillaries varied widely, with observed speeds reaching up to approximately 500 microm/s.

CONCLUSION

Fluorescence microendoscopy permits visualization of cochlear microcirculation with micron-scale optical resolution and determination of blood flow velocities through analysis of video sequences.

La maladie de Fabry : l'atteinte vasculaire multi-organe pourrait également intéresser la cochlée

PURPOSE

Fabry disease is an inborn error of metabolism due to a deficient activity of the lysosomal enzyme alpha-galactosidase A. The enzyme defect leads to the systemic accumulation of neutral glycosphingolipids in tissues, mainly in the vascular endothelium.

STRONG POINT

The aim of this paper is to present a review of the auditory manifestations in Fabry disease, and to discuss hypothesis on the vascular origin of deafness.

PERSPECTIVES

Sensorineural hearing loss in Fabry disease could be the first documented vascular pathology of the inner ear.

The posterior communicating arteries in the patients with sudden deafness: evaluation with magnetic resonance imaging (MRA)

Background

A strong association was suggested between a non-functioning posterior communicating artery (Pcom) of the circle of Willis and sudden deafness (SD). The purpose of this study was to determine the rate of depiction of Pcom on magnetic resonance angiography (MRA) in patients with SD.

Methods

Sixteen patients with SD (47.7 +/- 13.3 years; range, 24 – 76 years; nine males) were evaluated with intracranial MRA as well as magnetic resonance imaging (MRI) of the head. The depiction of Pcom on MRA was correlated with the laterality of SD. One hundred twenty-eight controls (49.1 +/- 8.4 years; range, 22 – 66 years; 87 male) were selected from neurologically normal subjects who underwent MR examinations as a part of an annual medical check-up in our hospital.

Results

Four (25%) of 16 SD patients had bilateral Pcom on MRA, four patients had unilateral Pcom and eight patients had bilaterally absent Pcom These results were not significantly different from the controls (p = 0.96). In 6 (37.5 %) of 16 SD patients, the ipsilateral Pcom was present on MRA, and 104 (40.6%) of 256 Pcom were present in 128 normal controls (p = 0.81).

Conclusion

Since there was no link between the occurrence of SD and the absence of the ipsilateral Pcom, our results cannot support the hypothesis that the absence of Pcom may be a risk factor for the occurrence of SD.

Digital subtraction angiography abnormalities in sudden unilateral profound hearing loss

CONCLUSION

The reduced caliber of the anterior inferior cerebellar artery (AICA) on the affected side in patients with sudden unilateral profound hearing loss (SUPHL) may reflect a perfusion deficit which, combined to a lesser degree with anatomic abnormalities in the vertebrobasilar system, would be implicated in the pathogenesis of SUPHL.

OBJECTIVE

To identify existing hemodynamic disturbances and anatomic abnormalities in patients with SUPHL using digital subtraction angiography.

MATERIAL AND METHODS

Ten patients aged 18-66 years and a control group of 25 subjects were included in the study. Both vertebral arteries (VAs) were selectively catheterized in all the patients.

RESULTS

In 7/10 patients (70%) the AICA on the side affected by SUPHL was smaller in caliber than the contralateral one after injection of contrast medium into the VA on the affected side. The situation was significantly different in the control group, whose angiography results demonstrated similarly sized AICAs in 84% of cases. Tortuosity of the VA on the affected side was encountered in two patients and important VA asymmetry in one.

Idiopathic sudden sensorineural hearing loss in children

OBJECTIVE

Although idiopathic sudden sensorineural hearing loss (ISSHL) is a frequent disease in adults, less is known about incidence and treatment of ISSHL in children.

METHOD

A retrospective chart analysis was performed to evaluate the frequency of ISSHL in children aged under 18 years between 2000 and 2003, who were treated in our department. Children received prednisolone intravenously at an initial dose of 3mg/kg bodyweight. Prednisolone dose was reduced to half every second day. The medication was given for a maximum of 14 days or finished 2 days after the hearing normalized in pure-tone audiometry. The follow-up was continued between 3 and 14 months.

RESULTS

The complete recovery rate was 57%, and the partial recovery was 36%. Initial hearing loss of 50dB and more was predictive for poor outcome in children (p=0.028). Presence of tinnitus was without relevance for the outcome. The incidence of ISSHL in the local area of about 250,000 inhabitants was 1/10,000 in children.

CONCLUSION

ISSHL seems to be a less frequent disease in children than in adults. Severe initial hearing loss is coupled with poor outcome. Under treatment with prednisolone hearing improvement was found in 13 of 14 patients.

Study of the Posterior Communicating Arteries of the Circle of Willis in Idiopathic Sudden Sensorineural Hearing Loss

OBJECTIVES

To evaluate the incidence of non-functioning posterior communicating arteries (PCoA) of the circle of Willis in patients presenting with idiopathic sudden sensorineural hearing loss (SSHL).

BACKGROUND

Pathogenesis of SSHL remains unclear despite several theories. A strong association between non-functioning PCoA of the circle of Willis and SSHL has been recently suggested, supporting the theory of vascular disorders.

SETTING

Tertiary referral center.

PATIENTS AND METHODS

Ultrasonographic Doppler flow measurements of the vertebrobasilar system were performed prospectively in 27 consecutive patients with idiopathic SSHL and in 27 healthy subjects.

RESULTS

A non-functioning PCoA was found in 4 patients with idiopathic SSHL and in 4 cases in the control group.

CONCLUSION

The results of our study did not show any association between non-functioning PCoA of the circle of Willis and idiopathic SSHL, contrasting with previous data. We do not recommend adding routine transcranial Doppler ultrasonography in the test-battery for SSHL.

Magnetic Resonance Imaging Findings in the Auditory Pathway of Patients With Sudden Deafness

OBJECTIVES

The objectives of this study were to evaluate magnetic resonance imaging (MRI) findings of patients with sudden sensorineural hearing loss (SSNHL) and to grade the findings based on their clinical importance.

STUDY DESIGN

A prospective clinical study.

SETTING

A tertiary referral center (university hospital).

PATIENTS

MRI findings of 82 consecutive patients with SSNHL fulfilling the inclusion criteria.

MAIN OUTCOME MEASURES

We studied 1.0-T MR images that were analyzed by one experienced neuroradiologist.

RESULTS

Of the six cases (7%) in which clearly hearing loss was obviously associated with the observed pathology, four patients had an acoustic neuroma in the internal auditory canal or cerebellopontine angle, one patient had changes at the level of pons, and one patient had an obliterated internal carotid artery. Of the six other patients (7%) in which MRI revealed changes that suggest a possible etiology to hearing loss, two patients showed a demyelinating process and four patients showed blood vessel abnormalities such as caroticocavernous fistula, abnormally locating vertebral or basilar artery, and a venous angioma.

CONCLUSIONS

Enhanced MR imaging seems to be a useful examination in patients with SSNHL. The aim should not be only to exclude specific retrocochlear etiologies, but by appropriate techniques, MRI could reveal both peripheral and central abnormalities.

Disorders of cochlear blood flow

The cochlea is principally supplied from the inner ear artery (labyrinthine artery), which is usually a branch of the anterior inferior cerebellar artery. Cochlear blood flow is a function of cochlear perfusion pressure, which is calculated as the difference between mean arterial blood pressure and inner ear fluid pressure. Many otologic disorders such as noise-induced hearing loss, endolymphatic hydrops and presbycusis are suspected of being related to alterations in cochlear blood flow. However, the human cochlea is not easily accessible for investigation because this delicate sensory organ is hidden deep in the temporal bone. In patients with sensorineural hearing loss, magnetic resonance imaging, laser-Doppler flowmetry and ultrasonography have been used to investigate the status of cochlear blood flow. There have been many reports of hearing loss that were considered to be caused by blood flow disturbance in the cochlea. However, direct evidence of blood flow disturbance in the cochlea is still lacking in most of the cases.

[Idiopathic sudden deafness]

PURPOSE

Sudden idiopathic deafness is a sensorineural hearing loss with no recognized causes at the time of onset. The impairment site is usually localized in the cochlea, but some cases of retrocochlear lesions (e.g., cerebellopontine angle tumors, degenerative neural diseases, neuraxial ischemic lesions) can induce sensorineural deafness. The medical management of patients presenting with sudden deafness aims at detecting a causal mechanism, and at administering emergency therapeutic drugs. The diagnosis of idiopathic sudden deafness can be definitely made when no causes are found. Usually, the impairing mechanism involves the cochlea. The pathophysiology of this sensorineural alteration is still unknown. It is most likely that several mechanisms are associated together, their common point being an impairment to the feedback loop of the organ of Corti.

CURRENT KNOWLEDGE AND KEY POINTS

It is very likely that reactivation of neurotropic viruses and/or cochlear ischemia are frequent etiologies. Whatever the cause, the treatment is to be administered urgently, and consists of a high-dose corticotherapy at the least. Other treatments have never really proven to be effective. It is secondarily checked that no retrocochlear pathological processes, such as a cerebellopontine angle tumor, is present, in particular in young people.

FUTURE PROSPECTS AND PROJECTS

One of the current objectives is to determine when cochlear ischemia is involved, in a mini-invasive manner, such as with laser Doppler flowmetry, so that the treatment can be optimized. From a therapeutic point of view, early acoustic protection has been proven to be effective in cases of cochlear ischemia in small laboratory animals. Its efficacy in case of sudden deafness, non-exclusive of other causes than ischemia, is being assessed in a multicentric project.