Imaging of Temporal Bone.

Multidetector computed tomography has been the benchmark for visualizing bony changes of the ear, but has recently been challenged by cone-beam computed tomography. In both methods, all inner ear bony structures can be visualized satisfactorily with 2D or 3D imaging. Both methods produce ionizing radiation and induce adverse health effects, especially among children. In 3T magnetic resonance imaging, the soft tissue can be imaged accurately. Use of gadolinium chelate (GdC) as a contrast agent allows the partition of fluid spaces to be visualized, such as the bulging of basilar and Reissner's membranes. Both intravenous and intratympanic administration of GdC has been used. The development of positive endolymph imaging method, which visualizes endolymph as a bright signal, and the use of image subtraction seems to allow more easily interpretable images. This long-awaited possibility of diagnosing endolymphatic hydrops in living human subjects has enabled the definition of Hydropic Ear Disease, encompassing typical Meniere's disease as well as its monosymptomatic variants and secondary conditions of endolymphatic hydrops. The next challenge in imaging of the temporal bone is to perform imaging at the cellular and molecular levels. This chapter provides an overview of current temporal bone imaging methods and a review of emerging concepts in temporal bone imaging technology.

On the classification of hydropic ear disease (Menière's disease).

More than 150 years after its initial description by Prosper Menière, the disease named after him is still at the center of scientific debates. Two recent developments have specifically created a breeding ground for controversy: (1) Since its first description 10 years ago, magnetic resonance imaging diagnosis of endolymphatic hydrops in living patients has seen an increasing and worldwide application. (2) The Bárány Society Classification Committee published diagnostic criteria for Menière's disease in 2015 and proposed a concept of the disease that has elicited widespread criticism. In order to promote the understanding of the underlying controversies and arguments, this article gives an overview of and discusses relevant classification proposals for Menière's disease, including the new classification system of hydropic ear disease.

[Superior canal dehiscence syndrome : Diagnosis with vestibular evoked myogenic potentials and fremitus nystagmus. German version]. / Dehiszenzsyndrom des oberen Bogengangs : Diagnostik mit vestibulär evozierten myogenen Potenzialen und Fremitusnystagmus.

BACKGROUND: Superior canal dehiscence syndrome (SCDS) is a relatively rare neurotological disorder that is characterized by a heterogeneous clinical picture. Recently, vestibular evoked myogenic potential (VEMP) measurementwas established for the diagnosis of SCDS. In the present study, a case series of patients with SCDS were analyzed, with a focus on VEMP. METHODS: Four patients with SCDS were prospectively examined with ocular VEMP (oVEMP) and cervical VEMP (cVEMP). The clinical features and the standard audiovestibular test battery results are summarized and analyzed. The diagnostic accuracy of VEMP testing is evaluated. RESULTS: The increased oVEMP amplitudes had a specificity of 100% in this patient population. All patients had normal caloric function and head impulse testing. The Tullio sign was observed in two patients. Three patients had autophony. The airbone gap was not greater than 10 dB in any of the patients. Two patients had marked fremitus nystagmus. All patients had a bony dehiscence of the superior semicircular canal on computed tomography imaging. CONCLUSION: The subjective and clinical features in this case series of SCDS patients were heterogeneous. However, objective oVEMP testing had the highest diagnostic value. Furthermore, we describe a new diagnostic clinical sign: fremitus nystagmus.

Superior canal dehiscence syndrome : Diagnosis with vestibular evoked myogenic potentials and fremitus nystagmus.

BACKGROUND: Superior canal dehiscence syndrome (SCDS) is a relatively rare neurotological disorder that is characterized by a heterogeneous clinical picture. Recently, vestibular evoked myogenic potential (VEMP) measurement was established for the diagnosis of SCDS. In the present study, a case series of patients with SCDS were analyzed, with a focus on VEMP. METHODS: Four patients with SCDS were prospectively examined with ocular VEMP (oVEMP) and cervical VEMP (cVEMP). The clinical features and the standard audiovestibular test battery results are summarized and analyzed. The diagnostic accuracy of VEMP testing is evaluated. RESULTS: The increased oVEMP amplitudes had a specificity of 100% in this patient population. All patients had normal caloric function and head impulse testing. The Tullio sign was observed in two patients. Three patients had autophony. The air-bone gap was not greater than 10 dB in any of the patients. Two patients had marked fremitus nystagmus. All patients had a bony dehiscence of the superior semicircular canal on computed tomography imaging. CONCLUSION: The subjective and clinical features in this case series of SCDS patients were heterogeneous. However, objective oVEMP testing had the highest diagnostic value. Furthermore, we describe a new diagnostic clinical sign: fremitus nystagmus.

Acute vestibular syndrome in cerebellar stroke : A case report and review of the literature.

The current paper reports on a patient with recurrent rotational vertigo and persistent dizziness and imbalance lasting several weeks, who underwent extensive neuro-otological and radiological examinations. Pathological findings initially included right-sided benign paroxysmal positional vertigo (BPPV), persistent horizontal spontaneous nystagmus (SPN) to the left, and a pathological bedside and video head impulse test (HIT) on the left. The pathological HIT on the left and the SPN to the left indicated a central origin. Therefore, cranial magnetic resonance imaging was performed which revealed a left-sided ischemic stroke in the territory of the medial branch of the posterior inferior cerebellar artery (mPICA).

[Acute vestibular syndrome following cerebellar stroke : Case report and literature review. German version]. / Akutes vestibuläres Syndrom nach Kleinhirninfarkt : Fallbericht und Literaturrecherche.

The current paper reports on a patient with recurrent rotational vertigo and persistent dizziness and imbalance lasting weeks, who underwent extensive neurootological and radiological examination. Pathological findings initially included right-sided benign paroxysmal positional vertigo (BPPV), persistent horizontal spontaneous nystagmus (SPN) to the left and a pathological bedside and video head impulse test (HIT) on the left. The pathological HIT on the left and SPN to the left indicated a central genesis. Therefore, cMRI was performed and revealed a left-sided cerebral infarction in the territory of the medial branch of the posterior inferior cerebellar artery (mPICA).

Clinical features of delayed endolymphatic hydrops and intralabyrinthine schwannoma : An imaging-confirmed comparative case series. English version.

BACKGROUND: The aim of this study was to compare the clinical history and audiovestibular function test results of patients suffering from intralabyrinthine schwannoma or delayed endolymphatic hydrops (DEH). PATIENTS AND METHODS: Five patients diagnosed with intralabyrinthine schwannoma by magnetic resonance imaging (MRI) and five patients diagnosed with DEH by locally enhanced inner ear MRI (LEIM) were retrospectively studied. RESULTS: All patients with intralabyrinthine schwannoma or DEH initially presented with hearing loss. Vertigo occurred in two patients with intralabyrinthine schwannoma and in all patients with DEH. While audiometry achieved poorer results for patients with intralabyrinthine schwannomas, vestibular function tests revealed normal results in about half of the patients in both groups. CONCLUSION: Patients with intralabyrinthine schwannomas may present with clinical symptoms similar to patients suffering from other inner ear disorders such as delayed endolymphatic hydrops and they may obtain similar findings in audiovestibular function tests. High-resolution magnetic resonance imaging with locally applied contrast agent may provide evidence of both underlying pathologies.

[Clinical features of delayed endolymphatic hydrops and intralabyrinthine schwannoma : An imaging-confirmed comparative case series. German version]. / Klinische Eigenschaften von "delayed endolymphatic hydrops" und intralabyrinthärem Schwannom : Eine bildgebungsbasierte komparative Fallserie.

BACKGROUND: The aim of this study was to compare the clinical history and the findings in audiovestibular function tests in patients suffering from intralabyrinthine schwannoma or delayed endolymphatic hydrops (DEH). PATIENTS AND METHODS: Five patients diagnosed with intralabyrinthine schwannoma by magnetic resonance imaging (MRI) and five patients diagnosed with DEH by locally enhanced inner ear MRI (LEIM) were retrospectively studied. RESULTS: All patients with intralabyrinthine schwannoma or DEH initially presented with hearing loss. Vertigo occurred in two patients with intralabyrinthine schwannoma and in all patients with DEH. While audiometry achieved poorer results for patients with intralabyrinthine schwannomas, vestibular function tests revealed normal results in about half of the patients in both groups. CONCLUSION: Patients with intralabyrinthine schwannomas may present with clinical symptoms similar to patients suffering from other inner ear disorders like delayed endolymphatic hydrops and may obtain similar findings in audiovestibular function tests. High-resolution MR imaging with locally applied contrast agent may provide evidence of both underlying pathologies.

What is Menière's disease? A contemporary re-evaluation of endolymphatic hydrops.

Menière's disease is a chronic condition with a prevalence of 200-500 per 100,000 and characterized by episodic attacks of vertigo, fluctuating hearing loss, tinnitus, aural pressure and a progressive loss of audiovestibular functions. Over 150 years ago, Prosper Menière was the first to recognize the inner ear as the site of lesion for this clinical syndrome. Over 75 years ago, endolymphatic hydrops was discovered as the pathologic correlate of Menière's disease. However, this pathologic finding could be ascertained only in post-mortem histologic studies. Due to this diagnostic dilemma and the variable manifestation of the various audiovestibular symptoms, diagnostic classification systems based on clinical findings have been repeatedly modified and have not been uniformly used in scientific publications on Menière's disease. Furthermore, the higher level measures of impact on quality of life such as vitality and social participation have been neglected hitherto. Recent developments of high-resolution MR imaging of the inner ear have now enabled us to visualize in vivo endolymphatic hydrops in patients with suspected Menière's disease. In this review, we summarize the existing knowledge from temporal bone histologic studies and from the emerging evidence on imaging-based evaluation of patients with suspected Menière's disease. These indicate that endolymphatic hydrops is responsible not only for the full-blown clinical triad of simultaneous attacks of auditory and vestibular dysfunction, but also for other clinical presentations such as "vestibular" and "cochlear Menière's disease". As a consequence, we propose a new terminology which is based on symptomatic and imaging characteristics of these clinical entities to clarify and simplify their diagnostic classification.

[Hydropic inner ear disease of the vestibular type]. / Hydropische Ohrerkrankung vom vestibulären Typ.

We report the case of a patient with episodic rotational vertigo for years. Ear symptoms were negated. The clinical diagnosis was not clear - Menière's disease, vestibular migraine and recurrent vertigo after vestibular neuritis all qualified for differential diagnoses. A locally enhanced inner-ear MRI established clarity by showing an endolymphatic hydrops in the vestibulum. Besides the classical triad of Menière's disease there are other clinical appearances of endolymphatic hydrops, which can be visualized with inner-ear MRI.

[Menière's Disease]. / Morbus Menière.

Menière`s disease is one of the most common inner ear and vestibular disorders. It is defined as the idiopathic syndrome of endolymphatic hydrops (ELH). Despite the development of several different animal models of ELH, its etiology and pathogenesis is still unresolved. In humans, endolymphatic hydrops may occur spontaneously or as a consequence of specific disorders with distinct inner ear pathologies, e. g., infectious labyrinthitis, noise induced hearing loss or vestibular schwannoma. Recent imaging studies using MRI have shown that hydropic ear disease is associated not only with the full triad of vertigo, hearing, loss and tinnitus/aural pressure, but also with inner ear symptoms that do not fulfill the clinical criteria of definite Menière's disease as set forth by the AAO-HNS. Therefore, terms like "atypical" or "cochlear"/"vestibular" Menière's disease or "forme fruste" should be avoided and the term "Menière's disease" should universally be applied according only to these guidelines. Besides that, the recent possibility of visualizing endolymphatic hydrops on MRI and thereby ascertaining the diagnosis in difficult cases and new audiovestibular function tests for the indirect detection of endolymphatic hydrops show promising results. Evidenced based reviews of currently available therapeutic options still reveal many uncertainties with regard to efficacy, with the exception of the ablative therapies, e. g., intratympanic gentamicin application.

MR volumetric assessment of endolymphatic hydrops.

OBJECTIVES: We aimed to volumetrically quantify endolymph and perilymph spaces of the inner ear in order to establish a methodological basis for further investigations into the pathophysiology and therapeutic monitoring of Menière's disease. METHODS: Sixteen patients (eight females, aged 38-71 years) with definite unilateral Menière's disease were included in this study. Magnetic resonance (MR) cisternography with a T2-SPACE sequence was combined with a Real reconstruction inversion recovery (Real-IR) sequence for delineation of inner ear fluid spaces. Machine learning and automated local thresholding segmentation algorithms were applied for three-dimensional (3D) reconstruction and volumetric quantification of endolymphatic hydrops. Test-retest reliability was assessed by the intra-class coefficient; correlation of cochlear endolymph volume ratio with hearing function was assessed by the Pearson correlation coefficient. RESULTS: Endolymph volume ratios could be reliably measured in all patients, with a mean (range) value of 15% (2-25) for the cochlea and 28% (12-40) for the vestibulum. Test-retest reliability was excellent, with an intra-class coefficient of 0.99. Cochlear endolymphatic hydrops was significantly correlated with hearing loss (r = 0.747, p = 0.001). CONCLUSIONS: MR imaging after local contrast application and image processing, including machine learning and automated local thresholding, enable the volumetric quantification of endolymphatic hydrops. This allows for a quantitative assessment of the effect of therapeutic interventions on endolymphatic hydrops. KEY POINTS: • Endolymphatic hydrops is the pathological hallmark of Menière's disease. • Endolymphatic hydrops can be visualized by locally enhanced ultra-high-resolution MR imaging. • Computer-aided image processing enables quantification of endolymphatic hydrops. • Endolymphatic hydrops correlates with hearing loss in patients with Menière's disease. • Therapeutic trials in Menière's disease can be monitored with this quantitative approach.

Diode laser versus radiofrequency treatment of the inferior turbinate - a randomized clinical trial.

BACKGROUND: Laser and radiofrequency induced volume reduction of the inferior turbinates are frequently used treatment modalities. Which of both is superior, however, is not clear to date due to a lack of controlled prospective studies. Here, we compare both methods regarding improvement of nasal breathing, complications, patient comfort and wound healing. METHODOLOGY: Prospective, randomized, single-blinded clinical trial with intra-individual design. After randomization, one side of the nose was treated with a 940nm diode laser and the other side with bipolar radiofrequency therapy. Pre- and postoperative evaluation was performed using visual analogue scales, nasal endoscopy and objective measurements of nasal patency. RESULTS: Of 27 enrolled patients, 26 completed the protocol. No severe complications were observed. Intraoperative discomfort was significantly more severe on the radiofrequency side. After three months, a significant reduction of nasal obstruction was observed for laser treatment and radiofrequency therapy with no significant difference between them. Objective parameters did not improve significantly. When asked which treatment modality they would chose again 50 % of the patients decided for radiofrequency treatment, 23 % for laser treatment, and 19 % for both. CONCLUSION: DLVR and RFVR are well-tolerated treatment modalities and both significantly reduce the degree of nasal obstruction in patients with hypertrophic inferior turbinates. There was no significant difference between both treatment modalities regarding efficiency.

Multiple indices of the 'bounce' phenomenon obtained from the same human ears.

Loud low-frequency sounds can induce temporary oscillatory changes in cochlear sensitivity, which have been termed the 'bounce' phenomenon. The origin of these sensitivity changes has been attributed to slow fluctuations in cochlear homeostasis, causing changes in the operating points of the outer hair cell mechano-electrical and electro-mechanical transducers. Here, we acquired three objective and subjective measures resulting in a comprehensive dataset of the bounce phenomenon in each of 22 normal-hearing human subjects. We analysed the level and phase of cubic and quadratic distortion product otoacoustic emissions and the auditory thresholds before and after presentation of a low-frequency stimulus (30 Hz sine wave, 120 dB SPL, 90 s) as a function of time. In addition, the perceived loudness of temporary, tinnitus-like sensations occurring in all subjects after cessation of the low-frequency stimulus was tracked over time. The majority of the subjects (70 %) showed a significant, biphasic change of quadratic, but not cubic, distortion product otoacoustic emissions of about 3-4 dB. Eighty-six percent of the tested subjects showed significant alterations of hearing thresholds after low-frequency stimulation. Four different types of threshold changes were observed, namely monophasic desensitisations (the majority of cases), monophasic sensitisations, biphasic alterations with initial sensitisation and biphasic alterations with initial desensitisation. The similar duration of the three bounce phenomenon measures indicates a common origin. The current findings are consistent with the hypothesis that slow oscillations of homeostatic control mechanisms and associated operating point shifts within the cochlea are the source of the bounce phenomenon.

Effect of standard-dose Betahistine on endolymphatic hydrops: an MRI pilot study.

This study aimed to assess whether standard-dose Betahistine (48 mg daily) exerts an effect upon the degree of endolymphatic hydrops in patients with Menière's disease using a retrospective case series in the setting of a tertiary neurotology referral centre. In six patients with definite unilateral Menière's disease, the degree of cochlear and vestibular endolymphatic hydrops was assessed before and after treatment with a standard dose of Betahistine (48 mg daily), using high-resolution 3 T MR imaging after intratympanic contrast medium application. The treatment duration was 3-7 months (mean 5 months), and the patients were followed-up for 6-29 months (mean 11 months). In the study cohort, the standard dose of Betahistine did not have an MR morphologically measurable beneficial effect on the degree of endolymphatic hydrops. The results indicated no effect of standard-dose Betahistine on endolymphatic hydrops found on high-resolution MR imaging. Possible explanations are: (1) insufficient dosage or duration of treatment with betahistine, (2) insufficient resolution of the MR imaging technique, and (3) insufficient length of follow-up. Further studies addressing these issues are warranted.

Characteristics and clinical applications of ocular vestibular evoked myogenic potentials.

Recently, ocular vestibular evoked myogenic potentials (oVEMPs) have been described and added to the neuro-otologic test battery as a new measure for the vestibulo-ocular reflex. oVEMPs represent extraocular muscle activity in response to otolith stimulation e.g. by air-conducted sound or bone-conducted vibration. In response to vestibular stimulation, electromyographic activity of the extraocular muscles can be recorded by means of surface electrodes placed beneath the contralateral eye. oVEMPs are likely to reflect predominantly utricular function, while the widely established cervical vestibular evoked myogenic potentials (cVEMPs) assess saccular function. Thus, measuring oVEMPs and cVEMPs in addition to caloric and head impulse testing provides further evaluation of the vestibular system and enables quick and cost-effective assessment of otolith function. This review summarizes the neurophysiological properties of oVEMPs, gives recommendations for recording conditions and discusses oVEMP alterations in various disorders of the vestibular system. With increasing insight into oVEMP characteristics in vestibular disorders, e.g. Menière's disease and superior semicircular canal dehiscence syndrome, oVEMPs are becoming a promising new diagnostic tool for evaluating utricular function.

Effect of transtympanic low-pressure therapy in patients with unilateral Menière's disease unresponsive to betahistine: a randomised, placebo-controlled, double-blinded, clinical trial.

OBJECTIVE: To determine the effect of the Meniett low-pressure generator on the subjective symptoms and audiovestibular disease markers of patients with unilateral Menière's disease unresponsive to betahistine treatment. METHODS: Randomised, placebo-controlled, double-blinded, clinical trial at a tertiary referral centre. After ventilation tube placement, patients were randomised to the active treatment or placebo group. Monitoring comprised audiometry and air caloric testing and a vertigo diary (enabling calculation of vertigo and activity scores, and the number of vertigo days, vertigo-free days and sick days). RESULTS: Sixty-eight patients completed the study. For the active treatment versus placebo group, the following pre- and post-treatment values, and significances for treatment effect comparisons, were respectively seen: cumulative vertigo scores, 22.47 and 15.97 vs 20.42 and 19.23 (p = 0.048); vertigo days, 6.5 and 4.08 vs 5.94 and 5.52 (p = 0.102); sick days, 3.08 and 0.78 vs 2.87 and 3.45 (p = 0.041); vertigo-free days, 14.47 and 17.61 vs 15.48 and 17.58 (p = 0.362); activity score, 23.61 and 13.42 vs 24.68 and 20.23 (p = 0.078); low-tone hearing threshold, 49.15 and 53.18 dB nHL vs 41.66 and 46.10 dB nHL (p > 0.05); and slow phase velocity in response to caloric stimulation, 18.86 and 18.72 °/second vs 14.97 and 15.95 °/second, (p > 0.05). CONCLUSION: Use of the Meniett low-pressure generator improved patients' vertigo but not their hearing or vestibular function. This safe, minimally invasive treatment is recommended as second-line treatment for unilateral Menière's disease.

Lemierre syndrome: a case report.

INTRODUCTION: Lemierre syndrome, also known as postanginal sepsis, is caused by Fusobacterium necrophorum. This rare disease is usually characterized by thrombophlebitis of the jugular vein and septic embolism after a history of sore throat. OBJECTIVE: Here, we discuss a case of Lemierre syndrome in a 22-year-old man with thrombophlebitis of the facial vein and fusobacteria growth in the blood culture but no obvious focus of inflammation. METHOD: Case report. CONCLUSION: Severe facial infection with high fever and a general feeling of malaise after a history of sore throat should raise the diagnostic possibility of facial vein thrombophlebitis due to F. necrophorum infection.