MRI contribution for the detection of endolymphatic hydrops in patients with superior canal dehiscence syndrome.

PURPOSE: Patients with superior semicircular canal dehiscence syndrome, which can only be treated by surgery, present cochleo-vestibular symptoms related to a third-mobile window but also endolymphatic hydrops. Since cVEMP and oVEMP are disturbed by the presence of the dehiscence, the aim of the study is to assess the value of MRI for the diagnosis of endolymphatic hydrops in patients with superior semicircular canal dehiscence syndrome in comparison with cVEMP and oVEMP. METHODS: In this retrospective cohort study we enrolled 33 ears in 24 patients with superior semicircular dehiscence syndrome who underwent a 4-h delayed intravenous Gd-enhanced 3D-FLAIR MRI and pure tone audiometry, cVEMP and oVEMP. For each patient MRI images were evaluated by two radiologists who used a compartmental endolymphatic hydrops grading system in comparison with cVEMP and oVEMP. RESULTS: Endolymphatic hydrops was found on MRI in 9 out of 33 SCDS ears (27.3%). We found no significant correlation between the presence of endolymphatic hydrops on MRI and cVEMP and oVEMP (p = 0.36 and p = 0.7, respectively). However, there was a significant correlation between the presence of endolymphatic hydrops on MRI and the degree of sensorineural hearing loss, Air Conduction-Pure Tone Average level (p = 0.012) and Bone Conduction-Pure Tone Average level (p = 0.09), respectively. CONCLUSION: We demonstrated that EH might be observed in 27.3% of superior semicircular dehiscence syndrome ears. The role of inner ear MRI is important to detect endolymphatic hydrops, since cVEMP and oVEMP are disturbed by the presence of the dehiscence, because these patients could benefit from a medical treatment. LEVEL OF EVIDENCE: Level 3.

Effectiveness and reliability of the four-step STANDING algorithm performed by interns and senior emergency physicians for predicting central causes of vertigo.

BACKGROUND: For emergency physicians (EPs), acute vertigo is a challenging complaint and learning a reliable clinical approach is needed. STANDING is a four-step bedside algorithm that requires (1) identifying spontaneous nystagmus with Frenzel glasses or, alternatively, a positional nystagmus; (2) characterizing the nystagmus direction; (3) assessing the vestibuloocular reflex (head impulse test); and (4) assessing the gait. The objective was to determine its accuracy for diagnosing central vertigo when using by naïve examiners as such as interns and its agreement with senior EPs. METHODS: This was a prospective 1-year diagnostic cohort study among patients with vertigo, vestibulovisual symptoms, or postural symptoms seen by 20 interns trained in the four-step examination. The algorithm was performed first by an intern and second by a senior EP and categorized as either worrisome when indicating a central diagnosis and benign or inconclusive when indicating a peripheral diagnosis. The reference test was diffusion-weighted brain magnetic resonance imaging. RESULTS: Among 312 patients included, 57 had a central diagnosis including 33 ischemic strokes (10.5%). The main etiology was benign paroxysmal positional vertigo (32.7%). The likelihood ratios were 4.63 and 10.33 for a worrisome STANDING, 0.09 and 0.01 for a benign STANDING, and 0.21 and 0.35 for an inconclusive STANDING, for interns and senior EPs, respectively. The algorithm showed sensitivities of 84.8% (95% CI 75.6%-93.9%) and 89.8% (95% CI 82.1%-97.5%), negative predictive values of 96.2% (95% CI 93.7%-98.6%) and 97.5% (95% CI 95.5%-99.5%), specificities of 88.9% (95% CI 85.1%-92.8%) and 91.3% (95% CI 87.8%-94.8%), and positive predictive values of 64.1% (95% CI 53.5%-74.8%) and 70.7% (95% CI 60.4%-81.0%), respectively. The agreement between interns and senior EPs was very substantial (B-statistic coefficient: 0.77) and almost perfect for each step: (1) 0.87, (2) 0.98, (3) 0.95, and (4) 0.99. CONCLUSIONS: With a single training session, the algorithm reached high accuracy and reliability for ruling out central causes of vertigo in the hands of both novices and experienced EPs. A future multicenter randomized controlled trial should further its impact on unnecessary neuroimaging use and patient's satisfaction.

Differentiating central from peripheral causes of acute vertigo in an emergency setting with the HINTS, STANDING, and ABCD2 tests: A diagnostic cohort study.

BACKGROUND: Diagnosing stroke in dizzy patients remains a challenge in emergency medicine. The accuracy of the neuroophthalmologic examination HINTS performed by emergency physicians (EPs) is unknown. Our objective was to determine the accuracy of the HINTS examination performed by trained EPs for diagnosing central cause of acute vertigo and unsteadiness and to compare it with another bedside clinical tool, STANDING, and with the history-based score ABCD2. METHODS: This was a prospective diagnostic cohort study among patients with isolated vertigo and unsteadiness seen in a single emergency department (ED). Trained EPs performed HINTS and STANDING tests blinded to attending physicians. ABCD2 ≥ 4 was used as the threshold and was calculated retrospectively. The criterion standard was diffusion-weighted brain magnetic resonance imaging (MRI). Peripheral diagnoses were established by a normal MRI, and etiologies were further refined by an otologic examination. RESULTS: We included 300 patients of whom 62 had a central lesion on neuroimaging including 49 strokes (79%). Of the 238 peripheral diagnoses, 159 were vestibulopathies, mainly benign paroxysmal positional vertigo (40%). HINTS and STANDING tests reached high sensitivities at 97% and 94% and NPVs at 99% and 98%, respectively. The ABCD2 score failed to predict half of central vertigo cases and had a sensitivity of 55% and a NPV of 87%. The STANDING test was more specific and had a better positive predictive value (PPV; 75% and 49%, respectively; positive likelihood ratio [LR+] = 3.71, negative likelihood ratio [LR-] = 0.09) than the HINTS test (67% and 44%, respectively; LR+ = 2.96, LR- = 0.04). The ABCD2 score was specific (82%, LR+ = 3.04, LR- = 0.56) but had a very low PPV (44%). CONCLUSIONS: In the hands of EPs, HINTS and STANDING tests outperformed ABCD2 in identifying central causes of vertigo. For diagnosing peripheral disorders, the STANDING algorithm is more specific than the HINTS test. HINTS and STANDING could be useful tools saving both time and costs related to unnecessary neuroimaging use.

Plasma Serotonin is Elevated in Adult Patients with Sudden Sensorineural Hearing Loss.

BACKGROUND: The roles of thrombophilia and cardiovascular risk factors in sudden sensorineural hearing loss (SSNHL) remain controversial. Cochlear microthrombosis and vasospasm have been hypothesized as possible pathogenic mechanisms of SSNHL. This article investigates the circulating serotonin and homocysteine levels besides thrombophilia screening in patients with idiopathic SSNHL. METHODS: A total of 133 SSNHL patients and age- and sex-matched controls were investigated (discovery cohort). Measurement included common inherited natural coagulation inhibitors, factor VIII, von Willebrand factor (VWF), antiphospholipid antibodies, homocysteine, and serotonin (whole blood, platelet, and plasma) levels, along with frequent relevant genetic variants. A validation cohort (128 SSNHL patients) was studied for homocysteine and serotonin levels. RESULTS AND CONCLUSION: In the discovery cohort, 58.6% of patients exhibited thrombophilia, of which most had a low to moderate titers of antiphospholipid antibodies and high levels of factor VIII/VWF. Twenty-seven patients (20%) had mild-to-moderate hyperhomocysteinemia or were homozygous for the methylenetetrahydrofolate reductase (MTHFR) C677T mutation. Regarding serotonin, SSNHL patients had elevated whole blood levels that remained within the normal range and normal platelet content. However, approximately 90% patients of both cohorts had elevated plasma serotonin. Elevated plasma serotoninemia was accompanied by serotonylation of platelet rhoA protein. This study shows that increased plasma serotonin appears as a biomarker of SSNHL (specificity: ∼96%, sensitivity: ∼90%) and could participate in the pathophysiology of SSNHL.

Relationship between video head impulse test, ocular and cervical vestibular evoked myogenic potentials, and compartmental magnetic resonance imaging classification in menière's disease.

OBJECTIVES/HYPOTHESIS: Currently, it is possible to assess in vivo the morphology of each compartment of the endolymphatic spaces 4 hours after an intravenous administration of gadolinium on magnetic resonance imaging (MRI). The aim of this study was to assess the correlation between otolithic and ampullar functions (cervical vestibular evoked myogenic potential [cVEMP], ocular vestibular evoked myogenic potential [oVEMP], video head impulse test [VHIT]) and delayed inner ear MRI based on a compartmental, anatomically based classification that included the cochlea, the saccule, the utricle, and the ampullas. STUDY DESIGN: Retrospective case-control study. METHODS: In this retrospective study, we performed three-dimensional fluid-attenuated inversion recovery sequences with delayed acquisition in 26 healthy subjects and 31 definite Menière's disease (MD) patients. Each subject was then graded on MRI on the basis on cochlear, saccular, utricular, and ampullar hydrops in MD patients. All patients underwent pure-tone audiometry, VHIT, cVEMP, and oVEMP testing. RESULTS: Cochlear, saccular, utricular, and ampullar hydrops were found on MRI in 88%, 91%, 50%, and 8.5% respectively. We found no significant correlation between the presence of saccular hydrops versus cVEMP, utricular hydrops versus oVEMP, and ampullar hydrops versus VHIT. However, the severity of endolymphatic hydrops on MRI was correlated to the degree of hearing loss. CONCLUSIONS: We proposed a compartmental, anatomically based classification for endolymphatic hydrops on MRI, which included the whole vestibular compartment. Using this classification, we observed increasing morphological changes as the disease evolved, affecting first the saccule, then the utricle, and finally the ampullas. The severity of vestibular endolymphatic hydrops is only correlated to hearing loss severity. LEVEL OF EVIDENCE: 3 Laryngoscope, 130:E444-E452, 2020.

Vestibular atelectasis: Myth or reality?

OBJECTIVES/HYPOTHESIS: Because delayed post-contrast three-dimensional fluid-attenuated inversion recovery imaging sequences enable the distinction between the utricle and the saccule, we raised the hypothesis that patients with vestibular atelectasis (VA) could show unilateral collapse of the utricle and the ampullas on imaging. STUDY DESIGN: Retrospective case series. METHODS: We retrospectively reviewed 200 patients who underwent 3 T magnetic resonance imaging (MRI) after intravenous administration of gadolinium. MRI scans were assessed for the presence of VA. The endolymphatic space was considered as collapsed when the utricle and at least two ampullas were not visible or were barely visible. RESULTS: We reported four patients with VA on MRI responsible for atypical clinical presentations of acute vestibular deficit. All patients presented a specific involvement of the pars superior sensory captors (utricle, ampullas), preserving the pars inferior sensory captors (cochlea and saccule). This was confirmed both clinically and on MRI. CONCLUSIONS: Our study is the first to describe in vivo unilateral collapse of the pars superior on delayed postcontrast MRI in patients with a clinical unilateral vestibular loss. LEVEL OF EVIDENCE: 4 Laryngoscope, 129:1689-1695, 2019.