The Correlation of a 2D Volume-Referencing Endolymphatic-Hydrops Grading System With Extra-Tympanic Electrocochleography in Patients With Definite Ménière's Disease

Abstract

Background: Although magnetic resonance imaging (MRI) of the membranous labyrinth and electrocochleography (ECochG) have been used to diagnose endolymphatic hydrops (ELH) in patients with Ménière's disease (MD), the relationship between imaging and ECochG is not well-documented.Objectives: This study evaluates the ELH using 3D-FLAIR MRI and extra-tympanic ECochG (ET-ECochG) and correlates the results from 3D-FLAIR MRI to those from ET-ECochG.Materials and Methods: 3D-FLAIR MRI images of 50 patients were assessed using a 2D volume-referencing grading system (VR scores, relative scores according to the known volumes of the cochlea, vestibule, and semicircular canals). Forty healthy subjects were included and compared to 51 definite MD ears of 50 patients while analyzing the ET-ECochG, which used a self-made bronze foil electrode. The amplitude ratio of the summating potential (SP) to the action potential (AP) (SP/AP) and the area ratio of SP to AP (Asp/Aap) were collected. Relative ELH grade scores were then correlated to ET-ECochG (SP/AP, Asp/Aap).Results: The VR scores showed a better correlation (r = 0.88) with the pure tone average (PTA), disease duration, and vertigo frequency of MD than the Bernaerts scores (grading the cochlea and vestibule separately) (r = 0.22). The SP/AP and Asp/Aap of the unilateral MD patients were statistically comparable to those measured in contralateral ears and the results between the definite MD ears with healthy ears were statistically comparable (p < 0.05). In a ROC analysis Asp/Aap (area under curve, AUC 0.98) significantly (p = 0.01) outperformed SP/AP (AUC 0.91). The total score of ELH, vestibular ELH, and cochlear ELH were also correlated with SP/AP and Asp/Aap. The strongest correlation was found between the Asp/Aap and cochlear ELH (r = 0.60).Conclusion: The 2D volume-referencing grading system was more meaningful than the Bernaerts scores. A correlation was found between ELH revealed by 3D-FLAIR MRI and the SP/AP of ET-ECochG in evaluating definite MD patients. The Asp/Aap appeared a more sensitive and reliable parameter than SP/AP for diagnosing the ELH of the membranous labyrinth.

Visualization of Endolymphatic Hydrops in Patients With Unilateral Idiopathic Sudden Sensorineural Hearing Loss With Four Types According to Chinese Criterion

“…FIGURE 3 | EH grading in three parts of the inner ear and the sum of VR scores. EH in cochlea were scored 0, 3, 6, and 9 for four grades while those in vestibule were scored 0, 4, 8, and 12 and those in the semicircular canals as 0, 5, 10, and 16 according to the volume-referencing scores (12). The sum score of three parts represented EH in the entire inner ear.…”

Vestibular Endolymphatic Hydrops Visualized by Magnetic Resonance Imaging and Its Correlation With Vestibular Functional Test in Patients With Unilateral Meniere's Disease

“…Furthermore, the significance of EH and vestibular function tests in patients with MD has not been fully characterized yet. The recent research published by our team modified the grading system of vestibular and semicircular canal hydrops (15). The "volume-referencing" grading system showed a better correlation with the MD clinical features and had more diagnostic value than previously published methods.…”

“…The scan parameters for the 3D-FLAIR sequence were as follows: time of repetition = 6,500 ms, time of echo = 286.1 ms, time of inversion = 1,950 ms, flip angle = 67 • , slice thickness = 0.6 mm, echo train length = 160, field of view = 200 * 200 mm, and matrix size = 256 * 256, voxel size = 0.78 * 0.78 * 1.1 mm. The scan time was 6 min 11 s. Three dimensional heavily T2weighted spectral attenuated inversion recovery (3D-T2-SPAIR) sequence was also performed with the following parameters: voxel size = 0.65 * 0.52 * 0.76 mm, scan time = 4 min 30 s, TR = 1,300 ms, TE = 254.7 ms, flip angle = 110 • , slice thickness = 0.4 mm, field of view = 200 * 200 mm, and matrix size = 384 * 384 (15).…”

“…When the perilymphatic enhancement is invisible, vestibular hydrops grade III is defined. The lateral semicircular canal was evaluated by the four-grade system proposed by our team in the previous study (15). We defined Grade 0 as no hydrops when a small visible herniation which was 1/3 less than the semicircular canal with perilymph surrounding, a larger herniation (>1/3) with hydrops as Grade I and the total invisibility of crura, which often accompany the stenosis of canals as Grade II.…”

Intravenous Delayed Gadolinium-Enhanced MR Imaging of the Endolymphatic Space: A Methodological Comparative Study

“…A more detailed clinical study and discussion can be found in another work (76). To date, correlations were found for SQ grades 3-point [electrocochleography (EcochG)(83,84)] and 4-point ordinal cochlear scale [PTA…”