Magnetic Resonance Imaging Findings in Sudden Sensorineural Hearing Loss

Abstract

Objective: To investigate the role of magnetic resonance imaging (MRI) in the diagnosis of sudden sensorineural hearing toss (SSNHL).Methods: Fifty-four consecutive patients affected by SSNHL were investigated using brain MRI. MRI was performed with an eightchannel phased-array head coil to study the entire audiovestibular pathway and the whole brain. The protocol study consisted of a highresolution study of the temporal bone, internal auditory canal (lACI, cerebellopontine angle (CPA). and brainstem combining 2 mm thinslice axial T2-weighted two-dimensional fast spin echo (FSE) and fluid-attenuated inversion recovery (FLAIR) sequences, pre-and postcontrast (gadolinium-diethylenetriamine pentaacetic acid) administration fat-suppressed axial Ti-weighted two-dimensional FSE sequences, and a Tj*-weighted three-dimensional Fourier transformation-constructive interference in steady state sequence (FT-CISS), with 0.4 mm ultrathin partitions. The rest of the brain was studied with a 4 mm axial T2-weighted FLAIR sequence.Results: Thirty-one of 54 (57%) cases of SSNHL presented with MRI abnormalities. In 6 of 54 cases, the detected abnormality was directly correlated to the clinical picture (2 labyrinthine hemorrhage, 1 cochlear inflammation, 1 acoustic neuroma, 1 arachnoid cyst of the CPA, and 1 case of white matter lesions in the pons, compatible with demyelinating plaques along the central audiovestibular nervous pathway, as the first expression of multiple sclerosis).Conclusions: An extensive MRI study of the audiovestibular nervous pathway and of the whole brain, pre-and postparamagnetic contrast administration, is recommended to rule out the wide spectrum of abnormalities that can cause SSNHL. SOMMAIRE Objectif: Investiguer le role de I'imagerie par resonance magnetique dans le diagnostic de la surdite de perception subite. Methode: Cinquante-quatre patients consecutifs avec un diagnostic de surdite subite ont ete investigues par IRM pour etudier tout le cerveau et les voies audiovestibulaires. Le protocole incluait une etude a haute resolution de I'os temporal, du conduit auditif interne, de Tangle ponto-cerebelleux et du tronc cerebral combinant des coupes axiales de 2 mm en T2, en sequence FLAIR, en T1 avant et apres contraste (gadolinium) et en T2 FT-CISS avec des coupes ultra-minces de 0.4 mm. Le reste du cerveau a ete etudie avec T2 en sequence FLAIR.Resultats: Trente-et-un des 54 cas (57%) de surdite subite avaient une anomalie a I'lRM. Dans 6 de ces cas, I'anomalie etait directement lie a I'episode clinique (2 hemorragies labyrinthiques, une inflammation cochleaire, un neurinome acoustique, un kyste arachoidien de Tangle ponto-cerebelleux et un cas probable de sclerose en plaque).Conclusion : Nous recommandons dans investigation de la surdite subite neuro-sensorielle, I'utilisation de I'lRM du cerveau et en particulier des voies vestibulo-cochleaires dans le but d'eliminer les nombreuses pathologies qui peuvent se cacher derriere cette entite cliniqua.

Analysis of the 3-Dimensional Fluid-Attenuated Inversion-Recovery (3D-FLAIR) Sequence in Idiopathic Sudden Sensorineural Hearing Loss

“…Of the 13 3D-FLAIR-positive patients, 7 (54%) showed multiple subsites of high-intensity signal, while 6 patients (46%) had only 1 subsite of hypersignal (5 cases in the cochlea only, and 1 case in the cochlear nerve) (Figure 1). In 3 patients (23%), there was high-intensity signal in T1-weighted MRI images; in 3 patients (23%), a highintensity signal only in the 3D-FLAIR sequence; and in 7 From the combined analyses of T1 and FLAIR sequences, and from the findings of other researchers, 7,9,12 we identified 3 possible radiologic patterns:…”

“…Thus, 3D-FLAIR hyperintensity indicates the modification of the inner ear protein composition that can be ascribed to a minor hemorrhage or to an acute inflammatory process. 9 Also, 3D-FLAIR imaging can detect the BLB breakdown as the enhancement of the endolabyrinthic fluid signal and/or nerve signal after gadolinium injection owing to its high sensitivity to magnetic susceptibility. 7 In our experience 3D-FLAIR imaging is more sensitive to hematolabyrinthic and hematonervous barrier breakdown than T1 imaging, with fat suppression increasing the diagnosis accuracy.…”

“…There are emerging data in the scientific literature 7,8 that the 3D-FLAIR sequence may provide diagnostic information in patients with ISSNHL, thus improving our possibility of detecting inner ear fluid anomalies by demonstrating alterations of the inner ear's fluid protein composition, conditions that are difficult to identify on T1-and T2-weighted MRIs. 9 However, the exact relationship between 3D-FLAIR findings and clinical signs is still unknown, and the role of 3D-FLAIR as an evaluative tool to discover prognostic indicators is only recently emerging. We therefore used the 3D-FLAIR MRI to investigate its diagnostic, clinical, and prognostic role in a selected population of patients affected by ISSNHL, and we compared our results with those of other centers.…”

Clinical Practice Guideline

“…In one study of patients with SHL, 57% of the MRI studies revealed some abnormality, but only 20% of these findings were directly related to the hearing loss. 113 In another study, the overall rate of abnormal findings was 34.5%, with 36% of these directly related to the hearing loss. 112 In general, the rate of incidental findings in patients with audiovestibular symptoms is significant (47.5%), but only a small fraction of these (2.5%) required additional referral or investigation.…”

“…The overall rate of pathogenic MRI abnormalities directly related to the SSNHL ranges from 7% to 13.75%. 60,98,[111][112][113] Therefore, MRI has the highest yield of any diagnostic test in the setting of SSNHL.…”