MRI-based inner ear assessment and Cochlin-Tomo protein-based perilymphatic fistula diagnostics in patients with acute hearing loss

The manifestation of perilymphatic fistula has so far been determined by clinical symptoms or by an intraoperative sign of a fistula. To date, there is no direct test to detect a perilymphatic fistula. CTP (Cochlin-Tomo protein), on the other hand, is an inner ear-specific protein which is used as a biochemical marker for the presence of a perilymphatic fistula. Inner ear-specific aspects can also be assessed by MRI examinations, in particular with 4-hour delayed intravenous gadolinium-enhanced MRI sequences. The aim of this study is to analyze the multimodal diagnostic measures with CTP examination and MRI scans to detect correlations in patients with acute hearing loss. In this prospective study, we performed an ELISA-based CTP detection test using middle ear lavage samples from 8 patients with acute hearing loss. In addition to the CTP examination, MRI examination was performed using different sequences as well as subjective and diagnostic evaluation of audio-vestibular symptoms. With all patients with spontaneous hearing loss (>60 dB) included in this study, the MRI scan showed increased CM uptake in the area of the vestibulum, cochlea and fundus of the internal auditory canal of the affected side. A positive CTP result was detected in three patients. In two of these patients, a relative CM recess of the vestibulum was observed on MRI. In these two cases, significantly higher CTP values were found than in the third patient, who did not show any CM recess of the vestibule on MRI. All three patients with CTP-positive results reported no rotatory vertigo. Using multimodal diagnostic measures such as CTP testing and 4-hour delayed intravenous gadolinium-enhanced 3D FLAIR MRI, a questionable relationship is found in patients with perilymphatic fistula.